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2026-02-02docs: fix 're-use' -> 'reuse' in documentationRhys Tumelty
Signed-off-by: Rhys Tumelty <rhys@tumelty.co.uk> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <20260128220233.179439-1-rhys@tumelty.co.uk>
2026-01-31Docs/admin-guide/mm/damon/usage: update stats update process for refresh_msSeongJae Park
DAMOS stats on sysfs was only manually updated. Recent addition of 'refresh_ms' knob enabled periodic and automated updates of the stats. The document for stats update process is not updated for the change, however. Update. Link: https://lkml.kernel.org/r/20260118180305.70023-7-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> 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: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-31Docs/admin-guide/mm/damon/usage: introduce DAMON modules at the beginningSeongJae Park
DAMON usage document provides a list of available DAMON interfaces with brief introduction at the beginning of the doc. The list is missing DAMON modules for special purposes, while it is one of the major suggested interfaces. Add an item for those to the list. Link: https://lkml.kernel.org/r/20260118180305.70023-6-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> 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: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-31mm: rename CONFIG_BALLOON_COMPACTION to CONFIG_BALLOON_MIGRATIONDavid Hildenbrand (Red Hat)
While compaction depends on migration, the other direction is not the case. So let's make it clearer that this is all about migration of balloon pages. Adjust all comments/docs in the core to talk about "migration" instead of "compaction". While at it add some "/* CONFIG_BALLOON_MIGRATION */". Link: https://lkml.kernel.org/r/20260119230133.3551867-23-david@kernel.org Signed-off-by: David Hildenbrand (Red Hat) <david@kernel.org> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Eugenio Pérez <eperezma@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jason Wang <jasowang@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@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: Oscar Salvador <osalvador@suse.de> Cc: SeongJae Park <sj@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-30xfs: allow setting errortags at mount timeChristoph Hellwig
Add an errortag mount option that enables an errortag with the default injection frequency. This allows injecting errors into the mount process instead of just on live file systems, and thus test mount error handling. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hans Holmberg <hans.holmberg@wdc.com> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2026-01-30docs: trusted-encryped: add PKWM as a new trust sourceNayna Jain
Update Documentation/security/keys/trusted-encrypted.rst and Documentation/ admin-guide/kernel-parameters.txt with PowerVM Key Wrapping Module (PKWM) as a new trust source Signed-off-by: Nayna Jain <nayna@linux.ibm.com> Signed-off-by: Srish Srinivasan <ssrish@linux.ibm.com> Tested-by: Nayna Jain <nayna@linux.ibm.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Link: https://patch.msgid.link/20260127145228.48320-7-ssrish@linux.ibm.com
2026-01-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.19-rc8). No adjacent changes, conflicts: drivers/net/ethernet/spacemit/k1_emac.c 2c84959167d64 ("net: spacemit: Check for netif_carrier_ok() in emac_stats_update()") f66086798f91f ("net: spacemit: Remove broken flow control support") https://lore.kernel.org/aXjAqZA3iEWD_DGM@sirena.org.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-29riscv: add kernel command line option to opt out of user CFIDeepak Gupta
Add a kernel command line option to disable part or all of user CFI. User backward CFI and forward CFI can be controlled independently. The kernel command line parameter "riscv_nousercfi" can take the following values: - "all" : Disable forward and backward cfi both - "bcfi" : Disable backward cfi - "fcfi" : Disable forward cfi Signed-off-by: Deepak Gupta <debug@rivosinc.com> Tested-by: Andreas Korb <andreas.korb@aisec.fraunhofer.de> # QEMU, custom CVA6 Tested-by: Valentin Haudiquet <valentin.haudiquet@canonical.com> Link: https://patch.msgid.link/20251112-v5_user_cfi_series-v23-21-b55691eacf4f@rivosinc.com [pjw@kernel.org: fixed warnings from checkpatch; cleaned up patch description, doc, printk text] Signed-off-by: Paul Walmsley <pjw@kernel.org>
2026-01-26Docs/admin-guide/mm/damon/lru_sort: document intervals autotuningSeongJae Park
Document a newly added DAMON_LRU_SORT module parameter for using monitoring intervals auto-tuning feature of DAMON. Link: https://lkml.kernel.org/r/20260113152717.70459-12-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Acked-by: wang lian <lianux.mm@gmail.com> Cc: David Hildenbrand <david@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> 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: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26Docs/admin-guide/mm/damon/lru_sort: document active_mem_bp parameterSeongJae Park
Document a newly added DAMON_LRU_SORT parameter for doing auto-tuning aiming an active to inactive memory size ratio. Link: https://lkml.kernel.org/r/20260113152717.70459-10-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Acked-by: wang lian <lianux.mm@gmail.com> Cc: David Hildenbrand <david@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> 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: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26Docs/admin-guide/mm/damon/lru_sort: document filter_young_pagesSeongJae Park
Document the new DAMON_LRU_SORT parameter, filter_young_pages. It can be used to use page level access re-check for the LRU sorting. Link: https://lkml.kernel.org/r/20260113152717.70459-8-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Acked-by: wang lian <lianux.mm@gmail.com> Cc: David Hildenbrand <david@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> 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: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26memcg-v1: remove folio_memcg_lock() doc referenceGreg Thelen
Commit a29c0e4b2e86 ("memcg-v1: remove memcg move locking code") removed folio_memcg_lock(). Delete the final lingering documentation reference. Link: https://lkml.kernel.org/r/20260101225552.3423108-1-gthelen@google.com Fixes: a29c0e4b2e86 ("memcg-v1: remove memcg move locking code") Signed-off-by: Greg Thelen <gthelen@google.com> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: SeongJae Park <sj@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Michal Koutný" <mkoutny@suse.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26Merge tag 'vfs-6.19-rc8.fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs fixes from Christian Brauner: - Fix the the buggy conversion of fuse_reverse_inval_entry() introduced during the creation rework - Disallow nfs delegation requests for directories by setting simple_nosetlease() - Require an opt-in for getting readdir flag bits outside of S_DT_MASK set in d_type - Fix scheduling delayed writeback work by only scheduling when the dirty time expiry interval is non-zero and cancel the delayed work if the interval is set to zero - Use rounded_jiffies_interval for dirty time work - Check the return value of sb_set_blocksize() for romfs - Wait for batched folios to be stable in __iomap_get_folio() - Use private naming for fuse hash size - Fix the stale dentry cleanup to prevent a race that causes a UAF * tag 'vfs-6.19-rc8.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: vfs: document d_dispose_if_unused() fuse: shrink once after all buckets have been scanned fuse: clean up fuse_dentry_tree_work() fuse: add need_resched() before unlocking bucket fuse: make sure dentry is evicted if stale fuse: fix race when disposing stale dentries fuse: use private naming for fuse hash size writeback: use round_jiffies_relative for dirtytime_work iomap: wait for batched folios to be stable in __iomap_get_folio romfs: check sb_set_blocksize() return value docs: clarify that dirtytime_expire_seconds=0 disables writeback writeback: fix 100% CPU usage when dirtytime_expire_interval is 0 readdir: require opt-in for d_type flags vboxsf: don't allow delegations to be set on directories ceph: don't allow delegations to be set on directories gfs2: don't allow delegations to be set on directories 9p: don't allow delegations to be set on directories smb/client: properly disallow delegations on directories nfs: properly disallow delegation requests on directories fuse: fix conversion of fuse_reverse_inval_entry() to start_removing()
2026-01-26Merge branch 'fixes' of into for-nextIlpo Järvinen
2026-01-26Merge 6.19-rc7 into char-misc-nextGreg Kroah-Hartman
We need the char/misc/iio fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-25net: expand NETDEV_RSS_KEY_LEN to 256 bytesEric Dumazet
NETDEV_RSS_KEY_LEN has been set to 52 bytes in 2014, until now. Jakub suggested we bump the size to 128 bytes or more. Some drivers (like idpf) were already working around the core limit. Since this change might cause some issues in admin scripts, bump it directly to 256 in one go. tjbp26:~# cat /proc/sys/net/core/netdev_rss_key | wc -c 768 tjbp26:~# ethtool -x eth1 RX flow hash indirection table for eth1 with 32 RX ring(s): ... RSS hash key: fe:16:5b:2f:93:85:c2:c9:c1:ef:bd:60:c6:e0:2b:99:4d:bf:b7:14:c8:1e:8d:cb:31:17:51:da:55:eb:91:d9:9e:f9:89:9b:44:a1:dc:08:72:3a:b3:d6:31:86:9a:fe:02:3a:0d:eb:a1:7c:f5:a3:51:3b:08:56:c9:3f:71:69:01:ba:70:38 RSS hash function: toeplitz: on xor: off crc32: off Suggested-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/netdev/20260122075206.504ec591@kernel.org/ Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260122190349.2771064-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-23Merge tag 'platform-drivers-x86-v6.19-3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86 Pull x86 platform driver fixes from Ilpo Järvinen: - acer-wmi: - Extend support for Acer Nitro AN515-58 - Fix missing capability check - amd/wbrf: Fix memory leak in wbrf_record() - asus-armoury: - Fix GA403U* matching - Fix FA608UM TDP data - Add many models - asus-wmi: Move OOBE presence check outside deprecation ifdef - hp-bioscfg: - Fix kernel panic in GET_INSTANCE_ID macro - Fix kobject warnings for empty attribute names - Correct GUID to uppercase (lowercase letter prevented autoloading the module) - mellanox: Fix SN5640/SN5610 LED platform data - docs: - alienware-wmi: Typo fix - amd_hsmp: Fix document link * tag 'platform-drivers-x86-v6.19-3' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (21 commits) platform/x86: acer-wmi: Fix missing capability check platform/x86: acer-wmi: Extend support for Acer Nitro AN515-58 platform/x86: asus-armoury: add support for GA403WW platform/x86: asus-armoury: keep the list ordered alphabetically platform/x86: asus-armoury: add support for G835L platform/x86: asus-armoury: fix ppt data for FA608UM platform/x86: hp-bioscfg: Fix automatic module loading platform/x86: hp-bioscfg: Fix kernel panic in GET_INSTANCE_ID macro platform/x86: hp-bioscfg: Fix kobject warnings for empty attribute names platform/x86: asus-wmi: fix sending OOBE at probe platform/x86: asus-armoury: add support for FA617XT platform/x86: asus-armoury: add support for FA401UV platform/x86: asus-armoury: add support for GV302XV platform/x86: asus-armoury: Add power limits for Asus G513QY platform/x86/amd: Fix memory leak in wbrf_record() platform/mellanox: Fix SN5640/SN5610 LED platform data docs: fix PPR for AMD EPYC broken link docs: alienware-wmi: fix typo platform/x86: asus-armoury: add support for GA403UV asus-armoury: fix ppt data for GA403U* renaming to GA403UI ...
2026-01-23Documentation: use a source-read extension for the index link boilerplateJani Nikula
The root document usually has a special :ref:`genindex` link to the generated index. This is also the case for Documentation/index.rst. The other index.rst files deeper in the directory hierarchy usually don't. For SPHINXDIRS builds, the root document isn't Documentation/index.rst, but some other index.rst in the hierarchy. Currently they have a ".. only::" block to add the index link when doing SPHINXDIRS html builds. This is obviously very tedious and repetitive. The link is also added to all index.rst files in the hierarchy for SPHINXDIRS builds, not just the root document. Put the boilerplate in a sphinx-includes/subproject-index.rst file, and include it at the end of the root document for subproject builds in an ad-hoc source-read extension defined in conf.py. For now, keep having the boilerplate in translations, because this approach currently doesn't cover translated index link headers. Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Tested-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> [jc: did s/doctree/kern_doc_dir/ ] Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <20260123143149.2024303-1-jani.nikula@intel.com>
2026-01-22rseq: Move slice_ext_nsec to debugfsPeter Zijlstra
Move changing the slice ext duration to debugfs, a sliglty less permanent interface. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20260121143207.923520192@infradead.org
2026-01-22rseq: Implement time slice extension enforcement timerThomas Gleixner
If a time slice extension is granted and the reschedule delayed, the kernel has to ensure that user space cannot abuse the extension and exceed the maximum granted time. It was suggested to implement this via the existing hrtick() timer in the scheduler, but that turned out to be problematic for several reasons: 1) It creates a dependency on CONFIG_SCHED_HRTICK, which can be disabled independently of CONFIG_HIGHRES_TIMERS 2) HRTICK usage in the scheduler can be runtime disabled or is only used for certain aspects of scheduling. 3) The function is calling into the scheduler code and that might have unexpected consequences when this is invoked due to a time slice enforcement expiry. Especially when the task managed to clear the grant via sched_yield(0). It would be possible to address #2 and #3 by storing state in the scheduler, but that is extra complexity and fragility for no value. Implement a dedicated per CPU hrtimer instead, which is solely used for the purpose of time slice enforcement. The timer is armed when an extension was granted right before actually returning to user mode in rseq_exit_to_user_mode_restart(). It is disarmed, when the task relinquishes the CPU. This is expensive as the timer is probably the first expiring timer on the CPU, which means it has to reprogram the hardware. But that's less expensive than going through a full hrtimer interrupt cycle for nothing. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://patch.msgid.link/20251215155709.068329497@linutronix.de
2026-01-22rseq: Provide static branch for time slice extensionsThomas Gleixner
Guard the time slice extension functionality with a static key, which can be disabled on the kernel command line. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20251215155708.733429292@linutronix.de
2026-01-21cgroup: Remove stale cpu.rt.max reference from documentationTejun Heo
cpu.rt.max was a proposed interface that never landed in mainline. Remove the reference from cgroup-v2 documentation. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Orestis Floros <orestisflo@gmail.com>
2026-01-20watchdog: softlockup: panic when lockup duration exceeds N thresholdsLi RongQing
The softlockup_panic sysctl is currently a binary option: panic immediately or never panic on soft lockups. Panicking on any soft lockup, regardless of duration, can be overly aggressive for brief stalls that may be caused by legitimate operations. Conversely, never panicking may allow severe system hangs to persist undetected. Extend softlockup_panic to accept an integer threshold, allowing the kernel to panic only when the normalized lockup duration exceeds N watchdog threshold periods. This provides finer-grained control to distinguish between transient delays and persistent system failures. The accepted values are: - 0: Don't panic (unchanged) - 1: Panic when duration >= 1 * threshold (20s default, original behavior) - N > 1: Panic when duration >= N * threshold (e.g., 2 = 40s, 3 = 60s.) The original behavior is preserved for values 0 and 1, maintaining full backward compatibility while allowing systems to tolerate brief lockups while still catching severe, persistent hangs. [lirongqing@baidu.com: v2] Link: https://lkml.kernel.org/r/20251218074300.4080-1-lirongqing@baidu.com Link: https://lkml.kernel.org/r/20251216074521.2796-1-lirongqing@baidu.com Signed-off-by: Li RongQing <lirongqing@baidu.com> Cc: Eduard Zingerman <eddyz87@gmail.com> Cc: Hao Luo <haoluo@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Fastabend <john.fastabend@gmail.com> Cc: KP Singh <kpsingh@kernel.org> Cc: Lance Yang <lance.yang@linux.dev> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Song Liu <song@kernel.org> Cc: Stanislav Fomichev <sdf@fomichev.me> Cc: Yonghong Song <yonghong.song@linux.dev> 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/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>
2026-01-20Docs/admin-guide/mm/damon/usage: update for max_nr_snapshotsSeongJae Park
Update DAMON usage document for the newly added DAMON sysfs interface file, max_nr_snapshots. Link: https://lkml.kernel.org/r/20251216080128.42991-11-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>
2026-01-20Docs/admin-guide/mm/damon/usage: update for nr_snapshots damos statSeongJae Park
Update DAMON usage document for the newly added damos stat, nr_snapshots. Link: https://lkml.kernel.org/r/20251216080128.42991-5-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>
2026-01-20zram: document writeback_batch_sizeSergey Senozhatsky
Add missing writeback_batch_size documentation. Link: https://lkml.kernel.org/r/20251201094754.4149975-4-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Brian Geffon <bgeffon@google.com> Cc: David Stevens <stevensd@google.com> Cc: Minchan Kim <minchan@google.com> Cc: Richard Chang <richardycc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20zram: introduce writeback_compressed device attributeRichard Chang
Introduce witeback_compressed device attribute to toggle compressed writeback (decompression on demand) feature. [senozhatsky@chromium.org: rewrote original patch, added documentation] Link: https://lkml.kernel.org/r/20251201094754.4149975-3-senozhatsky@chromium.org Signed-off-by: Richard Chang <richardycc@google.com> Co-developed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Brian Geffon <bgeffon@google.com> Cc: David Stevens <stevensd@google.com> Cc: Minchan Kim <minchan@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20Docs/mm/allocation-profiling: describe sysctrl limitations in debug modeSuren Baghdasaryan
When CONFIG_MEM_ALLOC_PROFILING_DEBUG=y, /proc/sys/vm/mem_profiling is read-only to avoid debug warnings in a scenario when an allocation is made while profiling is disabled (allocation does not get an allocation tag), then profiling gets enabled and allocation gets freed (warning due to the allocation missing allocation tag). Link: https://lkml.kernel.org/r/20260116184423.2708363-1-surenb@google.com Fixes: ebdf9ad4ca98 ("memprofiling: documentation") Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Acked-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Ran Xiaokai <ran.xiaokai@zte.com.cn> Cc: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-19dm-verity: add dm-verity keyringChristian Brauner
Add a dedicated ".dm-verity" keyring for root hash signature verification, similar to the ".fs-verity" keyring used by fs-verity. By default the keyring is unused retaining the exact same old behavior. For systems that provision additional keys only intended for dm-verity images during boot, the dm_verity.keyring_unsealed=1 kernel parameter leaves the keyring open. We want to use this in systemd as a way add keys during boot that are only used for creating dm-verity devices for later mounting and nothing else. The discoverable disk image (DDI) spec at [1] heavily relies on dm-verity and we would like to expand this even more. This will allow us to do that in a fully backward compatible way. Once provisioning is complete, userspace restricts and activates it for dm-verity verification. If userspace fully seals the keyring then it gains the guarantee that no new keys can be added. Link: https://uapi-group.org/specifications/specs/discoverable_partitions_specification [1] Co-developed-by: Aleksa Sarai <cyphar@cyphar.com> Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> Signed-off-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2026-01-17x86/acpi: Add acpi=spcr to use SPCR-provided default consoleShenghao Yang
The SPCR provided console on x86 is only available as a boot console when earlycon is provided on the kernel command line, and will not be present in /proc/consoles. While it's possible to retain the boot console with the keep_bootcon parameter, that leaves the console using the less efficient 8250_early driver. Users wanting to use the firmware suggested console (to avoid maintaining unique serial console parameters for different server models in large fleets) with the conventional driver have to parse the kernel log for the console parameters and reinsert them. [ 0.005091] ACPI: SPCR 0x000000007FFB5000 000059 (v04 ALASKA A M I 01072009 INTL 20250404) [ 0.073387] ACPI: SPCR: console: uart,io,0x3f8,115200 In commit 0231d00082f6 ("ACPI: SPCR: Make SPCR available to x86")¹ the SPCR console was only added as an option for earlycon but not as an ordinary console so users don't see console output changes. So users can opt in to an automatic SPCR console, make ACPI init add it if acpi=spcr is set. ¹https://lore.kernel.org/lkml/20180118150951.28964-1-prarit@redhat.com/ [ bp: Touchups. ] Signed-off-by: Shenghao Yang <me@shenghaoyang.info> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://patch.msgid.link/20260117072827.355360-1-me@shenghaoyang.info
2026-01-17Documentation: admin-guide: media: mgb4: Add GMSL1 & GMSL3-coax modules infoMartin Tůma
Add the mgb4 GMSL1 and GMSL3-coax modules info. Signed-off-by: Martin Tůma <martin.tuma@digiteqautomotive.com> Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
2026-01-16docs: make kptr_restrict and hash_pointers reference each otherMarc Herbert
vsprintf.c uses a mix of the `kernel.kptr_restrict` sysctl and the `hash_pointers` boot param to control pointer hashing. But that wasn't possible to tell without looking at the source code. They have a different focus and purpose. To avoid wasting the time of users trying to use one instead of the other, simply have them reference each other in the Documentation. Signed-off-by: Marc Herbert <marc.herbert@linux.intel.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <20260107-doc-hash-ptr-v2-1-cb4c161218d7@linux.intel.com>
2026-01-16Documentation: Fix typos and grammatical errorsNauman Sabir
Fix various typos and grammatical errors across documentation files: - Fix missing preposition 'in' in process/changes.rst - Correct 'result by' to 'result from' in admin-guide/README.rst - Fix 'before hand' to 'beforehand' in cgroup-v1/hugetlb.rst - Correct 'allows to limit' to 'allows limiting' in hugetlb.rst, cgroup-v2.rst, and kconfig-language.rst - Fix 'needs precisely know' to 'needs to precisely know' - Correct 'overcommited' to 'overcommitted' in hugetlb.rst - Fix subject-verb agreement: 'never causes' to 'never cause' - Fix 'there is enough' to 'there are enough' in hugetlb.rst - Fix 'metadatas' to 'metadata' in filesystems/erofs.rst - Fix 'hardwares' to 'hardware' in scsi/ChangeLog.sym53c8xx Signed-off-by: Nauman Sabir <officialnaumansabir@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Message-ID: <20260115230110.7734-1-officialnaumansabir@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2026-01-15Merge tag 'mm-hotfixes-stable-2026-01-15-08-03' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull misc fixes from Andrew Morton: - kerneldoc fixes from Bagas Sanjaya - DAMON fixes from SeongJae - mremap VMA-related fixes from Lorenzo - various singletons - please see the changelogs for details * tag 'mm-hotfixes-stable-2026-01-15-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (30 commits) drivers/dax: add some missing kerneldoc comment fields for struct dev_dax mm: numa,memblock: include <asm/numa.h> for 'numa_nodes_parsed' mailmap: add entry for Daniel Thompson tools/testing/selftests: fix gup_longterm for unknown fs mm/page_alloc: prevent pcp corruption with SMP=n iommu/sva: include mmu_notifier.h header mm: kmsan: fix poisoning of high-order non-compound pages tools/testing/selftests: add forked (un)/faulted VMA merge tests mm/vma: enforce VMA fork limit on unfaulted,faulted mremap merge too tools/testing/selftests: add tests for !tgt, src mremap() merges mm/vma: fix anon_vma UAF on mremap() faulted, unfaulted merge mm/zswap: fix error pointer free in zswap_cpu_comp_prepare() mm/damon/sysfs-scheme: cleanup access_pattern subdirs on scheme dir setup failure mm/damon/sysfs-scheme: cleanup quotas subdirs on scheme dir setup failure mm/damon/sysfs: cleanup attrs subdirs on context dir setup failure mm/damon/sysfs: cleanup intervals subdirs on attrs dir setup failure mm/damon/core: remove call_control in inactive contexts powerpc/watchdog: add support for hardlockup_sys_info sysctl mips: fix HIGHMEM initialization mm/hugetlb: ignore hugepage kernel args if hugepages are unsupported ...
2026-01-15platform/x86: thinkpad_acpi: Add sysfs to display details of damaged device.Nitin Joshi
Add new sysfs interface to identify the impacted component with location of device. Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca> Signed-off-by: Nitin Joshi <nitjoshi@gmail.com> Link: https://patch.msgid.link/20260106174519.6402-2-nitjoshi@gmail.com Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
2026-01-15platform/x86: thinkpad_acpi: Add support to detect hardware damage detection ↵Nitin Joshi
capability. Thinkpads are adding the ability to detect and report hardware damage status. Add new sysfs interface to identify whether hardware damage is detected or not. Initial support is available for the USB-C replaceable connector. Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca> Signed-off-by: Nitin Joshi <nitjoshi@gmail.com> Link: https://patch.msgid.link/20260106174519.6402-1-nitjoshi@gmail.com Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
2026-01-14docs: kernel-parameters: add kfence parametersMarco Elver
Add a brief summary for KFENCE's kernel command-line parameters in admin-guide/kernel-parameters. Link: https://lkml.kernel.org/r/20251222150018.1349672-1-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-14xen: introduce xen_console_io optionStefano Stabellini
Xen can support console_io hypercalls for any domains, not just dom0, depending on DEBUG and XSM policies. These hypercalls can be very useful for development and debugging. Introduce a kernel command line option xen_console_io to enable the usage of console_io hypercalls for any domain upon request. When xen_console_io is not specified, the current behavior is retained. Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Message-ID: <alpine.DEB.2.22.394.2601131522540.992863@ubuntu-linux-20-04-desktop>
2026-01-13net: add net.core.qdisc_max_burstEric Dumazet
In blamed commit, I added a check against the temporary queue built in __dev_xmit_skb(). Idea was to drop packets early, before any spinlock was acquired. if (unlikely(defer_count > READ_ONCE(q->limit))) { kfree_skb_reason(skb, SKB_DROP_REASON_QDISC_DROP); return NET_XMIT_DROP; } It turned out that HTB Qdisc has a zero q->limit. HTB limits packets on a per-class basis. Some of our tests became flaky. Add a new sysctl : net.core.qdisc_max_burst to control how many packets can be stored in the temporary lockless queue. Also add a new QDISC_BURST_DROP drop reason to better diagnose future issues. Thanks Neal ! Fixes: 100dfa74cad9 ("net: dev_queue_xmit() llist adoption") Reported-and-bisected-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Link: https://patch.msgid.link/20260107104159.3669285-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-01-12cgroup/cpuset: Don't invalidate sibling partitions on cpuset.cpus conflictWaiman Long
Currently, when setting a cpuset's cpuset.cpus to a value that conflicts with the cpuset.cpus/cpuset.cpus.exclusive of a sibling partition, the sibling's partition state becomes invalid. This is overly harsh and is probably not necessary. The cpuset.cpus.exclusive control file, if set, will override the cpuset.cpus of the same cpuset when creating a cpuset partition. So cpuset.cpus has less priority than cpuset.cpus.exclusive in setting up a partition. However, it cannot override a conflicting cpuset.cpus file in a sibling cpuset and the partition creation process will fail. This is inconsistent. That will also make using cpuset.cpus.exclusive less valuable as a tool to set up cpuset partitions as the users have to check if such a cpuset.cpus conflict exists or not. Fix these problems by making sure that once a cpuset.cpus.exclusive is set without failure, it will always be allowed to form a valid partition as long as at least one CPU can be granted from its parent irrespective of the state of the siblings' cpuset.cpus values. Of course, setting cpuset.cpus.exclusive will fail if it conflicts with the cpuset.cpus.exclusive or the cpuset.cpus.exclusive.effective value of a sibling. Partition can still be created by setting only cpuset.cpus without setting cpuset.cpus.exclusive. However, any conflicting CPUs in sibling's cpuset.cpus.exclusive.effective and cpuset.cpus.exclusive values will be removed from its cpuset.cpus.exclusive.effective as long as there is still one or more CPUs left and can be granted from its parent. This CPU stripping is currently done in rm_siblings_excl_cpus(). The new code will now try its best to enable the creation of new partitions with only cpuset.cpus set without invalidating existing ones. However it is not guaranteed that all the CPUs requested in cpuset.cpus will be used in the new partition even when all these CPUs can be granted from the parent. This is similar to the fact that cpuset.cpus.effective may not be able to include all the CPUs requested in cpuset.cpus. In this case, the parent may not able to grant all the exclusive CPUs requested in cpuset.cpus to cpuset.cpus.exclusive.effective if some of them have already been granted to other partitions earlier. With the creation of multiple sibling partitions by setting only cpuset.cpus, this does have the side effect that their exact cpuset.cpus.exclusive.effective settings will depend on the order of partition creation if there are conflicts. Due to the exclusive nature of the CPUs in a partition, it is not easy to make it fair other than the old behavior of invalidating all the conflicting partitions. For example, # echo "0-2" > A1/cpuset.cpus # echo "root" > A1/cpuset.cpus.partition # cat A1/cpuset.cpus.partition root # cat A1/cpuset.cpus.exclusive.effective 0-2 # echo "2-4" > B1/cpuset.cpus # echo "root" > B1/cpuset.cpus.partition # cat B1/cpuset.cpus.partition root # cat B1/cpuset.cpus.exclusive.effective 3-4 # cat B1/cpuset.cpus.effective 3-4 For users who want to be sure that they can get most of the CPUs they want, cpuset.cpus.exclusive should be used instead if they can set it successfully without failure. Setting cpuset.cpus.exclusive will guarantee that sibling conflicts from then onward is no longer possible. To make this change, we have to separate out the is_cpu_exclusive() check in cpus_excl_conflict() into a cgroup v1 only cpuset1_cpus_excl_conflict() helper. The cpus_allowed_validate_change() helper is now no longer needed and can be removed. Some existing tests in test_cpuset_prs.sh are updated and new ones are added to reflect the new behavior. The cgroup-v2.rst doc file is also updated the clarify what exclusive CPUs will be used when a partition is created. Reported-by: Sun Shaojie <sunshaojie@kylinos.cn> Closes: https://lore.kernel.org/lkml/20251117015708.977585-1-sunshaojie@kylinos.cn/ Signed-off-by: Waiman Long <longman@redhat.com> Reviewed-by: Chen Ridong <chenridong@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2026-01-12cgroup/cpuset: Don't fail cpuset.cpus change in v2Waiman Long
Commit fe8cd2736e75 ("cgroup/cpuset: Delay setting of CS_CPU_EXCLUSIVE until valid partition") introduced a new check to disallow the setting of a new cpuset.cpus.exclusive value that is a superset of a sibling's cpuset.cpus value so that there will at least be one CPU left in the sibling in case the cpuset becomes a valid partition root. This new check does have the side effect of failing a cpuset.cpus change that make it a subset of a sibling's cpuset.cpus.exclusive value. With v2, users are supposed to be allowed to set whatever value they want in cpuset.cpus without failure. To maintain this rule, the check is now restricted to only when cpuset.cpus.exclusive is being changed not when cpuset.cpus is changed. The cgroup-v2.rst doc file is also updated to reflect this change. Signed-off-by: Waiman Long <longman@redhat.com> Reviewed-by: Chen Ridong <chenridong@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2026-01-12Documentation: bug-hunting.rst: Remove wrong 'file:' syntaxPetr Vorel
Link to another document does not require 'file:', therefore it was shown in generated html. Preformatted text requires just ``...``. Signed-off-by: Petr Vorel <pvorel@suse.cz> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <20260111223643.174812-1-pvorel@suse.cz>
2026-01-12init: remove /proc/sys/kernel/real-root-devAskar Safin
It is not used anymore. Signed-off-by: Askar Safin <safinaskar@gmail.com> Link: https://patch.msgid.link/20251119222407.3333257-4-safinaskar@gmail.com Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-01-12initrd: remove deprecated code path (linuxrc)Askar Safin
Remove linuxrc initrd code path, which was deprecated in 2020. Initramfs and (non-initial) RAM disks (i. e. brd) still work. Both built-in and bootloader-supplied initramfs still work. Non-linuxrc initrd code path (i. e. using /dev/ram as final root filesystem) still works, but I put deprecation message into it. Also I deprecate command line parameters "noinitrd" and "ramdisk_start=". Signed-off-by: Askar Safin <safinaskar@gmail.com> Link: https://patch.msgid.link/20251119222407.3333257-3-safinaskar@gmail.com Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-01-12docs: clarify that dirtytime_expire_seconds=0 disables writebackLaveesh Bansal
Document that setting vm.dirtytime_expire_seconds to zero disables periodic dirtytime writeback, matching the behavior of the related dirty_writeback_centisecs sysctl which already documents this. Signed-off-by: Laveesh Bansal <laveeshb@laveeshbansal.com> Link: https://patch.msgid.link/20260106145059.543282-3-laveeshb@laveeshbansal.com Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-01-10iommu: Add page_ext for IOMMU_DEBUG_PAGEALLOCMostafa Saleh
Add a new config IOMMU_DEBUG_PAGEALLOC, which registers new data to page_ext. This config will be used by the IOMMU API to track pages mapped in the IOMMU to catch drivers trying to free kernel memory that they still map in their domains, causing all types of memory corruption. This behaviour is disabled by default and can be enabled using kernel cmdline iommu.debug_pagealloc. Acked-by: David Hildenbrand (Red Hat) <david@kernel.org> Reviewed-by: Pranjal Shrivastava <praan@google.com> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Signed-off-by: Mostafa Saleh <smostafa@google.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-01-09x86/resctrl: Add energy/perf choices to rdt boot optionTony Luck
Legacy resctrl features are enumerated by X86_FEATURE_* flags. These may be overridden by quirks to disable features in the case of errata. Users can use kernel command line options to either disable a feature, or to force enable a feature that was disabled by a quirk. A different approach is needed for hardware features that do not have an X86_FEATURE_* flag. Update parsing of the "rdt=" boot parameter to call the telemetry driver directly to handle new "perf" and "energy" options that controls activation of telemetry monitoring of the named type. By itself a "perf" or "energy" option controls the forced enabling or disabling (with ! prefix) of all event groups of the named type. A ":guid" suffix allows for fine grained control per event group. [ bp: s/intel_aet_option/intel_handle_aet_option/g ] Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
2026-01-08KVM: x86/pmu: Expose enable_mediated_pmu parameter to user spaceDapeng Mi
Expose enable_mediated_pmu parameter to user space, i.e. allow userspace to enable/disable mediated vPMU support. Document the mediated versus perf-based behavior as part of the kernel-parameters.txt entry, and opportunistically add an entry for the core enable_pmu param as well. Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Mingwei Zhang <mizhang@google.com> Tested-by: Xudong Hao <xudong.hao@intel.com> Co-developed-by: Sean Christopherson <seanjc@google.com> Tested-by: Manali Shukla <manali.shukla@amd.com> Link: https://patch.msgid.link/20251206001720.468579-34-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>