1. 07 11月, 2014 2 次提交
  2. 06 11月, 2014 17 次提交
  3. 31 10月, 2014 5 次提交
  4. 30 10月, 2014 4 次提交
    • J
      mm: memcontrol: fix missed end-writeback page accounting · d7365e78
      Johannes Weiner 提交于
      Commit 0a31bc97 ("mm: memcontrol: rewrite uncharge API") changed
      page migration to uncharge the old page right away.  The page is locked,
      unmapped, truncated, and off the LRU, but it could race with writeback
      ending, which then doesn't unaccount the page properly:
      
      test_clear_page_writeback()              migration
                                                 wait_on_page_writeback()
        TestClearPageWriteback()
                                                 mem_cgroup_migrate()
                                                   clear PCG_USED
        mem_cgroup_update_page_stat()
          if (PageCgroupUsed(pc))
            decrease memcg pages under writeback
      
        release pc->mem_cgroup->move_lock
      
      The per-page statistics interface is heavily optimized to avoid a
      function call and a lookup_page_cgroup() in the file unmap fast path,
      which means it doesn't verify whether a page is still charged before
      clearing PageWriteback() and it has to do it in the stat update later.
      
      Rework it so that it looks up the page's memcg once at the beginning of
      the transaction and then uses it throughout.  The charge will be
      verified before clearing PageWriteback() and migration can't uncharge
      the page as long as that is still set.  The RCU lock will protect the
      memcg past uncharge.
      
      As far as losing the optimization goes, the following test results are
      from a microbenchmark that maps, faults, and unmaps a 4GB sparse file
      three times in a nested fashion, so that there are two negative passes
      that don't account but still go through the new transaction overhead.
      There is no actual difference:
      
       old:     33.195102545 seconds time elapsed       ( +-  0.01% )
       new:     33.199231369 seconds time elapsed       ( +-  0.03% )
      
      The time spent in page_remove_rmap()'s callees still adds up to the
      same, but the time spent in the function itself seems reduced:
      
           # Children      Self  Command        Shared Object       Symbol
       old:     0.12%     0.11%  filemapstress  [kernel.kallsyms]   [k] page_remove_rmap
       new:     0.12%     0.08%  filemapstress  [kernel.kallsyms]   [k] page_remove_rmap
      Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
      Acked-by: NMichal Hocko <mhocko@suse.cz>
      Cc: Vladimir Davydov <vdavydov@parallels.com>
      Cc: <stable@vger.kernel.org>	[3.17.x]
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d7365e78
    • J
      mm: page-writeback: inline account_page_dirtied() into single caller · 3a3c02ec
      Johannes Weiner 提交于
      A follow-up patch would have changed the call signature.  To save the
      trouble, just fold it instead.
      Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
      Acked-by: NMichal Hocko <mhocko@suse.cz>
      Cc: Vladimir Davydov <vdavydov@parallels.com>
      Cc: <stable@vger.kernel.org>	[3.17.x]
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      3a3c02ec
    • D
      mm, thp: fix collapsing of hugepages on madvise · 6d50e60c
      David Rientjes 提交于
      If an anonymous mapping is not allowed to fault thp memory and then
      madvise(MADV_HUGEPAGE) is used after fault, khugepaged will never
      collapse this memory into thp memory.
      
      This occurs because the madvise(2) handler for thp, hugepage_madvise(),
      clears VM_NOHUGEPAGE on the stack and it isn't stored in vma->vm_flags
      until the final action of madvise_behavior().  This causes the
      khugepaged_enter_vma_merge() to be a no-op in hugepage_madvise() when
      the vma had previously had VM_NOHUGEPAGE set.
      
      Fix this by passing the correct vma flags to the khugepaged mm slot
      handler.  There's no chance khugepaged can run on this vma until after
      madvise_behavior() returns since we hold mm->mmap_sem.
      
      It would be possible to clear VM_NOHUGEPAGE directly from vma->vm_flags
      in hugepage_advise(), but I didn't want to introduce special case
      behavior into madvise_behavior().  I think it's best to just let it
      always set vma->vm_flags itself.
      Signed-off-by: NDavid Rientjes <rientjes@google.com>
      Reported-by: NSuleiman Souhlal <suleiman@google.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      6d50e60c
    • M
      drivers: of: add return value to of_reserved_mem_device_init() · 47f29df7
      Marek Szyprowski 提交于
      Driver calling of_reserved_mem_device_init() might be interested if the
      initialization has been successful or not, so add support for returning
      error code.
      
      This fixes a build warining caused by commit 7bfa5ab6 ("drivers:
      dma-coherent: add initialization from device tree"), which has been
      merged without this change and without fixing function return value.
      
      Fixes: 7bfa5ab6 ("drivers: dma-coherent: add initialization from device tree")
      Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
      Acked-by: NArnd Bergmann <arnd@arndb.de>
      Cc: Michal Nazarewicz <mina86@mina86.com>
      Cc: Grant Likely <grant.likely@linaro.org>
      Cc: Laura Abbott <lauraa@codeaurora.org>
      Cc: Josh Cartwright <joshc@codeaurora.org>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Kyungmin Park <kyungmin.park@samsung.com>
      Cc: Russell King <rmk+kernel@arm.linux.org.uk>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      47f29df7
  5. 29 10月, 2014 6 次提交
  6. 28 10月, 2014 6 次提交