1. 27 Mar, 2015 21 commits
  2. 26 Mar, 2015 14 commits
  3. 25 Mar, 2015 5 commits
    • Linus Torvalds's avatar
      Merge tag 'metag-fixes-v4.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag · 4c4fe4c2
      Linus Torvalds authored
      Pull arch/metag fix from James Hogan:
       "Another metag architecture fix for v4.0
      
        This is another single fix, for an include dependency problem when
        using ioremap_wc() from asm/io.h without also including asm/pgtable.h"
      
      * tag 'metag-fixes-v4.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag:
        metag: Fix ioremap_wc/ioremap_cached build errors
      4c4fe4c2
    • Linus Torvalds's avatar
      Merge branch 'akpm' (patches from Andrew) · 9c8e30d1
      Linus Torvalds authored
      Merge misc fixes from Andrew Morton:
       "15 fixes"
      
      * emailed patches from Andrew Morton <akpm@linux-foundation.org>:
        mm: numa: mark huge PTEs young when clearing NUMA hinting faults
        mm: numa: slow PTE scan rate if migration failures occur
        mm: numa: preserve PTE write permissions across a NUMA hinting fault
        mm: numa: group related processes based on VMA flags instead of page table flags
        hfsplus: fix B-tree corruption after insertion at position 0
        MAINTAINERS: add Jan as DMI/SMBIOS support maintainer
        fs/affs/file.c: unlock/release page on error
        mm/page_alloc.c: call kernel_map_pages in unset_migrateype_isolate
        mm/slub: fix lockups on PREEMPT && !SMP kernels
        mm/memory hotplug: postpone the reset of obsolete pgdat
        MAINTAINERS: correct rtc armada38x pattern entry
        mm/pagewalk.c: prevent positive return value of walk_page_test() from being passed to callers
        mm: fix anon_vma->degree underflow in anon_vma endless growing prevention
        drivers/rtc/rtc-mrst: fix suspend/resume
        aoe: update aoe maintainer information
      9c8e30d1
    • Mel Gorman's avatar
      mm: numa: mark huge PTEs young when clearing NUMA hinting faults · b7b04004
      Mel Gorman authored
      Base PTEs are marked young when the NUMA hinting information is cleared
      but the same does not happen for huge pages which this patch addresses.
      
      Note that migrated pages are not marked young as the base page migration
      code does not assume that migrated pages have been referenced.  This
      could be addressed but beyond the scope of this series which is aimed at
      Dave Chinners shrink workload that is unlikely to be affected by this
      issue.
      Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
      Cc: Dave Chinner <david@fromorbit.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b7b04004
    • Mel Gorman's avatar
      mm: numa: slow PTE scan rate if migration failures occur · 074c2381
      Mel Gorman authored
      Dave Chinner reported the following on https://lkml.org/lkml/2015/3/1/226
      
        Across the board the 4.0-rc1 numbers are much slower, and the degradation
        is far worse when using the large memory footprint configs. Perf points
        straight at the cause - this is from 4.0-rc1 on the "-o bhash=101073" config:
      
         -   56.07%    56.07%  [kernel]            [k] default_send_IPI_mask_sequence_phys
            - default_send_IPI_mask_sequence_phys
               - 99.99% physflat_send_IPI_mask
                  - 99.37% native_send_call_func_ipi
                       smp_call_function_many
                     - native_flush_tlb_others
                        - 99.85% flush_tlb_page
                             ptep_clear_flush
                             try_to_unmap_one
                             rmap_walk
                             try_to_unmap
                             migrate_pages
                             migrate_misplaced_page
                           - handle_mm_fault
                              - 99.73% __do_page_fault
                                   trace_do_page_fault
                                   do_async_page_fault
                                 + async_page_fault
                    0.63% native_send_call_func_single_ipi
                       generic_exec_single
                       smp_call_function_single
      
      This is showing excessive migration activity even though excessive
      migrations are meant to get throttled.  Normally, the scan rate is tuned
      on a per-task basis depending on the locality of faults.  However, if
      migrations fail for any reason then the PTE scanner may scan faster if
      the faults continue to be remote.  This means there is higher system CPU
      overhead and fault trapping at exactly the time we know that migrations
      cannot happen.  This patch tracks when migration failures occur and
      slows the PTE scanner.
      Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
      Reported-by: default avatarDave Chinner <david@fromorbit.com>
      Tested-by: default avatarDave Chinner <david@fromorbit.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      074c2381
    • Mel Gorman's avatar
      mm: numa: preserve PTE write permissions across a NUMA hinting fault · b191f9b1
      Mel Gorman authored
      Protecting a PTE to trap a NUMA hinting fault clears the writable bit
      and further faults are needed after trapping a NUMA hinting fault to set
      the writable bit again.  This patch preserves the writable bit when
      trapping NUMA hinting faults.  The impact is obvious from the number of
      minor faults trapped during the basis balancing benchmark and the system
      CPU usage;
      
        autonumabench
                                                   4.0.0-rc4             4.0.0-rc4
                                                    baseline              preserve
        Time System-NUMA01                  107.13 (  0.00%)      103.13 (  3.73%)
        Time System-NUMA01_THEADLOCAL       131.87 (  0.00%)       83.30 ( 36.83%)
        Time System-NUMA02                    8.95 (  0.00%)       10.72 (-19.78%)
        Time System-NUMA02_SMT                4.57 (  0.00%)        3.99 ( 12.69%)
        Time Elapsed-NUMA01                 515.78 (  0.00%)      517.26 ( -0.29%)
        Time Elapsed-NUMA01_THEADLOCAL      384.10 (  0.00%)      384.31 ( -0.05%)
        Time Elapsed-NUMA02                  48.86 (  0.00%)       48.78 (  0.16%)
        Time Elapsed-NUMA02_SMT              47.98 (  0.00%)       48.12 ( -0.29%)
      
                     4.0.0-rc4   4.0.0-rc4
                      baseline    preserve
        User          44383.95    43971.89
        System          252.61      201.24
        Elapsed         998.68     1000.94
      
        Minor Faults   2597249     1981230
        Major Faults       365         364
      
      There is a similar drop in system CPU usage using Dave Chinner's xfsrepair
      workload
      
                                            4.0.0-rc4             4.0.0-rc4
                                             baseline              preserve
        Amean    real-xfsrepair      454.14 (  0.00%)      442.36 (  2.60%)
        Amean    syst-xfsrepair      277.20 (  0.00%)      204.68 ( 26.16%)
      
      The patch looks hacky but the alternatives looked worse.  The tidest was
      to rewalk the page tables after a hinting fault but it was more complex
      than this approach and the performance was worse.  It's not generally
      safe to just mark the page writable during the fault if it's a write
      fault as it may have been read-only for COW so that approach was
      discarded.
      Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
      Reported-by: default avatarDave Chinner <david@fromorbit.com>
      Tested-by: default avatarDave Chinner <david@fromorbit.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b191f9b1