summaryrefslogtreecommitdiffstats
path: root/fs/proc/task_mmu.c
Commit message (Collapse)AuthorAgeFilesLines
* fs: proc: task_mmu: show page size in /proc/<pid>/numa_mapsRafael Aquini2015-02-121-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* fs/proc/task_mmu.c: add user-space support for resetting mm->hiwater_rss ↵Petr Cermak2015-02-121-0/+14
| | | | | | | | | | | | | | | | | | (peak RSS) 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>
* mm: /proc/pid/clear_refs: avoid split_huge_page()Kirill A. Shutemov2015-02-111-3/+44
| | | | | | | | | | | | | | | | | | | | | Currently pagewalker splits all THP pages on any clear_refs request. It's not necessary. We can handle this on PMD level. One side effect is that soft dirty will potentially see more dirty memory, since we will mark whole THP page dirty at once. Sanity checked with CRIU test suite. More testing is required. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP)Naoya Horiguchi2015-02-111-0/+3
| | | | | | | | | | | | | | | | | | | | | | walk_page_range() silently skips vma having VM_PFNMAP set, which leads to undesirable behaviour at client end (who called walk_page_range). For example for pagemap_read(), when no callbacks are called against VM_PFNMAP vma, pagemap_read() may prepare pagemap data for next virtual address range at wrong index. That could confuse and/or break userspace applications. This patch avoid this misbehavior caused by vma(VM_PFNMAP) like follows: - for pagemap_read() which has its own ->pte_hole(), call the ->pte_hole() over vma(VM_PFNMAP), - for clear_refs and queue_pages which have their own ->tests_walk, just return 1 and skip vma(VM_PFNMAP). This is no problem because these are not interested in hole regions, - for other callers, just skip the vma(VM_PFNMAP) as a default behavior. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Shiraz Hashim <shashim@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* numa_maps: remove numa_maps->vmaNaoya Horiguchi2015-02-111-16/+13
| | | | | | | | | | | | | | | | | pagewalk.c can handle vma in itself, so we don't have to pass vma via walk->private. And show_numa_map() walks pages on vma basis, so using walk_page_vma() is preferable. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* numa_maps: fix typo in gather_hugetbl_statsNaoya Horiguchi2015-02-111-3/+3
| | | | | | | | | | | | | | | | Just doing s/gather_hugetbl_stats/gather_hugetlb_stats/g, this makes code grep-friendly. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pagemap: use walk->vma instead of calling find_vma()Naoya Horiguchi2015-02-111-54/+14
| | | | | | | | | | | | | | | | | | | | | | | Page table walker has the information of the current vma in mm_walk, so we don't have to call find_vma() in each pagemap_(pte|hugetlb)_range() call any longer. Currently pagemap_pte_range() does vma loop itself, so this patch reduces many lines of code. NULL-vma check is omitted because we assume that we never run these callbacks on any address outside vma. And even if it were broken, NULL pointer dereference would be detected, so we can get enough information for debugging. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* clear_refs: remove clear_refs_private->vma and introduce clear_refs_test_walk()Naoya Horiguchi2015-02-111-24/+22
| | | | | | | | | | | | | | | | | clear_refs_write() has some prechecks to determine if we really walk over a given vma. Now we have a test_walk() callback to filter vmas, so let's utilize it. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* smaps: remove mem_size_stats->vma and use walk_page_vma()Naoya Horiguchi2015-02-111-8/+4
| | | | | | | | | | | | | | | | | pagewalk.c can handle vma in itself, so we don't have to pass vma via walk->private. And show_smap() walks pages on vma basis, so using walk_page_vma() is preferable. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc/pagemap: walk page tables under pte lockKonstantin Khlebnikov2015-02-111-5/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lockless access to pte in pagemap_pte_range() might race with page migration and trigger BUG_ON(!PageLocked()) in migration_entry_to_page(): CPU A (pagemap) CPU B (migration) lock_page() try_to_unmap(page, TTU_MIGRATION...) make_migration_entry() set_pte_at() <read *pte> pte_to_pagemap_entry() remove_migration_ptes() unlock_page() if(is_migration_entry()) migration_entry_to_page() BUG_ON(!PageLocked(page)) Also lockless read might be non-atomic if pte is larger than wordsize. Other pte walkers (smaps, numa_maps, clear_refs) already lock ptes. Fixes: 052fb0d635df ("proc: report file/anon bit in /proc/pid/pagemap") Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reported-by: Andrey Ryabinin <a.ryabinin@samsung.com> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: <stable@vger.kernel.org> [3.5+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: account pmd page tables to the processKirill A. Shutemov2015-02-111-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Dave noticed that unprivileged process can allocate significant amount of memory -- >500 MiB on x86_64 -- and stay unnoticed by oom-killer and memory cgroup. The trick is to allocate a lot of PMD page tables. Linux kernel doesn't account PMD tables to the process, only PTE. The use-cases below use few tricks to allocate a lot of PMD page tables while keeping VmRSS and VmPTE low. oom_score for the process will be 0. #include <errno.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/mman.h> #include <sys/prctl.h> #define PUD_SIZE (1UL << 30) #define PMD_SIZE (1UL << 21) #define NR_PUD 130000 int main(void) { char *addr = NULL; unsigned long i; prctl(PR_SET_THP_DISABLE); for (i = 0; i < NR_PUD ; i++) { addr = mmap(addr + PUD_SIZE, PUD_SIZE, PROT_WRITE|PROT_READ, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0); if (addr == MAP_FAILED) { perror("mmap"); break; } *addr = 'x'; munmap(addr, PMD_SIZE); mmap(addr, PMD_SIZE, PROT_WRITE|PROT_READ, MAP_ANONYMOUS|MAP_PRIVATE|MAP_FIXED, -1, 0); if (addr == MAP_FAILED) perror("re-mmap"), exit(1); } printf("PID %d consumed %lu KiB in PMD page tables\n", getpid(), i * 4096 >> 10); return pause(); } The patch addresses the issue by account PMD tables to the process the same way we account PTE. The main place where PMD tables is accounted is __pmd_alloc() and free_pmd_range(). But there're few corner cases: - HugeTLB can share PMD page tables. The patch handles by accounting the table to all processes who share it. - x86 PAE pre-allocates few PMD tables on fork. - Architectures with FIRST_USER_ADDRESS > 0. We need to adjust sanity check on exit(2). Accounting only happens on configuration where PMD page table's level is present (PMD is not folded). As with nr_ptes we use per-mm counter. The counter value is used to calculate baseline for badness score by oom-killer. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: David Rientjes <rientjes@google.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc: drop handling non-linear mappingsKirill A. Shutemov2015-02-101-16/+0
| | | | | | | | | We have to handle non-linear mappings for /proc/PID/{smaps,clear_refs} which is unused now. Let's drop it. 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>
* mm: fix huge zero page accounting in smaps reportKirill A. Shutemov2014-12-101-36/+68
| | | | | | | | | | | | | | | | | | | | | | | As a small zero page, huge zero page should not be accounted in smaps report as normal page. For small pages we rely on vm_normal_page() to filter out zero page, but vm_normal_page() is not designed to handle pmds. We only get here due hackish cast pmd to pte in smaps_pte_range() -- pte and pmd format is not necessary compatible on each and every architecture. Let's add separate codepath to handle pmds. follow_trans_huge_pmd() will detect huge zero page for us. We would need pmd_dirty() helper to do this properly. The patch adds it to THP-enabled architectures which don't yet have one. [akpm@linux-foundation.org: use do_div to fix 32-bit build] Signed-off-by: "Kirill A. Shutemov" <kirill@shutemov.name> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Tested-by: Fengwei Yin <yfw.kernel@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86, mpx: Introduce VM_MPX to indicate that a VMA is MPX specificQiaowei Ren2014-11-181-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MPX-enabled applications using large swaths of memory can potentially have large numbers of bounds tables in process address space to save bounds information. These tables can take up huge swaths of memory (as much as 80% of the memory on the system) even if we clean them up aggressively. In the worst-case scenario, the tables can be 4x the size of the data structure being tracked. IOW, a 1-page structure can require 4 bounds-table pages. Being this huge, our expectation is that folks using MPX are going to be keen on figuring out how much memory is being dedicated to it. So we need a way to track memory use for MPX. If we want to specifically track MPX VMAs we need to be able to distinguish them from normal VMAs, and keep them from getting merged with normal VMAs. A new VM_ flag set only on MPX VMAs does both of those things. With this flag, MPX bounds-table VMAs can be distinguished from other VMAs, and userspace can also walk /proc/$pid/smaps to get memory usage for MPX. In addition to this flag, we also introduce a special ->vm_ops specific to MPX VMAs (see the patch "add MPX specific mmap interface"), but currently different ->vm_ops do not by themselves prevent VMA merging, so we still need this flag. We understand that VM_ flags are scarce and are open to other options. Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: linux-mm@kvack.org Cc: linux-mips@linux-mips.org Cc: Dave Hansen <dave@sr71.net> Link: http://lkml.kernel.org/r/20141114151825.565625B3@viggo.jf.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY clearedPeter Feiner2014-10-141-5/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For VMAs that don't want write notifications, PTEs created for read faults have their write bit set. If the read fault happens after VM_SOFTDIRTY is cleared, then the PTE's softdirty bit will remain clear after subsequent writes. Here's a simple code snippet to demonstrate the bug: char* m = mmap(NULL, getpagesize(), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0); system("echo 4 > /proc/$PPID/clear_refs"); /* clear VM_SOFTDIRTY */ assert(*m == '\0'); /* new PTE allows write access */ assert(!soft_dirty(x)); *m = 'x'; /* should dirty the page */ assert(soft_dirty(x)); /* fails */ With this patch, write notifications are enabled when VM_SOFTDIRTY is cleared. Furthermore, to avoid unnecessary faults, write notifications are disabled when VM_SOFTDIRTY is set. As a side effect of enabling and disabling write notifications with care, this patch fixes a bug in mprotect where vm_page_prot bits set by drivers were zapped on mprotect. An analogous bug was fixed in mmap by commit c9d0bf241451 ("mm: uncached vma support with writenotify"). Signed-off-by: Peter Feiner <pfeiner@google.com> Reported-by: Peter Feiner <pfeiner@google.com> Suggested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Jamie Liu <jamieliu@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: softdirty: unmapped addresses between VMAs are cleanPeter Feiner2014-10-091-21/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a /proc/pid/pagemap read spans a [VMA, an unmapped region, then a VM_SOFTDIRTY VMA], the virtual pages in the unmapped region are reported as softdirty. Here's a program to demonstrate the bug: int main() { const uint64_t PAGEMAP_SOFTDIRTY = 1ul << 55; uint64_t pme[3]; int fd = open("/proc/self/pagemap", O_RDONLY);; char *m = mmap(NULL, 3 * getpagesize(), PROT_READ, MAP_ANONYMOUS | MAP_SHARED, -1, 0); munmap(m + getpagesize(), getpagesize()); pread(fd, pme, 24, (unsigned long) m / getpagesize() * 8); assert(pme[0] & PAGEMAP_SOFTDIRTY); /* passes */ assert(!(pme[1] & PAGEMAP_SOFTDIRTY)); /* fails */ assert(pme[2] & PAGEMAP_SOFTDIRTY); /* passes */ return 0; } (Note that all pages in new VMAs are softdirty until cleared). Tested: Used the program given above. I'm going to include this code in a selftest in the future. [n-horiguchi@ah.jp.nec.com: prevent pagemap_pte_range() from overrunning] Signed-off-by: Peter Feiner <pfeiner@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Jamie Liu <jamieliu@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mempolicy: fix show_numa_map() vs exec() + do_set_mempolicy() raceOleg Nesterov2014-10-091-24/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 9e7814404b77 "hold task->mempolicy while numa_maps scans." fixed the race with the exiting task but this is not enough. The current code assumes that get_vma_policy(task) should either see task->mempolicy == NULL or it should be equal to ->task_mempolicy saved by hold_task_mempolicy(), so we can never race with __mpol_put(). But this can only work if we can't race with do_set_mempolicy(), and thus we can't race with another do_set_mempolicy() or do_exit() after that. However, do_set_mempolicy()->down_write(mmap_sem) can not prevent this race. This task can exec, change it's ->mm, and call do_set_mempolicy() after that; in this case they take 2 different locks. Change hold_task_mempolicy() to use get_task_policy(), it never returns NULL, and change show_numa_map() to use __get_vma_policy() or fall back to proc_priv->task_mempolicy. Note: this is the minimal fix, we will cleanup this code later. I think hold_task_mempolicy() and release_task_mempolicy() should die, we can move this logic into show_numa_map(). Or we can move get_task_policy() outside of ->mmap_sem and !CONFIG_NUMA code at least. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Hugh Dickins <hughd@google.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc/maps: make vm_is_stack() logic namespace-friendlyOleg Nesterov2014-10-091-4/+21
| | | | | | | | | | | | | | | | | | | | | | | | | - Rename vm_is_stack() to task_of_stack() and change it to return "struct task_struct *" rather than the global (and thus wrong in general) pid_t. - Add the new pid_of_stack() helper which calls task_of_stack() and uses the right namespace to report the correct pid_t. Unfortunately we need to define this helper twice, in task_mmu.c and in task_nommu.c. perhaps it makes sense to add fs/proc/util.c and move at least pid_of_stack/task_of_stack there to avoid the code duplication. - Change show_map_vma() and show_numa_map() to use the new helper. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Greg Ungerer <gerg@uclinux.org> Cc: "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>
* proc/maps: replace proc_maps_private->pid with "struct inode *inode"Oleg Nesterov2014-10-091-2/+2
| | | | | | | | | | | | | | m_start() can use get_proc_task() instead, and "struct inode *" provides more potentially useful info, see the next changes. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Greg Ungerer <gerg@uclinux.org> Cc: "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>
* fs/proc/task_mmu.c: update m->version in the main loop in m_start()Oleg Nesterov2014-10-091-1/+4
| | | | | | | | | | | | | Change the main loop in m_start() to update m->version. Mostly for consistency, but this can help to avoid the same loop if the very 1st ->show() fails due to seq_overflow(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> 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>
* fs/proc/task_mmu.c: reintroduce m->version logicOleg Nesterov2014-10-091-0/+21
| | | | | | | | | | | | | | | | | | | Add the "last_addr" optimization back. Like before, every ->show() method checks !seq_overflow() and sets m->version = vma->vm_start. However, it also checks that m_next_vma(vma) != NULL, otherwise it sets m->version = -1 for the lockless "EOF" fast-path in m_start(). m_start() can simply do find_vma() + m_next_vma() if last_addr is not zero, the code looks clear and simple and this case is clearly separated from "scan vmas" path. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> 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>
* fs/proc/task_mmu.c: introduce m_next_vma() helperOleg Nesterov2014-10-091-5/+10
| | | | | | | | | | | | Extract the tail_vma/vm_next calculation from m_next() into the new trivial helper, m_next_vma(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> 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>
* fs/proc/task_mmu.c: simplify m_start() to make it readableOleg Nesterov2014-10-091-24/+10
| | | | | | | | | | | | | | | | | | | | | Now that m->version is gone we can cleanup m_start(). In particular, - Remove the "unsigned long" typecast, m->index can't be negative or exceed ->map_count. But lets use "unsigned int pos" to make it clear that "pos < map_count" is safe. - Remove the unnecessary "vma != NULL" check in the main loop. It can't be NULL unless we have a vm bug. - This also means that "pos < map_count" case can simply return the valid vma and avoid "goto" and subsequent checks. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> 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>
* fs/proc/task_mmu.c: kill the suboptimal and confusing m->version logicOleg Nesterov2014-10-091-34/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | m_start() carefully documents, checks, and sets "m->version = -1" if we are going to return NULL. The only problem is that we will be never called again if m_start() returns NULL, so this is simply pointless and misleading. Otoh, ->show() methods m->version = 0 if vma == tail_vma and this is just wrong, we want -1 in this case. And in fact we also want -1 if ->vm_next == NULL and ->tail_vma == NULL. And it is not used consistently, the "scan vmas" loop in m_start() should update last_addr too. Finally, imo the whole "last_addr" logic in m_start() looks horrible. find_vma(last_addr) is called unconditionally even if we are not going to use the result. But the main problem is that this code participates in tail_vma-or-NULL mess, and this looks simply unfixable. Remove this optimization. We will add it back after some cleanups. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> 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>
* fs/proc/task_mmu.c: shift "priv->task = NULL" from m_start() to m_stop()Oleg Nesterov2014-10-091-6/+3
| | | | | | | | | | | | | | | | 1. There is no reason to reset ->tail_vma in m_start(), if we return IS_ERR_OR_NULL() it won't be used. 2. m_start() also clears priv->task to ensure that m_stop() won't use the stale pointer if we fail before get_task_struct(). But this is ugly and confusing, move this initialization in m_stop(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> 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>
* fs/proc/task_mmu.c: cleanup the "tail_vma" horror in m_next()Oleg Nesterov2014-10-091-5/+3
| | | | | | | | | | | | | | | | | | | 1. Kill the first "vma != NULL" check. Firstly this is not possible, m_next() won't be called if ->start() or the previous ->next() returns NULL. And if it was possible the 2nd "vma != tail_vma" check is buggy, we should not wrongly return ->tail_vma. 2. Make this function readable. The logic is very simple, we should return check "vma != tail" once and return "vm_next || tail_vma". Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> 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>
* fs/proc/task_mmu.c: simplify the vma_stop() logicOleg Nesterov2014-10-091-16/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | m_start() drops ->mmap_sem and does mmput() if it retuns vsyscall vma. This is because in this case m_stop()->vma_stop() obviously can't use gate_vma->vm_mm. Now that we have proc_maps_private->mm we can simplify this logic: - Change m_start() to return with ->mmap_sem held unless it returns IS_ERR_OR_NULL(). - Change vma_stop() to use priv->mm and avoid the ugly vma checks, this makes "vm_area_struct *vma" unnecessary. - This also allows m_start() to use vm_stop(). - Cleanup m_next() to follow the new locking rule. Note: m_stop() looks very ugly, and this temporary uglifies it even more. Fixed by the next change. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> 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>
* fs/proc/task_mmu.c: shift mm_access() from m_start() to proc_maps_open()Oleg Nesterov2014-10-091-9/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A simple test-case from Kirill Shutemov cat /proc/self/maps >/dev/null chmod +x /proc/self/net/packet exec /proc/self/net/packet makes lockdep unhappy, cat/exec take seq_file->lock + cred_guard_mutex in the opposite order. It's a false positive and probably we should not allow "chmod +x" on proc files. Still I think that we should avoid mm_access() and cred_guard_mutex in sys_read() paths, security checking should happen at open time. Besides, this doesn't even look right if the task changes its ->mm between m_stop() and m_start(). Add the new "mm_struct *mm" member into struct proc_maps_private and change proc_maps_open() to initialize it using proc_mem_open(). Change m_start() to use priv->mm if atomic_inc_not_zero(mm_users) succeeds or return NULL (eof) otherwise. The only complication is that proc_maps_open() users should additionally do mmdrop() in fop->release(), add the new proc_map_release() helper for that. Note: this is the user-visible change, if the task execs after open("maps") the new ->mm won't be visible via this file. I hope this is fine, and this matches /proc/pid/mem bahaviour. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: "Kirill A. Shutemov" <kirill@shutemov.name> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> 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>
* fs/proc/task_mmu.c: unify/simplify do_maps_open() and numa_maps_open()Oleg Nesterov2014-10-091-28/+16
| | | | | | | | | | | | | | | do_maps_open() and numa_maps_open() are overcomplicated, they could use __seq_open_private(). Plus they do the same, just sizeof(*priv) Change them to use a new simple helper, proc_maps_open(ops, psize). This simplifies the code and allows us to do the next changes. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> 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>
* fs/proc/task_mmu.c: don't use task->mm in m_start() and show_*map()Oleg Nesterov2014-10-091-5/+3
| | | | | | | | | | | | | | | | | | | get_gate_vma(priv->task->mm) looks ugly and wrong, task->mm can be NULL or it can changed by exec right after mm_access(). And in theory this race is not harmless, the task can exec and then later exit and free the new mm_struct. In this case get_task_mm(oldmm) can't help, get_gate_vma(task->mm) can read the freed/unmapped memory. I think that priv->task should simply die and hold_task_mempolicy() logic can be simplified. tail_vma logic asks for cleanups too. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> 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>
* mm: softdirty: addresses before VMAs in PTE holes aren't softdirtyPeter Feiner2014-09-261-9/+18
| | | | | | | | | | | | | | | | | | | | | | | | In PTE holes that contain VM_SOFTDIRTY VMAs, unmapped addresses before VM_SOFTDIRTY VMAs are reported as softdirty by /proc/pid/pagemap. This bug was introduced in commit 68b5a6524856 ("mm: softdirty: respect VM_SOFTDIRTY in PTE holes"). That commit made /proc/pid/pagemap look at VM_SOFTDIRTY in PTE holes but neglected to observe the start of VMAs returned by find_vma. Tested: Wrote a selftest that creates a PMD-sized VMA then unmaps the first page and asserts that the page is not softdirty. I'm going to send the pagemap selftest in a later commit. Signed-off-by: Peter Feiner <pfeiner@google.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Jamie Liu <jamieliu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: softdirty: respect VM_SOFTDIRTY in PTE holesPeter Feiner2014-08-061-6/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | After a VMA is created with the VM_SOFTDIRTY flag set, /proc/pid/pagemap should report that the VMA's virtual pages are soft-dirty until VM_SOFTDIRTY is cleared (i.e., by the next write of "4" to /proc/pid/clear_refs). However, pagemap ignores the VM_SOFTDIRTY flag for virtual addresses that fall in PTE holes (i.e., virtual addresses that don't have a PMD, PUD, or PGD allocated yet). To observe this bug, use mmap to create a VMA large enough such that there's a good chance that the VMA will occupy an unused PMD, then test the soft-dirty bit on its pages. In practice, I found that a VMA that covered a PMD's worth of address space was big enough. This patch adds the necessary VMA lookup to the PTE hole callback in /proc/pid/pagemap's page walk and sets soft-dirty according to the VMAs' VM_SOFTDIRTY flag. Signed-off-by: Peter Feiner <pfeiner@google.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Hugh Dickins <hughd@google.com> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'next' (accumulated 3.16 merge window patches) into masterLinus Torvalds2014-06-081-9/+19
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that 3.15 is released, this merges the 'next' branch into 'master', bringing us to the normal situation where my 'master' branch is the merge window. * accumulated work in next: (6809 commits) ufs: sb mutex merge + mutex_destroy powerpc: update comments for generic idle conversion cris: update comments for generic idle conversion idle: remove cpu_idle() forward declarations nbd: zero from and len fields in NBD_CMD_DISCONNECT. mm: convert some level-less printks to pr_* MAINTAINERS: adi-buildroot-devel is moderated MAINTAINERS: add linux-api for review of API/ABI changes mm/kmemleak-test.c: use pr_fmt for logging fs/dlm/debug_fs.c: replace seq_printf by seq_puts fs/dlm/lockspace.c: convert simple_str to kstr fs/dlm/config.c: convert simple_str to kstr mm: mark remap_file_pages() syscall as deprecated mm: memcontrol: remove unnecessary memcg argument from soft limit functions mm: memcontrol: clean up memcg zoneinfo lookup mm/memblock.c: call kmemleak directly from memblock_(alloc|free) mm/mempool.c: update the kmemleak stack trace for mempool allocations lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations mm: introduce kmemleak_update_trace() mm/kmemleak.c: use %u to print ->checksum ...
| * fs/proc/task_mmu.c: replace seq_printf by seq_putsFabian Frederick2014-06-061-4/+4
| | | | | | | | | | | | | | Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * Merge branch 'x86/vdso' of ↵Linus Torvalds2014-06-051-0/+6
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next Pull x86 cdso updates from Peter Anvin: "Vdso cleanups and improvements largely from Andy Lutomirski. This makes the vdso a lot less ''special''" * 'x86/vdso' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/vdso, build: Make LE access macros clearer, host-safe x86/vdso, build: Fix cross-compilation from big-endian architectures x86/vdso, build: When vdso2c fails, unlink the output x86, vdso: Fix an OOPS accessing the HPET mapping w/o an HPET x86, mm: Replace arch_vma_name with vm_ops->name for vsyscalls x86, mm: Improve _install_special_mapping and fix x86 vdso naming mm, fs: Add vm_ops->name as an alternative to arch_vma_name x86, vdso: Fix an OOPS accessing the HPET mapping w/o an HPET x86, vdso: Remove vestiges of VDSO_PRELINK and some outdated comments x86, vdso: Move the vvar and hpet mappings next to the 64-bit vDSO x86, vdso: Move the 32-bit vdso special pages after the text x86, vdso: Reimplement vdso.so preparation in build-time C x86, vdso: Move syscall and sysenter setup into kernel/cpu/common.c x86, vdso: Clean up 32-bit vs 64-bit vdso params x86, mm: Ensure correct alignment of the fixmap
| | * mm, fs: Add vm_ops->name as an alternative to arch_vma_nameAndy Lutomirski2014-05-201-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | arch_vma_name sucks. It's a silly hack, and it's annoying to implement correctly. In fact, AFAICS, even the straightforward x86 implementation is incorrect (I suspect that it breaks if the vdso mapping is split or gets remapped). This adds a new vm_ops->name operation that can replace it. The followup patches will remove all uses of arch_vma_name on x86, fixing a couple of annoyances in the process. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/2eee21791bb36a0a408c5c2bdb382a9e6a41ca4a.1400538962.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * | mm: softdirty: clear VM_SOFTDIRTY flag inside clear_refs_write() instead of ↵Cyrill Gorcunov2014-06-041-5/+9
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | clear_soft_dirty() clear_refs_write() is called earlier than clear_soft_dirty() and it is more natural to clear VM_SOFTDIRTY (which belongs to VMA entry but not PTEs) that early instead of clearing it a way deeper inside call chain. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* / mm: add !pte_present() check on existing hugetlb_entry callbacksNaoya Horiguchi2014-06-061-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | The age table walker doesn't check non-present hugetlb entry in common path, so hugetlb_entry() callbacks must check it. The reason for this behavior is that some callers want to handle it in its own way. [ I think that reason is bogus, btw - it should just do what the regular code does, which is to call the "pte_hole()" function for such hugetlb entries - Linus] However, some callers don't check it now, which causes unpredictable result, for example when we have a race between migrating hugepage and reading /proc/pid/numa_maps. This patch fixes it by adding !pte_present checks on buggy callbacks. This bug exists for years and got visible by introducing hugepage migration. ChangeLog v2: - fix if condition (check !pte_present() instead of pte_present()) Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Rik van Riel <riel@redhat.com> Cc: <stable@vger.kernel.org> [3.12+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ Backported to 3.15. Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org> ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: per-thread vma cachingDavidlohr Bueso2014-04-071-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is a continuation of efforts trying to optimize find_vma(), avoiding potentially expensive rbtree walks to locate a vma upon faults. The original approach (https://lkml.org/lkml/2013/11/1/410), where the largest vma was also cached, ended up being too specific and random, thus further comparison with other approaches were needed. There are two things to consider when dealing with this, the cache hit rate and the latency of find_vma(). Improving the hit-rate does not necessarily translate in finding the vma any faster, as the overhead of any fancy caching schemes can be too high to consider. We currently cache the last used vma for the whole address space, which provides a nice optimization, reducing the total cycles in find_vma() by up to 250%, for workloads with good locality. On the other hand, this simple scheme is pretty much useless for workloads with poor locality. Analyzing ebizzy runs shows that, no matter how many threads are running, the mmap_cache hit rate is less than 2%, and in many situations below 1%. The proposed approach is to replace this scheme with a small per-thread cache, maximizing hit rates at a very low maintenance cost. Invalidations are performed by simply bumping up a 32-bit sequence number. The only expensive operation is in the rare case of a seq number overflow, where all caches that share the same address space are flushed. Upon a miss, the proposed replacement policy is based on the page number that contains the virtual address in question. Concretely, the following results are seen on an 80 core, 8 socket x86-64 box: 1) System bootup: Most programs are single threaded, so the per-thread scheme does improve ~50% hit rate by just adding a few more slots to the cache. +----------------+----------+------------------+ | caching scheme | hit-rate | cycles (billion) | +----------------+----------+------------------+ | baseline | 50.61% | 19.90 | | patched | 73.45% | 13.58 | +----------------+----------+------------------+ 2) Kernel build: This one is already pretty good with the current approach as we're dealing with good locality. +----------------+----------+------------------+ | caching scheme | hit-rate | cycles (billion) | +----------------+----------+------------------+ | baseline | 75.28% | 11.03 | | patched | 88.09% | 9.31 | +----------------+----------+------------------+ 3) Oracle 11g Data Mining (4k pages): Similar to the kernel build workload. +----------------+----------+------------------+ | caching scheme | hit-rate | cycles (billion) | +----------------+----------+------------------+ | baseline | 70.66% | 17.14 | | patched | 91.15% | 12.57 | +----------------+----------+------------------+ 4) Ebizzy: There's a fair amount of variation from run to run, but this approach always shows nearly perfect hit rates, while baseline is just about non-existent. The amounts of cycles can fluctuate between anywhere from ~60 to ~116 for the baseline scheme, but this approach reduces it considerably. For instance, with 80 threads: +----------------+----------+------------------+ | caching scheme | hit-rate | cycles (billion) | +----------------+----------+------------------+ | baseline | 1.06% | 91.54 | | patched | 99.97% | 14.18 | +----------------+----------+------------------+ [akpm@linux-foundation.org: fix nommu build, per Davidlohr] [akpm@linux-foundation.org: document vmacache_valid() logic] [akpm@linux-foundation.org: attempt to untangle header files] [akpm@linux-foundation.org: add vmacache_find() BUG_ON] [hughd@google.com: add vmacache_valid_mm() (from Oleg)] [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: adjust and enhance comments] Signed-off-by: Davidlohr Bueso <davidlohr@hp.com> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Michel Lespinasse <walken@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Tested-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* seq_file: remove "%n" usage from seq_file usersTetsuo Handa2013-11-151-14/+6
| | | | | | | | | | | | All seq_printf() users are using "%n" for calculating padding size, convert them to use seq_setwidth() / seq_pad() pair. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Joe Perches <joe@perches.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, thp: change pmd_trans_huge_lock() to return taken lockKirill A. Shutemov2013-11-151-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With split ptlock it's important to know which lock pmd_trans_huge_lock() took. This patch adds one more parameter to the function to return the lock. In most places migration to new api is trivial. Exception is move_huge_pmd(): we need to take two locks if pmd tables are different. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Alex Thorlton <athorlton@sgi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: convert mm->nr_ptes to atomic_long_tKirill A. Shutemov2013-11-151-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With split page table lock for PMD level we can't hold mm->page_table_lock while updating nr_ptes. Let's convert it to atomic_long_t to avoid races. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Alex Thorlton <athorlton@sgi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* /proc/pid/smaps: show VM_SOFTDIRTY flag in VmFlags lineNaoya Horiguchi2013-11-131-0/+3
| | | | | | | | | | | | | | 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>
* mm, mempolicy: make mpol_to_str robust and always succeedDavid Rientjes2013-11-131-8/+6
| | | | | | | | | | | | | | | | | | | | | | | mpol_to_str() should not fail. Currently, it either fails because the string buffer is too small or because a string hasn't been defined for a mempolicy mode. If a new mempolicy mode is introduced and no string is defined for it, just warn and return "unknown". If the buffer is too small, just truncate the string and return, the same behavior as snprintf(). This also fixes a bug where there was no NULL-byte termination when doing *p++ = '=' and *p++ ':' and maxlen has been reached. Signed-off-by: David Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Chen Gang <gang.chen@asianux.com> Cc: Rik van Riel <riel@redhat.com> Cc: Dave Jones <davej@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: /proc/pid/pagemap: inspect _PAGE_SOFT_DIRTY only on present pagesCyrill Gorcunov2013-10-161-1/+3
| | | | | | | | | | | | | | | | | | | | | | If a page we are inspecting is in swap we may occasionally report it as having soft dirty bit (even if it is clean). The pte_soft_dirty helper should be called on present pte only. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Matt Mackall <mpm@selenic.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/proc/task_mmu.c: check the return value of mpol_to_str()Chen Gang2013-09-111-1/+3
| | | | | | | | | | | | | | | mpol_to_str() may fail, and not fill the buffer (e.g. -EINVAL), so need check about it, or buffer may not be zero based, and next seq_printf() will cause issue. The failure return need after mpol_cond_put() to match get_vma_policy(). Signed-off-by: Chen Gang <gang.chen@asianux.com> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: track vma changes with VM_SOFTDIRTY bitCyrill Gorcunov2013-09-111-10/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pavel reported that in case if vma area get unmapped and then mapped (or expanded) in-place, the soft dirty tracker won't be able to recognize this situation since it works on pte level and ptes are get zapped on unmap, loosing soft dirty bit of course. So to resolve this situation we need to track actions on vma level, there VM_SOFTDIRTY flag comes in. When new vma area created (or old expanded) we set this bit, and keep it here until application calls for clearing soft dirty bit. Thus when user space application track memory changes now it can detect if vma area is renewed. Reported-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Matt Mackall <mpm@selenic.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Rob Landley <rob@landley.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/proc/task_mmu.c: fix buffer overflow in add_page_map()yonghua zheng2013-08-131-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | Recently we met quite a lot of random kernel panic issues after enabling CONFIG_PROC_PAGE_MONITOR. After debuggind we found this has something to do with following bug in pagemap: In struct pagemapread: struct pagemapread { int pos, len; pagemap_entry_t *buffer; bool v2; }; pos is number of PM_ENTRY_BYTES in buffer, but len is the size of buffer, it is a mistake to compare pos and len in add_page_map() for checking buffer is full or not, and this can lead to buffer overflow and random kernel panic issue. Correct len to be total number of PM_ENTRY_BYTES in buffer. [akpm@linux-foundation.org: document pagemapread.pos and .len units, fix PM_ENTRY_BYTES definition] Signed-off-by: Yonghua Zheng <younghua.zheng@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: save soft-dirty bits on file pagesCyrill Gorcunov2013-08-131-0/+2
| | | | | | | | | | | | | | | | | | | | | | Andy reported that if file page get reclaimed we lose the soft-dirty bit if it was there, so save _PAGE_BIT_SOFT_DIRTY bit when page address get encoded into pte entry. Thus when #pf happens on such non-present pte we can restore it back. Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: save soft-dirty bits on swapped pagesCyrill Gorcunov2013-08-131-6/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andy Lutomirski reported that if a page with _PAGE_SOFT_DIRTY bit set get swapped out, the bit is getting lost and no longer available when pte read back. To resolve this we introduce _PTE_SWP_SOFT_DIRTY bit which is saved in pte entry for the page being swapped out. When such page is to be read back from a swap cache we check for bit presence and if it's there we clear it and restore the former _PAGE_SOFT_DIRTY bit back. One of the problem was to find a place in pte entry where we can save the _PTE_SWP_SOFT_DIRTY bit while page is in swap. The _PAGE_PSE was chosen for that, it doesn't intersect with swap entry format stored in pte. Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-29 06:33:38 +0000