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2022-05-26Merge tag 'mm-stable-2022-05-25' of ↵Linus Torvalds1-56/+98
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "Almost all of MM here. A few things are still getting finished off, reviewed, etc. - Yang Shi has improved the behaviour of khugepaged collapsing of readonly file-backed transparent hugepages. - Johannes Weiner has arranged for zswap memory use to be tracked and managed on a per-cgroup basis. - Munchun Song adds a /proc knob ("hugetlb_optimize_vmemmap") for runtime enablement of the recent huge page vmemmap optimization feature. - Baolin Wang contributes a series to fix some issues around hugetlb pagetable invalidation. - Zhenwei Pi has fixed some interactions between hwpoisoned pages and virtualization. - Tong Tiangen has enabled the use of the presently x86-only page_table_check debugging feature on arm64 and riscv. - David Vernet has done some fixup work on the memcg selftests. - Peter Xu has taught userfaultfd to handle write protection faults against shmem- and hugetlbfs-backed files. - More DAMON development from SeongJae Park - adding online tuning of the feature and support for monitoring of fixed virtual address ranges. Also easier discovery of which monitoring operations are available. - Nadav Amit has done some optimization of TLB flushing during mprotect(). - Neil Brown continues to labor away at improving our swap-over-NFS support. - David Hildenbrand has some fixes to anon page COWing versus get_user_pages(). - Peng Liu fixed some errors in the core hugetlb code. - Joao Martins has reduced the amount of memory consumed by device-dax's compound devmaps. - Some cleanups of the arch-specific pagemap code from Anshuman Khandual. - Muchun Song has found and fixed some errors in the TLB flushing of transparent hugepages. - Roman Gushchin has done more work on the memcg selftests. ... and, of course, many smaller fixes and cleanups. Notably, the customary million cleanup serieses from Miaohe Lin" * tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (381 commits) mm: kfence: use PAGE_ALIGNED helper selftests: vm: add the "settings" file with timeout variable selftests: vm: add "test_hmm.sh" to TEST_FILES selftests: vm: check numa_available() before operating "merge_across_nodes" in ksm_tests selftests: vm: add migration to the .gitignore selftests/vm/pkeys: fix typo in comment ksm: fix typo in comment selftests: vm: add process_mrelease tests Revert "mm/vmscan: never demote for memcg reclaim" mm/kfence: print disabling or re-enabling message include/trace/events/percpu.h: cleanup for "percpu: improve percpu_alloc_percpu event trace" include/trace/events/mmflags.h: cleanup for "tracing: incorrect gfp_t conversion" mm: fix a potential infinite loop in start_isolate_page_range() MAINTAINERS: add Muchun as co-maintainer for HugeTLB zram: fix Kconfig dependency warning mm/shmem: fix shmem folio swapoff hang cgroup: fix an error handling path in alloc_pagecache_max_30M() mm: damon: use HPAGE_PMD_SIZE tracing: incorrect isolate_mote_t cast in mm_vmscan_lru_isolate nodemask.h: fix compilation error with GCC12 ...
2022-05-20mm: zswap: add basic meminfo and vmstat coverageJohannes Weiner1-0/+6
Currently it requires poking at debugfs to figure out the size and population of the zswap cache on a host. There are no counters for reads and writes against the cache. As a result, it's difficult to understand zswap behavior on production systems. Print zswap memory consumption and how many pages are zswapped out in /proc/meminfo. Count zswapouts and zswapins in /proc/vmstat. Link: https://lkml.kernel.org/r/20220510152847.230957-6-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: David Hildenbrand <david@redhat.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Roman Gushchin <guro@fb.com> Cc: Seth Jennings <sjenning@redhat.com> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-20Documentation: filesystems: proc: update meminfo sectionJohannes Weiner1-56/+92
Patch series "zswap: accounting & cgroup control", v2. Zswap can consume nearly a quarter of RAM in the default configuration, yet it's neither listed in /proc/meminfo, nor is it accounted and manageable on a per-cgroup basis. This makes reasoning about the memory situation on a host in general rather difficult. On shared/cgrouped hosts, the consequences are worse. First, workloads can escape memory containment and cause resource priority inversions: a lo-pri group can fill the global zswap pool and force a hi-pri group out to disk. Second, not all workloads benefit from zswap equally. Some even suffer when memory contents compress poorly, and are better off going to disk swap directly. On a host with mixed workloads, it's currently not possible to enable zswap for one workload but not for the other. This series implements the missing global accounting as well as cgroup tracking & control for zswap backing memory: - Patch 1 refreshes the very out-of-date meminfo documentation in Documentation/filesystems/proc.rst. - Patches 2-4 clean up related and adjacent options in Kconfig. Not actual dependencies, just things I noticed during development. - Patch 5 adds meminfo and vmstat coverage for zswap consumption and activity. - Patch 6 implements per-cgroup tracking & control of zswap memory. This patch (of 6): Add new entries. Minor corrections and cleanups. [hannes@cmpxchg.org: fix htmldocs warnings] Link: https://lkml.kernel.org/r/Ynve8dg4zJyhH2gW@cmpxchg.org [hannes@cmpxchg.org: change `Unevictable' wording, per David] Link: https://lkml.kernel.org/r/YnwFraZlVWQoCjz3@cmpxchg.org Link: https://lkml.kernel.org/r/20220510152847.230957-1-hannes@cmpxchg.org Link: https://lkml.kernel.org/r/20220510152847.230957-2-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: David Hildenbrand <david@redhat.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Roman Gushchin <guro@fb.com> Cc: Seth Jennings <sjenning@redhat.com> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-16block: remove last remaining traces of IDE documentationPaul Gortmaker1-85/+7
The last traces of the IDE driver went away in commit b7fb14d3ac63 ("ide: remove the legacy ide driver") but it left behind some traces of old documentation. As luck would have it Randy and I would submit similar changes within a week of each other to address this. As Randy's commit is in the doc tree already - this delta is just the stuff my removal contained that was not in Randy's IDE doc removal. Cc: Jens Axboe <axboe@kernel.dk> Cc: Christoph Hellwig <hch@lst.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Phillip Potter <phil@philpotter.co.uk> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Damien Le Moal <damien.lemoal@opensource.wdc.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Link: https://lore.kernel.org/all/20220427165917.GE12977@windriver.com [phil@philpotter.co.uk: removed diffs already added by others] Signed-off-by: Phillip Potter <phil@philpotter.co.uk> Link: https://lore.kernel.org/r/20220515205833.944139-5-phil@philpotter.co.uk Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-01-15mm: add a field to store names for private anonymous memoryColin Cross1-2/+4
In many userspace applications, and especially in VM based applications like Android uses heavily, there are multiple different allocators in use. At a minimum there is libc malloc and the stack, and in many cases there are libc malloc, the stack, direct syscalls to mmap anonymous memory, and multiple VM heaps (one for small objects, one for big objects, etc.). Each of these layers usually has its own tools to inspect its usage; malloc by compiling a debug version, the VM through heap inspection tools, and for direct syscalls there is usually no way to track them. On Android we heavily use a set of tools that use an extended version of the logic covered in Documentation/vm/pagemap.txt to walk all pages mapped in userspace and slice their usage by process, shared (COW) vs. unique mappings, backing, etc. This can account for real physical memory usage even in cases like fork without exec (which Android uses heavily to share as many private COW pages as possible between processes), Kernel SamePage Merging, and clean zero pages. It produces a measurement of the pages that only exist in that process (USS, for unique), and a measurement of the physical memory usage of that process with the cost of shared pages being evenly split between processes that share them (PSS). If all anonymous memory is indistinguishable then figuring out the real physical memory usage (PSS) of each heap requires either a pagemap walking tool that can understand the heap debugging of every layer, or for every layer's heap debugging tools to implement the pagemap walking logic, in which case it is hard to get a consistent view of memory across the whole system. Tracking the information in userspace leads to all sorts of problems. It either needs to be stored inside the process, which means every process has to have an API to export its current heap information upon request, or it has to be stored externally in a filesystem that somebody needs to clean up on crashes. It needs to be readable while the process is still running, so it has to have some sort of synchronization with every layer of userspace. Efficiently tracking the ranges requires reimplementing something like the kernel vma trees, and linking to it from every layer of userspace. It requires more memory, more syscalls, more runtime cost, and more complexity to separately track regions that the kernel is already tracking. This patch adds a field to /proc/pid/maps and /proc/pid/smaps to show a userspace-provided name for anonymous vmas. The names of named anonymous vmas are shown in /proc/pid/maps and /proc/pid/smaps as [anon:<name>]. Userspace can set the name for a region of memory by calling prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, start, len, (unsigned long)name) Setting the name to NULL clears it. The name length limit is 80 bytes including NUL-terminator and is checked to contain only printable ascii characters (including space), except '[',']','\','$' and '`'. Ascii strings are being used to have a descriptive identifiers for vmas, which can be understood by the users reading /proc/pid/maps or /proc/pid/smaps. Names can be standardized for a given system and they can include some variable parts such as the name of the allocator or a library, tid of the thread using it, etc. The name is stored in a pointer in the shared union in vm_area_struct that points to a null terminated string. Anonymous vmas with the same name (equivalent strings) and are otherwise mergeable will be merged. The name pointers are not shared between vmas even if they contain the same name. The name pointer is stored in a union with fields that are only used on file-backed mappings, so it does not increase memory usage. CONFIG_ANON_VMA_NAME kernel configuration is introduced to enable this feature. It keeps the feature disabled by default to prevent any additional memory overhead and to avoid confusing procfs parsers on systems which are not ready to support named anonymous vmas. The patch is based on the original patch developed by Colin Cross, more specifically on its latest version [1] posted upstream by Sumit Semwal. It used a userspace pointer to store vma names. In that design, name pointers could be shared between vmas. However during the last upstreaming attempt, Kees Cook raised concerns [2] about this approach and suggested to copy the name into kernel memory space, perform validity checks [3] and store as a string referenced from vm_area_struct. One big concern is about fork() performance which would need to strdup anonymous vma names. Dave Hansen suggested experimenting with worst-case scenario of forking a process with 64k vmas having longest possible names [4]. I ran this experiment on an ARM64 Android device and recorded a worst-case regression of almost 40% when forking such a process. This regression is addressed in the followup patch which replaces the pointer to a name with a refcounted structure that allows sharing the name pointer between vmas of the same name. Instead of duplicating the string during fork() or when splitting a vma it increments the refcount. [1] https://lore.kernel.org/linux-mm/20200901161459.11772-4-sumit.semwal@linaro.org/ [2] https://lore.kernel.org/linux-mm/202009031031.D32EF57ED@keescook/ [3] https://lore.kernel.org/linux-mm/202009031022.3834F692@keescook/ [4] https://lore.kernel.org/linux-mm/5d0358ab-8c47-2f5f-8e43-23b89d6a8e95@intel.com/ Changes for prctl(2) manual page (in the options section): PR_SET_VMA Sets an attribute specified in arg2 for virtual memory areas starting from the address specified in arg3 and spanning the size specified in arg4. arg5 specifies the value of the attribute to be set. Note that assigning an attribute to a virtual memory area might prevent it from being merged with adjacent virtual memory areas due to the difference in that attribute's value. Currently, arg2 must be one of: PR_SET_VMA_ANON_NAME Set a name for anonymous virtual memory areas. arg5 should be a pointer to a null-terminated string containing the name. The name length including null byte cannot exceed 80 bytes. If arg5 is NULL, the name of the appropriate anonymous virtual memory areas will be reset. The name can contain only printable ascii characters (including space), except '[',']','\','$' and '`'. This feature is available only if the kernel is built with the CONFIG_ANON_VMA_NAME option enabled. [surenb@google.com: docs: proc.rst: /proc/PID/maps: fix malformed table] Link: https://lkml.kernel.org/r/20211123185928.2513763-1-surenb@google.com [surenb: rebased over v5.15-rc6, replaced userpointer with a kernel copy, added input sanitization and CONFIG_ANON_VMA_NAME config. The bulk of the work here was done by Colin Cross, therefore, with his permission, keeping him as the author] Link: https://lkml.kernel.org/r/20211019215511.3771969-2-surenb@google.com Signed-off-by: Colin Cross <ccross@google.com> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Glauber <jan.glauber@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Minchan Kim <minchan@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rob Landley <rob@landley.net> Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com> Cc: Shaohua Li <shli@fusionio.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-10-12docs: proc.rst: mountinfo: align columnsChristoph Anton Mitterer1-11/+11
Signed-off-by: Christoph Anton Mitterer <mail@christoph.anton.mitterer.name> Link: https://lore.kernel.org/r/20211007040001.103413-3-mail@christoph.anton.mitterer.name Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-10-12docs: proc.rst: mountinfo: improved field numberingChristoph Anton Mitterer1-6/+6
Without reading thoroughly, one could easily oversee that there may be several fields after #6. Made it more clearly by changing the field numbering. Signed-off-by: Christoph Anton Mitterer <mail@christoph.anton.mitterer.name> Link: https://lore.kernel.org/r/20211007040001.103413-2-mail@christoph.anton.mitterer.name Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-07-01procfs/dmabuf: add inode number to /proc/*/fdinfoKalesh Singh1-6/+31
And 'ino' field to /proc/<pid>/fdinfo/<FD> and /proc/<pid>/task/<tid>/fdinfo/<FD>. The inode numbers can be used to uniquely identify DMA buffers in user space and avoids a dependency on /proc/<pid>/fd/* when accounting per-process DMA buffer sizes. Link: https://lkml.kernel.org/r/20210308170651.919148-2-kaleshsingh@google.com Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Christian König <christian.koenig@amd.com> Cc: Jann Horn <jannh@google.com> Cc: Jeff Vander Stoep <jeffv@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Hridya Valsaraju <hridya@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Alexey Gladkov <gladkov.alexey@gmail.com> Cc: Szabolcs Nagy <szabolcs.nagy@arm.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Michel Lespinasse <walken@google.com> Cc: Bernd Edlinger <bernd.edlinger@hotmail.de> Cc: Andrei Vagin <avagin@gmail.com> Cc: Helge Deller <deller@gmx.de> Cc: James Morris <jamorris@linux.microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01docs: proc.rst: meminfo: briefly describe gaps in memory accountingMike Rapoport1-2/+9
Add a paragraph that explains that it may happen that the counters in /proc/meminfo do not add up to the overall memory usage. Link: https://lkml.kernel.org/r/20210421061127.1182723-1-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-03-09docs: filesystem: Update smaps vm flag list to latestPeter Xu1-0/+4
We've missed a few documentation when adding new VM_* flags. Add the missing pieces so they'll be in sync now. Signed-off-by: Peter Xu <peterx@redhat.com> Link: https://lore.kernel.org/r/20210302000646.432358-1-peterx@redhat.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-02-25docs: proc.rst: fix indentation warningRandy Dunlap1-1/+1
Fix indentation snafu in proc.rst as reported by Stephen. next-20210219/Documentation/filesystems/proc.rst:697: WARNING: Unexpected indentation. Fixes: 93ea4a0b8fce ("Documentation: proc.rst: add more about the 6 fields in loadavg") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Link: https://lore.kernel.org/r/20210223060418.21443-1-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-02-22Documentation: proc.rst: add more about the 6 fields in loadavgRandy Dunlap1-0/+4
Address Jon's feedback on the previous patch by adding info about field separators in the /proc/loadavg file. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20210222034729.22350-1-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-02-05Documentation: /proc/loadavg: add 3 more field descriptionsRandy Dunlap1-1/+4
Update contents of /proc/loadavg: add 3 more fields. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: linux-doc@vger.kernel.org Link: https://lore.kernel.org/r/fe55b139-bd03-4762-199b-83be873cf7dd@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-12-16proc: provide details on indirect branch speculationAnand K Mistry1-0/+2
Similar to speculation store bypass, show information about the indirect branch speculation mode of a task in /proc/$pid/status. For testing/benchmarking, I needed to see whether IB (Indirect Branch) speculation (see Spectre-v2) is enabled on a task, to see whether an IBPB instruction should be executed on an address space switch. Unfortunately, this information isn't available anywhere else and currently the only way to get it is to hack the kernel to expose it (like this change). It also helped expose a bug with conditional IB speculation on certain CPUs. Another place this could be useful is to audit the system when using sanboxing. With this change, I can confirm that seccomp-enabled process have IB speculation force disabled as expected when the kernel command line parameter `spectre_v2_user=seccomp`. Since there's already a 'Speculation_Store_Bypass' field, I used that as precedent for adding this one. [amistry@google.com: remove underscores from field name to workaround documentation issue] Link: https://lkml.kernel.org/r/20201106131015.v2.1.I7782b0cedb705384a634cfd8898eb7523562da99@changeid Link: https://lkml.kernel.org/r/20201030172731.1.I7782b0cedb705384a634cfd8898eb7523562da99@changeid Signed-off-by: Anand K Mistry <amistry@google.com> Cc: Anthony Steinhauser <asteinhauser@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Anand K Mistry <amistry@google.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Alexey Gladkov <gladkov.alexey@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kees Cook <keescook@chromium.org> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: NeilBrown <neilb@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-01Documentation: document /proc api for arm64 MTE vm flagsSzabolcs Nagy1-0/+1
Document that /proc/PID/smaps shows PROT_MTE settings in VmFlags. Support for this was introduced in commit 9f3419315f3cdc41a7318e4d50ba18a592b30c8c arm64: mte: Add PROT_MTE support to mmap() and mprotect() Signed-off-by: Szabolcs Nagy <szabolcs.nagy@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-doc@vger.kernel.org Link: https://lore.kernel.org/r/20201106101940.5777-1-szabolcs.nagy@arm.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-08-12doc, mm: clarify /proc/<pid>/oom_score value rangeMichal Hocko1-0/+3
The exported value includes oom_score_adj so the range is no [0, 1000] as described in the previous section but rather [0, 2000]. Mention that fact explicitly. Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: David Rientjes <rientjes@google.com> Cc: Yafang Shao <laoar.shao@gmail.com> Link: http://lkml.kernel.org/r/20200709062603.18480-2-mhocko@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-12doc, mm: sync up oom_score_adj documentationMichal Hocko1-8/+0
There are at least two notes in the oom section. The 3% discount for root processes is gone since d46078b28889 ("mm, oom: remove 3% bonus for CAP_SYS_ADMIN processes"). Likewise children of the selected oom victim are not sacrificed since bbbe48029720 ("mm, oom: remove 'prefer children over parent' heuristic") Drop both of them. Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: David Rientjes <rientjes@google.com> Cc: Yafang Shao <laoar.shao@gmail.com> Link: http://lkml.kernel.org/r/20200709062603.18480-1-mhocko@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-07-13Documentation/filesystems/proc.rst: copy-editing cleanupRandy Dunlap1-56/+55
Clean up Documentation/filesystems/proc.rst. This is basically fixing lots of spelling, grammar, punctuation, typos, spacing, consistency, section numbering, and headings. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/a5f126e6-d67a-154a-1c87-d8f07542a21c@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-06-26docs: fs: proc.rst: convert a new chapter to ReSTMauro Carvalho Chehab1-23/+21
A new chapter was added to proc.rst. Adjust the markups to avoid this warning: Documentation/filesystems/proc.rst:2194: WARNING: Inconsistent literal block quoting. And to properly mark the code-blocks there. Fixes: 37e7647a7212 ("docs: proc: add documentation for "hidepid=4" and "subset=pid" options and new mount behavior") Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/de67ec04a2e735f4450eb3ce966f7d80b9438244.1592895969.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-06-19docs: fs: proc.rst: fix a warning due to a merge conflictMauro Carvalho Chehab1-1/+1
Changeset 424037b77519 ("mm: smaps: Report arm64 guarded pages in smaps") added a new parameter to a table. This causes Sphinx warnings, because there's now an extra "-" at the wrong place: /devel/v4l/docs/Documentation/filesystems/proc.rst:548: WARNING: Malformed table. Text in column margin in table line 29. == ======================================= rd readable ... bt - arm64 BTI guarded page == ======================================= Fixes: 424037b77519 ("mm: smaps: Report arm64 guarded pages in smaps") Fixes: c33e97efa9d9 ("docs: filesystems: convert proc.txt to ReST") Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/28c4f4c5c66c0fd7cbce83fe11963ea6154f1d47.1591137229.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-06-04Merge branch 'proc-linus' of ↵Linus Torvalds1-19/+73
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull proc updates from Eric Biederman: "This has four sets of changes: - modernize proc to support multiple private instances - ensure we see the exit of each process tid exactly - remove has_group_leader_pid - use pids not tasks in posix-cpu-timers lookup Alexey updated proc so each mount of proc uses a new superblock. This allows people to actually use mount options with proc with no fear of messing up another mount of proc. Given the kernel's internal mounts of proc for things like uml this was a real problem, and resulted in Android's hidepid mount options being ignored and introducing security issues. The rest of the changes are small cleanups and fixes that came out of my work to allow this change to proc. In essence it is swapping the pids in de_thread during exec which removes a special case the code had to handle. Then updating the code to stop handling that special case" * 'proc-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: proc: proc_pid_ns takes super_block as an argument remove the no longer needed pid_alive() check in __task_pid_nr_ns() posix-cpu-timers: Replace __get_task_for_clock with pid_for_clock posix-cpu-timers: Replace cpu_timer_pid_type with clock_pid_type posix-cpu-timers: Extend rcu_read_lock removing task_struct references signal: Remove has_group_leader_pid exec: Remove BUG_ON(has_group_leader_pid) posix-cpu-timer: Unify the now redundant code in lookup_task posix-cpu-timer: Tidy up group_leader logic in lookup_task proc: Ensure we see the exit of each process tid exactly once rculist: Add hlists_swap_heads_rcu proc: Use PIDTYPE_TGID in next_tgid Use proc_pid_ns() to get pid_namespace from the proc superblock proc: use named enums for better readability proc: use human-readable values for hidepid docs: proc: add documentation for "hidepid=4" and "subset=pid" options and new mount behavior proc: add option to mount only a pids subset proc: instantiate only pids that we can ptrace on 'hidepid=4' mount option proc: allow to mount many instances of proc in one pid namespace proc: rename struct proc_fs_info to proc_fs_opts
2020-06-02Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-2/+2
Merge updates from Andrew Morton: "A few little subsystems and a start of a lot of MM patches. Subsystems affected by this patch series: squashfs, ocfs2, parisc, vfs. With mm subsystems: slab-generic, slub, debug, pagecache, gup, swap, memcg, pagemap, memory-failure, vmalloc, kasan" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (128 commits) kasan: move kasan_report() into report.c mm/mm_init.c: report kasan-tag information stored in page->flags ubsan: entirely disable alignment checks under UBSAN_TRAP kasan: fix clang compilation warning due to stack protector x86/mm: remove vmalloc faulting mm: remove vmalloc_sync_(un)mappings() x86/mm/32: implement arch_sync_kernel_mappings() x86/mm/64: implement arch_sync_kernel_mappings() mm/ioremap: track which page-table levels were modified mm/vmalloc: track which page-table levels were modified mm: add functions to track page directory modifications s390: use __vmalloc_node in stack_alloc powerpc: use __vmalloc_node in alloc_vm_stack arm64: use __vmalloc_node in arch_alloc_vmap_stack mm: remove vmalloc_user_node_flags mm: switch the test_vmalloc module to use __vmalloc_node mm: remove __vmalloc_node_flags_caller mm: remove both instances of __vmalloc_node_flags mm: remove the prot argument to __vmalloc_node mm: remove the pgprot argument to __vmalloc ...
2020-06-02mm/writeback: discard NR_UNSTABLE_NFS, use NR_WRITEBACK insteadNeilBrown1-2/+2
After an NFS page has been written it is considered "unstable" until a COMMIT request succeeds. If the COMMIT fails, the page will be re-written. These "unstable" pages are currently accounted as "reclaimable", either in WB_RECLAIMABLE, or in NR_UNSTABLE_NFS which is included in a 'reclaimable' count. This might have made sense when sending the COMMIT required a separate action by the VFS/MM (e.g. releasepage() used to send a COMMIT). However now that all writes generated by ->writepages() will automatically be followed by a COMMIT (since commit 919e3bd9a875 ("NFS: Ensure we commit after writeback is complete")) it makes more sense to treat them as writeback pages. So this patch removes NR_UNSTABLE_NFS and accounts unstable pages in NR_WRITEBACK and WB_WRITEBACK. A particular effect of this change is that when wb_check_background_flush() calls wb_over_bg_threshold(), the latter will report 'true' a lot less often as the 'unstable' pages are no longer considered 'dirty' (as there is nothing that writeback can do about them anyway). Currently wb_check_background_flush() will trigger writeback to NFS even when there are relatively few dirty pages (if there are lots of unstable pages), this can result in small writes going to the server (10s of Kilobytes rather than a Megabyte) which hurts throughput. With this patch, there are fewer writes which are each larger on average. Where the NR_UNSTABLE_NFS count was included in statistics virtual-files, the entry is retained, but the value is hard-coded as zero. static trace points and warning printks which mentioned this counter no longer report it. [akpm@linux-foundation.org: re-layout comment] [akpm@linux-foundation.org: fix printk warning] Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Trond Myklebust <trond.myklebust@hammerspace.com> Acked-by: Michal Hocko <mhocko@suse.com> [mm] Cc: Christoph Hellwig <hch@lst.de> Cc: Chuck Lever <chuck.lever@oracle.com> Link: http://lkml.kernel.org/r/87d06j7gqa.fsf@notabene.neil.brown.name Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-02Merge tag 'docs-5.8' of git://git.lwn.net/linuxLinus Torvalds1-1/+1
Pull documentation updates from Jonathan Corbet: "A fair amount of stuff this time around, dominated by yet another massive set from Mauro toward the completion of the RST conversion. I *really* hope we are getting close to the end of this. Meanwhile, those patches reach pretty far afield to update document references around the tree; there should be no actual code changes there. There will be, alas, more of the usual trivial merge conflicts. Beyond that we have more translations, improvements to the sphinx scripting, a number of additions to the sysctl documentation, and lots of fixes" * tag 'docs-5.8' of git://git.lwn.net/linux: (130 commits) Documentation: fixes to the maintainer-entry-profile template zswap: docs/vm: Fix typo accept_threshold_percent in zswap.rst tracing: Fix events.rst section numbering docs: acpi: fix old http link and improve document format docs: filesystems: add info about efivars content Documentation: LSM: Correct the basic LSM description mailmap: change email for Ricardo Ribalda docs: sysctl/kernel: document unaligned controls Documentation: admin-guide: update bug-hunting.rst docs: sysctl/kernel: document ngroups_max nvdimm: fixes to maintainter-entry-profile Documentation/features: Correct RISC-V kprobes support entry Documentation/features: Refresh the arch support status files Revert "docs: sysctl/kernel: document ngroups_max" docs: move locking-specific documents to locking/ docs: move digsig docs to the security book docs: move the kref doc into the core-api book docs: add IRQ documentation at the core-api book docs: debugging-via-ohci1394.txt: add it to the core-api book docs: fix references for ipmi.rst file ...
2020-05-05docs: filesystems: convert sharedsubtree.txt to ReSTMauro Carvalho Chehab1-1/+1
- Add a SPDX header; - Adjust document and section titles; - Some whitespace fixes and new line breaks; - Mark literal blocks as such; - Add table markups; - Add it to filesystems/index.rst Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/6692b8abc177130e9e53aace94117a2ad076cab5.1588021877.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-05-05Merge branch 'for-next/bti-user' into for-next/btiWill Deacon1-0/+1
Merge in user support for Branch Target Identification, which narrowly missed the cut for 5.7 after a late ABI concern. * for-next/bti-user: arm64: bti: Document behaviour for dynamically linked binaries arm64: elf: Fix allnoconfig kernel build with !ARCH_USE_GNU_PROPERTY arm64: BTI: Add Kconfig entry for userspace BTI mm: smaps: Report arm64 guarded pages in smaps arm64: mm: Display guarded pages in ptdump KVM: arm64: BTI: Reset BTYPE when skipping emulated instructions arm64: BTI: Reset BTYPE when skipping emulated instructions arm64: traps: Shuffle code to eliminate forward declarations arm64: unify native/compat instruction skipping arm64: BTI: Decode BYTPE bits when printing PSTATE arm64: elf: Enable BTI at exec based on ELF program properties elf: Allow arch to tweak initial mmap prot flags arm64: Basic Branch Target Identification support ELF: Add ELF program property parsing support ELF: UAPI and Kconfig additions for ELF program properties
2020-04-22proc: use human-readable values for hidepidAlexey Gladkov1-26/+26
The hidepid parameter values are becoming more and more and it becomes difficult to remember what each new magic number means. Backward compatibility is preserved since it is possible to specify numerical value for the hidepid parameter. This does not break the fsconfig since it is not possible to specify a numerical value through it. All numeric values are converted to a string. The type FSCONFIG_SET_BINARY cannot be used to indicate a numerical value. Selftest has been added to verify this behavior. Suggested-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com> Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2020-04-22docs: proc: add documentation for "hidepid=4" and "subset=pid" options and ↵Alexey Gladkov1-0/+54
new mount behavior Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com> Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2020-03-03docs: filesystems: convert proc.txt to ReSTMauro Carvalho Chehab1-0/+2169
This document has a nice format! Unfortunately, not exactly ReST. So, several adjustments were required: - Add a SPDX header; - Adjust document and section titles; - Whitespace fixes and new line breaks; - Mark literal blocks as such; - Add table markups; - Add table captions; - Add it to filesystems/index.rst. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/1d113d860188de416ca3b0b97371dc2195433d5b.1581955849.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>