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2016-07-26thp: update Documentation/{vm/transhuge,filesystems/proc}.txtKirill A. Shutemov1-0/+9
Add info about tmpfs/shmem with huge pages. Link: http://lkml.kernel.org/r/1466021202-61880-38-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-10irq/Documentation: Correct result of echnoing 5 to smp_affinityJohn Kacur1-1/+1
This command: echo 5 > /proc/irq/10/smp_affinity means only the first and third (not fourth) CPUs can handle irqs That is, CPU0 is the first CPU and CPU2 is the third cpu Signed-off-by: John Kacur <jkacur@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1466168715-8410-1-git-send-email-jkacur@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-20procfs: expose umask in /proc/<PID>/statusRichard W.M. Jones1-0/+1
It's not possible to read the process umask without also modifying it, which is what umask(2) does. A library cannot read umask safely, especially if the main program might be multithreaded. Add a new status line ("Umask") in /proc/<PID>/status. It contains the file mode creation mask (umask) in octal. It is only shown for tasks which have task->fs. This patch is adapted from one originally written by Pierre Carrier. The use case is that we have endless trouble with people setting weird umask() values (usually on the grounds of "security"), and then everything breaking. I'm on the hook to fix these. We'd like to add debugging to our program so we can dump out the umask in debug reports. Previous versions of the patch used a syscall so you could only read your own umask. That's all I need. However there was quite a lot of push-back from those, so this new version exports it in /proc. See: https://lkml.org/lkml/2016/4/13/704 [umask2] https://lkml.org/lkml/2016/4/13/487 [getumask] Signed-off-by: Richard W.M. Jones <rjones@redhat.com> Acked-by: Konstantin Khlebnikov <koct9i@gmail.com> Acked-by: Jerome Marchand <jmarchan@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Michal Hocko <mhocko@kernel.org> Cc: Pierre Carrier <pierre@spotify.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-17proc: add /proc/<pid>/timerslack_ns interfaceJohn Stultz1-0/+18
This patch provides a proc/PID/timerslack_ns interface which exposes a task's timerslack value in nanoseconds and allows it to be changed. This allows power/performance management software to set timer slack for other threads according to its policy for the thread (such as when the thread is designated foreground vs. background activity) If the value written is non-zero, slack is set to that value. Otherwise sets it to the default for the thread. This interface checks that the calling task has permissions to to use PTRACE_MODE_ATTACH_FSCREDS on the target task, so that we can ensure arbitrary apps do not change the timer slack for other apps. Signed-off-by: John Stultz <john.stultz@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Oren Laadan <orenl@cellrox.com> Cc: Ruchi Kandoi <kandoiruchi@google.com> Cc: Rom Lemarchand <romlem@android.com> Cc: Android Kernel Team <kernel-team@android.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-03mm: polish virtual memory accountingKonstantin Khlebnikov1-2/+2
* add VM_STACK as alias for VM_GROWSUP/DOWN depending on architecture * always account VMAs with flag VM_STACK as stack (as it was before) * cleanup classifying helpers * update comments and documentation Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com> Tested-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-03proc: revert /proc/<pid>/maps [stack:TID] annotationJohannes Weiner1-6/+3
Commit b76437579d13 ("procfs: mark thread stack correctly in proc/<pid>/maps") added [stack:TID] annotation to /proc/<pid>/maps. Finding the task of a stack VMA requires walking the entire thread list, turning this into quadratic behavior: a thousand threads means a thousand stacks, so the rendering of /proc/<pid>/maps needs to look at a million combinations. The cost is not in proportion to the usefulness as described in the patch. Drop the [stack:TID] annotation to make /proc/<pid>/maps (and /proc/<pid>/numa_maps) usable again for higher thread counts. The [stack] annotation inside /proc/<pid>/task/<tid>/maps is retained, as identifying the stack VMA there is an O(1) operation. Siddesh said: "The end users needed a way to identify thread stacks programmatically and there wasn't a way to do that. I'm afraid I no longer remember (or have access to the resources that would aid my memory since I changed employers) the details of their requirement. However, I did do this on my own time because I thought it was an interesting project for me and nobody really gave any feedback then as to its utility, so as far as I am concerned you could roll back the main thread maps information since the information is available in the thread-specific files" Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Siddhesh Poyarekar <siddhesh.poyarekar@gmail.com> Cc: Shaohua Li <shli@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-17Merge tag 'docs-4.5' of git://git.lwn.net/linuxLinus Torvalds1-1/+1
Pull documentation updates from Jon Corbet: "A relatively boring cycle in the docs tree. There's a few kernel-doc fixes and various document tweaks. One patch reaches out of the documentation subtree to fix a comment in init/do_mounts_rd.c. There didn't seem to be anybody more appropriate to take that one, so I accepted it" * tag 'docs-4.5' of git://git.lwn.net/linux: (29 commits) thermal: add description for integral_cutoff unit Documentation: update libhugetlbfs site url Documentation: Explain pci=conf1,conf2 more verbosely DMA-API: fix confusing sentence in Documentation/DMA-API.txt Documentation: translations: update linux cross reference link Documentation: fix typo in CodingStyle init, Documentation: Remove ramdisk_blocksize mentions Documentation-getdelays: Apply a recommendation from "checkpatch.pl" in main() Documentation: HOWTO: update versions from 3.x to 4.x Documentation: remove outdated references from translations Doc: treewide: Fix grammar "a" to "an" Documentation: cpu-hotplug: Fix sysfs mount instructions can-doc: Add hint about getting timestamps Fix CFQ I/O scheduler parameter name in documentation Documentation: arm: remove dead links from Marvell Berlin docs Documentation: HOWTO: update code cross reference link Doc: Docbook/iio: Fix typo in iio.tmpl DocBook: make index.html generation less verbose by default DocBook: Cleanup: remove an unused $(call) line DocBook: Add a help message for DOCBOOKS env var ...
2016-01-14Documentation/filesystems: describe the shared memory usage/accountingRodrigo Freire1-0/+2
The Shared Memory accounting support is present in Kernel since commit 4b02108ac1b3 ("mm: oom analysis: add shmem vmstat") and in userland free(1) since 2014. This patch updates the Documentation to reflect this change. Signed-off-by: Rodrigo Freire <rfreire@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14mm, procfs: breakdown RSS for anon, shmem and file in /proc/pid/statusJerome Marchand1-2/+11
There are several shortcomings with the accounting of shared memory (SysV shm, shared anonymous mapping, mapping of a tmpfs file). The values in /proc/<pid>/status and <...>/statm don't allow to distinguish between shmem memory and a shared mapping to a regular file, even though theirs implication on memory usage are quite different: during reclaim, file mapping can be dropped or written back on disk, while shmem needs a place in swap. Also, to distinguish the memory occupied by anonymous and file mappings, one has to read the /proc/pid/statm file, which has a field for the file mappings (again, including shmem) and total memory occupied by these mappings (i.e. equivalent to VmRSS in the <...>/status file. Getting the value for anonymous mappings only is thus not exactly user-friendly (the statm file is intended to be rather efficiently machine-readable). To address both of these shortcomings, this patch adds a breakdown of VmRSS in /proc/<pid>/status via new fields RssAnon, RssFile and RssShmem, making use of the previous preparatory patch. These fields tell the user the memory occupied by private anonymous pages, mapped regular files and shmem, respectively. Other existing fields in /status and /statm files are left without change. The /statm file can be extended in the future, if there's a need for that. Example (part of) /proc/pid/status output including the new Rss* fields: VmPeak: 2001008 kB VmSize: 2001004 kB VmLck: 0 kB VmPin: 0 kB VmHWM: 5108 kB VmRSS: 5108 kB RssAnon: 92 kB RssFile: 1324 kB RssShmem: 3692 kB VmData: 192 kB VmStk: 136 kB VmExe: 4 kB VmLib: 1784 kB VmPTE: 3928 kB VmPMD: 20 kB VmSwap: 0 kB HugetlbPages: 0 kB [vbabka@suse.cz: forward-porting, tweak changelog] Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14mm, proc: account for shmem swap in /proc/pid/smapsVlastimil Babka1-1/+4
Currently, /proc/pid/smaps will always show "Swap: 0 kB" for shmem-backed mappings, even if the mapped portion does contain pages that were swapped out. This is because unlike private anonymous mappings, shmem does not change pte to swap entry, but pte_none when swapping the page out. In the smaps page walk, such page thus looks like it was never faulted in. This patch changes smaps_pte_entry() to determine the swap status for such pte_none entries for shmem mappings, similarly to how mincore_page() does it. Swapped out shmem pages are thus accounted for. For private mappings of tmpfs files that COWed some of the pages, swaped out status of the original shmem pages is naturally ignored. If some of the private copies was also swapped out, they are accounted via their page table swap entries, so the resulting reported swap usage is then a sum of both swapped out private copies, and swapped out shmem pages that were not COWed. No double accounting can thus happen. The accounting is arguably still not as precise as for private anonymous mappings, since now we will count also pages that the process in question never accessed, but another process populated them and then let them become swapped out. I believe it is still less confusing and subtle than not showing any swap usage by shmem mappings at all. Swapped out counter might of interest of users who would like to prevent from future swapins during performance critical operation and pre-fault them at their convenience. Especially for larger swapped out regions the cost of swapin is much higher than a fresh page allocation. So a differentiation between pte_none vs. swapped out is important for those usecases. One downside of this patch is that it makes /proc/pid/smaps more expensive for shmem mappings, as we consult the radix tree for each pte_none entry, so the overal complexity is O(n*log(n)). I have measured this on a process that creates a 2GB mapping and dirties single pages with a stride of 2MB, and time how long does it take to cat /proc/pid/smaps of this process 100 times. Private anonymous mapping: real 0m0.949s user 0m0.116s sys 0m0.348s Mapping of a /dev/shm/file: real 0m3.831s user 0m0.180s sys 0m3.212s The difference is rather substantial, so the next patch will reduce the cost for shared or read-only mappings. In a less controlled experiment, I've gathered pids of processes on my desktop that have either '/dev/shm/*' or 'SYSV*' in smaps. This included the Chrome browser and some KDE processes. Again, I've run cat /proc/pid/smaps on each 100 times. Before this patch: real 0m9.050s user 0m0.518s sys 0m8.066s After this patch: real 0m9.221s user 0m0.541s sys 0m8.187s This suggests low impact on average systems. Note that this patch doesn't attempt to adjust the SwapPss field for shmem mappings, which would need extra work to determine who else could have the pages mapped. Thus the value stays zero except for COWed swapped out pages in a shmem mapping, which are accounted as usual. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: Jerome Marchand <jmarchan@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14mm, documentation: clarify /proc/pid/status VmSwap limitations for shmemVlastimil Babka1-1/+2
This series is based on Jerome Marchand's [1] so let me quote the first paragraph from there: There are several shortcomings with the accounting of shared memory (sysV shm, shared anonymous mapping, mapping to a tmpfs file). The values in /proc/<pid>/status and statm don't allow to distinguish between shmem memory and a shared mapping to a regular file, even though their implications on memory usage are quite different: at reclaim, file mapping can be dropped or written back on disk while shmem needs a place in swap. As for shmem pages that are swapped-out or in swap cache, they aren't accounted at all. The original motivation for myself is that a customer found (IMHO rightfully) confusing that e.g. top output for process swap usage is unreliable with respect to swapped out shmem pages, which are not accounted for. The fundamental difference between private anonymous and shmem pages is that the latter has PTE's converted to pte_none, and not swapents. As such, they are not accounted to the number of swapents visible e.g. in /proc/pid/status VmSwap row. It might be theoretically possible to use swapents when swapping out shmem (without extra cost, as one has to change all mappers anyway), and on swap in only convert the swapent for the faulting process, leaving swapents in other processes until they also fault (so again no extra cost). But I don't know how many assumptions this would break, and it would be too disruptive change for a relatively small benefit. Instead, my approach is to document the limitation of VmSwap, and provide means to determine the swap usage for shmem areas for those who are interested and willing to pay the price, using /proc/pid/smaps. Because outside of ipcs, I don't think it's possible to currently to determine the usage at all. The previous patchset [1] did introduce new shmem-specific fields into smaps output, and functions to determine the values. I take a simpler approach, noting that smaps output already has a "Swap: X kB" line, where currently X == 0 always for shmem areas. I think we can just consider this a bug and provide the proper value by consulting the radix tree, as e.g. mincore_page() does. In the patch changelog I explain why this is also not perfect (and cannot be without swapents), but still arguably much better than showing a 0. The last two patches are adapted from Jerome's patchset and provide a VmRSS breakdown to RssAnon, RssFile and RssShm in /proc/pid/status. Hugh noted that this is a welcome addition, and I agree that it might help e.g. debugging process memory usage at albeit non-zero, but still rather low cost of extra per-mm counter and some page flag checks. [1] http://lwn.net/Articles/611966/ This patch (of 6): The documentation for /proc/pid/status does not mention that the value of VmSwap counts only swapped out anonymous private pages, and not swapped out pages of the underlying shmem objects (for shmem mappings). This is not obvious, so document this limitation. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Jerome Marchand <jmarchan@redhat.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14Documentation: update libhugetlbfs site urlSeongJae Park1-1/+1
The site for libhugetlbfs has moved from sourceforge to github. This commit updates the old url. Signed-off-by: SeongJae Park <sj38.park@gmail.com> Acked-by: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2015-11-10Merge tag 'libnvdimm-for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimmLinus Torvalds1-10/+12
Pull libnvdimm updates from Dan Williams: "Outside of the new ACPI-NFIT hot-add support this pull request is more notable for what it does not contain, than what it does. There were a handful of development topics this cycle, dax get_user_pages, dax fsync, and raw block dax, that need more more iteration and will wait for 4.5. The patches to make devm and the pmem driver NUMA aware have been in -next for several weeks. The hot-add support has not, but is contained to the NFIT driver and is passing unit tests. The coredump support is straightforward and was looked over by Jeff. All of it has received a 0day build success notification across 107 configs. Summary: - Add support for the ACPI 6.0 NFIT hot add mechanism to process updates of the NFIT at runtime. - Teach the coredump implementation how to filter out DAX mappings. - Introduce NUMA hints for allocations made by the pmem driver, and as a side effect all devm allocations now hint their NUMA node by default" * tag 'libnvdimm-for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: coredump: add DAX filtering for FDPIC ELF coredumps coredump: add DAX filtering for ELF coredumps acpi: nfit: Add support for hot-add nfit: in acpi_nfit_init, break on a 0-length table pmem, memremap: convert to numa aware allocations devm_memremap_pages: use numa_mem_id devm: make allocations numa aware by default devm_memremap: convert to return ERR_PTR devm_memunmap: use devres_release() pmem: kill memremap_pmem() x86, mm: quiet arch_add_memory()
2015-11-09coredump: add DAX filtering for ELF coredumpsRoss Zwisler1-10/+12
Add two new flags to the existing coredump mechanism for ELF files to allow us to explicitly filter DAX mappings. This is desirable because DAX mappings, like hugetlb mappings, have the potential to be very large. Update the coredump_filter documentation in Documentation/filesystems/proc.txt so that it addresses the new DAX coredump flags. Also update the documented default value of coredump_filter to be consistent with the core(5) man page. The documentation being updated talks about bit 4, Dump ELF headers, which is enabled if CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is turned on in the kernel config. This kernel config option defaults to "y" if both ELF binaries and coredump are enabled. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-11-05Documentation/filesystems/proc.txt: a little tidyingHugh Dickins1-8/+5
There's an odd line about "Locked" at the head of the description of /proc/meminfo: it seems to have strayed from /proc/PID/smaps, so lead it back there. Move "Swap" and "SwapPss" descriptions down above it, to match the order in the file (though "PageSize"s still undescribed). The example of "Locked: 374 kB" (the same as Pss, neither Rss nor Size) is so unlikely as to be misleading: just make it 0, this is /bin/bash text; which would be "dw" (disabled write) not "de" (do not expand). Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-05mm Documentation: undoc non-linear vmasHugh Dickins1-1/+0
While updating some mm Documentation, I came across a few straggling references to the non-linear vmas which were happily removed in v4.0. Delete them. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-05mm: hugetlb: proc: add HugetlbPages field to /proc/PID/statusNaoya Horiguchi1-0/+2
Currently there's no easy way to get per-process usage of hugetlb pages, which is inconvenient because userspace applications which use hugetlb typically want to control their processes on the basis of how much memory (including hugetlb) they use. So this patch simply provides easy access to the info via /proc/PID/status. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Joern Engel <joern@logfs.org> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-05mm: hugetlb: proc: add hugetlb-related fields to /proc/PID/smapsNaoya Horiguchi1-0/+8
Currently /proc/PID/smaps provides no usage info for vma(VM_HUGETLB), which is inconvenient when we want to know per-task or per-vma base hugetlb usage. To solve this, this patch adds new fields for hugetlb usage like below: Size: 20480 kB Rss: 0 kB Pss: 0 kB Shared_Clean: 0 kB Shared_Dirty: 0 kB Private_Clean: 0 kB Private_Dirty: 0 kB Referenced: 0 kB Anonymous: 0 kB AnonHugePages: 0 kB Shared_Hugetlb: 18432 kB Private_Hugetlb: 2048 kB Swap: 0 kB KernelPageSize: 2048 kB MMUPageSize: 2048 kB Locked: 0 kB VmFlags: rd wr mr mw me de ht [hughd@google.com: fix Private_Hugetlb alignment ] Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Joern Engel <joern@logfs.org> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-01fs/proc, core/debug: Don't expose absolute kernel addresses via wchanIngo Molnar1-2/+3
So the /proc/PID/stat 'wchan' field (the 30th field, which contains the absolute kernel address of the kernel function a task is blocked in) leaks absolute kernel addresses to unprivileged user-space: seq_put_decimal_ull(m, ' ', wchan); The absolute address might also leak via /proc/PID/wchan as well, if KALLSYMS is turned off or if the symbol lookup fails for some reason: static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns, struct pid *pid, struct task_struct *task) { unsigned long wchan; char symname[KSYM_NAME_LEN]; wchan = get_wchan(task); if (lookup_symbol_name(wchan, symname) < 0) { if (!ptrace_may_access(task, PTRACE_MODE_READ)) return 0; seq_printf(m, "%lu", wchan); } else { seq_printf(m, "%s", symname); } return 0; } This isn't ideal, because for example it trivially leaks the KASLR offset to any local attacker: fomalhaut:~> printf "%016lx\n" $(cat /proc/$$/stat | cut -d' ' -f35) ffffffff8123b380 Most real-life uses of wchan are symbolic: ps -eo pid:10,tid:10,wchan:30,comm and procps uses /proc/PID/wchan, not the absolute address in /proc/PID/stat: triton:~/tip> strace -f ps -eo pid:10,tid:10,wchan:30,comm 2>&1 | grep wchan | tail -1 open("/proc/30833/wchan", O_RDONLY) = 6 There's one compatibility quirk here: procps relies on whether the absolute value is non-zero - and we can provide that functionality by outputing "0" or "1" depending on whether the task is blocked (whether there's a wchan address). These days there appears to be very little legitimate reason user-space would be interested in the absolute address. The absolute address is mostly historic: from the days when we didn't have kallsyms and user-space procps had to do the decoding itself via the System.map. So this patch sets all numeric output to "0" or "1" and keeps only symbolic output, in /proc/PID/wchan. ( The absolute sleep address can generally still be profiled via perf, by tasks with sufficient privileges. ) Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: <stable@vger.kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: kasan-dev <kasan-dev@googlegroups.com> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/20150930135917.GA3285@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-08mm: /proc/pid/smaps:: show proportional swap share of the mappingMinchan Kim1-5/+13
We want to know per-process workingset size for smart memory management on userland and we use swap(ex, zram) heavily to maximize memory efficiency so workingset includes swap as well as RSS. On such system, if there are lots of shared anonymous pages, it's really hard to figure out exactly how many each process consumes memory(ie, rss + wap) if the system has lots of shared anonymous memory(e.g, android). This patch introduces SwapPss field on /proc/<pid>/smaps so we can get more exact workingset size per process. Bongkyu tested it. Result is below. 1. 50M used swap SwapTotal: 461976 kB SwapFree: 411192 kB $ adb shell cat /proc/*/smaps | grep "SwapPss:" | awk '{sum += $2} END {print sum}'; 48236 $ adb shell cat /proc/*/smaps | grep "Swap:" | awk '{sum += $2} END {print sum}'; 141184 2. 240M used swap SwapTotal: 461976 kB SwapFree: 216808 kB $ adb shell cat /proc/*/smaps | grep "SwapPss:" | awk '{sum += $2} END {print sum}'; 230315 $ adb shell cat /proc/*/smaps | grep "Swap:" | awk '{sum += $2} END {print sum}'; 1387744 [akpm@linux-foundation.org: simplify kunmap_atomic() call] Signed-off-by: Minchan Kim <minchan@kernel.org> Reported-by: Bongkyu Kim <bongkyu.kim@lge.com> Tested-by: Bongkyu Kim <bongkyu.kim@lge.com> Cc: Hugh Dickins <hughd@google.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-07docs: add VmPMD description in procChen Hanxiao1-0/+1
commit dc6c9a35b66b ("mm: account pmd page tables to the process") add VmPMD in /proc/PID/status. This patch add a description in proc.txt for it. Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2015-05-07Docs: proc: fix kernel versionChen Hanxiao1-1/+1
Change the kernel version in table 1-2 from 3.20 to 4.1 Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com> Reviewed-by: Nathan Scott <nathans@redhat.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2015-04-18Merge tag 'docs-for-linus' of git://git.lwn.net/linux-2.6Linus Torvalds1-3/+3
Pull documentation updates from Jonathan Corbet: "Numerous fixes, the overdue removal of the i2o docs, some new Chinese translations, and, hopefully, the README fix that will end the flow of identical patches to that file" * tag 'docs-for-linus' of git://git.lwn.net/linux-2.6: (34 commits) Documentation/memcg: update memcg/kmem status Documentation: blackfin: Makefile: Typo building issue Documentation/vm/pagemap.txt: correct location of page-types tool Documentation/memory-barriers.txt: typo fix doc: Add guest_nice column to example output of `cat /proc/stat' Documentation/kernel-parameters: Move "eagerfpu" to its right place Documentation: gpio: Update ACPI part of the document to mention _DSD docs/completion.txt: Various tweaks and corrections doc: completion: context, scope and language fixes Documentation:Update Documentation/zh_CN/arm64/memory.txt Documentation:Update Documentation/zh_CN/arm64/booting.txt Documentation: Chinese translation of arm64/legacy_instructions.txt DocBook media: fix broken EIA hyperlink Documentation: tweak the maintainers entry README: Change gzip/bzip2 to xz compression format README: Update version number reference doc:pci: Fix typo in Documentation/PCI Documentation: drm: Use '->' when describing access through pointers. Documentation: Remove mentioning of block barriers Documentation/email-clients.txt: Fix one grammar mistake, add extra info about TB ...
2015-04-17proc: show locks in /proc/pid/fdinfo/XAndrey Vagin1-0/+4
Let's show locks which are associated with a file descriptor in its fdinfo file. Currently we don't have a reliable way to determine who holds a lock. We can find some information in /proc/locks, but PID which is reported there can be wrong. For example, a process takes a lock, then forks a child and dies. In this case /proc/locks contains the parent pid, which can be reused by another process. $ cat /proc/locks ... 6: FLOCK ADVISORY WRITE 324 00:13:13431 0 EOF ... $ ps -C rpcbind PID TTY TIME CMD 332 ? 00:00:00 rpcbind $ cat /proc/332/fdinfo/4 pos: 0 flags: 0100000 mnt_id: 22 lock: 1: FLOCK ADVISORY WRITE 324 00:13:13431 0 EOF $ ls -l /proc/332/fd/4 lr-x------ 1 root root 64 Mar 5 14:43 /proc/332/fd/4 -> /run/rpcbind.lock $ ls -l /proc/324/fd/ total 0 lrwx------ 1 root root 64 Feb 27 14:50 0 -> /dev/pts/0 lrwx------ 1 root root 64 Feb 27 14:50 1 -> /dev/pts/0 lrwx------ 1 root root 64 Feb 27 14:49 2 -> /dev/pts/0 You can see that the process with the 324 pid doesn't hold the lock. This information is required for proper dumping and restoring file locks. Signed-off-by: Andrey Vagin <avagin@openvz.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Acked-by: Jeff Layton <jlayton@poochiereds.net> Acked-by: "J. Bruce Fields" <bfields@fieldses.org> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17docs: add missing and new /proc/PID/status file entries, fix typosNathan Scott1-3/+8
docs: add missing and new /proc/PID/status file entries, fix typos Signed-off-by: Nathan Scott <nathans@redhat.com> Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-04doc: Add guest_nice column to example output of `cat /proc/stat'Tobias Klauser1-3/+3
Commit ce0e7b28fb75cb00 ("sched, cpuacct: Fix niced guest time accounting") added the guest_nice column to /proc/stat, but the example output of `cat /proc/stat' in Documentation/filesystems/proc.txt wasn't updated accordingly. Do so now. Cc: Ryota Ozaki <ozaki.ryota@gmail.com> Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2015-02-12fs: proc: task_mmu: show page size in /proc/<pid>/numa_mapsRafael Aquini1-15/+15
The output of /proc/$pid/numa_maps is in terms of number of pages like anon=22 or dirty=54. Here's some output: 7f4680000000 default file=/hugetlb/bigfile anon=50 dirty=50 N0=50 7f7659600000 default file=/anon_hugepage\040(deleted) anon=50 dirty=50 N0=50 7fff8d425000 default stack anon=50 dirty=50 N0=50 Looks like we have a stack and a couple of anonymous hugetlbfs areas page which both use the same amount of memory. They don't. The 'bigfile' uses 1GB pages and takes up ~50GB of space. The anon_hugepage uses 2MB pages and takes up ~100MB of space while the stack uses normal 4k pages. You can go over to smaps to figure out what the page size _really_ is with KernelPageSize or MMUPageSize. But, I think this is a pretty nasty and counterintuitive interface as it stands. This patch introduces 'kernelpagesize_kB' line element to /proc/<pid>/numa_maps report file in order to help identifying the size of pages that are backing memory areas mapped by a given task. This is specially useful to help differentiating between HUGE and GIGANTIC page backed VMAs. This patch is based on Dave Hansen's proposal and reviewer's follow-ups taken from the following dicussion threads: * https://lkml.org/lkml/2011/9/21/454 * https://lkml.org/lkml/2014/12/20/66 Signed-off-by: Rafael Aquini <aquini@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Dave Hansen <dave.hansen@intel.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12Documentation/filesystems/proc.txt: add /proc/pid/numa_maps interface explanation snippetRafael Aquini1-0/+33
Add a small section to proc.txt doc in order to document its /proc/pid/numa_maps interface. It does not introduce any functional changes, just documentation. Signed-off-by: Rafael Aquini <aquini@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12fs/proc/task_mmu.c: add user-space support for resetting mm->hiwater_rss (peak RSS)Petr Cermak1-0/+4
Peak resident size of a process can be reset back to the process's current rss value by writing "5" to /proc/pid/clear_refs. The driving use-case for this would be getting the peak RSS value, which can be retrieved from the VmHWM field in /proc/pid/status, per benchmark iteration or test scenario. [akpm@linux-foundation.org: clarify behaviour in documentation] Signed-off-by: Petr Cermak <petrcermak@chromium.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Primiano Tucci <primiano@chromium.org> Cc: Petr Cermak <petrcermak@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-0/+23
Merge second set of updates from Andrew Morton: "More of MM" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (83 commits) mm/nommu.c: fix arithmetic overflow in __vm_enough_memory() mm/mmap.c: fix arithmetic overflow in __vm_enough_memory() vmstat: Reduce time interval to stat update on idle cpu mm/page_owner.c: remove unnecessary stack_trace field Documentation/filesystems/proc.txt: describe /proc/<pid>/map_files mm: incorporate read-only pages into transparent huge pages vmstat: do not use deferrable delayed work for vmstat_update mm: more aggressive page stealing for UNMOVABLE allocations mm: always steal split buddies in fallback allocations mm: when stealing freepages, also take pages created by splitting buddy page mincore: apply page table walker on do_mincore() mm: /proc/pid/clear_refs: avoid split_huge_page() mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP) mempolicy: apply page table walker on queue_pages_range() arch/powerpc/mm/subpage-prot.c: use walk->vma and walk_page_vma() memcg: cleanup preparation for page table walk numa_maps: remove numa_maps->vma numa_maps: fix typo in gather_hugetbl_stats pagemap: use walk->vma instead of calling find_vma() clear_refs: remove clear_refs_private->vma and introduce clear_refs_test_walk() ...
2015-02-11Documentation/filesystems/proc.txt: describe /proc/<pid>/map_filesCyrill Gorcunov1-0/+23
[akpm@linux-foundation.org: tweaks] Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Kees Cook <keescook@chromium.org> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Calvin Owens <calvinowens@fb.com> Cc: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-01-28Fixes column alignment in table of contents entry 1.9 in Documentation/filesystems/proc.txtTrace Pillars1-1/+1
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2014-11-24Documentation: fix formatting to make 's' happyMaisa Roponen1-1/+1
"That letter [the last s] is sad because all the others have those things [=] below them and it does not." This patch fixes the tragedy so all the letters can be happy again. Signed-off-by: Maisa Roponen <maisa.roponen@gmail.com> [The author being 4 years old needed some assistance] Signed-off-by: Tero Roponen <tero.roponen@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2014-07-18docs: Procfs -- Document timerfd outputCyrill Gorcunov1-0/+19
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Andrey Vagin <avagin@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Vladimir Davydov <vdavydov@parallels.com> Link: http://lkml.kernel.org/r/20140715215703.199905126@openvz.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-06-04Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial into nextLinus Torvalds1-3/+4
Pull trivial tree changes from Jiri Kosina: "Usual pile of patches from trivial tree that make the world go round" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (23 commits) staging: go7007: remove reference to CONFIG_KMOD aic7xxx: Remove obsolete preprocessor define of: dma: doc fixes doc: fix incorrect formula to calculate CommitLimit value doc: Note need of bc in the kernel build from 3.10 onwards mm: Fix printk typo in dmapool.c modpost: Fix comment typo "Modules.symvers" Kconfig.debug: Grammar s/addition/additional/ wimax: Spelling s/than/that/, wording s/destinatary/recipient/ aic7xxx: Spelling s/termnation/termination/ arm64: mm: Remove superfluous "the" in comment of: Spelling s/anonymouns/anonymous/ dma: imx-sdma: Spelling s/determnine/determine/ ath10k: Improve grammar in comments ath6kl: Spelling s/determnine/determine/ of: Improve grammar for of_alias_get_id() documentation drm/exynos: Spelling s/contro/control/ radio-bcm2048.c: fix wrong overflow check doc: printk-formats: do not mention casts for u64/s64 doc: spelling error changes ...
2014-05-25Documentation: update /proc/stat "intr" count summaryJan Moskyto Matejka1-2/+3
The sum at the beginning of line "intr" includes also unnumbered interrupts. It implies that the sum at the beginning isn't the sum of the remainder of the line, not even an estimation. Fixed the documentation to mention that. This behaviour was added to /proc/stat in commit a2eddfa95919 ("x86: make /proc/stat account for all interrupts") Signed-off-by: Jan Moskyto Matejka <mq@suse.cz> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-22doc: fix incorrect formula to calculate CommitLimit valuePetr Oros1-1/+2
The formula to calculate "CommitLimit" value mentioned in kernel documentation is incorrect. Right formula is: CommitLimit = ([total RAM pages] - [total huge TLB pages]) * overcommit_ratio / 100 + [total swap pages] Signed-off-by: Petr Oros <poros@redhat.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-05-05doc: spelling error changesCarlos Garcia1-2/+2
Fixed multiple spelling errors. Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Carlos E. Garcia <carlos@cgarcia.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-04-07proc: show mnt_id in /proc/pid/fdinfoAndrey Vagin1-5/+12
Currently we don't have a way how to determing from which mount point file has been opened. This information is required for proper dumping and restoring file descriptos due to presence of mount namespaces. It's possible, that two file descriptors are opened using the same paths, but one fd references mount point from one namespace while the other fd -- from other namespace. $ ls -l /proc/1/fd/1 lrwx------ 1 root root 64 Mar 19 23:54 /proc/1/fd/1 -> /dev/null $ cat /proc/1/fdinfo/1 pos: 0 flags: 0100002 mnt_id: 16 $ cat /proc/1/mountinfo | grep ^16 16 32 0:4 / /dev rw,nosuid shared:2 - devtmpfs devtmpfs rw,size=1013356k,nr_inodes=253339,mode=755 Signed-off-by: Andrey Vagin <avagin@openvz.org> Acked-by: Pavel Emelyanov <xemul@parallels.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Rob Landley <rob@landley.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-30mm, oom: base root bonus on current usageDavid Rientjes1-2/+2
A 3% of system memory bonus is sometimes too excessive in comparison to other processes. With commit a63d83f427fb ("oom: badness heuristic rewrite"), the OOM killer tries to avoid killing privileged tasks by subtracting 3% of overall memory (system or cgroup) from their per-task consumption. But as a result, all root tasks that consume less than 3% of overall memory are considered equal, and so it only takes 33+ privileged tasks pushing the system out of memory for the OOM killer to do something stupid and kill dhclient or other root-owned processes. For example, on a 32G machine it can't tell the difference between the 1M agetty and the 10G fork bomb member. The changelog describes this 3% boost as the equivalent to the global overcommit limit being 3% higher for privileged tasks, but this is not the same as discounting 3% of overall memory from _every privileged task individually_ during OOM selection. Replace the 3% of system memory bonus with a 3% of current memory usage bonus. By giving root tasks a bonus that is proportional to their actual size, they remain comparable even when relatively small. In the example above, the OOM killer will discount the 1M agetty's 256 badness points down to 179, and the 10G fork bomb's 262144 points down to 183500 points and make the right choice, instead of discounting both to 0 and killing agetty because it's first in the task list. Signed-off-by: David Rientjes <rientjes@google.com> Reported-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-22Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivialLinus Torvalds1-1/+1
Pull trivial tree updates from Jiri Kosina: "Usual rocket science stuff from trivial.git" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits) neighbour.h: fix comment sched: Fix warning on make htmldocs caused by wait.h slab: struct kmem_cache is protected by slab_mutex doc: Fix typo in USB Gadget Documentation of/Kconfig: Spelling s/one/once/ mkregtable: Fix sscanf handling lp5523, lp8501: comment improvements thermal: rcar: comment spelling treewide: fix comments and printk msgs IXP4xx: remove '1 &&' from a condition check in ixp4xx_restart() Documentation: update /proc/uptime field description Documentation: Fix size parameter for snprintf arm: fix comment header and macro name asm-generic: uaccess: Spelling s/a ny/any/ mtd: onenand: fix comment header doc: driver-model/platform.txt: fix a typo drivers: fix typo in DEVTMPFS_MOUNT Kconfig help text doc: Fix typo (acces_process_vm -> access_process_vm) treewide: Fix typos in printk drivers/gpu/drm/qxl/Kconfig: reformat the help text ...
2014-01-21/proc/meminfo: provide estimated available memoryRik van Riel1-0/+9
Many load balancing and workload placing programs check /proc/meminfo to estimate how much free memory is available. They generally do this by adding up "free" and "cached", which was fine ten years ago, but is pretty much guaranteed to be wrong today. It is wrong because Cached includes memory that is not freeable as page cache, for example shared memory segments, tmpfs, and ramfs, and it does not include reclaimable slab memory, which can take up a large fraction of system memory on mostly idle systems with lots of files. Currently, the amount of memory that is available for a new workload, without pushing the system into swap, can be estimated from MemFree, Active(file), Inactive(file), and SReclaimable, as well as the "low" watermarks from /proc/zoneinfo. However, this may change in the future, and user space really should not be expected to know kernel internals to come up with an estimate for the amount of free memory. It is more convenient to provide such an estimate in /proc/meminfo. If things change in the future, we only have to change it in one place. Signed-off-by: Rik van Riel <riel@redhat.com> Reported-by: Erik Mouw <erik.mouw_2@nxp.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-02Documentation: update /proc/uptime field descriptionRob Landley1-1/+1
/proc/uptime has two fields, update description to describe both ala http://lkml.indiana.edu/hypermail/linux/kernel/1312.3/01454.html Signed-off-by: Rob Landley <rob@landley.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-11-13/proc/pid/smaps: show VM_SOFTDIRTY flag in VmFlags lineNaoya Horiguchi1-0/+1
This flag shows that the VMA is "newly created" and thus represents "dirty" in the task's VM. You can clear it by "echo 4 > /proc/pid/clear_refs." Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Pavel Emelyanov <xemul@parallels.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11Documentation/filesystems/proc.txt: fix mistake in the description of Committed_ASMinto Joseph1-10/+9
Fix mistake in the description of Committed_AS in kernel documentation. Signed-off-by: Minto Joseph <mvaliyav@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm: soft-dirty bits for user memory changes trackingPavel Emelyanov1-1/+6
The soft-dirty is a bit on a PTE which helps to track which pages a task writes to. In order to do this tracking one should 1. Clear soft-dirty bits from PTEs ("echo 4 > /proc/PID/clear_refs) 2. Wait some time. 3. Read soft-dirty bits (55'th in /proc/PID/pagemap2 entries) To do this tracking, the writable bit is cleared from PTEs when the soft-dirty bit is. Thus, after this, when the task tries to modify a page at some virtual address the #PF occurs and the kernel sets the soft-dirty bit on the respective PTE. Note, that although all the task's address space is marked as r/o after the soft-dirty bits clear, the #PF-s that occur after that are processed fast. This is so, since the pages are still mapped to physical memory, and thus all the kernel does is finds this fact out and puts back writable, dirty and soft-dirty bits on the PTE. Another thing to note, is that when mremap moves PTEs they are marked with soft-dirty as well, since from the user perspective mremap modifies the virtual memory at mremap's new address. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Glauber Costa <glommer@parallels.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17docs: update documentation about /proc/<pid>/fdinfo/<fd> fanotify outputCyrill Gorcunov1-11/+17
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrey Vagin <avagin@openvz.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: James Bottomley <jbottomley@parallels.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Matthew Helsley <matt.helsley@gmail.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@onelan.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17docs: add documentation about /proc/<pid>/fdinfo/<fd> outputCyrill Gorcunov1-0/+82
[akpm@linux-foundation.org: tweak documentation] Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrey Vagin <avagin@openvz.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: James Bottomley <jbottomley@parallels.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Matthew Helsley <matt.helsley@gmail.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@onelan.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17/proc/pid/status: add "Seccomp" fieldKees Cook1-0/+2
It is currently impossible to examine the state of seccomp for a given process. While attaching with gdb and attempting "call prctl(PR_GET_SECCOMP,...)" will work with some situations, it is not reliable. If the process is in seccomp mode 1, this query will kill the process (prctl not allowed), if the process is in mode 2 with prctl not allowed, it will similarly be killed, and in weird cases, if prctl is filtered to return errno 0, it can look like seccomp is disabled. When reviewing the state of running processes, there should be a way to externally examine the seccomp mode. ("Did this build of Chrome end up using seccomp?" "Did my distro ship ssh with seccomp enabled?") This adds the "Seccomp" line to /proc/$pid/status. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: James Morris <jmorris@namei.org> Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17procfs: add VmFlags field in smaps outputCyrill Gorcunov1-2/+38
During c/r sessions we've found that there is no way at the moment to fetch some VMA associated flags, such as mlock() and madvise(). This leads us to a problem -- we don't know if we should call for mlock() and/or madvise() after restore on the vma area we're bringing back to life. This patch intorduces a new field into "smaps" output called VmFlags, where all set flags associated with the particular VMA is shown as two letter mnemonics. [ Strictly speaking for c/r we only need mlock/madvise bits but it has been said that providing just a few flags looks somehow inconsistent. So all flags are here now. ] This feature is made available on CONFIG_CHECKPOINT_RESTORE=n kernels, as other applications may start to use these fields. The data is encoded in a somewhat awkward two letters mnemonic form, to encourage userspace to be prepared for fields being added or removed in the future. [a.p.zijlstra@chello.nl: props to use for_each_set_bit] [sfr@canb.auug.org.au: props to use array instead of struct] [akpm@linux-foundation.org: overall redesign and simplification] [akpm@linux-foundation.org: remove unneeded braces per sfr, avoid using bloaty for_each_set_bit()] Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>