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authorTakashi Iwai <tiwai@suse.de>2015-10-07 20:11:21 +0200
committerTakashi Iwai <tiwai@suse.de>2015-10-07 20:11:21 +0200
commit601d62959d08a450d4666c728ddd2f47c5ba1cfe (patch)
tree52d9f3c1a2528a9de405d5a19014f3f94b16b35d /mm/memcontrol.c
parent225db5762dc1a35b26850477ffa06e5cd0097243 (diff)
parente4fc141d2a022a63c87a4851b3c688eca6a1647b (diff)
Merge tag 'asoc-fix-v4.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linussound-4.3-rc5
ASoC: Fixes for v4.3 Quite a few fixes here but they're all very small and driver specific, none of them really stand out if you aren't using the relevant hardware but they're all useful if you do happen to have an affected device.
Diffstat (limited to 'mm/memcontrol.c')
-rw-r--r--mm/memcontrol.c31
1 files changed, 18 insertions, 13 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6ddaeba34e09..1fedbde68f59 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -644,12 +644,14 @@ mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
}
/*
+ * Return page count for single (non recursive) @memcg.
+ *
* Implementation Note: reading percpu statistics for memcg.
*
* Both of vmstat[] and percpu_counter has threshold and do periodic
* synchronization to implement "quick" read. There are trade-off between
* reading cost and precision of value. Then, we may have a chance to implement
- * a periodic synchronizion of counter in memcg's counter.
+ * a periodic synchronization of counter in memcg's counter.
*
* But this _read() function is used for user interface now. The user accounts
* memory usage by memory cgroup and he _always_ requires exact value because
@@ -659,17 +661,24 @@ mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
*
* If there are kernel internal actions which can make use of some not-exact
* value, and reading all cpu value can be performance bottleneck in some
- * common workload, threashold and synchonization as vmstat[] should be
+ * common workload, threshold and synchronization as vmstat[] should be
* implemented.
*/
-static long mem_cgroup_read_stat(struct mem_cgroup *memcg,
- enum mem_cgroup_stat_index idx)
+static unsigned long
+mem_cgroup_read_stat(struct mem_cgroup *memcg, enum mem_cgroup_stat_index idx)
{
long val = 0;
int cpu;
+ /* Per-cpu values can be negative, use a signed accumulator */
for_each_possible_cpu(cpu)
val += per_cpu(memcg->stat->count[idx], cpu);
+ /*
+ * Summing races with updates, so val may be negative. Avoid exposing
+ * transient negative values.
+ */
+ if (val < 0)
+ val = 0;
return val;
}
@@ -1254,7 +1263,7 @@ void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
continue;
- pr_cont(" %s:%ldKB", mem_cgroup_stat_names[i],
+ pr_cont(" %s:%luKB", mem_cgroup_stat_names[i],
K(mem_cgroup_read_stat(iter, i)));
}
@@ -2819,14 +2828,11 @@ static unsigned long tree_stat(struct mem_cgroup *memcg,
enum mem_cgroup_stat_index idx)
{
struct mem_cgroup *iter;
- long val = 0;
+ unsigned long val = 0;
- /* Per-cpu values can be negative, use a signed accumulator */
for_each_mem_cgroup_tree(iter, memcg)
val += mem_cgroup_read_stat(iter, idx);
- if (val < 0) /* race ? */
- val = 0;
return val;
}
@@ -3169,7 +3175,7 @@ static int memcg_stat_show(struct seq_file *m, void *v)
for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
continue;
- seq_printf(m, "%s %ld\n", mem_cgroup_stat_names[i],
+ seq_printf(m, "%s %lu\n", mem_cgroup_stat_names[i],
mem_cgroup_read_stat(memcg, i) * PAGE_SIZE);
}
@@ -3194,13 +3200,13 @@ static int memcg_stat_show(struct seq_file *m, void *v)
(u64)memsw * PAGE_SIZE);
for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
- long long val = 0;
+ unsigned long long val = 0;
if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
continue;
for_each_mem_cgroup_tree(mi, memcg)
val += mem_cgroup_read_stat(mi, i) * PAGE_SIZE;
- seq_printf(m, "total_%s %lld\n", mem_cgroup_stat_names[i], val);
+ seq_printf(m, "total_%s %llu\n", mem_cgroup_stat_names[i], val);
}
for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) {
@@ -4179,7 +4185,6 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
if (memcg_wb_domain_init(memcg, GFP_KERNEL))
goto out_free_stat;
- spin_lock_init(&memcg->pcp_counter_lock);
return memcg;
out_free_stat: