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2026-01-22rseq: Add fields and constants for time slice extensionThomas Gleixner
Aside of a Kconfig knob add the following items: - Two flag bits for the rseq user space ABI, which allow user space to query the availability and enablement without a syscall. - A new member to the user space ABI struct rseq, which is going to be used to communicate request and grant between kernel and user space. - A rseq state struct to hold the kernel state of this - Documentation of the new mechanism Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20251215155708.669472597@linutronix.de
2026-01-21Merge tag 'nf-next-26-01-20' of ↵Jakub Kicinski
https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next Florian Westphal says: ==================== Subject: netfilter: updates for net-next 1) Speed up nftables transactions after earlier transaction failed. Due to a (harmeless) bug we remained in slow paranoia mode until a successful transaction completes. 2) Allow generic tracker to resolve clashes, this avoids very rare packet drops. From Yuto Hamaguchi. 3) Increase the cleanup budget to 64 entries in nf_conncount to reap more entries in one go, from Fernando Fernandez Mancera. 4) Allow icmp trackers to resolve clashes, this avoids very rare initial packet drop with test cases that have high-frequency pings. After this all trackers except tcp and sctp allow clash resolution. 5) Disentangle netfilter headers, don't include nftables/xtables headers in subsystems that are unrelated. 6) Don't rely on implicit includes coming from nf_conntrack_proto_gre.h. 7) Allow nfnetlink_queue nfq instance struct to get accounted via memcg, from Scott Mitchell. 8) Reject bogus xt target/match data upfront via netlink policiy in nft_compat interface rather than relying on x_tables API to do it. 9) Fix nf_conncount breakage when trying to limit loopback flows via prerouting rule, from Fernando Fernandez Mancera. This is a recent breakage but not seen as urgent enough to rush this via net tree at this late stage in development cycle. 10) Fix a possible off-by-one when parsing tcp option in xtables tcpmss match. Also handled via -next due to late stage in development cycle. * tag 'nf-next-26-01-20' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next: netfilter: xt_tcpmss: check remaining length before reading optlen netfilter: nf_conncount: fix tracking of connections from localhost netfilter: nft_compat: add more restrictions on netlink attributes netfilter: nfnetlink_queue: nfqnl_instance GFP_ATOMIC -> GFP_KERNEL_ACCOUNT allocation netfilter: nf_conntrack: don't rely on implicit includes netfilter: don't include xt and nftables.h in unrelated subsystems netfilter: nf_conntrack: enable icmp clash support netfilter: nf_conncount: increase the connection clean up limit to 64 netfilter: nf_conntrack: Add allow_clash to generic protocol handler netfilter: nf_tables: reset table validation state on abort ==================== Link: https://patch.msgid.link/20260120191803.22208-1-fw@strlen.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-21net: phylink: introduce helpers for replaying link callbacksVladimir Oltean
Some drivers of MAC + tightly integrated PCS (example: SJA1105 + XPCS covered by same reset domain) need to perform resets at runtime. The reset is triggered by the MAC driver, and it needs to restore its and the PCS' registers, all invisible to phylink. However, there is a desire to simplify the API through which the MAC and the PCS interact, so this becomes challenging. Phylink holds all the necessary state to help with this operation, and can offer two helpers which walk the MAC and PCS drivers again through the callbacks required during a destructive reset operation. The procedure is as follows: Before reset, MAC driver calls phylink_replay_link_begin(): - Triggers phylink mac_link_down() and pcs_link_down() methods After reset, MAC driver calls phylink_replay_link_end(): - Triggers phylink mac_config() -> pcs_config() -> mac_link_up() -> pcs_link_up() methods. MAC and PCS registers are restored with no other custom driver code. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Link: https://patch.msgid.link/20260119121954.1624535-3-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-21net: pcs: pcs-mtk-lynxi: pass SGMIISYS OF node to PCSVladimir Oltean
The Mediatek LynxI PCS is used from the MT7530 DSA driver (where it does not have an OF presence) and from mtk_eth_soc, where it does (Documentation/devicetree/bindings/net/pcs/mediatek,sgmiisys.yaml informs of a combined clock provider + SGMII PCS "SGMIISYS" syscon block). Currently, mtk_eth_soc parses the SGMIISYS OF node for the "mediatek,pnswap" property and sets a bit in the "flags" argument of mtk_pcs_lynxi_create() if set. I'd like to deprecate "mediatek,pnswap" in favour of a property which takes the current phy-mode into consideration. But this is only known at mtk_pcs_lynxi_config() time, and not known at mtk_pcs_lynxi_create(), when the SGMIISYS OF node is parsed. To achieve that, we must pass the OF node of the PCS, if it exists, to mtk_pcs_lynxi_create(), and let the PCS take a reference on it and handle property parsing whenever it wants. Use the fwnode API which is more general than OF (in case we ever need to describe the PCS using some other format). This API should be NULL tolerant, so add no particular tests for the mt7530 case. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Link: https://patch.msgid.link/20260119091220.1493761-5-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-21net: always inline __skb_incr_checksum_unnecessary()Eric Dumazet
clang does not inline this helper in GRO fast path. We can save space and cpu cycles. $ scripts/bloat-o-meter -t vmlinux.0 vmlinux.1 add/remove: 0/2 grow/shrink: 2/0 up/down: 156/-218 (-62) Function old new delta tcp6_gro_complete 227 311 +84 tcp4_gro_complete 325 397 +72 __pfx___skb_incr_checksum_unnecessary 32 - -32 __skb_incr_checksum_unnecessary 186 - -186 Total: Before=22592724, After=22592662, chg -0.00% Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260120164903.1912995-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-21tcp: preserve const qualifier in tcp_rsk() and inet_rsk()Eric Dumazet
We can change tcp_rsk() and inet_rsk() to propagate their argument const qualifier thanks to container_of_const(). Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260120125353.1470456-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-21Merge branch ↵Jakub Kicinski
'add-devm_clk_bulk_get_optional_enable-helper-and-use-in-axi-ethernet-driver' Suraj Gupta says: ==================== Add devm_clk_bulk_get_optional_enable() helper and use in AXI Ethernet driver This patch series introduces a new managed clock framework helper function and demonstrates its usage in AXI ethernet driver. Device drivers frequently need to get optional bulk clocks, prepare them, and enable them during probe, while ensuring automatic cleanup on device unbind. Currently, this requires three separate operations with manual cleanup handling. The new devm_clk_bulk_get_optional_enable() helper combines these operations into a single managed call, eliminating boilerplate code and following the established pattern of devm_clk_bulk_get_all_enabled(). ==================== Link: https://patch.msgid.link/20260116192725.972966-1-suraj.gupta2@amd.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-21clk: Add devm_clk_bulk_get_optional_enable() helperSuraj Gupta
Add a new managed clock framework helper function that combines getting optional bulk clocks and enabling them in a single operation. The devm_clk_bulk_get_optional_enable() function simplifies the common pattern where drivers need to get optional bulk clocks, prepare and enable them, and have them automatically disabled/unprepared and freed when the device is unbound. This new API follows the established pattern of devm_clk_bulk_get_all_enabled() and reduces boilerplate code in drivers that manage multiple optional clocks. Suggested-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Suraj Gupta <suraj.gupta2@amd.com> Reviewed-by: Brian Masney <bmasney@redhat.com> Acked-by: Stephen Boyd <sboyd@kernel.org> Link: https://patch.msgid.link/20260116192725.972966-2-suraj.gupta2@amd.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-21io_uring/eventfd: remove unused ctx->evfd_last_cq_tail memberJens Axboe
A previous commit got rid of any use of this member, but forgot to remove it. Kill it. Fixes: f4bb2f65bb81 ("io_uring/eventfd: move ctx->evfd_last_cq_tail into io_ev_fd") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-01-21Merge tag 'qcom-drivers-for-6.20' of ↵Arnd Bergmann
https://git.kernel.org/pub/scm/linux/kernel/git/qcom/linux into soc/drivers Qualcomm driver updates for v6.20 Support multiple wait queues in the SCM firmware interface and provide discovery of the wait queue interrupt to deal with the cases where bootloader didn't patch the DeviceTree with the IRQ information. Refactor the MDT loader and the SCM driver's peripheral authentication service interface and introduce support for passing a remoteproc resource table to the firmware. The remoteproc patches that uses this and uses this to configure the IOMMU are included here due to bidirectional dependencies. The end result is remoteproc support on the Glymur platform. Enable QSEECOM and thereby UEFI variable access, on the Surface Pro 11. Make the QMI interface endianness aware, to support ath1Xk on big endian machines. Add the Glymur support in LLCC driver. * tag 'qcom-drivers-for-6.20' of https://git.kernel.org/pub/scm/linux/kernel/git/qcom/linux: (33 commits) soc: qcom: preserve CPU endianness for QMI_DATA_LEN soc: qcom: fix QMI encoding/decoding for basic elements soc: qcom: check QMI basic element error codes soc: qcom: ubwc: add missing include remoteproc: qcom: pas: Enable Secure PAS support with IOMMU managed by Linux remoteproc: pas: Extend parse_fw callback to fetch resources via SMC call firmware: qcom_scm: Add qcom_scm_pas_get_rsc_table() to get resource table firmware: qcom_scm: Add SHM bridge handling for PAS when running without QHEE firmware: qcom_scm: Refactor qcom_scm_pas_init_image() firmware: qcom_scm: Add a prep version of auth_and_reset function soc: qcom: mdtloader: Remove qcom_mdt_pas_init() from exported symbols soc: qcom: mdtloader: Add PAS context aware qcom_mdt_pas_load() function remoteproc: pas: Replace metadata context with PAS context structure firmware: qcom_scm: Introduce PAS context allocator helper function firmware: qcom_scm: Rename peripheral as pas_id firmware: qcom_scm: Remove redundant piece of code dt-bindings: remoteproc: qcom,pas: Add iommus property soc: qcom: cmd-db: Use devm_memremap() to fix memory leak in cmd_db_dev_probe soc: qcom: pmic_glink_altmode: Consume TBT3/USB4 mode notifications dt-bindings: qcom,pdc: document the Milos Power Domain Controller ... Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2026-01-21Merge tag 'imx-drivers-6.20' of ↵Arnd Bergmann
https://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux into soc/drivers i.MX drivers changes for 6.20: - A few changes from Peng Fan adding dump syslog support for i.MX System Manager firmware driver, cleaning up soc-imx9 driver, fixing error handling for soc-imx8m driver * tag 'imx-drivers-6.20' of https://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux: soc: imx8m: Fix error handling for clk_prepare_enable() soc: imx: Spport i.MX9[4,52] soc: imx: Use dev_err_probe() for i.MX9 soc: imx: Use device-managed APIs for i.MX9 firmware: imx: sm-misc: Dump syslog info firmware: arm_scmi: imx: Support getting syslog of MISC protocol Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2026-01-21Merge tag 'samsung-drivers-6.20' of ↵Arnd Bergmann
https://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux into soc/drivers Samsung SoC drivers for v6.20 1. Several improvements in Exynos ChipID Socinfo driver and finally adding Google GS101 SoC support. 2. Few cleanups from old code. 3. Documenting Axis Artpec-9 SoC PMU (Power Management Unit). * tag 'samsung-drivers-6.20' of https://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux: ARM: s3c: remove a leftover hwmon-s3c.h header file dt-bindings: soc: samsung: exynos-pmu: Drop unnecessary select schema soc: samsung: exynos-chipid: add google,gs101-otp support soc: samsung: exynos-chipid: downgrade dev_info to dev_dbg for soc info soc: samsung: exynos-chipid: rename method dt-bindings: nvmem: add google,gs101-otp soc: samsung: exynos-chipid: use dev_err_probe where appropiate soc: samsung: exynos-chipid: use devm action to unregister soc device dt-bindings: samsung: exynos-pmu: Add compatible for ARTPEC-9 SoC Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2026-01-21Merge tag 'tee-sysfs-for-6.20' of ↵Arnd Bergmann
git://git.kernel.org/pub/scm/linux/kernel/git/jenswi/linux-tee into soc/drivers TEE sysfs for 6.20 - Add an optional generic sysfs attribute for TEE revision - Implement revision reporting for OP-TEE using both SMC and FF-A ABIs * tag 'tee-sysfs-for-6.20' of git://git.kernel.org/pub/scm/linux/kernel/git/jenswi/linux-tee: tee: optee: store OS revision for TEE core tee: add revision sysfs attribute Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2026-01-21Merge tag 'tee-bus-callback-for-6.20' of ↵Arnd Bergmann
git://git.kernel.org/pub/scm/linux/kernel/git/jenswi/linux-tee into soc/drivers TEE bus callback for 6.20 - Move from generic device_driver to TEE bus-specific callbacks - Add module_tee_client_driver() and registration helpers to reduce boilerplate - Convert several client drivers (TPM, KEYS, firmware, EFI, hwrng, and RTC) - Update documentation and fix kernel-doc warnings * tag 'tee-bus-callback-for-6.20' of git://git.kernel.org/pub/scm/linux/kernel/git/jenswi/linux-tee: tpm/tpm_ftpm_tee: Fix kdoc after function renames tpm/tpm_ftpm_tee: Make use of tee bus methods tpm/tpm_ftpm_tee: Make use of tee specific driver registration KEYS: trusted: Make use of tee bus methods KEYS: trusted: Migrate to use tee specific driver registration function firmware: tee_bnxt: Make use of tee bus methods firmware: tee_bnxt: Make use of module_tee_client_driver() firmware: arm_scmi: Make use of tee bus methods firmware: arm_scmi: optee: Make use of module_tee_client_driver() efi: stmm: Make use of tee bus methods efi: stmm: Make use of module_tee_client_driver() hwrng: optee - Make use of tee bus methods hwrng: optee - Make use of module_tee_client_driver() rtc: optee: Make use of tee bus methods rtc: optee: Migrate to use tee specific driver registration function tee: Adapt documentation to cover recent additions tee: Add probe, remove and shutdown bus callbacks to tee_client_driver tee: Add some helpers to reduce boilerplate for tee client drivers Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2026-01-21Merge tag 'renesas-drivers-for-v6.20-tag2' of ↵Arnd Bergmann
git://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-devel into soc/drivers Renesas driver updates for v6.20 (take two) - Add and use for_each_of_imap_item() iterator, - Add support for the RZ/N1 GPIO Interrupt Multiplexer. * tag 'renesas-drivers-for-v6.20-tag2' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-devel: soc: renesas: Add support for RZ/N1 GPIO Interrupt Multiplexer irqchip/renesas-rza1: Use for_each_of_imap_item iterator irqchip/ls-extirq: Use for_each_of_imap_item iterator of: unittest: Add a test case for for_each_of_imap_item iterator of/irq: Introduce for_each_of_imap_item Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2026-01-21Revert "mmc: rtsx_pci: add quirk to disable MMC_CAP_AGGRESSIVE_PM for RTS525A"Greg Kroah-Hartman
This reverts commit 5f0bf80cc5e04d31eeb201683e0b477c24bd18e7. This was asked to be reverted as it is not the correct way to do this. Fixes: 5f0bf80cc5e0 ("mmc: rtsx_pci: add quirk to disable MMC_CAP_AGGRESSIVE_PM for RTS525A") Cc: Matthew Schwartz <matthew.schwartz@linux.dev> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-21Revert "mmc: rtsx: reset power state on suspend"Greg Kroah-Hartman
This reverts commit eac85fbd0867c25ac517f58fae401d65c627edff. This is not the correct change, so revert it for now. Fixes: eac85fbd0867 ("mmc: rtsx: reset power state on suspend") Cc: Matthew Schwartz <matthew.schwartz@linux.dev> Cc: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-21block: add a bio_reuse helperChristoph Hellwig
Add a helper to allow an existing bio to be resubmitted without having to re-add the payload. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Hans Holmberg <hans.holmberg@wdc.com> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2026-01-21mm/page_ext: Add page_ext_get_from_phys()Mostafa Saleh
The IOMMU code operates on physical addresses which can be outside of system RAM. Add a new function page_ext_get_from_phys() to abstract the logic of checking the address and returning the page_ext. Signed-off-by: Mostafa Saleh <smostafa@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-01-21platform/x86/amd/pmf: Introduce new interface to export NPU metricsShyam Sundar S K
The PMF driver retrieves NPU metrics data from the PMFW. Introduce a new interface to make NPU metrics accessible to other drivers like AMDXDNA driver, which can access and utilize this information as needed. Reviewed-by: Mario Limonciello <mario.limonciello@amd.com> Co-developed-by: Patil Rajesh Reddy <Patil.Reddy@amd.com> Signed-off-by: Patil Rajesh Reddy <Patil.Reddy@amd.com> Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> [lizhi: save return value of is_npu_metrics_supported() and return it] Signed-off-by: Lizhi Hou <lizhi.hou@amd.com> Link: https://patch.msgid.link/20260115173448.403826-1-lizhi.hou@amd.com Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
2026-01-21crypto: ccp - Send PSP_CMD_TEE_RING_DESTROY when PSP_CMD_TEE_RING_INIT failsMario Limonciello (AMD)
The hibernate resume sequence involves loading a resume kernel that is just used for loading the hibernate image before shifting back to the existing kernel. During that hibernate resume sequence the resume kernel may have loaded the ccp driver. If this happens the resume kernel will also have called PSP_CMD_TEE_RING_INIT but it will never have called PSP_CMD_TEE_RING_DESTROY. This is problematic because the existing kernel needs to re-initialize the ring. One could argue that the existing kernel should call destroy as part of restore() but there is no guarantee that the resume kernel did or didn't load the ccp driver. There is also no callback opportunity for the resume kernel to destroy before handing back control to the existing kernel. Similar problems could potentially exist with the use of kdump and crash handling. I actually reproduced this issue like this: 1) rmmod ccp 2) hibernate the system 3) resume the system 4) modprobe ccp The resume kernel will have loaded ccp but never destroyed and then when I try to modprobe it fails. Because of these possible cases add a flow that checks the error code from the PSP_CMD_TEE_RING_INIT call and tries to call PSP_CMD_TEE_RING_DESTROY if it failed. If this succeeds then call PSP_CMD_TEE_RING_INIT again. Fixes: f892a21f51162 ("crypto: ccp - use generic power management") Reported-by: Lars Francke <lars.francke@gmail.com> Closes: https://lore.kernel.org/platform-driver-x86/CAD-Ua_gfJnQSo8ucS_7ZwzuhoBRJ14zXP7s8b-zX3ZcxcyWePw@mail.gmail.com/ Tested-by: Yijun Shen <Yijun.Shen@Dell.com> Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org> Reviewed-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> Acked-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://patch.msgid.link/20260116041132.153674-6-superm1@kernel.org Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
2026-01-21phy: hdmi: Add HDMI 2.1 FRL configuration optionsCristian Ciocaltea
The HDMI 2.1 specification introduced the Fixed Rate Link (FRL) mode, aiming to replace the older Transition-Minimized Differential Signaling (TMDS) mode used in previous HDMI versions to support much higher bandwidths (up to 48 Gbps) for modern video and audio formats. FRL has been designed to support ultra high resolution formats at high refresh rates like 8K@60Hz or 4K@120Hz, and eliminates the need for dynamic bandwidth adjustments, which reduces latency. It operates with 3 or 4 lanes at different link rates: 3Gbps, 6Gbps, 8Gbps, 10Gbps or 12Gbps. Add support for configuring the FRL mode for HDMI PHYs. Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com> Link: https://patch.msgid.link/20260113-phy-hdptx-frl-v6-1-8d5f97419c0b@collabora.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2026-01-20kallsyms/ftrace: set module buildid in ftrace_mod_address_lookup()Petr Mladek
__sprint_symbol() might access an invalid pointer when kallsyms_lookup_buildid() returns a symbol found by ftrace_mod_address_lookup(). The ftrace lookup function must set both @modname and @modbuildid the same way as module_address_lookup(). Link: https://lkml.kernel.org/r/20251128135920.217303-7-pmladek@suse.com Fixes: 9294523e3768 ("module: add printk formats to add module build ID to stacktraces") Signed-off-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Aaron Tomlin <atomlin@atomlin.com> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkman <daniel@iogearbox.net> Cc: Daniel Gomez <da.gomez@samsung.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Kees Cook <kees@kernel.org> Cc: Luis Chamberalin <mcgrof@kernel.org> Cc: Marc Rutland <mark.rutland@arm.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Petr Pavlu <petr.pavlu@suse.com> Cc: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20kallsyms/bpf: rename __bpf_address_lookup() to bpf_address_lookup()Petr Mladek
bpf_address_lookup() has been used only in kallsyms_lookup_buildid(). It was supposed to set @modname and @modbuildid when the symbol was in a module. But it always just cleared @modname because BPF symbols were never in a module. And it did not clear @modbuildid because the pointer was not passed. The wrapper is no longer needed. Both @modname and @modbuildid are now always initialized to NULL in kallsyms_lookup_buildid(). Remove the wrapper and rename __bpf_address_lookup() to bpf_address_lookup() because this variant is used everywhere. [akpm@linux-foundation.org: fix loongarch] Link: https://lkml.kernel.org/r/20251128135920.217303-6-pmladek@suse.com Fixes: 9294523e3768 ("module: add printk formats to add module build ID to stacktraces") Signed-off-by: Petr Mladek <pmladek@suse.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: Aaron Tomlin <atomlin@atomlin.com> Cc: Daniel Borkman <daniel@iogearbox.net> Cc: Daniel Gomez <da.gomez@samsung.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Kees Cook <kees@kernel.org> Cc: Luis Chamberalin <mcgrof@kernel.org> Cc: Marc Rutland <mark.rutland@arm.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Petr Pavlu <petr.pavlu@suse.com> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20module: add helper function for reading module_buildid()Petr Mladek
Add a helper function for reading the optional "build_id" member of struct module. It is going to be used also in ftrace_mod_address_lookup(). Use "#ifdef" instead of "#if IS_ENABLED()" to match the declaration of the optional field in struct module. Link: https://lkml.kernel.org/r/20251128135920.217303-4-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Daniel Gomez <da.gomez@samsung.com> Reviewed-by: Petr Pavlu <petr.pavlu@suse.com> Cc: Aaron Tomlin <atomlin@atomlin.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkman <daniel@iogearbox.net> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Kees Cook <kees@kernel.org> Cc: Luis Chamberalin <mcgrof@kernel.org> Cc: Marc Rutland <mark.rutland@arm.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20array_size.h: add ARRAY_END()Alejandro Colomar
Patch series "Add ARRAY_END(), and use it to fix off-by-one bugs", v6. Add ARRAY_END(), and use it to fix off-by-one bugs ARRAY_END() is a macro to calculate a pointer to one past the last element of an array argument. This is a very common pointer, which is used to iterate over all elements of an array: for (T *p = a; p < ARRAY_END(a); p++) ... Of course, this pointer should never be dereferenced. A pointer one past the last element of an array should not be dereferenced; it's perfectly fine to hold such a pointer --and a good thing to do--, but the only thing it should be used for is comparing it with other pointers derived from the same array. Due to how special these pointers are, it would be good to use consistent naming. It's common to name such a pointer 'end' --in fact, we have many such cases in the kernel--. C++ even standardized this name with std::end(). Let's try naming such pointers 'end', and try also avoid using 'end' for pointers that are not the result of ARRAY_END(). It has been incorrectly suggested that these pointers are dangerous, and that they should never be used, suggesting to use something like #define ARRAY_LAST(a) ((a) + ARRAY_SIZE(a) - 1) for (T *p = a; p <= ARRAY_LAST(a); p++) ... This is bogus, as it doesn't scale down to arrays of 0 elements. In the case of an array of 0 elements, ARRAY_LAST() would underflow the pointer, which not only it can't be dereferenced, it can't even be held (it produces Undefined Behavior). That would be a footgun. Such arrays don't exist per the ISO C standard; however, GCC supports them as an extension (with partial support, though; GCC has a few bugs which need to be fixed). This patch set fixes a few places where it was intended to use the array end (that is, one past the last element), but accidentally a pointer to the last element was used instead, thus wasting one byte. It also replaces other places where the array end was correctly calculated with ARRAY_SIZE(), by using the simpler ARRAY_END(). Also, there was one drivers/ file that already defined this macro. We remove that definition, to not conflict with this one. This patch (of 4): ARRAY_END() returns a pointer one past the end of the last element in the array argument. This pointer is useful for iterating over the elements of an array: for (T *p = a, p < ARRAY_END(a); p++) ... Link: https://lkml.kernel.org/r/cover.1765449750.git.alx@kernel.org Link: https://lkml.kernel.org/r/5973cfb674192bc8e533485dbfb54e3062896be1.1765449750.git.alx@kernel.org Signed-off-by: Alejandro Colomar <alx@kernel.org> Cc: Kees Cook <kees@kernel.org> Cc: Christopher Bazley <chris.bazley.wg14@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Marco Elver <elver@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Jann Horn <jannh@google.com> Cc: Maciej W. Rozycki <macro@orcam.me.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20kernel.h: drop hex.h and update all hex.h usersRandy Dunlap
Remove <linux/hex.h> from <linux/kernel.h> and update all users/callers of hex.h interfaces to directly #include <linux/hex.h> as part of the process of putting kernel.h on a diet. Removing hex.h from kernel.h means that 36K C source files don't have to pay the price of parsing hex.h for the roughly 120 C source files that need it. This change has been build-tested with allmodconfig on most ARCHes. Also, all users/callers of <linux/hex.h> in the entire source tree have been updated if needed (if not already #included). Link: https://lkml.kernel.org/r/20251215005206.2362276-1-rdunlap@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Yury Norov (NVIDIA) <yury.norov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20mm/vmstat: remove unused node and zone state helpersWei Yang
Several helper functions for managing node and zone states have become obsolete and no longer have any callers within the kernel. inc_node_state() inc_zone_state() dec_zone_state() This commit removes the dead code. Link: https://lkml.kernel.org/r/20251225210213.2553-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Joshua Hahn <joshua.hahnjy@gmail.com> Acked-by: David Hildenbrand (Red Hat) <david@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20mm, hugetlb: implement movable_gigantic_pages sysctlGregory Price
This reintroduces a concept removed by: commit d6cb41cc44c6 ("mm, hugetlb: remove hugepages_treat_as_movable sysctl") This sysctl provides flexibility between ZONE_MOVABLE use cases: 1) onlining memory in ZONE_MOVABLE to maintain hotplug compatibility 2) onlining memory in ZONE_MOVABLE to make hugepage allocate reliable When ZONE_MOVABLE is used to make huge page allocation more reliable, disallowing gigantic pages memory in this region is pointless. If hotplug is not a requirement, we can loosen the restrictions to allow 1GB gigantic pages in ZONE_MOVABLE. Since 1GB can be difficult to migrate / has impacts on compaction / defragmentation, we don't enable this by default. Notably, 1GB pages can only be migrated if another 1GB page is available - so hot-unplug will fail if such a page cannot be found. However, since there are scenarios where gigantic pages are migratable, we should allow use of these on movable regions. When not valid 1GB is available for migration, hot-unplug will retry indefinitely (or until interrupted). For example: echo 0 > node0/hugepages/..-1GB/nr_hugepages # clear node0 1GB pages echo 1 > node1/hugepages/..-1GB/nr_hugepages # reserve node1 1GB page ./alloc_huge_node1 & # Allocate a 1GB page on node1 ./node1_offline & # attempt to offline all node1 memory echo 1 > node0/hugepages/..-1GB/nr_hugepages # reserve node0 1GB page In this example, node1_offline will block indefinitely until the final step, when a node0 1GB page is made available. Note: Boot-time CMA is not possible for driver-managed hotplug memory, as CMA requires the memory to be registered as SystemRAM at boot time. Additionally, 1GB huge pages are not supported by THP. Link: https://lkml.kernel.org/r/20251221125603.2364174-1-gourry@gourry.net Signed-off-by: Gregory Price <gourry@gourry.net> Suggested-by: David Rientjes <rientjes@google.com> Link: https://lore.kernel.org/all/20180201193132.Hk7vI_xaU%25akpm@linux-foundation.org/ Acked-by: David Hildenbrand (Red Hat) <david@kernel.org> Acked-by: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: "David Hildenbrand (Red Hat)" <david@kernel.org> Cc: Gregory Price <gourry@gourry.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20mm: cleanup vma_iter_bulk_allocWentao Guan
commit d24062914837 ("fork: use __mt_dup() to duplicate maple tree in dup_mmap()"), removed the only user and mas_expected_entries has been removed, since commit e3852a1213ffc ("maple_tree: Drop bulk insert support"). Also cleanup the mas_expected_entries in maple_tree.h. No functional change. Link: https://lkml.kernel.org/r/20251106110929.3522073-1-guanwentao@uniontech.com Signed-off-by: Wentao Guan <guanwentao@uniontech.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Cheng Nie <niecheng1@uniontech.com> Cc: Guan Wentao <guanwentao@uniontech.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Jann Horn <jannh@google.com> Cc: Pedro Falcato <pfalcato@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20mm: clarify GFP_ATOMIC/GFP_NOWAIT doc-commentBrendan Jackman
The current description of contexts where it's invalid to make GFP_ATOMIC and GFP_NOWAIT calls is rather vague. Replace this with a direct description of the actual contexts of concern and refer to the RT docs where this is explained more discursively. While rejigging this prose, also move the documentation of GFP_NOWAIT to the GFP_NOWAIT section. Link: https://lore.kernel.org/all/d912480a-5229-4efe-9336-b31acded30f5@suse.cz/ Link: https://lkml.kernel.org/r/20251219-b4-gfp_atomic-comment-v2-1-4c4ce274c2b6@google.com Signed-off-by: Brendan Jackman <jackmanb@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Hildenbrand (Red Hat) <david@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20mm/mm_init: replace simple_strtoul with kstrtobool in set_hashdistThorsten Blum
Use bool for 'hashdist' and replace simple_strtoul() with kstrtobool() for parsing the 'hashdist=' boot parameter. Unlike simple_strtoul(), which returns an unsigned long, kstrtobool() converts the string directly to bool and avoids implicit casting. Check the return value of kstrtobool() and reject invalid values. This adds error handling while preserving behavior for existing values, and removes use of the deprecated simple_strtoul() helper. The current code silently sets 'hashdist = 0' if parsing fails, instead of leaving the default value (HASHDIST_DEFAULT) unchanged. Additionally, kstrtobool() accepts common boolean strings such as "on" and "off". Link: https://lkml.kernel.org/r/20251217110214.50807-1-thorsten.blum@linux.dev Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20maple_tree: remove struct maple_allocSidhartha Kumar
struct maple_alloc is deprecated after the maple tree conversion to sheaves, remove the references from the header file. Link: https://lkml.kernel.org/r/20251203224511.469978-1-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20mm/block/fs: remove laptop_modeJohannes Weiner
Laptop mode was introduced to save battery, by delaying and consolidating writes and thereby maximize the time rotating hard drives wouldn't have to spin. Luckily, rotating hard drives, with their high spin-up times and power draw, are a thing of the past for battery-powered devices. Reclaim has also since changed to not write single filesystem pages anymore, and regular filesystem writeback is lumpy by design. The juice doesn't appear worth the squeeze anymore. The footprint of the feature is small, but nevertheless it's a complicating factor in mm, block, filesystems. Developers don't think about it, and it likely hasn't been tested with new reclaim and writeback changes in years. Let's sunset it. Keep the sysctl with a deprecation warning around for a few more cycles, but remove all functionality behind it. [akpm@linux-foundation.org: fix Documentation/admin-guide/laptops/index.rst] Link: https://lkml.kernel.org/r/20251216185201.GH905277@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Suggested-by: Christoph Hellwig <hch@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Deepanshu Kartikey <kartikey406@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20mm/damon/core: implement max_nr_snapshotsSeongJae Park
There are DAMOS use cases that require user-space centric control of its activation and deactivation. Having the control plane on the user-space, or using DAMOS as a way for monitoring results collection are such examples. DAMON parameters online commit, DAMOS quotas and watermarks can be useful for this purpose. However, those features work only at the sub-DAMON-snapshot level. In some use cases, the DAMON-snapshot level control is required. For example, in DAMOS-based monitoring results collection use case, the user online-installs a DAMOS scheme with DAMOS_STAT action, wait it be applied to whole regions of a single DAMON-snapshot, retrieves the stats and tried regions information, and online-uninstall the scheme. It is efficient to ensure the lifetime of the scheme as no more no less one snapshot consumption. To support such use cases, introduce a new DAMOS core API per-scheme parameter, namely max_nr_snapshots. As the name implies, it is the upper limit of nr_snapshots, which is a DAMOS stat that represents the number of DAMON-snapshots that the scheme has fully applied. If the limit is set with a non-zero value and nr_snapshots reaches or exceeds the limit, the scheme is deactivated. Link: https://lkml.kernel.org/r/20251216080128.42991-8-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20mm/damon: update damos kerneldoc for stat fieldSeongJae Park
Commit 0e92c2ee9f45 ("mm/damon/schemes: account scheme actions that successfully applied") has replaced ->stat_count and ->stat_sz of 'struct damos' with ->stat. The commit mistakenly did not update the related kernel doc comment, though. Update the comment. Link: https://lkml.kernel.org/r/20251216080128.42991-7-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20mm/damon/core: introduce nr_snapshots damos statSeongJae Park
Patch series "mm/damon: introduce {,max_}nr_snapshots and tracepoint for damos stats". Introduce three changes for improving DAMOS stat's provided information, deterministic control, and reading usability. DAMOS provides stats that are important for understanding its behavior. It lacks information about how many DAMON-generated monitoring output snapshots it has worked on. Add a new stat, nr_snapshots, to show the information. Users can control DAMOS schemes in multiple ways. Using the online parameters commit feature, they can install and uninstall DAMOS schemes whenever they want while keeping DAMON runs. DAMOS quotas and watermarks can be used for manually or automatically turning on/off or adjusting the aggressiveness of the scheme. DAMOS filters can be used for applying the scheme to specific memory entities based on their types and locations. Some users want their DAMOS scheme to be applied to only specific number of DAMON snapshots, for more deterministic control. One example use case is tracepoint based snapshot reading. Add a new knob, max_nr_snapshots, to support this. If the nr_snapshots parameter becomes same to or greater than the value of this parameter, the scheme is deactivated. Users can read DAMOS stats via DAMON's sysfs interface. For deep level investigations on environments having advanced tools like perf and bpftrace, exposing the stats via a tracepoint can be useful. Implement a new tracepoint, namely damon:damos_stat_after_apply_interval. First five patches (patches 1-5) of this series implement the new stat, nr_snapshots, on the core layer (patch 1), expose on DAMON sysfs user interface (patch 2), and update documents (patches 3-5). Following six patches (patches 6-11) are for the new stat based DAMOS deactivation (max_nr_snapshots). The first one (patch 6) of this group updates a kernel-doc comment before making further changes. Then an implementation of it on the core layer (patch 7), an introduction of a new DAMON sysfs interface file for users of the feature (patch 8), and three updates of the documents (patches 9-11) follow. The final one (patch 12) introduces the new tracepoint that exposes the DAMOS stat values for each scheme apply interval. This patch (of 12): DAMON generates monitoring results snapshots for every sampling interval. DAMOS applies given schemes on the regions of the snapshots, for every apply interval of the scheme. DAMOS stat informs a given scheme has tried to how many memory entities and applied, in the region and byte level. In some use cases including user-space oriented tuning and investigations, it is useful to know that in the DAMON-snapshot level. Introduce a new stat, namely nr_snapshots for DAMON core API callers. [sj@kernel.org: fix wrong list_is_last() call in damons_is_last_region()] Link: https://lkml.kernel.org/r/20260114152049.99727-1-sj@kernel.org Link: https://lkml.kernel.org/r/20251216080128.42991-1-sj@kernel.org Link: https://lkml.kernel.org/r/20251216080128.42991-2-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20mm: memcontrol: rename mem_cgroup_from_slab_obj()Johannes Weiner
In addition to slab objects, this function is used for resolving non-slab kernel pointers. This has caused confusion in recent refactoring work. Rename it to mem_cgroup_from_virt(), sticking with terminology established by the virt_to_<foo>() converters. Link: https://lore.kernel.org/linux-mm/20251113161424.GB3465062@cmpxchg.org/ Link: https://lkml.kernel.org/r/20251210154301.720133-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20memcg: remove mem_cgroup_size()Chen Ridong
The mem_cgroup_size helper is used only in apply_proportional_protection to read the current memory usage. Its semantics are unclear and inconsistent with other sites, which directly call page_counter_read for the same purpose. Remove this helper and get its usage via mem_cgroup_protection for clarity. Additionally, rename the local variable 'cgroup_size' to 'usage' to better reflect its meaning. No functional changes intended. Link: https://lkml.kernel.org/r/20251211013019.2080004-3-chenridong@huaweicloud.com Signed-off-by: Chen Ridong <chenridong@huawei.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Cc: Michal Koutný <mkoutny@suse.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Lu Jialin <lujialin4@huawei.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20mm: folio_zero_user: clear page rangesAnkur Arora
Use batch clearing in clear_contig_highpages() instead of clearing a single page at a time. Exposing larger ranges enables the processor to optimize based on extent. To do this we just switch to using clear_user_highpages() which would in turn use clear_user_pages() or clear_pages(). Batched clearing, when running under non-preemptible models, however, has latency considerations. In particular, we need periodic invocations of cond_resched() to keep to reasonable preemption latencies. This is a problem because the clearing primitives do not, or might not be able to, call cond_resched() to check if preemption is needed. So, limit the worst case preemption latency by doing the clearing in units of no more than PROCESS_PAGES_NON_PREEMPT_BATCH pages. (Preemptible models already define away most of cond_resched(), so the batch size is ignored when running under those.) PROCESS_PAGES_NON_PREEMPT_BATCH: for architectures with "fast" clear-pages (ones that define clear_pages()), we define it as 32MB worth of pages. This is meant to be large enough to allow the processor to optimize the operation and yet small enough that we see reasonable preemption latency for when this optimization is not possible (ex. slow microarchitectures, memory bandwidth saturation.) This specific value also allows for a cacheline allocation elision optimization (which might help unrelated applications by not evicting potentially useful cache lines) that kicks in recent generations of AMD Zen processors at around LLC-size (32MB is a typical size). At the same time 32MB is small enough that even with poor clearing bandwidth (say ~10GBps), time to clear 32MB should be well below the scheduler's default warning threshold (sysctl_resched_latency_warn_ms=100). "Slow" architectures (don't have clear_pages()) will continue to use the base value (single page). Performance == Testing a demand fault workload shows a decent improvement in bandwidth with pg-sz=1GB. Bandwidth with pg-sz=2MB stays flat. $ perf bench mem mmap -p $pg-sz -f demand -s 64GB -l 5 contiguous-pages batched-pages (GBps +- %stdev) (GBps +- %stdev) pg-sz=2MB 23.58 +- 1.95% 25.34 +- 1.18% + 7.50% preempt=* pg-sz=1GB 25.09 +- 0.79% 39.22 +- 2.32% + 56.31% preempt=none|voluntary pg-sz=1GB 25.71 +- 0.03% 52.73 +- 0.20% [#] +110.16% preempt=full|lazy [#] We perform much better with preempt=full|lazy because, not needing explicit invocations of cond_resched() we can clear the full extent (pg-sz=1GB) as a single unit which the processor can optimize for. (Unless otherwise noted, all numbers are on AMD Genoa (EPYC 9J13); region-size=64GB, local node; 2.56 GHz, boost=0.) Analysis == pg-sz=1GB: the improvement we see falls in two buckets depending on the batch size in use. For batch-size=32MB the number of cachelines allocated (L1-dcache-loads) -- which stay relatively flat for smaller batches, start to drop off because cacheline allocation elision kicks in. And as can be seen below, at batch-size=1GB, we stop allocating cachelines almost entirely. (Not visible here but from testing with intermediate sizes, the allocation change kicks in only at batch-size=32MB and ramps up from there.) contigous-pages 6,949,417,798 L1-dcache-loads # 883.599 M/sec ( +- 0.01% ) (35.75%) 3,226,709,573 L1-dcache-load-misses # 46.43% of all L1-dcache accesses ( +- 0.05% ) (35.75%) batched,32MB 2,290,365,772 L1-dcache-loads # 471.171 M/sec ( +- 0.36% ) (35.72%) 1,144,426,272 L1-dcache-load-misses # 49.97% of all L1-dcache accesses ( +- 0.58% ) (35.70%) batched,1GB 63,914,157 L1-dcache-loads # 17.464 M/sec ( +- 8.08% ) (35.73%) 22,074,367 L1-dcache-load-misses # 34.54% of all L1-dcache accesses ( +- 16.70% ) (35.70%) The dropoff is also visible in L2 prefetch hits (miss numbers are on similar lines): contiguous-pages 3,464,861,312 l2_pf_hit_l2.all # 437.722 M/sec ( +- 0.74% ) (15.69%) batched,32MB 883,750,087 l2_pf_hit_l2.all # 181.223 M/sec ( +- 1.18% ) (15.71%) batched,1GB 8,967,943 l2_pf_hit_l2.all # 2.450 M/sec ( +- 17.92% ) (15.77%) This largely decouples the frontend from the backend since the clearing operation does not need to wait on loads from memory (we still need cacheline ownership but that's a shorter path). This is most visible if we rerun the test above with (boost=1, 3.66 GHz). $ perf bench mem mmap -p $pg-sz -f demand -s 64GB -l 5 contiguous-pages batched-pages (GBps +- %stdev) (GBps +- %stdev) pg-sz=2MB 26.08 +- 1.72% 26.13 +- 0.92% - preempt=* pg-sz=1GB 26.99 +- 0.62% 48.85 +- 2.19% + 80.99% preempt=none|voluntary pg-sz=1GB 27.69 +- 0.18% 75.18 +- 0.25% +171.50% preempt=full|lazy Comparing the batched-pages numbers from the boost=0 ones and these: for a clock-speed gain of 42% we gain 24.5% for batch-size=32MB and 42.5% for batch-size=1GB. In comparison the baseline contiguous-pages case and both the pg-sz=2MB ones are largely backend bound so gain no more than ~10%. Other platforms tested, Intel Icelakex (Oracle X9) and ARM64 Neoverse-N1 (Ampere Altra) both show an improvement of ~35% for pg-sz=2MB|1GB. The first goes from around 8GBps to 11GBps and the second from 32GBps to 44 GBPs. [ankur.a.arora@oracle.com: move the unit computation and make it a const Link: https://lkml.kernel.org/r/20260108060406.1693853-1-ankur.a.arora@oracle.com Link: https://lkml.kernel.org/r/20260107072009.1615991-8-ankur.a.arora@oracle.com Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com> Acked-by: David Hildenbrand (Red Hat) <david@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Konrad Rzessutek Wilk <konrad.wilk@oracle.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Li Zhe <lizhe.67@bytedance.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mateusz Guzik <mjguzik@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Raghavendra K T <raghavendra.kt@amd.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20highmem: introduce clear_user_highpages()Ankur Arora
Define clear_user_highpages() which uses the range clearing primitive, clear_user_pages(). We can safely use this when CONFIG_HIGHMEM is disabled and if the architecture does not have clear_user_highpage. The first is needed to ensure that contiguous page ranges stay contiguous which precludes intermediate maps via HIGMEM. The second, because if the architecture has clear_user_highpage(), it likely needs flushing magic when clearing the page, magic that we aren't privy to. For both of those cases, just fallback to a loop around clear_user_highpage(). Link: https://lkml.kernel.org/r/20260107072009.1615991-4-ankur.a.arora@oracle.com Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com> Acked-by: David Hildenbrand (Red Hat) <david@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Konrad Rzessutek Wilk <konrad.wilk@oracle.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Li Zhe <lizhe.67@bytedance.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mateusz Guzik <mjguzik@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Raghavendra K T <raghavendra.kt@amd.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20mm: introduce clear_pages() and clear_user_pages()Ankur Arora
Introduce clear_pages(), to be overridden by architectures that support more efficient clearing of consecutive pages. Also introduce clear_user_pages(), however, we will not expect this function to be overridden anytime soon. As we do for clear_user_page(), define clear_user_pages() only if the architecture does not define clear_user_highpage(). That is because if the architecture does define clear_user_highpage(), then it likely needs some flushing magic when clearing user pages or highpages. This means we can get away without defining clear_user_pages(), since, much like its single page sibling, its only potential user is the generic clear_user_highpages() which should instead be using clear_user_highpage(). Link: https://lkml.kernel.org/r/20260107072009.1615991-3-ankur.a.arora@oracle.com Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com> Acked-by: David Hildenbrand (Red Hat) <david@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Konrad Rzessutek Wilk <konrad.wilk@oracle.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Li Zhe <lizhe.67@bytedance.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mateusz Guzik <mjguzik@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Raghavendra K T <raghavendra.kt@amd.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20treewide: provide a generic clear_user_page() variantDavid Hildenbrand
Patch series "mm: folio_zero_user: clear page ranges", v11. This series adds clearing of contiguous page ranges for hugepages. The series improves on the current discontiguous clearing approach in two ways: - clear pages in a contiguous fashion. - use batched clearing via clear_pages() wherever exposed. The first is useful because it allows us to make much better use of hardware prefetchers. The second, enables advertising the real extent to the processor. Where specific instructions support it (ex. string instructions on x86; "mops" on arm64 etc), a processor can optimize based on this because, instead of seeing a sequence of 8-byte stores, or a sequence of 4KB pages, it sees a larger unit being operated on. For instance, AMD Zen uarchs (for extents larger than LLC-size) switch to a mode where they start eliding cacheline allocation. This is helpful not just because it results in higher bandwidth, but also because now the cache is not evicting useful cachelines and replacing them with zeroes. Demand faulting a 64GB region shows performance improvement: $ perf bench mem mmap -p $pg-sz -f demand -s 64GB -l 5 baseline +series (GBps +- %stdev) (GBps +- %stdev) pg-sz=2MB 11.76 +- 1.10% 25.34 +- 1.18% [*] +115.47% preempt=* pg-sz=1GB 24.85 +- 2.41% 39.22 +- 2.32% + 57.82% preempt=none|voluntary pg-sz=1GB (similar) 52.73 +- 0.20% [#] +112.19% preempt=full|lazy [*] This improvement is because switching to sequential clearing allows the hardware prefetchers to do a much better job. [#] For pg-sz=1GB a large part of the improvement is because of the cacheline elision mentioned above. preempt=full|lazy improves upon that because, not needing explicit invocations of cond_resched() to ensure reasonable preemption latency, it can clear the full extent as a single unit. In comparison the maximum extent used for preempt=none|voluntary is PROCESS_PAGES_NON_PREEMPT_BATCH (32MB). When provided the full extent the processor forgoes allocating cachelines on this path almost entirely. (The hope is that eventually, in the fullness of time, the lazy preemption model will be able to do the same job that none or voluntary models are used for, allowing us to do away with cond_resched().) Raghavendra also tested previous version of the series on AMD Genoa and sees similar improvement [1] with preempt=lazy. $ perf bench mem map -p $page-size -f populate -s 64GB -l 10 base patched change pg-sz=2MB 12.731939 GB/sec 26.304263 GB/sec 106.6% pg-sz=1GB 26.232423 GB/sec 61.174836 GB/sec 133.2% This patch (of 8): Let's drop all variants that effectively map to clear_page() and provide it in a generic variant instead. We'll use the macro clear_user_page to indicate whether an architecture provides it's own variant. Also, clear_user_page() is only called from the generic variant of clear_user_highpage(), so define it only if the architecture does not provide a clear_user_highpage(). And, for simplicity define it in linux/highmem.h. Note that for parisc, clear_page() and clear_user_page() map to clear_page_asm(), so we can just get rid of the custom clear_user_page() implementation. There is a clear_user_page_asm() function on parisc, that seems to be unused. Not sure what's up with that. Link: https://lkml.kernel.org/r/20260107072009.1615991-1-ankur.a.arora@oracle.com Link: https://lkml.kernel.org/r/20260107072009.1615991-2-ankur.a.arora@oracle.com Signed-off-by: David Hildenbrand <david@redhat.com> Co-developed-by: Ankur Arora <ankur.a.arora@oracle.com> Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ankur Arora <ankur.a.arora@oracle.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: David Hildenbrand <david@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Konrad Rzessutek Wilk <konrad.wilk@oracle.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Li Zhe <lizhe.67@bytedance.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mateusz Guzik <mjguzik@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Raghavendra K T <raghavendra.kt@amd.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20mm: enable lazy_mmu sections to nestKevin Brodsky
Despite recent efforts to prevent lazy_mmu sections from nesting, it remains difficult to ensure that it never occurs - and in fact it does occur on arm64 in certain situations (CONFIG_DEBUG_PAGEALLOC). Commit 1ef3095b1405 ("arm64/mm: Permit lazy_mmu_mode to be nested") made nesting tolerable on arm64, but without truly supporting it: the inner call to leave() disables the batching optimisation before the outer section ends. This patch actually enables lazy_mmu sections to nest by tracking the nesting level in task_struct, in a similar fashion to e.g. pagefault_{enable,disable}(). This is fully handled by the generic lazy_mmu helpers that were recently introduced. lazy_mmu sections were not initially intended to nest, so we need to clarify the semantics w.r.t. the arch_*_lazy_mmu_mode() callbacks. This patch takes the following approach: * The outermost calls to lazy_mmu_mode_{enable,disable}() trigger calls to arch_{enter,leave}_lazy_mmu_mode() - this is unchanged. * Nested calls to lazy_mmu_mode_{enable,disable}() are not forwarded to the arch via arch_{enter,leave} - lazy MMU remains enabled so the assumption is that these callbacks are not relevant. However, existing code may rely on a call to disable() to flush any batched state, regardless of nesting. arch_flush_lazy_mmu_mode() is therefore called in that situation. A separate interface was recently introduced to temporarily pause the lazy MMU mode: lazy_mmu_mode_{pause,resume}(). pause() fully exits the mode *regardless of the nesting level*, and resume() restores the mode at the same nesting level. pause()/resume() are themselves allowed to nest, so we actually store two nesting levels in task_struct: enable_count and pause_count. A new helper is_lazy_mmu_mode_active() is introduced to determine whether we are currently in lazy MMU mode; this will be used in subsequent patches to replace the various ways arch's currently track whether the mode is enabled. In summary (enable/pause represent the values *after* the call): lazy_mmu_mode_enable() -> arch_enter() enable=1 pause=0 lazy_mmu_mode_enable() -> ø enable=2 pause=0 lazy_mmu_mode_pause() -> arch_leave() enable=2 pause=1 lazy_mmu_mode_resume() -> arch_enter() enable=2 pause=0 lazy_mmu_mode_disable() -> arch_flush() enable=1 pause=0 lazy_mmu_mode_disable() -> arch_leave() enable=0 pause=0 Note: is_lazy_mmu_mode_active() is added to <linux/sched.h> to allow arch headers included by <linux/pgtable.h> to use it. Link: https://lkml.kernel.org/r/20251215150323.2218608-10-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Acked-by: David Hildenbrand (Red Hat) <david@kernel.org> Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David Hildenbrand <david@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Venkat Rao Bagalkote <venkat88@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20mm: bail out of lazy_mmu_mode_* in interrupt contextKevin Brodsky
The lazy MMU mode cannot be used in interrupt context. This is documented in <linux/pgtable.h>, but isn't consistently handled across architectures. arm64 ensures that calls to lazy_mmu_mode_* have no effect in interrupt context, because such calls do occur in certain configurations - see commit b81c688426a9 ("arm64/mm: Disable barrier batching in interrupt contexts"). Other architectures do not check this situation, most likely because it hasn't occurred so far. Let's handle this in the new generic lazy_mmu layer, in the same fashion as arm64: bail out of lazy_mmu_mode_* if in_interrupt(). Also remove the arm64 handling that is now redundant. Both arm64 and x86/Xen also ensure that any lazy MMU optimisation is disabled while in interrupt (see queue_pte_barriers() and xen_get_lazy_mode() respectively). This will be handled in the generic layer in a subsequent patch. Link: https://lkml.kernel.org/r/20251215150323.2218608-9-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Acked-by: David Hildenbrand (Red Hat) <david@kernel.org> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David Hildenbrand <david@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Venkat Rao Bagalkote <venkat88@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20mm: introduce generic lazy_mmu helpersKevin Brodsky
The implementation of the lazy MMU mode is currently entirely arch-specific; core code directly calls arch helpers: arch_{enter,leave}_lazy_mmu_mode(). We are about to introduce support for nested lazy MMU sections. As things stand we'd have to duplicate that logic in every arch implementing lazy_mmu - adding to a fair amount of logic already duplicated across lazy_mmu implementations. This patch therefore introduces a new generic layer that calls the existing arch_* helpers. Two pair of calls are introduced: * lazy_mmu_mode_enable() ... lazy_mmu_mode_disable() This is the standard case where the mode is enabled for a given block of code by surrounding it with enable() and disable() calls. * lazy_mmu_mode_pause() ... lazy_mmu_mode_resume() This is for situations where the mode is temporarily disabled by first calling pause() and then resume() (e.g. to prevent any batching from occurring in a critical section). The documentation in <linux/pgtable.h> will be updated in a subsequent patch. No functional change should be introduced at this stage. The implementation of enable()/resume() and disable()/pause() is currently identical, but nesting support will change that. Most of the call sites have been updated using the following Coccinelle script: @@ @@ { ... - arch_enter_lazy_mmu_mode(); + lazy_mmu_mode_enable(); ... - arch_leave_lazy_mmu_mode(); + lazy_mmu_mode_disable(); ... } @@ @@ { ... - arch_leave_lazy_mmu_mode(); + lazy_mmu_mode_pause(); ... - arch_enter_lazy_mmu_mode(); + lazy_mmu_mode_resume(); ... } A couple of notes regarding x86: * Xen is currently the only case where explicit handling is required for lazy MMU when context-switching. This is purely an implementation detail and using the generic lazy_mmu_mode_* functions would cause trouble when nesting support is introduced, because the generic functions must be called from the current task. For that reason we still use arch_leave() and arch_enter() there. * x86 calls arch_flush_lazy_mmu_mode() unconditionally in a few places, but only defines it if PARAVIRT_XXL is selected, and we are removing the fallback in <linux/pgtable.h>. Add a new fallback definition to <asm/pgtable.h> to keep things building. Link: https://lkml.kernel.org/r/20251215150323.2218608-8-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David Hildenbrand (Red Hat) <david@kernel.org> Cc: David S. Miller <davem@davemloft.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Venkat Rao Bagalkote <venkat88@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20mm: introduce CONFIG_ARCH_HAS_LAZY_MMU_MODEKevin Brodsky
Architectures currently opt in for implementing lazy_mmu helpers by defining __HAVE_ARCH_ENTER_LAZY_MMU_MODE. In preparation for introducing a generic lazy_mmu layer that will require storage in task_struct, let's switch to a cleaner approach: instead of defining a macro, select a CONFIG option. This patch introduces CONFIG_ARCH_HAS_LAZY_MMU_MODE and has each arch select it when it implements lazy_mmu helpers. __HAVE_ARCH_ENTER_LAZY_MMU_MODE is removed and <linux/pgtable.h> relies on the new CONFIG instead. On x86, lazy_mmu helpers are only implemented if PARAVIRT_XXL is selected. This creates some complications in arch/x86/boot/, because a few files manually undefine PARAVIRT* options. As a result <asm/paravirt.h> does not define the lazy_mmu helpers, but this breaks the build as <linux/pgtable.h> only defines them if !CONFIG_ARCH_HAS_LAZY_MMU_MODE. There does not seem to be a clean way out of this - let's just undefine that new CONFIG too. Link: https://lkml.kernel.org/r/20251215150323.2218608-7-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com> Acked-by: Andreas Larsson <andreas@gaisler.com> [sparc] Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David Hildenbrand (Red Hat) <david@kernel.org> Cc: David S. Miller <davem@davemloft.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Venkat Rao Bagalkote <venkat88@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20mm: clarify lazy_mmu sleeping constraintsKevin Brodsky
The lazy MMU mode documentation makes clear that an implementation should not assume that preemption is disabled or any lock is held upon entry to the mode; however it says nothing about what code using the lazy MMU interface should expect. In practice sleeping is forbidden (for generic code) while the lazy MMU mode is active: say it explicitly. Link: https://lkml.kernel.org/r/20251215150323.2218608-6-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com> Acked-by: David Hildenbrand (Red Hat) <david@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David S. Miller <davem@davemloft.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Venkat Rao Bagalkote <venkat88@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20net: remove HIPPI support and RoadRunner HIPPI driverEthan Nelson-Moore
HIPPI has not been relevant for over two decades. It was rapidly eclipsed by Fibre Channel, and even when it was new, it was confined to very high-end hardware. The HIPPI code has only received tree-wide changes and fixes by inspection in the entire Git history. Remove HIPPI support and the rrunner HIPPI driver, and move the former maintainer to the CREDITS file. Keep the include/uapi/linux/if_hippi.h header because it is used by the TUN code, and to avoid breaking userspace, however unlikely that may be. Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com> Link: https://patch.msgid.link/20260119022451.22344-1-enelsonmoore@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-20Revert "Merge branch 'netkit-support-for-io_uring-zero-copy-and-af_xdp'"Jakub Kicinski
This reverts commit 77b9c4a438fc66e2ab004c411056b3fb71a54f2c, reversing changes made to 4515ec4ad58a37e70a9e1256c0b993958c9b7497: 931420a2fc36 ("selftests/net: Add netkit container tests") ab771c938d9a ("selftests/net: Make NetDrvContEnv support queue leasing") 6be87fbb2776 ("selftests/net: Add env for container based tests") 61d99ce3dfc2 ("selftests/net: Add bpf skb forwarding program") 920da3634194 ("netkit: Add xsk support for af_xdp applications") eef51113f8af ("netkit: Add netkit notifier to check for unregistering devices") b5ef109d22d4 ("netkit: Implement rtnl_link_ops->alloc and ndo_queue_create") b5c3fa4a0b16 ("netkit: Add single device mode for netkit") 0073d2fd679d ("xsk: Proxy pool management for leased queues") 1ecea95dd3b5 ("xsk: Extend xsk_rcv_check validation") 804bf334d08a ("net: Proxy netdev_queue_get_dma_dev for leased queues") 0caa9a8ddec3 ("net: Proxy net_mp_{open,close}_rxq for leased queues") ff8889ff9107 ("net, ethtool: Disallow leased real rxqs to be resized") 9e2103f36110 ("net: Add lease info to queue-get response") 31127deddef4 ("net: Implement netdev_nl_queue_create_doit") a5546e18f77c ("net: Add queue-create operation") The series will conflict with io_uring work, and the code needs more polish. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
generated by cgit v1.2.3 (git 2.46.0) at 2026-04-06 12:15:49 +0000