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authorLinus Torvalds <torvalds@linux-foundation.org>2015-12-09 00:35:52 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2015-12-09 00:35:52 +0300
commit5406812e59761f6ba33ea0bf97e426666bdb0e28 (patch)
treee332877ab352be841ff709f307c6d70788771044 /mm
parent633bb7388bf399b2d4b16951404d69f34f9ddbec (diff)
parent0b98f0c04245877ae0b625a7f0aa55b8ff98e0c4 (diff)
downloadlinux-5406812e59761f6ba33ea0bf97e426666bdb0e28.tar.xz
Merge branch 'for-4.4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo: "More change than I'd have liked at this stage. The pids controller and the changes made to cgroup core to support it introduced and revealed several important issues. - Assigning membership to a newly created task and migrating it can race leading to incorrect accounting. Oleg fixed it by widening threadgroup synchronization. It looks like we'll be able to merge it with a different percpu rwsem which is used in fork path making things simpler and cheaper. - The recent change to extend cgroup membership to zombies (so that pid accounting can extend till the pid is actually released) missed pinning the underlying data structures leading to use-after-free. Fixed. - v2 hierarchy was calling subsystem callbacks with the wrong target cgroup_subsys_state based on the incorrect assumption that they share the same target. pids is the first controller affected by this. Subsys callbacks updated so that they can deal with multi-target migrations" * 'for-4.4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup_pids: don't account for the root cgroup cgroup: fix handling of multi-destination migration from subtree_control enabling cgroup_freezer: simplify propagation of CGROUP_FROZEN clearing in freezer_attach() cgroup: pids: kill pids_fork(), simplify pids_can_fork() and pids_cancel_fork() cgroup: pids: fix race between cgroup_post_fork() and cgroup_migrate() cgroup: make css_set pin its css's to avoid use-afer-free cgroup: fix cftype->file_offset handling
Diffstat (limited to 'mm')
-rw-r--r--mm/memcontrol.c45
1 files changed, 23 insertions, 22 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 9acfb165eb52..c92a65b2b4ab 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4779,23 +4779,18 @@ static void mem_cgroup_clear_mc(void)
spin_unlock(&mc.lock);
}
-static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static int mem_cgroup_can_attach(struct cgroup_taskset *tset)
{
- struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+ struct cgroup_subsys_state *css;
+ struct mem_cgroup *memcg;
struct mem_cgroup *from;
struct task_struct *leader, *p;
struct mm_struct *mm;
unsigned long move_flags;
int ret = 0;
- /*
- * We are now commited to this value whatever it is. Changes in this
- * tunable will only affect upcoming migrations, not the current one.
- * So we need to save it, and keep it going.
- */
- move_flags = READ_ONCE(memcg->move_charge_at_immigrate);
- if (!move_flags)
+ /* charge immigration isn't supported on the default hierarchy */
+ if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
return 0;
/*
@@ -4805,13 +4800,23 @@ static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
* multiple.
*/
p = NULL;
- cgroup_taskset_for_each_leader(leader, tset) {
+ cgroup_taskset_for_each_leader(leader, css, tset) {
WARN_ON_ONCE(p);
p = leader;
+ memcg = mem_cgroup_from_css(css);
}
if (!p)
return 0;
+ /*
+ * We are now commited to this value whatever it is. Changes in this
+ * tunable will only affect upcoming migrations, not the current one.
+ * So we need to save it, and keep it going.
+ */
+ move_flags = READ_ONCE(memcg->move_charge_at_immigrate);
+ if (!move_flags)
+ return 0;
+
from = mem_cgroup_from_task(p);
VM_BUG_ON(from == memcg);
@@ -4842,8 +4847,7 @@ static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
return ret;
}
-static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset)
{
if (mc.to)
mem_cgroup_clear_mc();
@@ -4985,10 +4989,10 @@ retry:
atomic_dec(&mc.from->moving_account);
}
-static void mem_cgroup_move_task(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void mem_cgroup_move_task(struct cgroup_taskset *tset)
{
- struct task_struct *p = cgroup_taskset_first(tset);
+ struct cgroup_subsys_state *css;
+ struct task_struct *p = cgroup_taskset_first(tset, &css);
struct mm_struct *mm = get_task_mm(p);
if (mm) {
@@ -5000,17 +5004,14 @@ static void mem_cgroup_move_task(struct cgroup_subsys_state *css,
mem_cgroup_clear_mc();
}
#else /* !CONFIG_MMU */
-static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static int mem_cgroup_can_attach(struct cgroup_taskset *tset)
{
return 0;
}
-static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset)
{
}
-static void mem_cgroup_move_task(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void mem_cgroup_move_task(struct cgroup_taskset *tset)
{
}
#endif