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2025-11-24pagemap: update BUDDY flag documentationRichard Weinberger
Since v4.6 the BUDDY flag is set for _all_ pages in the block and no longer just for the first one. This change was introduced by: commit 832fc1de01ae ("/proc/kpageflags: return KPF_BUDDY for "tail" buddy pages") Strictly speaking, this was an ABI change, but as nobody has noticed since 2016, let's just update the documentation. Link: https://lkml.kernel.org/r/20251122211920.3410371-1-richard@nod.at Signed-off-by: Richard Weinberger <richard@nod.at> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: David Hildenbrand (Red Hat) <david@kernel.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Vladimir Davydov <vdavydov@virtuozzo.com>> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-21x86/resctrl: Add SDCIAE feature in the command line optionsBabu Moger
Add a kernel command-line parameter to enable or disable the exposure of the L3 Smart Data Cache Injection Allocation Enforcement (SDCIAE) hardware feature to resctrl. Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://patch.msgid.link/c623edf7cb369ba9da966de47d9f1b666778a40e.1762995456.git.babu.moger@amd.com
2025-11-21Documentation/admin-guide: fix typo and comment in cscope exampleJiakai Xu
This patch updates the Linux documentation for cscope, fixing two issues: 1. Corrects the typo in the command line: c"scope -d -p10 -> cscope -d -p10 2. Fixes the related documentation comment for clarity and correctness: cscope by default cscope.out database. -> cscope by default uses the cscope.out database. Signed-off-by: Jiakai Xu <jiakaiPeanut@gmail.com> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <20251119065727.3500015-1-jiakaiPeanut@gmail.com>
2025-11-20sys_info: add a default kernel sys_info maskFeng Tang
Which serves as a global default sys_info mask. When users want the same system information for many error cases (panic, hung, lockup ...), they can chose to set this global knob only once, while not setting up each individual sys_info knobs. This just adds a 'lazy' option, and doesn't change existing kernel behavior as the mask is 0 by default. Link: https://lkml.kernel.org/r/20251113111039.22701-5-feng.tang@linux.alibaba.com Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lance Yang <ioworker0@gmail.com> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20watchdog: add sys_info sysctls to dump sys info on system lockupFeng Tang
When soft/hard lockup happens, developers may need different kinds of system information (call-stacks, memory info, locks, etc.) to help debugging. Add 'softlockup_sys_info' and 'hardlockup_sys_info' sysctl knobs to take human readable string like "tasks,mem,timers,locks,ftrace,...", and when system lockup happens, all requested information will be printed out. (refer kernel/sys_info.c for more details). Link: https://lkml.kernel.org/r/20251113111039.22701-4-feng.tang@linux.alibaba.com Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lance Yang <ioworker0@gmail.com> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20hung_task: add hung_task_sys_info sysctl to dump sys info on task-hungFeng Tang
When task-hung happens, developers may need different kinds of system information (call-stacks, memory info, locks, etc.) to help debugging. Add 'hung_task_sys_info' sysctl knob to take human readable string like "tasks,mem,timers,locks,ftrace,...", and when task-hung happens, all requested information will be dumped. (refer kernel/sys_info.c for more details). Meanwhile, the newly introduced sys_info() call is used to unify some existing info-dumping knobs. [feng.tang@linux.alibaba.com: maintain consistecy established behavior, per Lance and Petr] Link: https://lkml.kernel.org/r/aRncJo1mA5Zk77Hr@U-2FWC9VHC-2323.local Link: https://lkml.kernel.org/r/20251113111039.22701-3-feng.tang@linux.alibaba.com Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com> Suggested-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Cc: Jonathan Corbet <corbet@lwn.net> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20docs: panic: correct some sys_ifo names in sysctl docFeng Tang
Patch series "Enable hung_task and lockup cases to dump system info on demand", v2. When working on kernel stability issues: panic, task-hung and soft/hard lockup are frequently met. And to debug them, user may need lots of system information at that time, like task call stacks, lock info, memory info, ftrace dump, etc. panic case already uses sys_info() for this purpose, and has a 'panic_sys_info' sysctl(also support cmdline setup) interface to take human readable string like "tasks,mem,timers,locks,ftrace,..." to control what kinds of information is needed. Which is also helpful to debug task-hung and lockup cases. So this patchset introduces the similar sys_info sysctl interface for task-hung and lockup cases. his is mainly for debugging and the info dumping could be intrusive, like dumping call stack for all tasks when system has huge number of tasks, similarly for ftrace dump (we may add tracing_stop() and tracing_start() around it) Locally these have been used in our bug chasing for stability issues and were helpful. As Andrew suggested, add a configurable global 'kernel_sys_info' knob. When error scenarios like panic/hung-task/lockup etc doesn't setup their own sys_info knob and calls sys_info() with parameter "0", this global knob will take effect. It could be used for other kernel cases like OOM, which may not need one dedicated sys_info knob. This patch (of 4): Some sys_info names wered forgotten to change in patch iterations, while the right names are defined in kernel/sys_info.c. Link: https://lkml.kernel.org/r/20251113111039.22701-1-feng.tang@linux.alibaba.com Link: https://lkml.kernel.org/r/20251113111039.22701-2-feng.tang@linux.alibaba.com Fixes: d747755917bf ("panic: add 'panic_sys_info' sysctl to take human readable string parameter") Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lance Yang <ioworker0@gmail.com> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-18dm verity fec: Expose corrected block count via statusShubhankar Mishra
Enhance visibility into dm-verity Forward Error Correction (FEC) activity. While FEC can correct on-disk corruptions, the number of successful correction events is not readily exposed through a standard interface. This change integrates FEC statistics into the verity target's .status handler for STATUSTYPE_INFO. The info output now includes count of corrected block by FEC. The counter is a per-device instance atomic64_t, maintained within the struct dm_verity_fec, tracking blocks successfully repaired by FEC on this specific device instance since it was created. This approach aligns with the standard Device Mapper mechanism for targets to report runtime information, as used by other targets like dm-integrity. This patch also updates Documentation/admin-guide/device-mapper/verity.rst to reflect the new status information. Tested: Induced single-bit errors on a block device protected by dm-verity with FEC on android phone. Confirmed 'dmctl status <device>' on Android reports an incrementing 'fec_corrected_blocks' count after the corrupted blocks were accessed. Signed-off-by: Shubhankar Mishra <shubhankarm@google.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2025-11-18Documentation/kernel-parameters: Move the kernel build optionsBorislav Petkov (AMD)
Move the kernel build options abbreviations to the .txt file so that they are together instead of one having to go hunt them in the .rst file. Tweak the formatting so that the inclusion of kernel-parameters.txt still keeps the whole thing somewhat presentable in the html output too. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <20251112114641.8230-1-bp@kernel.org>
2025-11-18Documentation/kernel-parameters: fix typo in retbleed= kernel parameter ↵Xie Yuanbin
description Fixes a typo in the retbleed= parameter description, changing "migitation" to "mitigation". Fixes: 7fbf47c7ce50 ("x86/bugs: Add AMD retbleed= boot parameter") Signed-off-by: Xie Yuanbin <qq570070308@gmail.com> Acked-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <20251116145302.3681-1-qq570070308@gmail.com>
2025-11-18powerpc/64s/slb: Add no_slb_preload early cmdline paramRitesh Harjani (IBM)
no_slb_preload cmdline can come useful in quickly disabling and/or testing the performance impact of userspace slb preloads. Recently there was a slb multi-hit issue due to slb preload cache which was very difficult to triage. This cmdline option allows to quickly disable preloads and verify if the issue exists in preload cache or somewhere else. This can also be a useful option to see the effect of slb preloads for any application workload e.g. number of slb faults with or w/o slb preloads. with slb_preload: slb_faults (minimal initrd boot): 15 slb_faults (full systemd boot): 300 with no_slb_preload: slb_faults (minimal initrd boot): 33 slb_faults (full systemd boot): 138180 Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Link: https://patch.msgid.link/de484b55c45d831bc2db63945f455153c89a9a65.1761834163.git.ritesh.list@gmail.com
2025-11-17Documentation: admin-guide: blockdev: update zloop parametersDamien Le Moal
In Documentation/admin-guide/blockdev/zoned_loop.rst, add the description of the zone_append and ordered_zone_append configuration arguments of zloop "add" command (device creation). Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-11-16mm/swap: do not choose swap device according to numa nodeBaoquan He
Patch series "mm/swapfile.c: select swap devices of default priority round robin", v5. Currently, on system with multiple swap devices, swap allocation will select one swap device according to priority. The swap device with the highest priority will be chosen to allocate firstly. People can specify a priority from 0 to 32767 when swapon a swap device, or the system will set it from -2 then downwards by default. Meanwhile, on NUMA system, the swap device with node_id will be considered first on that NUMA node of the node_id. In the current code, an array of plist, swap_avail_heads[nid], is used to organize swap devices on each NUMA node. For each NUMA node, there is a plist organizing all swap devices. The 'prio' value in the plist is the negated value of the device's priority due to plist being sorted from low to high. The swap device owning one node_id will be promoted to the front position on that NUMA node, then other swap devices are put in order of their default priority. E.g I got a system with 8 NUMA nodes, and I setup 4 zram partition as swap devices. Current behaviour: their priorities will be(note that -1 is skipped): NAME TYPE SIZE USED PRIO /dev/zram0 partition 16G 0B -2 /dev/zram1 partition 16G 0B -3 /dev/zram2 partition 16G 0B -4 /dev/zram3 partition 16G 0B -5 And their positions in the 8 swap_avail_lists[nid] will be: swap_avail_lists[0]: /* node 0's available swap device list */ zram0 -> zram1 -> zram2 -> zram3 prio:1 prio:3 prio:4 prio:5 swap_avali_lists[1]: /* node 1's available swap device list */ zram1 -> zram0 -> zram2 -> zram3 prio:1 prio:2 prio:4 prio:5 swap_avail_lists[2]: /* node 2's available swap device list */ zram2 -> zram0 -> zram1 -> zram3 prio:1 prio:2 prio:3 prio:5 swap_avail_lists[3]: /* node 3's available swap device list */ zram3 -> zram0 -> zram1 -> zram2 prio:1 prio:2 prio:3 prio:4 swap_avail_lists[4-7]: /* node 4,5,6,7's available swap device list */ zram0 -> zram1 -> zram2 -> zram3 prio:2 prio:3 prio:4 prio:5 The adjustment for swap device with node_id intended to decrease the pressure of lock contention for one swap device by taking different swap device on different node. The adjustment was introduced in commit a2468cc9bfdf ("swap: choose swap device according to numa node"). However, the adjustment is a little coarse-grained. On the node, the swap device sharing the node's id will always be selected firstly by node's CPUs until exhausted, then next one. And on other nodes where no swap device shares its node id, swap device with priority '-2' will be selected firstly until exhausted, then next with priority '-3'. This is the swapon output during the process high pressure vm-scability test is being taken. It's clearly showing zram0 is heavily exploited until exhausted. =================================== [root@hp-dl385g10-03 ~]# swapon NAME TYPE SIZE USED PRIO /dev/zram0 partition 16G 15.7G -2 /dev/zram1 partition 16G 3.4G -3 /dev/zram2 partition 16G 3.4G -4 /dev/zram3 partition 16G 2.6G -5 The node based strategy on selecting swap device is much better then the old way one by one selecting swap device. However it is still unreasonable because swap devices are assumed to have similar accessing speed if no priority is specified when swapon. It's unfair and doesn't make sense just because one swap device is swapped on firstly, its priority will be higher than the one swapped on later. So in this patchset, change is made to select the swap device round robin if default priority. In code, the plist array swap_avail_heads[nid] is replaced with a plist swap_avail_head which reverts commit a2468cc9bfdf. Meanwhile, on top of the revert, further change is taken to make any device w/o specified priority get the same default priority '-1'. Surely, swap device with specified priority are always put foremost, this is not impacted. If you care about their different accessing speed, then use 'swapon -p xx' to deploy priority for your swap devices. New behaviour: swap_avail_list: /* one global available swap device list */ zram0 -> zram1 -> zram2 -> zram3 prio:1 prio:1 prio:1 prio:1 This is the swapon output during the process high pressure vm-scability being taken, all is selected round robin: ======================================= [root@hp-dl385g10-03 linux]# swapon NAME TYPE SIZE USED PRIO /dev/zram0 partition 16G 12.6G -1 /dev/zram1 partition 16G 12.6G -1 /dev/zram2 partition 16G 12.6G -1 /dev/zram3 partition 16G 12.6G -1 With the change, we can see about 18% efficiency promotion as below: vm-scability test: ================== Test with: usemem --init-time -O -y -x -n 31 2G (4G memcg, zram as swap) Before: After: System time: 637.92 s 526.74 s (lower is better) Sum Throughput: 3546.56 MB/s 4207.56 MB/s (higher is better) Single process Throughput: 114.40 MB/s 135.72 MB/s (higher is better) free latency: 10138455.99 us 6810119.01 us (low is better) This patch (of 2): This reverts commit a2468cc9bfdf ("swap: choose swap device according to numa node"). After this patch, the behaviour will change back to pre-commit a2468cc9bfdf. Means the priority will be set from -1 then downwards by default, and when swapping, it will exhault swap device one by one according to priority from high to low. This is preparation work for later change. [root@hp-dl385g10-03 ~]# swapon NAME TYPE SIZE USED PRIO /dev/zram0 partition 16G 16G -1 /dev/zram1 partition 16G 966.2M -2 /dev/zram2 partition 16G 0B -3 /dev/zram3 partition 16G 0B -4 Link: https://lkml.kernel.org/r/20251028034308.929550-1-bhe@redhat.com Link: https://lkml.kernel.org/r/20251028034308.929550-2-bhe@redhat.com Signed-off-by: Baoquan He <bhe@redhat.com> Suggested-by: Chris Li <chrisl@kernel.org> Acked-by: Chris Li <chrisl@kernel.org> Acked-by: Nhat Pham <nphamcs@gmail.com> Reviewed-by: Kairui Song <kasong@tencent.com> Cc: Barry Song <baohua@kernel.org> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16Docs/admin-guide/mm/damon/usage: document obsolete_target fileSeongJae Park
Document the newly added obsolete_target DAMON sysfs file. Link: https://lkml.kernel.org/r/20251023012535.69625-5-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Reviewed-by: Bijan Tabatabai <bijan311@gmail.com> Cc: David Hildenbrand <david@redhat.com> 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: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm: shmem/tmpfs hugepage defaults config choiceDmitry Ilvokhin
Allow to override defaults for shemem and tmpfs at config time. This is consistent with how transparent hugepages can be configured. Same results can be achieved with the existing 'transparent_hugepage_shmem' and 'transparent_hugepage_tmpfs' settings in the kernel command line, but it is more convenient to define basic settings at config time instead of changing kernel command line later. Defaults for shmem and tmpfs were not changed. They are remained the same as before: 'never' for both cases. Options 'deny' and 'force' are omitted intentionally since these are special values and supposed to be used for emergencies or testing and are not expected to be permanent ones. Primary motivation for adding config option is to enable policy enforcement at build time. In large-scale production environments (Meta's for example), the kernel configuration is often maintained centrally close to the kernel code itself and owned by the kernel engineers, while boot parameters are managed independently (e.g. by provisioning systems). In such setups, the kernel build defines the supported and expected behavior in a single place, but there is no reliable or uniform control over the kernel command line options. A build-time default allows kernel integrators to enforce a predictable hugepage policy for shmem/tmpfs on a base layer, ensuring reproducible behavior and avoiding configuration drift caused by possible boot-time differences. In short, primary benefit is mostly operational: it provides a way to codify preferred policy in the kernel configuration, which is versioned, reviewed, and tested as part of the kernel build process, rather than depending on potentially variable boot parameters. [d@ilvokhin.com: v2] Link: https://lkml.kernel.org/r/aQECPpjd-fU_TC79@shell.ilvokhin.com Link: https://lkml.kernel.org/r/aPpv8sAa2sYgNu3L@shell.ilvokhin.com Signed-off-by: Dmitry Ilvokhin <d@ilvokhin.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Kiryl Shutsemau <kas@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Liam Howlett <liam.howlett@oracle.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>
2025-11-16Docs/admin-guide/mm/damon/stat: document negative idle timeSeongJae Park
Commit a983a26d5298 ("mm/damon/stat: expose negative idle time") introduced the negative idle time feature for DAMON_STAT. But it is not documented. Document it on the usage document. Link: https://lkml.kernel.org/r/20251026182216.118200-9-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Hildenbrand <david@redhat.com> 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>
2025-11-16Docs/admin-guide/mm/damon/stat: document aggr_interval_us parameterSeongJae Park
Commit cc7ceb1d14b0 ("mm/damon/stat: expose the current tuned aggregation interval"), has introduced 'aggr_interval_us' parameter for DAMON_STAT. But the new parameter is not yet documented. Document it on the usage document for the module. Link: https://lkml.kernel.org/r/20251026182216.118200-8-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Hildenbrand <david@redhat.com> 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>
2025-11-16Docs/admin-guide/mm/damon/lru_sort: document addr_unit parameterSeongJae Park
Commit 2e0fe9245d6b ("mm/damon/lru_sort: support addr_unit for DAMON_LRU_SORT") introduced the 'addr_unit' parameter for DAMON_LRU_SORT. But the usage document is not updated for that. Update the document. Link: https://lkml.kernel.org/r/20251026182216.118200-7-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Hildenbrand <david@redhat.com> 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>
2025-11-16Docs/admin-guide/mm/damon/reclaim: document addr_unit parameterSeongJae Park
Commit 7db551fcfb2a ("mm/damon/reclaim: support addr_unit for DAMON_RECLAIM") introduced the 'addr_unit' parameter for DAMON_RECLAIM. But the usage document is not updated for that. Update the document. Link: https://lkml.kernel.org/r/20251026182216.118200-6-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Hildenbrand <david@redhat.com> 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>
2025-11-16Docs/admin-guide/mm/damon/usage: document empty target regions commit behaviorSeongJae Park
Committing a monitoring target with empty target regions is for keeping the current monitoring results. This behavior was introduced by commit 973233600676 ("mm/damon/sysfs: update monitoring target regions for online input commit"). The behavior is not documented, though. Update the usage document for clarifying this behavior. Link: https://lkml.kernel.org/r/20251026182216.118200-5-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Hildenbrand <david@redhat.com> 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>
2025-11-16Docs/admin-guide/mm/damon/stat: fix a typo: s/sampling events/sampling interval/SeongJae Park
It is a contextual typo. Fix it. Link: https://lkml.kernel.org/r/20251026182216.118200-4-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Hildenbrand <david@redhat.com> 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>
2025-11-16Docs/admin-guide/mm/damon/usage: document DAMOS quota goal path fileSeongJae Park
A new DAMON sysfs interface file, namely 'path' has been added under DAMOS quota goal directory, for specifying the cgroup for DAMOS_QUOTA_NODE_MEMCG_{USED,FREE}_BP metrics. Document it on the usage document. Link: https://lkml.kernel.org/r/20251017212706.183502-10-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16memcg: net: track network throttling due to memcg memory pressureShakeel Butt
The kernel can throttle network sockets if the memory cgroup associated with the corresponding socket is under memory pressure. The throttling actions include clamping the transmit window, failing to expand receive or send buffers, aggressively prune out-of-order receive queue, FIN deferred to a retransmitted packet and more. Let's add memcg metric to track such throttling actions. At the moment memcg memory pressure is defined through vmpressure and in future it may be defined using PSI or we may add more flexible way for the users to define memory pressure, maybe through ebpf. However the potential throttling actions will remain the same, so this newly introduced metric will continue to track throttling actions irrespective of how memcg memory pressure is defined. Link: https://lkml.kernel.org/r/20251016161035.86161-1-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Daniel Sedlak <daniel.sedlak@cdn77.com> Cc: David S. Miller <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kacinski <kuba@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Neal Cardwell <ncardwell@google.com> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Simon Horman <horms@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Willem de Bruijn <willemb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16Docs/admin-guide/mm/zswap: s/red-black tree/xarray/SeongJae Park
The change from commit 796c2c23e14e ("zswap: replace RB tree with xarray") is not reflected on the document. Update the document. Link: https://lkml.kernel.org/r/20251003203851.43128-5-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Acked-by: Yosry Ahmed <yosry.ahmed@linux.dev> Acked-by: Nhat Pham <nphamcs@gmail.com> Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev> Cc: Chris Li <chrisl@kernel.org> Cc: David Hildenbrand <david@redhat.com> 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: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-15Documentation: admin-guide: media: add rockchip camera interfaceMichael Riesch
Add a document that describes the different variants of the Rockchip Camera Interface (CIF), their hardware layout, as well as their representation in the media controller centric rkcif device driver, which is located under drivers/media/platform/rockchip/rkcif. Reviewed-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> Signed-off-by: Michael Riesch <michael.riesch@collabora.com> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
2025-11-14docs: cgroup: No special handling of unpopulated memcgsMichal Koutný
The current kernel doesn't handle unpopulated cgroups any special regarding reclaim protection. Furthermore, this wasn't a case even when this was introduced in bf8d5d52ffe89 ("memcg: introduce memory.min") Drop the incorrect documentation. (Implementation taking into account the inner-node constraint may be added later.) Signed-off-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2025-11-14docs: cgroup: Note about sibling relative reclaim protectionMichal Koutný
Signed-off-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2025-11-14docs: cgroup: Explain reclaim protection targetMichal Koutný
The protection target is necessary to understand how effective reclaim protection applies in the hierarchy. Signed-off-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2025-11-14Documentation: thermal: Document thermal throttling on Intel platformsSrinivas Pandruvada
Add documentation for Intel thermal throttling reporting events. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Tested-by: Randy Dunlap <rdunlap@infradead.org> [ rjw: Subject adjustment, file name change, minor edits ] Link: https://patch.msgid.link/20251113212104.221632-1-srinivas.pandruvada@linux.intel.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-11-14Documentation: media: mali-c55: Document the mali-c55 parameter settingDaniel Scally
Document the mali-c55 parameter setting by expanding the relevant pages in both admin-guide/ and userspace-api/. Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Nayden Kanchev <nayden.kanchev@arm.com> Co-developed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com> Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com> Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
2025-11-14Documentation: media: mali-c55: Add Statistics documentationDaniel Scally
Add documentation explaining the ability to capture statistics from the mali-c55 driver's new V4L2 device, as well as the various tap points from which those statistics can be drawn in the ISP's processing flow. Additionally add a page detailing the new V4L2 meta format for the mali-c55 statistics. Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Nayden Kanchev <nayden.kanchev@arm.com> Co-developed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com> Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com> Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
2025-11-14media: Documentation: Add Mali-C55 ISP DocumentationDaniel Scally
Add a documentation page for the mali-c55 driver, which gives a brief overview of the hardware and explains how to use the driver's capture devices and the crop/scaler functions. Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Nayden Kanchev <nayden.kanchev@arm.com> Co-developed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com> Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com> Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
2025-11-13bcache: remove discard sysfs interface documentColy Li
This patch removes documents of bcache discard sysfs interface, it drops discard related sections from, - Documentation/ABI/testing/sysfs-block-bcache - Documentation/admin-guide/bcache.rst Signed-off-by: Coly Li <colyli@fnnas.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-11-12dynamic_debug: add support for print stackYe Bin
In practical problem diagnosis, especially during the boot phase, it is often desirable to know the call sequence. However, currently, apart from adding print statements and recompiling the kernel, there seems to be no good alternative. If dynamic_debug supported printing the call stack, it would be very helpful for diagnosing issues. This patch add support '+d' for dump stack. Link: https://lkml.kernel.org/r/20251025080003.312536-1-yebin@huaweicloud.com Signed-off-by: Ye Bin <yebin10@huawei.com> Cc: Jason Baron <jbaron@akamai.com> Cc: Jim Cromie <jim.cromie@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-12hung_task: panic when there are more than N hung tasks at the same timeLi RongQing
The hung_task_panic sysctl is currently a blunt instrument: it's all or nothing. Panicking on a single hung task can be an overreaction to a transient glitch. A more reliable indicator of a systemic problem is when multiple tasks hang simultaneously. Extend hung_task_panic to accept an integer threshold, allowing the kernel to panic only when N hung tasks are detected in a single scan. This provides finer control to distinguish between isolated incidents and system-wide failures. The accepted values are: - 0: Don't panic (unchanged) - 1: Panic on the first hung task (unchanged) - N > 1: Panic after N hung tasks are detected in a single scan The original behavior is preserved for values 0 and 1, maintaining full backward compatibility. [lance.yang@linux.dev: new changelog] Link: https://lkml.kernel.org/r/20251015063615.2632-1-lirongqing@baidu.com Signed-off-by: Li RongQing <lirongqing@baidu.com> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Lance Yang <lance.yang@linux.dev> Tested-by: Lance Yang <lance.yang@linux.dev> Acked-by: Andrew Jeffery <andrew@codeconstruct.com.au> [aspeed_g5_defconfig] Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Hildenbrand <david@redhat.com> Cc: Florian Wesphal <fw@strlen.de> Cc: Jakub Kacinski <kuba@kernel.org> Cc: Jason A. Donenfeld <jason@zx2c4.com> Cc: Joel Granados <joel.granados@kernel.org> Cc: Joel Stanley <joel@jms.id.au> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kees Cook <kees@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Phil Auld <pauld@redhat.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Shuah Khan <shuah@kernel.org> Cc: Simon Horman <horms@kernel.org> Cc: Stanislav Fomichev <sdf@fomichev.me> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-11powerpc/kdump: Add support for crashkernel CMA reservationSourabh Jain
Commit 35c18f2933c5 ("Add a new optional ",cma" suffix to the crashkernel= command line option") and commit ab475510e042 ("kdump: implement reserve_crashkernel_cma") added CMA support for kdump crashkernel reservation. Extend crashkernel CMA reservation support to powerpc. The following changes are made to enable CMA reservation on powerpc: - Parse and obtain the CMA reservation size along with other crashkernel parameters - Call reserve_crashkernel_cma() to allocate the CMA region for kdump - Include the CMA-reserved ranges in the usable memory ranges for the kdump kernel to use. - Exclude the CMA-reserved ranges from the crash kernel memory to prevent them from being exported through /proc/vmcore. With the introduction of the CMA crashkernel regions, crash_exclude_mem_range() needs to be called multiple times to exclude both crashk_res and crashk_cma_ranges from the crash memory ranges. To avoid repetitive logic for validating mem_ranges size and handling reallocation when required, this functionality is moved to a new wrapper function crash_exclude_mem_range_guarded(). To ensure proper CMA reservation, reserve_crashkernel_cma() is called after pageblock_order is initialized. Update kernel-parameters.txt to document CMA support for crashkernel on powerpc architecture. Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Link: https://patch.msgid.link/20251107080334.708028-1-sourabhjain@linux.ibm.com
2025-11-11md: allow configuring logical block sizeLi Nan
Previously, raid array used the maximum logical block size (LBS) of all member disks. Adding a larger LBS disk at runtime could unexpectedly increase RAID's LBS, risking corruption of existing partitions. This can be reproduced by: ``` # LBS of sd[de] is 512 bytes, sdf is 4096 bytes. mdadm -CRq /dev/md0 -l1 -n3 /dev/sd[de] missing --assume-clean # LBS is 512 cat /sys/block/md0/queue/logical_block_size # create partition md0p1 parted -s /dev/md0 mklabel gpt mkpart primary 1MiB 100% lsblk | grep md0p1 # LBS becomes 4096 after adding sdf mdadm --add -q /dev/md0 /dev/sdf cat /sys/block/md0/queue/logical_block_size # partition lost partprobe /dev/md0 lsblk | grep md0p1 ``` Simply restricting larger-LBS disks is inflexible. In some scenarios, only disks with 512 bytes LBS are available currently, but later, disks with 4KB LBS may be added to the array. Making LBS configurable is the best way to solve this scenario. After this patch, the raid will: - store LBS in disk metadata - add a read-write sysfs 'mdX/logical_block_size' Future mdadm should support setting LBS via metadata field during RAID creation and the new sysfs. Though the kernel allows runtime LBS changes, users should avoid modifying it after creating partitions or filesystems to prevent compatibility issues. Only 1.x metadata supports configurable LBS. 0.90 metadata inits all fields to default values at auto-detect. Supporting 0.90 would require more extensive changes and no such use case has been observed. Note that many RAID paths rely on PAGE_SIZE alignment, including for metadata I/O. A larger LBS than PAGE_SIZE will result in metadata read/write failures. So this config should be prevented. Link: https://lore.kernel.org/linux-raid/20251103125757.1405796-6-linan666@huaweicloud.com Signed-off-by: Li Nan <linan122@huawei.com> Reviewed-by: Xiao Ni <xni@redhat.com> Signed-off-by: Yu Kuai <yukuai@fnnas.com>
2025-11-10docs: Fix missing word in spectre.rstpierwill
Corrects a missing word in the hardware vulnerability docs. Signed-off-by: Will Pierce <pierwill@protonmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <Ru-d3ltJIyY4Oc6tzHwpSiDeFwSLHEzd7Utcr6iobgIy1B8wLRI4f6JiCb0a9n-0-r19d0dyLL3yS8KWVcyHfpkyDErWXYTkI3AJfUPTNCc=@protonmail.com>
2025-11-10Documentation: laptops: Add documentation for uniwill laptopsArmin Wolf
Add documentation for admins regarding Uniwill laptops. This should help them to setup the uniwill-laptop driver, which sadly cannot be loaded automatically. Reported-by: cyear <chumuzero@gmail.com> Closes: https://github.com/lm-sensors/lm-sensors/issues/508 Closes: https://github.com/Wer-Wolf/uniwill-laptop/issues/3 Signed-off-by: Armin Wolf <W_Armin@gmx.de> Link: https://patch.msgid.link/20251102172942.17879-3-W_Armin@gmx.de Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
2025-11-07net: increase skb_defer_max default to 128Eric Dumazet
skb_defer_max value is very conservative, and can be increased to avoid too many calls to kick_defer_list_purge(). Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Link: https://patch.msgid.link/20251106202935.1776179-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-06mfd: wl1273-core: Remove the headerDr. David Alan Gilbert
The wl1273 FM radio is on Arnd's unused driver list: https://lore.kernel.org/lkml/a15bb180-401d-49ad-a212-0c81d613fbc8@app.fastmail.com/ Other patches have removed the core, the ASoC code and the Radio code. With all those in, remove the header. Also, tidy the ref in the docs. Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Lee Jones <lee@kernel.org>
2025-11-06EDAC: Remove the legacy EDAC sysfs interfaceAvadhut Naik
Commit 199747106934 ("edac: add a new per-dimm API and make the old per-virtual-rank API obsolete") introduced a new per-DIMM sysfs interface for EDAC making the old per-virtual-rank sysfs interface obsolete. Since this new sysfs interface was introduced more than a decade ago, remove the obsolete legacy interface. Signed-off-by: Avadhut Naik <avadhut.naik@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20251106015727.1987246-1-avadhut.naik@amd.com
2025-11-04rseq: Provide static branch for runtime debuggingThomas Gleixner
Config based debug is rarely turned on and is not available easily when things go wrong. Provide a static branch to allow permanent integration of debug mechanisms along with the usual toggles in Kconfig, command line and debugfs. Requested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://patch.msgid.link/20251027084307.089270547@linutronix.de
2025-11-03Documentation: intel-pstate: Use :ref: directive for internal linkingBagas Sanjaya
intel_pstate docs uses standard reST construct (`Section title`_) for cross-referencing sections (internal linking), rather than for external links. Incorrect cross-references are not caught when these are written in that syntax, however (fortunately docutils 0.22 raise duplicate target warnings that get fixed in cb908f8b0acc7e ("Documentation: intel_pstate: fix duplicate hyperlink target errors")). Convert the cross-references to use :ref: directive, which doesn't exhibit this problem. Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> [ rjw: Changelog tweak ] Link: https://patch.msgid.link/20251101055614.32270-1-bagasdotme@gmail.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-11-03thunderbolt: Update NVM firmware upgrade documentationAlan Borzeszkowski
Update guide about firmware upgrade of Thunderbolt devices, replacing outdated recommendations with the use of modern "fwupd" tool. Signed-off-by: Alan Borzeszkowski <alan.borzeszkowski@linux.intel.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2025-10-30PM: hibernate: make compression threads configurableXueqin Luo
The number of compression/decompression threads has a direct impact on hibernate image generation and resume latency. Using more threads can reduce overall resume time, but on systems with fewer CPU cores it may also introduce contention and reduce efficiency. Performance was evaluated on an 8-core ARM system, averaged over 10 runs: Threads Hibernate(s) Resume(s) -------------------------------- 3 12.14 18.86 4 12.28 17.48 5 11.09 16.77 6 11.08 16.44 With 5–6 threads, resume latency improves by approximately 12% compared to the default 3-thread configuration, with negligible impact on hibernate time. Introduce a new kernel parameter `hibernate_compression_threads=` that allows users and integrators to tune the number of compression/decompression threads at boot. This provides a way to balance performance and CPU utilization across a wide range of hardware without recompiling the kernel. Signed-off-by: Xueqin Luo <luoxueqin@kylinos.cn> Link: https://patch.msgid.link/f24b3ca6416e230a515a154ed4c121d72a7e05a6.1761046167.git.luoxueqin@kylinos.cn Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-10-29Documentation: fix reference to PR_SPEC_L1D_FLUSHBrendan Jackman
PR_SET_L1D_FLUSH does not exist. Signed-off-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <20251015-l1d-flush-doc-v1-2-f8cefea3f2f2@google.com>
2025-10-29Documentation: intel_pstate: fix duplicate hyperlink target errorsSwaraj Gaikwad
Fix reST warnings in Documentation/admin-guide/pm/intel_pstate.rst caused by missing explicit hyperlink labels for section titles. Before this change, the following errors were printed during `make htmldocs`: Documentation/admin-guide/pm/intel_pstate.rst:401: ERROR: Indirect hyperlink target (id="id6") refers to target "passive mode", which is a duplicate, and cannot be used as a unique reference. Documentation/admin-guide/pm/intel_pstate.rst:517: ERROR: Indirect hyperlink target (id="id9") refers to target "active mode", which is a duplicate, and cannot be used as a unique reference. Documentation/admin-guide/pm/intel_pstate.rst:611: ERROR: Indirect hyperlink target (id="id15") refers to target "global attributes", which is a duplicate, and cannot be used as a unique reference. ERROR: Duplicate target name, cannot be used as a unique reference: "passive mode", "active mode", "global attributes". These errors occurred because the sections "Active Mode", "Active Mode With HWP", "Passive Mode", and "Global Attributes" did not define explicit hyperlink labels. As a result, Sphinx auto-generated duplicate anchors when the same titles appeared multiple times within the document. Because of this, the generated HTML documentation contained broken references such as: `active mode <Active Mode_>`_ `passive mode <Passive Mode_>`_ `global attributes <Global Attributes_>`_ This patch adds explicit hyperlink labels for the affected sections, ensuring all references are unique and correctly resolved. After applying this patch, `make htmldocs` completes without any warnings, and all hyperlinks in intel_pstate.html render properly. Signed-off-by: Swaraj Gaikwad <swarajgaikwad1925@gmail.com> Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> [ rjw: Subject adjustment ] Link: https://patch.msgid.link/20251029134737.42229-1-swarajgaikwad1925@gmail.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-10-17docs: admin-guide: Fix a typo in kernel-parameters.txtYohei Kojima
Fix a typo in the stacktrace parameter description in kernel-parameters.txt Signed-off-by: Yohei Kojima <Yohei.Kojima@sony.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <edda15e3fcae13265278d3c3bd93ab077345d78f.1760498951.git.Yohei.Kojima@sony.com>
2025-10-16net: Introduce net.core.bypass_prot_mem sysctl.Kuniyuki Iwashima
If a socket has sk->sk_bypass_prot_mem flagged, the socket opts out of the global protocol memory accounting. Let's control the flag by a new sysctl knob. The flag is written once during socket(2) and is inherited to child sockets. Tested with a script that creates local socket pairs and send()s a bunch of data without recv()ing. Setup: # mkdir /sys/fs/cgroup/test # echo $$ >> /sys/fs/cgroup/test/cgroup.procs # sysctl -q net.ipv4.tcp_mem="1000 1000 1000" # ulimit -n 524288 Without net.core.bypass_prot_mem, charged to tcp_mem & memcg # python3 pressure.py & # cat /sys/fs/cgroup/test/memory.stat | grep sock sock 22642688 <-------------------------------------- charged to memcg # cat /proc/net/sockstat| grep TCP TCP: inuse 2006 orphan 0 tw 0 alloc 2008 mem 5376 <-- charged to tcp_mem # ss -tn | head -n 5 State Recv-Q Send-Q Local Address:Port Peer Address:Port ESTAB 2000 0 127.0.0.1:34479 127.0.0.1:53188 ESTAB 2000 0 127.0.0.1:34479 127.0.0.1:49972 ESTAB 2000 0 127.0.0.1:34479 127.0.0.1:53868 ESTAB 2000 0 127.0.0.1:34479 127.0.0.1:53554 # nstat | grep Pressure || echo no pressure TcpExtTCPMemoryPressures 1 0.0 With net.core.bypass_prot_mem=1, charged to memcg only: # sysctl -q net.core.bypass_prot_mem=1 # python3 pressure.py & # cat /sys/fs/cgroup/test/memory.stat | grep sock sock 2757468160 <------------------------------------ charged to memcg # cat /proc/net/sockstat | grep TCP TCP: inuse 2006 orphan 0 tw 0 alloc 2008 mem 0 <- NOT charged to tcp_mem # ss -tn | head -n 5 State Recv-Q Send-Q Local Address:Port Peer Address:Port ESTAB 111000 0 127.0.0.1:36019 127.0.0.1:49026 ESTAB 110000 0 127.0.0.1:36019 127.0.0.1:45630 ESTAB 110000 0 127.0.0.1:36019 127.0.0.1:44870 ESTAB 111000 0 127.0.0.1:36019 127.0.0.1:45274 # nstat | grep Pressure || echo no pressure no pressure Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Link: https://patch.msgid.link/20251014235604.3057003-4-kuniyu@google.com