1. 06 Jul, 2017 6 commits
  2. 09 Mar, 2017 1 commit
  3. 23 Feb, 2017 2 commits
  4. 08 Oct, 2016 2 commits
  5. 21 May, 2016 2 commits
  6. 20 May, 2016 1 commit
    • Vaishali Thakkar's avatar
      mm/hugetlb: introduce hugetlb_bad_size() · 9fee021d
      Vaishali Thakkar authored
      
      
      When any unsupported hugepage size is specified, 'hugepagesz=' and
      'hugepages=' should be ignored during command line parsing until any
      supported hugepage size is found.  But currently incorrect number of
      hugepages are allocated when unsupported size is specified as it fails
      to ignore the 'hugepages=' command.
      
      Test case:
      
      Note that this is specific to x86 architecture.
      
      Boot the kernel with command line option 'hugepagesz=256M hugepages=X'.
      After boot, dmesg output shows that X number of hugepages of the size 2M
      is pre-allocated instead of 0.
      
      So, to handle such command line options, introduce new routine
      hugetlb_bad_size.  The routine hugetlb_bad_size sets the global variable
      parsed_valid_hugepagesz.  We are using parsed_valid_hugepagesz to save
      the state when unsupported hugepagesize is found so that we can ignore
      the 'hugepages=' parameters after that and then reset the variable when
      supported hugepage size is found.
      
      The routine hugetlb_bad_size can be called while setting 'hugepagesz='
      parameter in an architecture specific code.
      Signed-off-by: default avatarVaishali Thakkar <vaishali.thakkar@oracle.com>
      Reviewed-by: default avatarMike Kravetz <mike.kravetz@oracle.com>
      Reviewed-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
      Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
      Cc: Dominik Dingel <dingel@linux.vnet.ibm.com>
      Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9fee021d
  7. 16 Jan, 2016 1 commit
  8. 15 Jan, 2016 1 commit
  9. 21 Dec, 2015 1 commit
    • David Woods's avatar
      arm64: hugetlb: add support for PTE contiguous bit · 66b3923a
      David Woods authored
      
      
      The arm64 MMU supports a Contiguous bit which is a hint that the TTE
      is one of a set of contiguous entries which can be cached in a single
      TLB entry.  Supporting this bit adds new intermediate huge page sizes.
      
      The set of huge page sizes available depends on the base page size.
      Without using contiguous pages the huge page sizes are as follows.
      
       4KB:   2MB  1GB
      64KB: 512MB
      
      With a 4KB granule, the contiguous bit groups together sets of 16 pages
      and with a 64KB granule it groups sets of 32 pages.  This enables two new
      huge page sizes in each case, so that the full set of available sizes
      is as follows.
      
       4KB:  64KB   2MB  32MB  1GB
      64KB:   2MB 512MB  16GB
      
      If a 16KB granule is used then the contiguous bit groups 128 pages
      at the PTE level and 32 pages at the PMD level.
      
      If the base page size is set to 64KB then 2MB pages are enabled by
      default.  It is possible in the future to make 2MB the default huge
      page size for both 4KB and 64KB granules.
      Reviewed-by: default avatarChris Metcalf <cmetcalf@ezchip.com>
      Reviewed-by: default avatarSteve Capper <steve.capper@linaro.org>
      Signed-off-by: default avatarDavid Woods <dwoods@ezchip.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      66b3923a
  10. 06 Nov, 2015 1 commit
  11. 08 Sep, 2015 5 commits
    • Mike Kravetz's avatar
      hugetlbfs: add hugetlbfs_fallocate() · 70c3547e
      Mike Kravetz authored
      
      
      This is based on the shmem version, but it has diverged quite a bit.  We
      have no swap to worry about, nor the new file sealing.  Add
      synchronication via the fault mutex table to coordinate page faults,
      fallocate allocation and fallocate hole punch.
      
      What this allows us to do is move physical memory in and out of a
      hugetlbfs file without having it mapped.  This also gives us the ability
      to support MADV_REMOVE since it is currently implemented using
      fallocate().  MADV_REMOVE lets madvise() remove pages from the middle of
      a hugetlbfs file, which wasn't possible before.
      
      hugetlbfs fallocate only operates on whole huge pages.
      
      Based on code by Dave Hansen.
      Signed-off-by: default avatarMike Kravetz <mike.kravetz@oracle.com>
      Reviewed-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Acked-by: default avatarHillf Danton <hillf.zj@alibaba-inc.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Davidlohr Bueso <dave@stgolabs.net>
      Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
      Cc: Christoph Hellwig <hch@infradead.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      70c3547e
    • Mike Kravetz's avatar
      hugetlbfs: New huge_add_to_page_cache helper routine · ab76ad54
      Mike Kravetz authored
      
      
      Currently, there is only a single place where hugetlbfs pages are added
      to the page cache.  The new fallocate code be adding a second one, so
      break the functionality out into its own helper.
      Signed-off-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
      Signed-off-by: default avatarMike Kravetz <mike.kravetz@oracle.com>
      Reviewed-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Acked-by: default avatarHillf Danton <hillf.zj@alibaba-inc.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Davidlohr Bueso <dave@stgolabs.net>
      Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
      Cc: Christoph Hellwig <hch@infradead.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ab76ad54
    • Mike Kravetz's avatar
      hugetlbfs: truncate_hugepages() takes a range of pages · b5cec28d
      Mike Kravetz authored
      
      
      Modify truncate_hugepages() to take a range of pages (start, end)
      instead of simply start.  If an end value of LLONG_MAX is passed, the
      current "truncate" functionality is maintained.  Existing callers are
      modified to pass LLONG_MAX as end of range.  By keying off end ==
      LLONG_MAX, the routine behaves differently for truncate and hole punch.
      Page removal is now synchronized with page allocation via faults by
      using the fault mutex table.  The hole punch case can experience the
      rare region_del error and must handle accordingly.
      
      Add the routine hugetlb_fix_reserve_counts to fix up reserve counts in
      the case where region_del returns an error.
      
      Since the routine handles more than just the truncate case, it is
      renamed to remove_inode_hugepages().  To be consistent, the routine
      truncate_huge_page() is renamed remove_huge_page().
      
      Downstream of remove_inode_hugepages(), the routine
      hugetlb_unreserve_pages() is also modified to take a range of pages.
      hugetlb_unreserve_pages is modified to detect an error from region_del and
      pass it back to the caller.
      Signed-off-by: default avatarMike Kravetz <mike.kravetz@oracle.com>
      Reviewed-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Acked-by: default avatarHillf Danton <hillf.zj@alibaba-inc.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Davidlohr Bueso <dave@stgolabs.net>
      Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
      Cc: Christoph Hellwig <hch@infradead.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b5cec28d
    • Mike Kravetz's avatar
      mm/hugetlb: expose hugetlb fault mutex for use by fallocate · c672c7f2
      Mike Kravetz authored
      
      
      hugetlb page faults are currently synchronized by the table of mutexes
      (htlb_fault_mutex_table).  fallocate code will need to synchronize with
      the page fault code when it allocates or deletes pages.  Expose
      interfaces so that fallocate operations can be synchronized with page
      faults.  Minor name changes to be more consistent with other global
      hugetlb symbols.
      Signed-off-by: default avatarMike Kravetz <mike.kravetz@oracle.com>
      Reviewed-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Acked-by: default avatarHillf Danton <hillf.zj@alibaba-inc.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Davidlohr Bueso <dave@stgolabs.net>
      Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
      Cc: Christoph Hellwig <hch@infradead.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c672c7f2
    • Mike Kravetz's avatar
      mm/hugetlb: add cache of descriptors to resv_map for region_add · 5e911373
      Mike Kravetz authored
      
      
      hugetlbfs is used today by applications that want a high degree of
      control over huge page usage.  Often, large hugetlbfs files are used to
      map a large number huge pages into the application processes.  The
      applications know when page ranges within these large files will no
      longer be used, and ideally would like to release them back to the
      subpool or global pools for other uses.  The fallocate() system call
      provides an interface for preallocation and hole punching within files.
      This patch set adds fallocate functionality to hugetlbfs.
      
      fallocate hole punch will want to remove a specific range of pages.
      When pages are removed, their associated entries in the region/reserve
      map will also be removed.  This will break an assumption in the
      region_chg/region_add calling sequence.  If a new region descriptor must
      be allocated, it is done as part of the region_chg processing.  In this
      way, region_add can not fail because it does not need to attempt an
      allocation.
      
      To prepare for fallocate hole punch, create a "cache" of descriptors
      that can be used by region_add if necessary.  region_chg will ensure
      there are sufficient entries in the cache.  It will be necessary to
      track the number of in progress add operations to know a sufficient
      number of descriptors reside in the cache.  A new routine region_abort
      is added to adjust this in progress count when add operations are
      aborted.  vma_abort_reservation is also added for callers creating
      reservations with vma_needs_reservation/vma_commit_reservation.
      
      [akpm@linux-foundation.org: fix typo in comment, use more cols]
      Signed-off-by: default avatarMike Kravetz <mike.kravetz@oracle.com>
      Reviewed-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Acked-by: default avatarHillf Danton <hillf.zj@alibaba-inc.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Davidlohr Bueso <dave@stgolabs.net>
      Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
      Cc: Christoph Hellwig <hch@infradead.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5e911373
  12. 17 Jul, 2015 1 commit
  13. 15 Apr, 2015 4 commits
    • Naoya Horiguchi's avatar
      mm: hugetlb: cleanup using paeg_huge_active() · 7e1f049e
      Naoya Horiguchi authored
      
      
      Now we have an easy access to hugepages' activeness, so existing helpers to
      get the information can be cleaned up.
      
      [akpm@linux-foundation.org: s/PageHugeActive/page_huge_active/]
      Signed-off-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: Hugh Dickins <hughd@google.com>
      Reviewed-by: default avatarMichal Hocko <mhocko@suse.cz>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: David Rientjes <rientjes@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      7e1f049e
    • Mike Kravetz's avatar
      hugetlbfs: accept subpool min_size mount option and setup accordingly · 7ca02d0a
      Mike Kravetz authored
      
      
      Make 'min_size=<value>' be an option when mounting a hugetlbfs.  This
      option takes the same value as the 'size' option.  min_size can be
      specified without specifying size.  If both are specified, min_size must
      be less that or equal to size else the mount will fail.  If min_size is
      specified, then at mount time an attempt is made to reserve min_size
      pages.  If the reservation fails, the mount fails.  At umount time, the
      reserved pages are released.
      Signed-off-by: default avatarMike Kravetz <mike.kravetz@oracle.com>
      Cc: Davidlohr Bueso <dave@stgolabs.net>
      Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: David Rientjes <rientjes@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      7ca02d0a
    • Mike Kravetz's avatar
      hugetlbfs: add minimum size tracking fields to subpool structure · c6a91820
      Mike Kravetz authored
      
      
      hugetlbfs allocates huge pages from the global pool as needed.  Even if
      the global pool contains a sufficient number pages for the filesystem size
      at mount time, those global pages could be grabbed for some other use.  As
      a result, filesystem huge page allocations may fail due to lack of pages.
      
      Applications such as a database want to use huge pages for performance
      reasons.  hugetlbfs filesystem semantics with ownership and modes work
      well to manage access to a pool of huge pages.  However, the application
      would like some reasonable assurance that allocations will not fail due to
      a lack of huge pages.  At application startup time, the application would
      like to configure itself to use a specific number of huge pages.  Before
      starting, the application can check to make sure that enough huge pages
      exist in the system global pools.  However, there are no guarantees that
      those pages will be available when needed by the application.  What the
      application wants is exclusive use of a subset of huge pages.
      
      Add a new hugetlbfs mount option 'min_size=<value>' to indicate that the
      specified number of pages will be available for use by the filesystem.  At
      mount time, this number of huge pages will be reserved for exclusive use
      of the filesystem.  If there is not a sufficient number of free pages, the
      mount will fail.  As pages are allocated to and freeed from the
      filesystem, the number of reserved pages is adjusted so that the specified
      minimum is maintained.
      
      This patch (of 4):
      
      Add a field to the subpool structure to indicate the minimimum number of
      huge pages to always be used by this subpool.  This minimum count includes
      allocated pages as well as reserved pages.  If the minimum number of pages
      for the subpool have not been allocated, pages are reserved up to this
      minimum.  An additional field (rsv_hpages) is used to track the number of
      pages reserved to meet this minimum size.  The hstate pointer in the
      subpool is convenient to have when reserving and unreserving the pages.
      Signed-off-by: default avatarMike Kravetz <mike.kravetz@oracle.com>
      Cc: Davidlohr Bueso <dave@stgolabs.net>
      Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: David Rientjes <rientjes@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c6a91820
    • Kirill A. Shutemov's avatar
      mm: consolidate all page-flags helpers in <linux/page-flags.h> · e8c6158f
      Kirill A. Shutemov authored
      
      
      Currently we take a naive approach to page flags on compound pages - we
      set the flag on the page without consideration if the flag makes sense
      for tail page or for compound page in general.  This patchset try to
      sort this out by defining per-flag policy on what need to be done if
      page-flag helper operate on compound page.
      
      The last patch in the patchset also sanitizes usege of page->mapping for
      tail pages.  We don't define the meaning of page->mapping for tail
      pages.  Currently it's always NULL, which can be inconsistent with head
      page and potentially lead to problems.
      
      For now I caught one case of illegal usage of page flags or ->mapping:
      sound subsystem allocates pages with __GFP_COMP and maps them with PTEs.
      It leads to setting dirty bit on tail pages and access to tail_page's
      ->mapping.  I don't see any bad behaviour caused by this, but worth
      fixing anyway.
      
      This patchset makes more sense if you take my THP refcounting into
      account: we will see more compound pages mapped with PTEs and we need to
      define behaviour of flags on compound pages to avoid bugs.
      
      This patch (of 16):
      
      We have page-flags helper function declarations/definitions spread over
      several header files.  Let's consolidate them in <linux/page-flags.h>.
      Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Acked-by: default avatarHugh Dickins <hughd@google.com>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: Steve Capper <steve.capper@linaro.org>
      Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Jerome Marchand <jmarchan@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e8c6158f
  14. 12 Feb, 2015 1 commit
    • Naoya Horiguchi's avatar
      mm/hugetlb: take page table lock in follow_huge_pmd() · e66f17ff
      Naoya Horiguchi authored
      We have a race condition between move_pages() and freeing hugepages, where
      move_pages() calls follow_page(FOLL_GET) for hugepages internally and
      tries to get its refcount without preventing concurrent freeing.  This
      race crashes the kernel, so this patch fixes it by moving FOLL_GET code
      for hugepages into follow_huge_pmd() with taking the page table lock.
      
      This patch intentionally removes page==NULL check after pte_page.
      This is justified because pte_page() never returns NULL for any
      architectures or configurations.
      
      This patch changes the behavior of follow_huge_pmd() for tail pages and
      then tail pages can be pinned/returned.  So the caller must be changed to
      properly handle the returned tail pages.
      
      We could have a choice to add the similar locking to
      follow_huge_(addr|pud) for consistency, but it's not necessary because
      currently these functions don't support FOLL_GET flag, so let's leave it
      for future development.
      
      Here is the reproducer:
      
        $ cat movepages.c
        #include <stdio.h>
        #include <stdlib.h>
        #include <numaif.h>
      
        #define ADDR_INPUT      0x700000000000UL
        #define HPS             0x200000
        #define PS              0x1000
      
        int main(int argc, char *argv[]) {
                int i;
                int nr_hp = strtol(argv[1], NULL, 0);
                int nr_p  = nr_hp * HPS / PS;
                int ret;
                void **addrs;
                int *status;
                int *nodes;
                pid_t pid;
      
                pid = strtol(argv[2], NULL, 0);
                addrs  = malloc(sizeof(char *) * nr_p + 1);
                status = malloc(sizeof(char *) * nr_p + 1);
                nodes  = malloc(sizeof(char *) * nr_p + 1);
      
                while (1) {
                        for (i = 0; i < nr_p; i++) {
                                addrs[i] = (void *)ADDR_INPUT + i * PS;
                                nodes[i] = 1;
                                status[i] = 0;
                        }
                        ret = numa_move_pages(pid, nr_p, addrs, nodes, status,
                                              MPOL_MF_MOVE_ALL);
                        if (ret == -1)
                                err("move_pages");
      
                        for (i = 0; i < nr_p; i++) {
                                addrs[i] = (void *)ADDR_INPUT + i * PS;
                                nodes[i] = 0;
                                status[i] = 0;
                        }
                        ret = numa_move_pages(pid, nr_p, addrs, nodes, status,
                                              MPOL_MF_MOVE_ALL);
                        if (ret == -1)
                                err("move_pages");
                }
                return 0;
        }
      
        $ cat hugepage.c
        #include <stdio.h>
        #include <sys/mman.h>
        #include <string.h>
      
        #define ADDR_INPUT      0x700000000000UL
        #define HPS             0x200000
      
        int main(int argc, char *argv[]) {
                int nr_hp = strtol(argv[1], NULL, 0);
                char *p;
      
                while (1) {
                        p = mmap((void *)ADDR_INPUT, nr_hp * HPS, PROT_READ | PROT_WRITE,
                                 MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, -1, 0);
                        if (p != (void *)ADDR_INPUT) {
                                perror("mmap");
                                break;
                        }
                        memset(p, 0, nr_hp * HPS);
                        munmap(p, nr_hp * HPS);
                }
        }
      
        $ sysctl vm.nr_hugepages=40
        $ ./hugepage 10 &
        $ ./movepages 10 $(pgrep -f hugepage)
      
      Fixes: e632a938
      
       ("mm: migrate: add hugepage migration code to move_pages()")
      Signed-off-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Reported-by: default avatarHugh Dickins <hughd@google.com>
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Luiz Capitulino <lcapitulino@redhat.com>
      Cc: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
      Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
      Cc: Steve Capper <steve.capper@linaro.org>
      Cc: <stable@vger.kernel.org>	[3.12+]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e66f17ff
  15. 10 Feb, 2015 1 commit
  16. 11 Dec, 2014 1 commit
  17. 14 Nov, 2014 1 commit
  18. 07 Aug, 2014 1 commit
  19. 31 Jul, 2014 1 commit
    • Atsushi Kumagai's avatar
      kexec: export free_huge_page to VMCOREINFO · 8f1d26d0
      Atsushi Kumagai authored
      PG_head_mask was added into VMCOREINFO to filter huge pages in b3acc56b
      
      
      ("kexec: save PG_head_mask in VMCOREINFO"), but makedumpfile still need
      another symbol to filter *hugetlbfs* pages.
      
      If a user hope to filter user pages, makedumpfile tries to exclude them by
      checking the condition whether the page is anonymous, but hugetlbfs pages
      aren't anonymous while they also be user pages.
      
      We know it's possible to detect them in the same way as PageHuge(),
      so we need the start address of free_huge_page():
      
          int PageHuge(struct page *page)
          {
                  if (!PageCompound(page))
                          return 0;
      
                  page = compound_head(page);
                  return get_compound_page_dtor(page) == free_huge_page;
          }
      
      For that reason, this patch changes free_huge_page() into public
      to export it to VMCOREINFO.
      Signed-off-by: default avatarAtsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp>
      Acked-by: default avatarBaoquan He <bhe@redhat.com>
      Cc: Vivek Goyal <vgoyal@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8f1d26d0
  20. 04 Jun, 2014 3 commits
  21. 06 May, 2014 1 commit
    • Nishanth Aravamudan's avatar
      hugetlb: ensure hugepage access is denied if hugepages are not supported · 457c1b27
      Nishanth Aravamudan authored
      
      
      Currently, I am seeing the following when I `mount -t hugetlbfs /none
      /dev/hugetlbfs`, and then simply do a `ls /dev/hugetlbfs`.  I think it's
      related to the fact that hugetlbfs is properly not correctly setting
      itself up in this state?:
      
        Unable to handle kernel paging request for data at address 0x00000031
        Faulting instruction address: 0xc000000000245710
        Oops: Kernel access of bad area, sig: 11 [#1]
        SMP NR_CPUS=2048 NUMA pSeries
        ....
      
      In KVM guests on Power, in a guest not backed by hugepages, we see the
      following:
      
        AnonHugePages:         0 kB
        HugePages_Total:       0
        HugePages_Free:        0
        HugePages_Rsvd:        0
        HugePages_Surp:        0
        Hugepagesize:         64 kB
      
      HPAGE_SHIFT == 0 in this configuration, which indicates that hugepages
      are not supported at boot-time, but this is only checked in
      hugetlb_init().  Extract the check to a helper function, and use it in a
      few relevant places.
      
      This does make hugetlbfs not supported (not registered at all) in this
      environment.  I believe this is fine, as there are no valid hugepages
      and that won't change at runtime.
      
      [akpm@linux-foundation.org: use pr_info(), per Mel]
      [akpm@linux-foundation.org: fix build when HPAGE_SHIFT is undefined]
      Signed-off-by: default avatarNishanth Aravamudan <nacc@linux.vnet.ibm.com>
      Reviewed-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      Acked-by: default avatarMel Gorman <mgorman@suse.de>
      Cc: Randy Dunlap <rdunlap@infradead.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      457c1b27
  22. 03 Apr, 2014 2 commits