The patch titled
cpuset: fix possible races in cpu/memory hotplug
has been added to the -mm tree. Its filename is
cpuset-fix-possible-races-in-cpu-memory-hotplug.patch
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------------------------------------------------------
Subject: cpuset: fix possible races in cpu/memory hotplug
From: Li Zefan <lizf@xxxxxxxxxxxxxx>
Change to cpuset->cpus_allowed and cpuset->mems_allowed should be protected
by callback_mutex, otherwise the reader may read wrong cpus/mems. This is
cpuset's lock rule.
Signed-off-by: Li Zefan <lizf@xxxxxxxxxxxxxx>
Cc: Paul Menage <menage@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/cpuset.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff -puN kernel/cpuset.c~cpuset-fix-possible-races-in-cpu-memory-hotplug kernel/cpuset.c
--- a/kernel/cpuset.c~cpuset-fix-possible-races-in-cpu-memory-hotplug
+++ a/kernel/cpuset.c
@@ -1995,7 +1995,9 @@ static int cpuset_track_online_cpus(stru
}
cgroup_lock();
+ mutex_lock(&callback_mutex);
cpumask_copy(top_cpuset.cpus_allowed, cpu_online_mask);
+ mutex_unlock(&callback_mutex);
scan_for_empty_cpusets(&top_cpuset);
ndoms = generate_sched_domains(&doms, &attr);
cgroup_unlock();
@@ -2018,11 +2020,12 @@ static int cpuset_track_online_nodes(str
cgroup_lock();
switch (action) {
case MEM_ONLINE:
- top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
- break;
case MEM_OFFLINE:
+ mutex_lock(&callback_mutex);
top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
- scan_for_empty_cpusets(&top_cpuset);
+ mutex_unlock(&callback_mutex);
+ if (action == MEM_OFFLINE)
+ scan_for_empty_cpusets(&top_cpuset);
break;
default:
break;
_
Patches currently in -mm which might be from lizf@xxxxxxxxxxxxxx are
origin.patch
linux-next.patch
relax-ns_can_attach-checks-to-allow-attaching-to-grandchild-cgroups.patch
cgroup-css-id-support.patch
cgroup-fix-frequent-ebusy-at-rmdir.patch
memcg-use-css-id.patch
memcg-hierarchical-stat.patch
memcg-fix-shrinking-memory-to-return-ebusy-by-fixing-retry-algorithm.patch
memcg-fix-oom-killer-under-memcg.patch
cpuset-fix-possible-races-in-cpu-memory-hotplug.patch
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