When attempting to charge pages, we first charge the memory counter and then the memory+swap counter. If one of the counters is at its limit, we enter reclaim, but if it's the memory+swap counter, reclaim shouldn't swap because that wouldn't change the situation. However, if the counters have the same limits, we never get to the memory+swap limit. To know whether reclaim should swap or not, there is a state flag that indicates whether the limits are equal and whether hitting the memory limit implies hitting the memory+swap limit.
Just try the memory+swap counter first. Signed-off-by: Johannes Weiner <[email protected]> --- mm/memcontrol.c | 47 +++++++++++++---------------------------------- 1 file changed, 13 insertions(+), 34 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 1ec22bf380d0..89c920156c2a 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -315,9 +315,6 @@ struct mem_cgroup { /* OOM-Killer disable */ int oom_kill_disable; - /* set when res.limit == memsw.limit */ - bool memsw_is_minimum; - /* protect arrays of thresholds */ struct mutex thresholds_lock; @@ -1804,8 +1801,6 @@ static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg, if (flags & MEM_CGROUP_RECLAIM_NOSWAP) noswap = true; - if (!(flags & MEM_CGROUP_RECLAIM_SHRINK) && memcg->memsw_is_minimum) - noswap = true; for (loop = 0; loop < MEM_CGROUP_MAX_RECLAIM_LOOPS; loop++) { if (loop) @@ -2543,16 +2538,17 @@ retry: goto done; size = batch * PAGE_SIZE; - if (!res_counter_charge(&memcg->res, size, &fail_res)) { - if (!do_swap_account) + if (!do_swap_account || + !res_counter_charge(&memcg->memsw, size, &fail_res)) { + if (!res_counter_charge(&memcg->res, size, &fail_res)) goto done_restock; - if (!res_counter_charge(&memcg->memsw, size, &fail_res)) - goto done_restock; - res_counter_uncharge(&memcg->res, size); + if (do_swap_account) + res_counter_uncharge(&memcg->memsw, size); + mem_over_limit = mem_cgroup_from_res_counter(fail_res, res); + } else { mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw); flags |= MEM_CGROUP_RECLAIM_NOSWAP; - } else - mem_over_limit = mem_cgroup_from_res_counter(fail_res, res); + } if (batch > nr_pages) { batch = nr_pages; @@ -3615,7 +3611,6 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, unsigned long long val) { int retry_count; - u64 memswlimit, memlimit; int ret = 0; int children = mem_cgroup_count_children(memcg); u64 curusage, oldusage; @@ -3642,24 +3637,16 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, * We have to guarantee memcg->res.limit <= memcg->memsw.limit. */ mutex_lock(&set_limit_mutex); - memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); - if (memswlimit < val) { + if (res_counter_read_u64(&memcg->memsw, RES_LIMIT) < val) { ret = -EINVAL; mutex_unlock(&set_limit_mutex); break; } - memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); - if (memlimit < val) + if (res_counter_read_u64(&memcg->res, RES_LIMIT) < val) enlarge = 1; ret = res_counter_set_limit(&memcg->res, val); - if (!ret) { - if (memswlimit == val) - memcg->memsw_is_minimum = true; - else - memcg->memsw_is_minimum = false; - } mutex_unlock(&set_limit_mutex); if (!ret) @@ -3684,7 +3671,7 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, unsigned long long val) { int retry_count; - u64 memlimit, memswlimit, oldusage, curusage; + u64 oldusage, curusage; int children = mem_cgroup_count_children(memcg); int ret = -EBUSY; int enlarge = 0; @@ -3703,22 +3690,14 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, * We have to guarantee memcg->res.limit <= memcg->memsw.limit. */ mutex_lock(&set_limit_mutex); - memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT); - if (memlimit > val) { + if (res_counter_read_u64(&memcg->res, RES_LIMIT) > val) { ret = -EINVAL; mutex_unlock(&set_limit_mutex); break; } - memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT); - if (memswlimit < val) + if (res_counter_read_u64(&memcg->memsw, RES_LIMIT) < val) enlarge = 1; ret = res_counter_set_limit(&memcg->memsw, val); - if (!ret) { - if (memlimit == val) - memcg->memsw_is_minimum = true; - else - memcg->memsw_is_minimum = false; - } mutex_unlock(&set_limit_mutex); if (!ret) -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
