1. 11 May, 2016 1 commit
    • Namhyung Kim's avatar
      perf diff: Fix duplicated output column · e9d848cb
      Namhyung Kim authored
      The commit b97511c5 ("perf tools: Add overhead/overhead_children
      keys defaults via string") moved initialization of column headers but it
      missed to check the sort__mode.  As 'perf diff' doesn't call
      perf_hpp__init(), the setup_overhead() also should not be called.
      
      Before:
      
        # Baseline    Delta  Children  Overhead  Shared Object        Symbol
        # ........  .......  ........  ........  ...................  .......................
        #
            28.48%  -28.47%    28.48%    28.48%  [kernel.vmlinux ]    [k] intel_idle
            11.51%  -11.47%    11.51%    11.51%  libxul.so            [.] 0x0000000001a360f7
             3.49%   -3.49%     3.49%     3.49%  [kernel.vmlinux]     [k] generic_exec_single
             2.91%   -2.89%     2.91%     2.91%  libdbus-1.so.3.8.11  [.] 0x000000000000cdc2
             2.86%   -2.85%     2.86%     2.86%  libxcb.so.1.1.0      [.] 0x000000000000c890
             2.44%   -2.39%     2.44%     2.44%  [kernel.vmlinux]     [k] perf_event_aux_ctx
      
      After:
      
        # Baseline    Delta  Shared Object        Symbol
        # ........  .......  ...................  .......................
        #
            28.48%  -28.47%  [kernel.vmlinux]     [k] intel_idle
            11.51%  -11.47%  libxul.so            [.] 0x0000000001a360f7
             3.49%   -3.49%  [kernel.vmlinux]     [k] generic_exec_single
             2.91%   -2.89%  libdbus-1.so.3.8.11  [.] 0x000000000000cdc2
             2.86%   -2.85%  libxcb.so.1.1.0      [.] 0x000000000000c890
             2.44%   -2.39%  [kernel.vmlinux]     [k] perf_event_aux_ctx
      Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
      Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
      Cc: <stable@vger.kernel.org> # 4.5+
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Fixes: b97511c5 ("perf tools: Add overhead/overhead_children keys defaults via string")
      Link: http://lkml.kernel.org/r/1462890384-12486-2-git-send-email-acme@kernel.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      e9d848cb
  2. 10 May, 2016 10 commits
    • Linus Torvalds's avatar
      Merge tag 'pci-v4.6-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci · c5114626
      Linus Torvalds authored
      Pull PCI fixes from Bjorn Helgaas:
       "Since v4.5, we've WARNed during resume if a PCI device, including a
        Thunderbolt device, was added while we were suspended.  A change we
        merged for v4.6-rc1 turned that warning into a system hang.  These
        enumeration patches from Lukas Wunner fix this issue:
      
         - Fix BUG on device attach failure
         - Do not treat EPROBE_DEFER as device attach failure"
      
      * tag 'pci-v4.6-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
        PCI: Do not treat EPROBE_DEFER as device attach failure
        PCI: Fix BUG on device attach failure
      c5114626
    • Linus Torvalds's avatar
      Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 7ec02e3b
      Linus Torvalds authored
      Pull x86 fixes from Ingo Molnar:
       "Two topology corner case fixes, and a MAINTAINERS file update for
        mmiotrace maintenance"
      
      * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86/topology: Set x86_max_cores to 1 for CONFIG_SMP=n
        MAINTAINERS: Add mmiotrace entry
        x86/topology: Handle CPUID bogosity gracefully
      7ec02e3b
    • Linus Torvalds's avatar
      Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · ac244065
      Linus Torvalds authored
      Pull scheduler fixes from Ingo Molnar:
       "A UP kernel cpufreq fix and a rt/dl scheduler corner case fix"
      
      * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        sched/rt, sched/dl: Don't push if task's scheduling class was changed
        sched/fair: Fix !CONFIG_SMP kernel cpufreq governor breakage
      ac244065
    • Xunlei Pang's avatar
      sched/rt, sched/dl: Don't push if task's scheduling class was changed · 13b5ab02
      Xunlei Pang authored
      We got this warning:
      
          WARNING: CPU: 1 PID: 2468 at kernel/sched/core.c:1161 set_task_cpu+0x1af/0x1c0
          [...]
          Call Trace:
      
          dump_stack+0x63/0x87
          __warn+0xd1/0xf0
          warn_slowpath_null+0x1d/0x20
          set_task_cpu+0x1af/0x1c0
          push_dl_task.part.34+0xea/0x180
          push_dl_tasks+0x17/0x30
          __balance_callback+0x45/0x5c
          __sched_setscheduler+0x906/0xb90
          SyS_sched_setattr+0x150/0x190
          do_syscall_64+0x62/0x110
          entry_SYSCALL64_slow_path+0x25/0x25
      
      This corresponds to:
      
          WARN_ON_ONCE(p->state == TASK_RUNNING &&
                   p->sched_class == &fair_sched_class &&
                   (p->on_rq && !task_on_rq_migrating(p)))
      
      It happens because in find_lock_later_rq(), the task whose scheduling
      class was changed to fair class is still pushed away as if it were
      a deadline task ...
      
      So, check in find_lock_later_rq() after double_lock_balance(), if the
      scheduling class of the deadline task was changed, break and retry.
      
      Apply the same logic to RT tasks.
      Signed-off-by: default avatarXunlei Pang <xlpang@redhat.com>
      Reviewed-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Juri Lelli <juri.lelli@arm.com>
      Link: http://lkml.kernel.org/r/1462767091-1215-1-git-send-email-xlpang@redhat.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      13b5ab02
    • Thomas Gleixner's avatar
      x86/topology: Set x86_max_cores to 1 for CONFIG_SMP=n · 8d415ee2
      Thomas Gleixner authored
      Josef reported that the uncore driver trips over with CONFIG_SMP=n because
      x86_max_cores is 16 instead of 12.
      
      The reason is, that for SMP=n the extended topology detection is a NOOP and
      the cache leaf is used to determine the number of cores. That's wrong in two
      aspects:
      
      1) The cache leaf enumerates the maximum addressable number of cores in the
         package, which is obviously not correct
      
      2) UP has no business with topology bits at all.
      
      Make intel_num_cpu_cores() return 1 for CONFIG_SMP=n
      Reported-by: default avatarJosef Bacik <jbacik@fb.com>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: kernel-team <Kernel-team@fb.com>
      Cc: Kan Liang <kan.liang@intel.com>
      Link: http://lkml.kernel.org/r/761b4a2a-0332-7954-f030-c6639f949612@fb.com
      8d415ee2
    • Linus Torvalds's avatar
      Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm · 2d0bd953
      Linus Torvalds authored
      Pull libnvdimm build fix from Dan Williams:
       "A build fix for the usage of HPAGE_SIZE in the last libnvdimm pull
        request.
      
        I have taken note that the kbuild robot build success test does not
        include results for alpha_allmodconfig.  Thanks to Guenter for the
        report.  It's tagged for -stable since the original fix will land
        there and cause build problems"
      
      * 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
        libnvdimm, pfn: fix ARCH=alpha allmodconfig build failure
      2d0bd953
    • Andy Lutomirski's avatar
      perf/core: Change the default paranoia level to 2 · 0161028b
      Andy Lutomirski authored
      Allowing unprivileged kernel profiling lets any user dump follow kernel
      control flow and dump kernel registers.  This most likely allows trivial
      kASLR bypassing, and it may allow other mischief as well.  (Off the top
      of my head, the PERF_SAMPLE_REGS_INTR output during /dev/urandom reads
      could be quite interesting.)
      Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
      Acked-by: default avatarKees Cook <keescook@chromium.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      0161028b
    • Linus Torvalds's avatar
      Merge branch 'akpm' (patches from Andrew) · 5c56b563
      Linus Torvalds authored
      Merge fixes from Andrew Morton:
       "2 fixes"
      
      * emailed patches from Andrew Morton <akpm@linux-foundation.org>:
        zsmalloc: fix zs_can_compact() integer overflow
        Revert "proc/base: make prompt shell start from new line after executing "cat /proc/$pid/wchan""
      5c56b563
    • Sergey Senozhatsky's avatar
      zsmalloc: fix zs_can_compact() integer overflow · 44f43e99
      Sergey Senozhatsky authored
      zs_can_compact() has two race conditions in its core calculation:
      
      unsigned long obj_wasted = zs_stat_get(class, OBJ_ALLOCATED) -
      				zs_stat_get(class, OBJ_USED);
      
      1) classes are not locked, so the numbers of allocated and used
         objects can change by the concurrent ops happening on other CPUs
      2) shrinker invokes it from preemptible context
      
      Depending on the circumstances, thus, OBJ_ALLOCATED can become
      less than OBJ_USED, which can result in either very high or
      negative `total_scan' value calculated later in do_shrink_slab().
      
      do_shrink_slab() has some logic to prevent those cases:
      
       vmscan: shrink_slab: zs_shrinker_scan+0x0/0x28 [zsmalloc] negative objects to delete nr=-62
       vmscan: shrink_slab: zs_shrinker_scan+0x0/0x28 [zsmalloc] negative objects to delete nr=-62
       vmscan: shrink_slab: zs_shrinker_scan+0x0/0x28 [zsmalloc] negative objects to delete nr=-64
       vmscan: shrink_slab: zs_shrinker_scan+0x0/0x28 [zsmalloc] negative objects to delete nr=-62
       vmscan: shrink_slab: zs_shrinker_scan+0x0/0x28 [zsmalloc] negative objects to delete nr=-62
       vmscan: shrink_slab: zs_shrinker_scan+0x0/0x28 [zsmalloc] negative objects to delete nr=-62
      
      However, due to the way `total_scan' is calculated, not every
      shrinker->count_objects() overflow can be spotted and handled.
      To demonstrate the latter, I added some debugging code to do_shrink_slab()
      (x86_64) and the results were:
      
       vmscan: OVERFLOW: shrinker->count_objects() == -1 [18446744073709551615]
       vmscan: but total_scan > 0: 92679974445502
       vmscan: resulting total_scan: 92679974445502
      [..]
       vmscan: OVERFLOW: shrinker->count_objects() == -1 [18446744073709551615]
       vmscan: but total_scan > 0: 22634041808232578
       vmscan: resulting total_scan: 22634041808232578
      
      Even though shrinker->count_objects() has returned an overflowed value,
      the resulting `total_scan' is positive, and, what is more worrisome, it
      is insanely huge. This value is getting used later on in
      shrinker->scan_objects() loop:
      
              while (total_scan >= batch_size ||
                     total_scan >= freeable) {
                      unsigned long ret;
                      unsigned long nr_to_scan = min(batch_size, total_scan);
      
                      shrinkctl->nr_to_scan = nr_to_scan;
                      ret = shrinker->scan_objects(shrinker, shrinkctl);
                      if (ret == SHRINK_STOP)
                              break;
                      freed += ret;
      
                      count_vm_events(SLABS_SCANNED, nr_to_scan);
                      total_scan -= nr_to_scan;
      
                      cond_resched();
              }
      
      `total_scan >= batch_size' is true for a very-very long time and
      'total_scan >= freeable' is also true for quite some time, because
      `freeable < 0' and `total_scan' is large enough, for example,
      22634041808232578. The only break condition, in the given scheme of
      things, is shrinker->scan_objects() == SHRINK_STOP test, which is a
      bit too weak to rely on, especially in heavy zsmalloc-usage scenarios.
      
      To fix the issue, take a pool stat snapshot and use it instead of
      racy zs_stat_get() calls.
      
      Link: http://lkml.kernel.org/r/20160509140052.3389-1-sergey.senozhatsky@gmail.comSigned-off-by: default avatarSergey Senozhatsky <sergey.senozhatsky@gmail.com>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: <stable@vger.kernel.org>        [4.3+]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      44f43e99
    • Robin Humble's avatar
      Revert "proc/base: make prompt shell start from new line after executing "cat /proc/$pid/wchan"" · 1e92a61c
      Robin Humble authored
      This reverts the 4.6-rc1 commit 7e2bc81d ("proc/base: make prompt
      shell start from new line after executing "cat /proc/$pid/wchan")
      because it breaks /proc/$PID/whcan formatting in ps and top.
      
      Revert also because the patch is inconsistent - it adds a newline at the
      end of only the '0' wchan, and does not add a newline when
      /proc/$PID/wchan contains a symbol name.
      
      eg.
      $ ps -eo pid,stat,wchan,comm
      PID STAT WCHAN  COMMAND
      ...
      1189 S    -      dbus-launch
      1190 Ssl  0
      dbus-daemon
      1198 Sl   0
      lightdm
      1299 Ss   ep_pol systemd
      1301 S    -      (sd-pam)
      1304 Ss   wait   sh
      Signed-off-by: default avatarRobin Humble <plaguedbypenguins@gmail.com>
      Cc: Minfei Huang <mnfhuang@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1e92a61c
  3. 09 May, 2016 11 commits
  4. 08 May, 2016 2 commits
  5. 07 May, 2016 12 commits
  6. 06 May, 2016 4 commits