diff options
author | David S. Miller <davem@davemloft.net> | 2015-10-02 17:21:25 +0300 |
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committer | David S. Miller <davem@davemloft.net> | 2015-10-02 17:21:25 +0300 |
commit | f6d3125fa3c2f55ddf7cf69365c41089de6cfae6 (patch) | |
tree | ff2bcb135ebf090d7b383d55123b621f4590632c /mm/memcontrol.c | |
parent | 2dc6a0303b89de4c92b44f5278d61b6b6c9c20eb (diff) | |
parent | 36f8dafe52b0d0726edd5102900e37192f1d3c65 (diff) | |
download | linux-f6d3125fa3c2f55ddf7cf69365c41089de6cfae6.tar.xz |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
net/dsa/slave.c
net/dsa/slave.c simply had overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'mm/memcontrol.c')
-rw-r--r-- | mm/memcontrol.c | 31 |
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: |