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| author |   Linus Torvalds <torvalds@linux-foundation.org> | 2014-09-27 16:45:33 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-09-27 16:45:33 -0700 |
| commit | 6111da3432b10b2c56a21a5d8671aee46435326d (patch) | |
| tree | dc85fcc0b58ab24754367794c5b617117afce734 /Documentation | |
| parent | Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc (diff) | |
| parent | cpuset: PF_SPREAD_PAGE and PF_SPREAD_SLAB should be atomic flags (diff) | |
| download | linux-dev-6111da3432b10b2c56a21a5d8671aee46435326d.tar.xz linux-dev-6111da3432b10b2c56a21a5d8671aee46435326d.zip | |
Merge branch 'for-3.17-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
"This is quite late but these need to be backported anyway.
This is the fix for a long-standing cpuset bug which existed from
2009. cpuset makes use of PF_SPREAD_{PAGE|SLAB} flags to modify the
task's memory allocation behavior according to the settings of the
cpuset it belongs to; unfortunately, when those flags have to be
changed, cpuset did so directly even whlie the target task is running,
which is obviously racy as task->flags may be modified by the task
itself at any time. This obscure bug manifested as corrupt
PF_USED_MATH flag leading to a weird crash.
The bug is fixed by moving the flag to task->atomic_flags. The first
two are prepatory ones to help defining atomic_flags accessors and the
third one is the actual fix"
* 'for-3.17-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cpuset: PF_SPREAD_PAGE and PF_SPREAD_SLAB should be atomic flags
sched: add macros to define bitops for task atomic flags
sched: fix confusing PFA_NO_NEW_PRIVS constant
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/cgroups/cpusets.txt | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/Documentation/cgroups/cpusets.txt b/Documentation/cgroups/cpusets.txt index 7740038d82bc..3c94ff3f9693 100644 --- a/Documentation/cgroups/cpusets.txt +++ b/Documentation/cgroups/cpusets.txt @@ -345,14 +345,14 @@ the named feature on. The implementation is simple. Setting the flag 'cpuset.memory_spread_page' turns on a per-process flag -PF_SPREAD_PAGE for each task that is in that cpuset or subsequently +PFA_SPREAD_PAGE for each task that is in that cpuset or subsequently joins that cpuset. The page allocation calls for the page cache -is modified to perform an inline check for this PF_SPREAD_PAGE task +is modified to perform an inline check for this PFA_SPREAD_PAGE task flag, and if set, a call to a new routine cpuset_mem_spread_node() returns the node to prefer for the allocation. Similarly, setting 'cpuset.memory_spread_slab' turns on the flag -PF_SPREAD_SLAB, and appropriately marked slab caches will allocate +PFA_SPREAD_SLAB, and appropriately marked slab caches will allocate pages from the node returned by cpuset_mem_spread_node(). The cpuset_mem_spread_node() routine is also simple. It uses the |