1. 22 1月, 2014 40 次提交
    • V
      mm: compaction: reset cached scanner pfn's before reading them · d3132e4b
      Vlastimil Babka 提交于
      Compaction caches pfn's for its migrate and free scanners to avoid
      scanning the whole zone each time.  In compact_zone(), the cached values
      are read to set up initial values for the scanners.  There are several
      situations when these cached pfn's are reset to the first and last pfn
      of the zone, respectively.  One of these situations is when a compaction
      has been deferred for a zone and is now being restarted during a direct
      compaction, which is also done in compact_zone().
      
      However, compact_zone() currently reads the cached pfn's *before*
      resetting them.  This means the reset doesn't affect the compaction that
      performs it, and with good chance also subsequent compactions, as
      update_pageblock_skip() is likely to be called and update the cached
      pfn's to those being processed.  Another chance for a successful reset
      is when a direct compaction detects that migration and free scanners
      meet (which has its own problems addressed by another patch) and sets
      update_pageblock_skip flag which kswapd uses to do the reset because it
      goes to sleep.
      
      This is clearly a bug that results in non-deterministic behavior, so
      this patch moves the cached pfn reset to be performed *before* the
      values are read.
      Signed-off-by: NVlastimil Babka <vbabka@suse.cz>
      Acked-by: NMel Gorman <mgorman@suse.de>
      Acked-by: NRik van Riel <riel@redhat.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d3132e4b
    • V
      mm: compaction: encapsulate defer reset logic · de6c60a6
      Vlastimil Babka 提交于
      Currently there are several functions to manipulate the deferred
      compaction state variables.  The remaining case where the variables are
      touched directly is when a successful allocation occurs in direct
      compaction, or is expected to be successful in the future by kswapd.
      Here, the lowest order that is expected to fail is updated, and in the
      case of successful allocation, the deferred status and counter is reset
      completely.
      
      Create a new function compaction_defer_reset() to encapsulate this
      functionality and make it easier to understand the code.  No functional
      change.
      Signed-off-by: NVlastimil Babka <vbabka@suse.cz>
      Acked-by: NMel Gorman <mgorman@suse.de>
      Reviewed-by: NRik van Riel <riel@redhat.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      de6c60a6
    • M
      mm: compaction: trace compaction begin and end · 0eb927c0
      Mel Gorman 提交于
      The broad goal of the series is to improve allocation success rates for
      huge pages through memory compaction, while trying not to increase the
      compaction overhead.  The original objective was to reintroduce
      capturing of high-order pages freed by the compaction, before they are
      split by concurrent activity.  However, several bugs and opportunities
      for simple improvements were found in the current implementation, mostly
      through extra tracepoints (which are however too ugly for now to be
      considered for sending).
      
      The patches mostly deal with two mechanisms that reduce compaction
      overhead, which is caching the progress of migrate and free scanners,
      and marking pageblocks where isolation failed to be skipped during
      further scans.
      
      Patch 1 (from mgorman) adds tracepoints that allow calculate time spent in
              compaction and potentially debug scanner pfn values.
      
      Patch 2 encapsulates the some functionality for handling deferred compactions
              for better maintainability, without a functional change
              type is not determined without being actually needed.
      
      Patch 3 fixes a bug where cached scanner pfn's are sometimes reset only after
              they have been read to initialize a compaction run.
      
      Patch 4 fixes a bug where scanners meeting is sometimes not properly detected
              and can lead to multiple compaction attempts quitting early without
              doing any work.
      
      Patch 5 improves the chances of sync compaction to process pageblocks that
              async compaction has skipped due to being !MIGRATE_MOVABLE.
      
      Patch 6 improves the chances of sync direct compaction to actually do anything
              when called after async compaction fails during allocation slowpath.
      
      The impact of patches were validated using mmtests's stress-highalloc
      benchmark with mmtests's stress-highalloc benchmark on a x86_64 machine
      with 4GB memory.
      
      Due to instability of the results (mostly related to the bugs fixed by
      patches 2 and 3), 10 iterations were performed, taking min,mean,max
      values for success rates and mean values for time and vmstat-based
      metrics.
      
      First, the default GFP_HIGHUSER_MOVABLE allocations were tested with the
      patches stacked on top of v3.13-rc2.  Patch 2 is OK to serve as baseline
      due to no functional changes in 1 and 2.  Comments below.
      
      stress-highalloc
                                   3.13-rc2              3.13-rc2              3.13-rc2              3.13-rc2              3.13-rc2
                                    2-nothp               3-nothp               4-nothp               5-nothp               6-nothp
      Success 1 Min          9.00 (  0.00%)       10.00 (-11.11%)       43.00 (-377.78%)       43.00 (-377.78%)       33.00 (-266.67%)
      Success 1 Mean        27.50 (  0.00%)       25.30 (  8.00%)       45.50 (-65.45%)       45.90 (-66.91%)       46.30 (-68.36%)
      Success 1 Max         36.00 (  0.00%)       36.00 (  0.00%)       47.00 (-30.56%)       48.00 (-33.33%)       52.00 (-44.44%)
      Success 2 Min         10.00 (  0.00%)        8.00 ( 20.00%)       46.00 (-360.00%)       45.00 (-350.00%)       35.00 (-250.00%)
      Success 2 Mean        26.40 (  0.00%)       23.50 ( 10.98%)       47.30 (-79.17%)       47.60 (-80.30%)       48.10 (-82.20%)
      Success 2 Max         34.00 (  0.00%)       33.00 (  2.94%)       48.00 (-41.18%)       50.00 (-47.06%)       54.00 (-58.82%)
      Success 3 Min         65.00 (  0.00%)       63.00 (  3.08%)       85.00 (-30.77%)       84.00 (-29.23%)       85.00 (-30.77%)
      Success 3 Mean        76.70 (  0.00%)       70.50 (  8.08%)       86.20 (-12.39%)       85.50 (-11.47%)       86.00 (-12.13%)
      Success 3 Max         87.00 (  0.00%)       86.00 (  1.15%)       88.00 ( -1.15%)       87.00 (  0.00%)       87.00 (  0.00%)
      
                  3.13-rc2    3.13-rc2    3.13-rc2    3.13-rc2    3.13-rc2
                   2-nothp     3-nothp     4-nothp     5-nothp     6-nothp
      User         6437.72     6459.76     5960.32     5974.55     6019.67
      System       1049.65     1049.09     1029.32     1031.47     1032.31
      Elapsed      1856.77     1874.48     1949.97     1994.22     1983.15
      
                                    3.13-rc2    3.13-rc2    3.13-rc2    3.13-rc2    3.13-rc2
                                     2-nothp     3-nothp     4-nothp     5-nothp     6-nothp
      Minor Faults                 253952267   254581900   250030122   250507333   250157829
      Major Faults                       420         407         506         530         530
      Swap Ins                             4           9           9           6           6
      Swap Outs                          398         375         345         346         333
      Direct pages scanned            197538      189017      298574      287019      299063
      Kswapd pages scanned           1809843     1801308     1846674     1873184     1861089
      Kswapd pages reclaimed         1806972     1798684     1844219     1870509     1858622
      Direct pages reclaimed          197227      188829      298380      286822      298835
      Kswapd efficiency                  99%         99%         99%         99%         99%
      Kswapd velocity                953.382     970.449     952.243     934.569     922.286
      Direct efficiency                  99%         99%         99%         99%         99%
      Direct velocity                104.058     101.832     153.961     143.200     148.205
      Percentage direct scans             9%          9%         13%         13%         13%
      Zone normal velocity           347.289     359.676     348.063     339.933     332.983
      Zone dma32 velocity            710.151     712.605     758.140     737.835     737.507
      Zone dma velocity                0.000       0.000       0.000       0.000       0.000
      Page writes by reclaim         557.600     429.000     353.600     426.400     381.800
      Page writes file                   159          53           7          79          48
      Page writes anon                   398         375         345         346         333
      Page reclaim immediate             825         644         411         575         420
      Sector Reads                   2781750     2769780     2878547     2939128     2910483
      Sector Writes                 12080843    12083351    12012892    12002132    12010745
      Page rescued immediate               0           0           0           0           0
      Slabs scanned                  1575654     1545344     1778406     1786700     1794073
      Direct inode steals               9657       10037       15795       14104       14645
      Kswapd inode steals              46857       46335       50543       50716       51796
      Kswapd skipped wait                  0           0           0           0           0
      THP fault alloc                     97          91          81          71          77
      THP collapse alloc                 456         506         546         544         565
      THP splits                           6           5           5           4           4
      THP fault fallback                   0           1           0           0           0
      THP collapse fail                   14          14          12          13          12
      Compaction stalls                 1006         980        1537        1536        1548
      Compaction success                 303         284         562         559         578
      Compaction failures                702         696         974         976         969
      Page migrate success           1177325     1070077     3927538     3781870     3877057
      Page migrate failure                 0           0           0           0           0
      Compaction pages isolated      2547248     2306457     8301218     8008500     8200674
      Compaction migrate scanned    42290478    38832618   153961130   154143900   159141197
      Compaction free scanned       89199429    79189151   356529027   351943166   356326727
      Compaction cost                   1566        1426        5312        5156        5294
      NUMA PTE updates                     0           0           0           0           0
      NUMA hint faults                     0           0           0           0           0
      NUMA hint local faults               0           0           0           0           0
      NUMA hint local percent            100         100         100         100         100
      NUMA pages migrated                  0           0           0           0           0
      AutoNUMA cost                        0           0           0           0           0
      
      Observations:
      
      - The "Success 3" line is allocation success rate with system idle
        (phases 1 and 2 are with background interference).  I used to get stable
        values around 85% with vanilla 3.11.  The lower min and mean values came
        with 3.12.  This was bisected to commit 81c0a2bb ("mm: page_alloc: fair
        zone allocator policy") As explained in comment for patch 3, I don't
        think the commit is wrong, but that it makes the effect of compaction
        bugs worse.  From patch 3 onwards, the results are OK and match the 3.11
        results.
      
      - Patch 4 also clearly helps phases 1 and 2, and exceeds any results
        I've seen with 3.11 (I didn't measure it that thoroughly then, but it
        was never above 40%).
      
      - Compaction cost and number of scanned pages is higher, especially due
        to patch 4.  However, keep in mind that patches 3 and 4 fix existing
        bugs in the current design of compaction overhead mitigation, they do
        not change it.  If overhead is found unacceptable, then it should be
        decreased differently (and consistently, not due to random conditions)
        than the current implementation does.  In contrast, patches 5 and 6
        (which are not strictly bug fixes) do not increase the overhead (but
        also not success rates).  This might be a limitation of the
        stress-highalloc benchmark as it's quite uniform.
      
      Another set of results is when configuring stress-highalloc t allocate
      with similar flags as THP uses:
       (GFP_HIGHUSER_MOVABLE|__GFP_NOMEMALLOC|__GFP_NORETRY|__GFP_NO_KSWAPD)
      
      stress-highalloc
                                   3.13-rc2              3.13-rc2              3.13-rc2              3.13-rc2              3.13-rc2
                                      2-thp                 3-thp                 4-thp                 5-thp                 6-thp
      Success 1 Min          2.00 (  0.00%)        7.00 (-250.00%)       18.00 (-800.00%)       19.00 (-850.00%)       26.00 (-1200.00%)
      Success 1 Mean        19.20 (  0.00%)       17.80 (  7.29%)       29.20 (-52.08%)       29.90 (-55.73%)       32.80 (-70.83%)
      Success 1 Max         27.00 (  0.00%)       29.00 ( -7.41%)       35.00 (-29.63%)       36.00 (-33.33%)       37.00 (-37.04%)
      Success 2 Min          3.00 (  0.00%)        8.00 (-166.67%)       21.00 (-600.00%)       21.00 (-600.00%)       32.00 (-966.67%)
      Success 2 Mean        19.30 (  0.00%)       17.90 (  7.25%)       32.20 (-66.84%)       32.60 (-68.91%)       35.70 (-84.97%)
      Success 2 Max         27.00 (  0.00%)       30.00 (-11.11%)       36.00 (-33.33%)       37.00 (-37.04%)       39.00 (-44.44%)
      Success 3 Min         62.00 (  0.00%)       62.00 (  0.00%)       85.00 (-37.10%)       75.00 (-20.97%)       64.00 ( -3.23%)
      Success 3 Mean        66.30 (  0.00%)       65.50 (  1.21%)       85.60 (-29.11%)       83.40 (-25.79%)       83.50 (-25.94%)
      Success 3 Max         70.00 (  0.00%)       69.00 (  1.43%)       87.00 (-24.29%)       86.00 (-22.86%)       87.00 (-24.29%)
      
                  3.13-rc2    3.13-rc2    3.13-rc2    3.13-rc2    3.13-rc2
                     2-thp       3-thp       4-thp       5-thp       6-thp
      User         6547.93     6475.85     6265.54     6289.46     6189.96
      System       1053.42     1047.28     1043.23     1042.73     1038.73
      Elapsed      1835.43     1821.96     1908.67     1912.74     1956.38
      
                                    3.13-rc2    3.13-rc2    3.13-rc2    3.13-rc2    3.13-rc2
                                       2-thp       3-thp       4-thp       5-thp       6-thp
      Minor Faults                 256805673   253106328   253222299   249830289   251184418
      Major Faults                       395         375         423         434         448
      Swap Ins                            12          10          10          12           9
      Swap Outs                          530         537         487         455         415
      Direct pages scanned             71859       86046      153244      152764      190713
      Kswapd pages scanned           1900994     1870240     1898012     1892864     1880520
      Kswapd pages reclaimed         1897814     1867428     1894939     1890125     1877924
      Direct pages reclaimed           71766       85908      153167      152643      190600
      Kswapd efficiency                  99%         99%         99%         99%         99%
      Kswapd velocity               1029.000    1067.782    1000.091     991.049     951.218
      Direct efficiency                  99%         99%         99%         99%         99%
      Direct velocity                 38.897      49.127      80.747      79.983      96.468
      Percentage direct scans             3%          4%          7%          7%          9%
      Zone normal velocity           351.377     372.494     348.910     341.689     335.310
      Zone dma32 velocity            716.520     744.414     731.928     729.343     712.377
      Zone dma velocity                0.000       0.000       0.000       0.000       0.000
      Page writes by reclaim         669.300     604.000     545.700     538.900     429.900
      Page writes file                   138          66          58          83          14
      Page writes anon                   530         537         487         455         415
      Page reclaim immediate             806         655         772         548         517
      Sector Reads                   2711956     2703239     2811602     2818248     2839459
      Sector Writes                 12163238    12018662    12038248    11954736    11994892
      Page rescued immediate               0           0           0           0           0
      Slabs scanned                  1385088     1388364     1507968     1513292     1558656
      Direct inode steals               1739        2564        4622        5496        6007
      Kswapd inode steals              47461       46406       47804       48013       48466
      Kswapd skipped wait                  0           0           0           0           0
      THP fault alloc                    110          82          84          69          70
      THP collapse alloc                 445         482         467         462         539
      THP splits                           6           5           4           5           3
      THP fault fallback                   3           0           0           0           0
      THP collapse fail                   15          14          14          14          13
      Compaction stalls                  659         685        1033        1073        1111
      Compaction success                 222         225         410         427         456
      Compaction failures                436         460         622         646         655
      Page migrate success            446594      439978     1085640     1095062     1131716
      Page migrate failure                 0           0           0           0           0
      Compaction pages isolated      1029475     1013490     2453074     2482698     2565400
      Compaction migrate scanned     9955461    11344259    24375202    27978356    30494204
      Compaction free scanned       27715272    28544654    80150615    82898631    85756132
      Compaction cost                    552         555        1344        1379        1436
      NUMA PTE updates                     0           0           0           0           0
      NUMA hint faults                     0           0           0           0           0
      NUMA hint local faults               0           0           0           0           0
      NUMA hint local percent            100         100         100         100         100
      NUMA pages migrated                  0           0           0           0           0
      AutoNUMA cost                        0           0           0           0           0
      
      There are some differences from the previous results for THP-like allocations:
      
      - Here, the bad result for unpatched kernel in phase 3 is much more
        consistent to be between 65-70% and not related to the "regression" in
        3.12.  Still there is the improvement from patch 4 onwards, which brings
        it on par with simple GFP_HIGHUSER_MOVABLE allocations.
      
      - Compaction costs have increased, but nowhere near as much as the
        non-THP case.  Again, the patches should be worth the gained
        determininsm.
      
      - Patches 5 and 6 somewhat increase the number of migrate-scanned pages.
         This is most likely due to __GFP_NO_KSWAPD flag, which means the cached
        pfn's and pageblock skip bits are not reset by kswapd that often (at
        least in phase 3 where no concurrent activity would wake up kswapd) and
        the patches thus help the sync-after-async compaction.  It doesn't
        however show that the sync compaction would help so much with success
        rates, which can be again seen as a limitation of the benchmark
        scenario.
      
      This patch (of 6):
      
      Add two tracepoints for compaction begin and end of a zone.  Using this it
      is possible to calculate how much time a workload is spending within
      compaction and potentially debug problems related to cached pfns for
      scanning.  In combination with the direct reclaim and slab trace points it
      should be possible to estimate most allocation-related overhead for a
      workload.
      Signed-off-by: NMel Gorman <mgorman@suse.de>
      Signed-off-by: NVlastimil Babka <vbabka@suse.cz>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0eb927c0
    • M
      memcg, oom: lock mem_cgroup_print_oom_info · 947b3dd1
      Michal Hocko 提交于
      mem_cgroup_print_oom_info uses a static buffer (memcg_name) to store the
      name of the cgroup.  This is not safe as pointed out by David Rientjes
      because memcg oom is locked only for its hierarchy and nothing prevents
      another parallel hierarchy to trigger oom as well and overwrite the
      already in-use buffer.
      
      This patch introduces oom_info_lock hidden inside
      mem_cgroup_print_oom_info which is held throughout the function.  It
      makes access to memcg_name safe and as a bonus it also prevents parallel
      memcg ooms to interleave their statistics which would make the printed
      data hard to analyze otherwise.
      Signed-off-by: NMichal Hocko <mhocko@suse.cz>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Acked-by: NDavid Rientjes <rientjes@google.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      947b3dd1
    • M
      sched: add tracepoints related to NUMA task migration · 286549dc
      Mel Gorman 提交于
      This patch adds three tracepoints
       o trace_sched_move_numa	when a task is moved to a node
       o trace_sched_swap_numa	when a task is swapped with another task
       o trace_sched_stick_numa	when a numa-related migration fails
      
      The tracepoints allow the NUMA scheduler activity to be monitored and the
      following high-level metrics can be calculated
      
       o NUMA migrated stuck	 nr trace_sched_stick_numa
       o NUMA migrated idle	 nr trace_sched_move_numa
       o NUMA migrated swapped nr trace_sched_swap_numa
       o NUMA local swapped	 trace_sched_swap_numa src_nid == dst_nid (should never happen)
       o NUMA remote swapped	 trace_sched_swap_numa src_nid != dst_nid (should == NUMA migrated swapped)
       o NUMA group swapped	 trace_sched_swap_numa src_ngid == dst_ngid
      			 Maybe a small number of these are acceptable
      			 but a high number would be a major surprise.
      			 It would be even worse if bounces are frequent.
       o NUMA avg task migs.	 Average number of migrations for tasks
       o NUMA stddev task mig	 Self-explanatory
       o NUMA max task migs.	 Maximum number of migrations for a single task
      
      In general the intent of the tracepoints is to help diagnose problems
      where automatic NUMA balancing appears to be doing an excessive amount
      of useless work.
      
      [akpm@linux-foundation.org: remove semicolon-after-if, repair coding-style]
      Signed-off-by: NMel Gorman <mgorman@suse.de>
      Reviewed-by: NRik van Riel <riel@redhat.com>
      Cc: Alex Thorlton <athorlton@sgi.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      286549dc
    • M
      mm: numa: do not automatically migrate KSM pages · 64a9a34e
      Mel Gorman 提交于
      KSM pages can be shared between tasks that are not necessarily related
      to each other from a NUMA perspective.  This patch causes those pages to
      be ignored by automatic NUMA balancing so they do not migrate and do not
      cause unrelated tasks to be grouped together.
      Signed-off-by: NMel Gorman <mgorman@suse.de>
      Reviewed-by: NRik van Riel <riel@redhat.com>
      Cc: Alex Thorlton <athorlton@sgi.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      64a9a34e
    • M
      mm: numa: trace tasks that fail migration due to rate limiting · af1839d7
      Mel Gorman 提交于
      A low local/remote numa hinting fault ratio is potentially explained by
      failed migrations.  This patch adds a tracepoint that fires when
      migration fails due to migration rate limitation.
      Signed-off-by: NMel Gorman <mgorman@suse.de>
      Reviewed-by: NRik van Riel <riel@redhat.com>
      Cc: Alex Thorlton <athorlton@sgi.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      af1839d7
    • M
      mm: numa: limit scope of lock for NUMA migrate rate limiting · 1c5e9c27
      Mel Gorman 提交于
      NUMA migrate rate limiting protects a migration counter and window using
      a lock but in some cases this can be a contended lock.  It is not
      critical that the number of pages be perfect, lost updates are
      acceptable.  Reduce the importance of this lock.
      Signed-off-by: NMel Gorman <mgorman@suse.de>
      Reviewed-by: NRik van Riel <riel@redhat.com>
      Cc: Alex Thorlton <athorlton@sgi.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1c5e9c27
    • M
      mm: numa: make NUMA-migrate related functions static · 1c30e017
      Mel Gorman 提交于
      numamigrate_update_ratelimit and numamigrate_isolate_page only have
      callers in mm/migrate.c.  This patch makes them static.
      Signed-off-by: NMel Gorman <mgorman@suse.de>
      Reviewed-by: NRik van Riel <riel@redhat.com>
      Cc: Alex Thorlton <athorlton@sgi.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1c30e017
    • X
      lib/show_mem.c: show num_poisoned_pages when oom · 25487d73
      Xishi Qiu 提交于
      Show num_poisoned_pages when oom, it is a little helpful to find the
      reason.  Also it will be emitted anytime show_mem() is called.
      Signed-off-by: NXishi Qiu <qiuxishi@huawei.com>
      Suggested-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Acked-by: NMichal Hocko <mhocko@suse.cz>
      Acked-by: NDavid Rientjes <rientjes@google.com>
      Reviewed-by: NWanpeng Li <liwanp@linux.vnet.ibm.com>
      Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      25487d73
    • W
      mm/hwpoison: add '#' to hwpoison_inject · 4883e997
      Wanpeng Li 提交于
      Add '#' to hwpoison_inject just as done in madvise_hwpoison.
      Signed-off-by: NWanpeng Li <liwanp@linux.vnet.ibm.com>
      Reviewed-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Reviewed-by: NVladimir Murzin <murzin.v@gmail.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      4883e997
    • G
      mm/memblock: use WARN_ONCE when MAX_NUMNODES passed as input parameter · 560dca27
      Grygorii Strashko 提交于
      Check nid parameter and produce warning if it has deprecated
      MAX_NUMNODES value.  Also re-assign NUMA_NO_NODE value to the nid
      parameter in this case.
      
      These will help to identify the wrong API usage (the caller) and make
      code simpler.
      Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Tejun Heo <tj@kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      560dca27
    • G
      x86/mm: memblock: switch to use NUMA_NO_NODE · 9a28f9dc
      Grygorii Strashko 提交于
      Update X86 code to use NUMA_NO_NODE instead of MAX_NUMNODES while
      calling memblock APIs, because memblock API will be changed to use
      NUMA_NO_NODE and will produce warning during boot otherwise.
      
      See:
       https://lkml.org/lkml/2013/12/9/898Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
      Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Acked-by: NDavid Rientjes <rientjes@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9a28f9dc
    • S
      arch/arm/mach-omap2/omap_hwmod.c: use memblock apis for early memory allocations · b6cb5bab
      Santosh Shilimkar 提交于
      Switch to memblock interfaces for early memory allocator instead of
      bootmem allocator.  No functional change in beahvior than what it is in
      current code from bootmem users points of view.
      
      Archs already converted to NO_BOOTMEM now directly use memblock
      interfaces instead of bootmem wrappers build on top of memblock.  And
      the archs which still uses bootmem, these new apis just fallback to
      exiting bootmem APIs.
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Grygorii Strashko <grygorii.strashko@ti.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Tony Lindgren <tony@atomide.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b6cb5bab
    • S
      arch/arm/mm/init.c: use memblock apis for early memory allocations · cfb66586
      Santosh Shilimkar 提交于
      Switch to memblock interfaces for early memory allocator instead of
      bootmem allocator.  No functional change in beahvior than what it is in
      current code from bootmem users points of view.
      
      Archs already converted to NO_BOOTMEM now directly use memblock
      interfaces instead of bootmem wrappers build on top of memblock.  And
      the archs which still uses bootmem, these new apis just fallback to
      exiting bootmem APIs.
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Grygorii Strashko <grygorii.strashko@ti.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Tony Lindgren <tony@atomide.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      cfb66586
    • S
      arch/arm/kernel/: use memblock apis for early memory allocations · 9233d2be
      Santosh Shilimkar 提交于
      Switch to memblock interfaces for early memory allocator instead of
      bootmem allocator.  No functional change in beahvior than what it is in
      current code from bootmem users points of view.
      
      Archs already converted to NO_BOOTMEM now directly use memblock
      interfaces instead of bootmem wrappers build on top of memblock.  And
      the archs which still uses bootmem, these new apis just fallback to
      exiting bootmem APIs.
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Grygorii Strashko <grygorii.strashko@ti.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Tony Lindgren <tony@atomide.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9233d2be
    • S
      drivers/firmware/memmap.c: use memblock apis for early memory allocations · 4fc0bc58
      Santosh Shilimkar 提交于
      Switch to memblock interfaces for early memory allocator instead of
      bootmem allocator.  No functional change in beahvior than what it is in
      current code from bootmem users points of view.
      
      Archs already converted to NO_BOOTMEM now directly use memblock
      interfaces instead of bootmem wrappers build on top of memblock.  And
      the archs which still uses bootmem, these new apis just fallback to
      exiting bootmem APIs.
      Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Tony Lindgren <tony@atomide.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      4fc0bc58
    • S
      mm/memory_hotplug.c: use memblock apis for early memory allocations · 9e43aa2b
      Santosh Shilimkar 提交于
      Correct ensure_zone_is_initialized() function description according to
      the introduced memblock APIs for early memory allocations.
      Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Tony Lindgren <tony@atomide.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9e43aa2b
    • S
      mm/percpu.c: use memblock apis for early memory allocations · 999c17e3
      Santosh Shilimkar 提交于
      Switch to memblock interfaces for early memory allocator instead of
      bootmem allocator.  No functional change in beahvior than what it is in
      current code from bootmem users points of view.
      
      Archs already converted to NO_BOOTMEM now directly use memblock
      interfaces instead of bootmem wrappers build on top of memblock.  And
      the archs which still uses bootmem, these new apis just fallback to
      exiting bootmem APIs.
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Grygorii Strashko <grygorii.strashko@ti.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Tony Lindgren <tony@atomide.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      999c17e3
    • G
      mm/page_cgroup.c: use memblock apis for early memory allocations · 0d036e9e
      Grygorii Strashko 提交于
      Switch to memblock interfaces for early memory allocator instead of
      bootmem allocator.  No functional change in beahvior than what it is in
      current code from bootmem users points of view.
      
      Archs already converted to NO_BOOTMEM now directly use memblock
      interfaces instead of bootmem wrappers build on top of memblock.  And
      the archs which still uses bootmem, these new apis just fallback to
      exiting bootmem APIs.
      Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Grygorii Strashko <grygorii.strashko@ti.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Tony Lindgren <tony@atomide.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0d036e9e
    • G
      mm/hugetlb.c: use memblock apis for early memory allocations · 8b89a116
      Grygorii Strashko 提交于
      Switch to memblock interfaces for early memory allocator instead of
      bootmem allocator.  No functional change in beahvior than what it is in
      current code from bootmem users points of view.
      
      Archs already converted to NO_BOOTMEM now directly use memblock
      interfaces instead of bootmem wrappers build on top of memblock.  And
      the archs which still uses bootmem, these new apis just fallback to
      exiting bootmem APIs.
      Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Tony Lindgren <tony@atomide.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8b89a116
    • S
      mm/sparse: use memblock apis for early memory allocations · bb016b84
      Santosh Shilimkar 提交于
      Switch to memblock interfaces for early memory allocator instead of
      bootmem allocator.  No functional change in beahvior than what it is in
      current code from bootmem users points of view.
      
      Archs already converted to NO_BOOTMEM now directly use memblock
      interfaces instead of bootmem wrappers build on top of memblock.  And
      the archs which still uses bootmem, these new apis just fallback to
      exiting bootmem APIs.
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Grygorii Strashko <grygorii.strashko@ti.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Tony Lindgren <tony@atomide.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      bb016b84
    • S
      lib/cpumask.c: use memblock apis for early memory allocations · c1529500
      Santosh Shilimkar 提交于
      Switch to memblock interfaces for early memory allocator instead of
      bootmem allocator.  No functional change in beahvior than what it is in
      current code from bootmem users points of view.
      
      Archs already converted to NO_BOOTMEM now directly use memblock
      interfaces instead of bootmem wrappers build on top of memblock.  And
      the archs which still uses bootmem, these new apis just fallback to
      exiting bootmem APIs.
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Grygorii Strashko <grygorii.strashko@ti.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Tony Lindgren <tony@atomide.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c1529500
    • S
      lib/swiotlb.c: use memblock apis for early memory allocations · 457ff1de
      Santosh Shilimkar 提交于
      Switch to memblock interfaces for early memory allocator instead of
      bootmem allocator.  No functional change in beahvior than what it is in
      current code from bootmem users points of view.
      
      Archs already converted to NO_BOOTMEM now directly use memblock
      interfaces instead of bootmem wrappers build on top of memblock.  And
      the archs which still uses bootmem, these new apis just fallback to
      exiting bootmem APIs.
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Grygorii Strashko <grygorii.strashko@ti.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Tony Lindgren <tony@atomide.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      457ff1de
    • S
      kernel/power/snapshot.c: use memblock apis for early memory allocations · c2f69cda
      Santosh Shilimkar 提交于
      Switch to memblock interfaces for early memory allocator instead of
      bootmem allocator.  No functional change in beahvior than what it is in
      current code from bootmem users points of view.
      
      Archs already converted to NO_BOOTMEM now directly use memblock
      interfaces instead of bootmem wrappers build on top of memblock.  And
      the archs which still uses bootmem, these new apis just fallback to
      exiting bootmem APIs.
      Acked-by: N"Rafael J. Wysocki" <rjw@sisk.pl>
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Grygorii Strashko <grygorii.strashko@ti.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Tony Lindgren <tony@atomide.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c2f69cda
    • S
      mm/page_alloc.c: use memblock apis for early memory allocations · 6782832e
      Santosh Shilimkar 提交于
      Switch to memblock interfaces for early memory allocator instead of
      bootmem allocator.  No functional change in beahvior than what it is in
      current code from bootmem users points of view.
      
      Archs already converted to NO_BOOTMEM now directly use memblock
      interfaces instead of bootmem wrappers build on top of memblock.  And
      the archs which still uses bootmem, these new apis just fallback to
      exiting bootmem APIs.
      Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tony Lindgren <tony@atomide.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      6782832e
    • S
      kernel/printk/printk.c: use memblock apis for early memory allocations · 9da791df
      Santosh Shilimkar 提交于
      Switch to memblock interfaces for early memory allocator instead of
      bootmem allocator.  No functional change in beahvior than what it is in
      current code from bootmem users points of view.
      
      Archs already converted to NO_BOOTMEM now directly use memblock
      interfaces instead of bootmem wrappers build on top of memblock.  And
      the archs which still uses bootmem, these new apis just fallback to
      exiting bootmem APIs.
      Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tony Lindgren <tony@atomide.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9da791df
    • S
      init/main.c: use memblock apis for early memory allocations · 098b081b
      Santosh Shilimkar 提交于
      Switch to memblock interfaces for early memory allocator instead of
      bootmem allocator.  No functional change in beahvior than what it is in
      current code from bootmem users points of view.
      
      Archs already converted to NO_BOOTMEM now directly use memblock
      interfaces instead of bootmem wrappers build on top of memblock.  And
      the archs which still uses bootmem, these new apis just fall back to
      exiting bootmem APIs.
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Grygorii Strashko <grygorii.strashko@ti.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tony Lindgren <tony@atomide.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      098b081b
    • S
      mm/memblock: add memblock memory allocation apis · 26f09e9b
      Santosh Shilimkar 提交于
      Introduce memblock memory allocation APIs which allow to support PAE or
      LPAE extension on 32 bits archs where the physical memory start address
      can be beyond 4GB.  In such cases, existing bootmem APIs which operate
      on 32 bit addresses won't work and needs memblock layer which operates
      on 64 bit addresses.
      
      So we add equivalent APIs so that we can replace usage of bootmem with
      memblock interfaces.  Architectures already converted to NO_BOOTMEM use
      these new memblock interfaces.  The architectures which are still not
      converted to NO_BOOTMEM continue to function as is because we still
      maintain the fal lback option of bootmem back-end supporting these new
      interfaces.  So no functional change as such.
      
      In long run, once all the architectures moves to NO_BOOTMEM, we can get
      rid of bootmem layer completely.  This is one step to remove the core
      code dependency with bootmem and also gives path for architectures to
      move away from bootmem.
      
      The proposed interface will became active if both CONFIG_HAVE_MEMBLOCK
      and CONFIG_NO_BOOTMEM are specified by arch.  In case
      !CONFIG_NO_BOOTMEM, the memblock() wrappers will fallback to the
      existing bootmem apis so that arch's not converted to NO_BOOTMEM
      continue to work as is.
      
      The meaning of MEMBLOCK_ALLOC_ACCESSIBLE and MEMBLOCK_ALLOC_ANYWHERE
      is kept same.
      
      [akpm@linux-foundation.org: s/depricated/deprecated/]
      Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tony Lindgren <tony@atomide.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      26f09e9b
    • G
      mm/memblock: switch to use NUMA_NO_NODE instead of MAX_NUMNODES · b1154233
      Grygorii Strashko 提交于
      It's recommended to use NUMA_NO_NODE everywhere to select "process any
      node" behavior or to indicate that "no node id specified".
      
      Hence, update __next_free_mem_range*() API's to accept both NUMA_NO_NODE
      and MAX_NUMNODES, but emit warning once on MAX_NUMNODES, and correct
      corresponding API's documentation to describe new behavior.  Also,
      update other memblock/nobootmem APIs where MAX_NUMNODES is used
      dirrectly.
      
      The change was suggested by Tejun Heo.
      Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tony Lindgren <tony@atomide.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b1154233
    • G
      mm/memblock: reorder parameters of memblock_find_in_range_node · 87029ee9
      Grygorii Strashko 提交于
      Reorder parameters of memblock_find_in_range_node to be consistent with
      other memblock APIs.
      
      The change was suggested by Tejun Heo <tj@kernel.org>.
      Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tony Lindgren <tony@atomide.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      87029ee9
    • G
      mm/memblock: drop WARN and use SMP_CACHE_BYTES as a default alignment · 79f40fab
      Grygorii Strashko 提交于
      Don't produce warning and interpret 0 as "default align" equal to
      SMP_CACHE_BYTES in case if caller of memblock_alloc_base_nid() doesn't
      specify alignment for the block (align == 0).
      
      This is done in preparation of introducing common memblock alloc interface
      to make code behavior consistent.  More details are in below thread :
      
      	https://lkml.org/lkml/2013/10/13/117.
      Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tony Lindgren <tony@atomide.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      79f40fab
    • G
      mm/memblock: remove unnecessary inclusions of bootmem.h · 869a84e1
      Grygorii Strashko 提交于
      Clean-up to remove depedency with bootmem headers.
      Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Reviewed-by: NTejun Heo <tj@kernel.org>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tony Lindgren <tony@atomide.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      869a84e1
    • G
      mm/bootmem: remove duplicated declaration of __free_pages_bootmem() · 10e89523
      Grygorii Strashko 提交于
      The __free_pages_bootmem is used internally by MM core and already
      defined in internal.h.  So, remove duplicated declaration.
      Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Reviewed-by: NTejun Heo <tj@kernel.org>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tony Lindgren <tony@atomide.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      10e89523
    • G
      mm/memblock: debug: don't free reserved array if !ARCH_DISCARD_MEMBLOCK · fd615c4e
      Grygorii Strashko 提交于
      Now the Nobootmem allocator will always try to free memory allocated for
      reserved memory regions (free_low_memory_core_early()) without taking
      into to account current memblock debugging configuration
      (CONFIG_ARCH_DISCARD_MEMBLOCK and CONFIG_DEBUG_FS state).
      
      As result if:
      
       - CONFIG_DEBUG_FS defined
       - CONFIG_ARCH_DISCARD_MEMBLOCK not defined;
       - reserved memory regions array have been resized during boot
      
      then:
      
       - memory allocated for reserved memory regions array will be freed to
         buddy allocator;
       - debug_fs entry "sys/kernel/debug/memblock/reserved" will show garbage
         instead of state of memory reservations.  like:
         0: 0x98393bc0..0x9a393bbf
         1: 0xff120000..0xff11ffff
         2: 0x00000000..0xffffffff
      
      Hence, do not free memory allocated for reserved memory regions if
      defined(CONFIG_DEBUG_FS) && !defined(CONFIG_ARCH_DISCARD_MEMBLOCK).
      Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Reviewed-by: NTejun Heo <tj@kernel.org>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tony Lindgren <tony@atomide.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      fd615c4e
    • S
      x86: memblock: set current limit to max low memory address · 5b6e5295
      Santosh Shilimkar 提交于
      The memblock current limit value is used to limit early boot memory
      allocations below max low memory address by default, as the kernel can
      access only to the low memory.
      
      Hence, set memblock current limit value to the max mapped low memory
      address instead of max mapped memory address.
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Grygorii Strashko <grygorii.strashko@ti.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Paul Walmsley <paul@pwsan.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tony Lindgren <tony@atomide.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      5b6e5295
    • O
      oom_kill: add rcu_read_lock() into find_lock_task_mm() · 4d4048be
      Oleg Nesterov 提交于
      find_lock_task_mm() expects it is called under rcu or tasklist lock, but
      it seems that at least oom_unkillable_task()->task_in_mem_cgroup() and
      mem_cgroup_out_of_memory()->oom_badness() can call it lockless.
      
      Perhaps we could fix the callers, but this patch simply adds rcu lock
      into find_lock_task_mm().  This also allows to simplify a bit one of its
      callers, oom_kill_process().
      Signed-off-by: NOleg Nesterov <oleg@redhat.com>
      Cc: Sergey Dyasly <dserrg@gmail.com>
      Cc: Sameer Nanda <snanda@chromium.org>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Mandeep Singh Baines <msb@chromium.org>
      Cc: "Ma, Xindong" <xindong.ma@intel.com>
      Reviewed-by: NMichal Hocko <mhocko@suse.cz>
      Cc: "Tu, Xiaobing" <xiaobing.tu@intel.com>
      Acked-by: NDavid Rientjes <rientjes@google.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      4d4048be
    • O
      oom_kill: has_intersects_mems_allowed() needs rcu_read_lock() · ad962441
      Oleg Nesterov 提交于
      At least out_of_memory() calls has_intersects_mems_allowed() without
      even rcu_read_lock(), this is obviously buggy.
      
      Add the necessary rcu_read_lock().  This means that we can not simply
      return from the loop, we need "bool ret" and "break".
      
      While at it, swap the names of task_struct's (the argument and the
      local).  This cleans up the code a little bit and avoids the unnecessary
      initialization.
      Signed-off-by: NOleg Nesterov <oleg@redhat.com>
      Reviewed-by: NSergey Dyasly <dserrg@gmail.com>
      Tested-by: NSergey Dyasly <dserrg@gmail.com>
      Reviewed-by: NSameer Nanda <snanda@chromium.org>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Mandeep Singh Baines <msb@chromium.org>
      Cc: "Ma, Xindong" <xindong.ma@intel.com>
      Reviewed-by: NMichal Hocko <mhocko@suse.cz>
      Cc: "Tu, Xiaobing" <xiaobing.tu@intel.com>
      Acked-by: NDavid Rientjes <rientjes@google.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ad962441
    • O
      oom_kill: change oom_kill.c to use for_each_thread() · 1da4db0c
      Oleg Nesterov 提交于
      Change oom_kill.c to use for_each_thread() rather than the racy
      while_each_thread() which can loop forever if we race with exit.
      
      Note also that most users were buggy even if while_each_thread() was
      fine, the task can exit even _before_ rcu_read_lock().
      
      Fortunately the new for_each_thread() only requires the stable
      task_struct, so this change fixes both problems.
      Signed-off-by: NOleg Nesterov <oleg@redhat.com>
      Reviewed-by: NSergey Dyasly <dserrg@gmail.com>
      Tested-by: NSergey Dyasly <dserrg@gmail.com>
      Reviewed-by: NSameer Nanda <snanda@chromium.org>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Mandeep Singh Baines <msb@chromium.org>
      Cc: "Ma, Xindong" <xindong.ma@intel.com>
      Reviewed-by: NMichal Hocko <mhocko@suse.cz>
      Cc: "Tu, Xiaobing" <xiaobing.tu@intel.com>
      Acked-by: NDavid Rientjes <rientjes@google.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1da4db0c
    • O
      introduce for_each_thread() to replace the buggy while_each_thread() · 0c740d0a
      Oleg Nesterov 提交于
      while_each_thread() and next_thread() should die, almost every lockless
      usage is wrong.
      
      1. Unless g == current, the lockless while_each_thread() is not safe.
      
         while_each_thread(g, t) can loop forever if g exits, next_thread()
         can't reach the unhashed thread in this case. Note that this can
         happen even if g is the group leader, it can exec.
      
      2. Even if while_each_thread() itself was correct, people often use
         it wrongly.
      
         It was never safe to just take rcu_read_lock() and loop unless
         you verify that pid_alive(g) == T, even the first next_thread()
         can point to the already freed/reused memory.
      
      This patch adds signal_struct->thread_head and task->thread_node to
      create the normal rcu-safe list with the stable head.  The new
      for_each_thread(g, t) helper is always safe under rcu_read_lock() as
      long as this task_struct can't go away.
      
      Note: of course it is ugly to have both task_struct->thread_node and the
      old task_struct->thread_group, we will kill it later, after we change
      the users of while_each_thread() to use for_each_thread().
      
      Perhaps we can kill it even before we convert all users, we can
      reimplement next_thread(t) using the new thread_head/thread_node.  But
      we can't do this right now because this will lead to subtle behavioural
      changes.  For example, do/while_each_thread() always sees at least one
      task, while for_each_thread() can do nothing if the whole thread group
      has died.  Or thread_group_empty(), currently its semantics is not clear
      unless thread_group_leader(p) and we need to audit the callers before we
      can change it.
      
      So this patch adds the new interface which has to coexist with the old
      one for some time, hopefully the next changes will be more or less
      straightforward and the old one will go away soon.
      Signed-off-by: NOleg Nesterov <oleg@redhat.com>
      Reviewed-by: NSergey Dyasly <dserrg@gmail.com>
      Tested-by: NSergey Dyasly <dserrg@gmail.com>
      Reviewed-by: NSameer Nanda <snanda@chromium.org>
      Acked-by: NDavid Rientjes <rientjes@google.com>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Mandeep Singh Baines <msb@chromium.org>
      Cc: "Ma, Xindong" <xindong.ma@intel.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: "Tu, Xiaobing" <xiaobing.tu@intel.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0c740d0a