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[209.85.220.65]) by mx.google.com with SMTPS id j74sor3441571pfj.62.2018.01.08.14.42.59 for (Google Transport Security); Mon, 08 Jan 2018 14:43:00 -0800 (PST) From: Yu Zhao Subject: [PATCH v4] memcg: refactor mem_cgroup_resize_limit() Date: Mon, 8 Jan 2018 14:42:38 -0800 Message-Id: <20180108224238.14583-1-yuzhao@google.com> In-Reply-To: <20170601230212.30578-1-yuzhao@google.com> References: <20170601230212.30578-1-yuzhao@google.com> Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner , Michal Hocko , Vladimir Davydov Cc: Andrew Morton , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Yu Zhao mem_cgroup_resize_limit() and mem_cgroup_resize_memsw_limit() have identical logics. Refactor code so we don't need to keep two pieces of code that does same thing. Signed-off-by: Yu Zhao Acked-by: Vladimir Davydov Acked-by: Michal Hocko --- mm/memcontrol.c | 77 +++++++++++++-------------------------------------------- 1 file changed, 17 insertions(+), 60 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index ac2ffd5e02b9..9af733fa9381 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2467,13 +2467,15 @@ static inline int mem_cgroup_move_swap_account(swp_entry_t entry, static DEFINE_MUTEX(memcg_limit_mutex); static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, - unsigned long limit) + unsigned long limit, bool memsw) { unsigned long curusage; unsigned long oldusage; bool enlarge = false; int retry_count; int ret; + bool limits_invariant; + struct page_counter *counter = memsw ? &memcg->memsw : &memcg->memory; /* * For keeping hierarchical_reclaim simple, how long we should retry @@ -2483,7 +2485,7 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, retry_count = MEM_CGROUP_RECLAIM_RETRIES * mem_cgroup_count_children(memcg); - oldusage = page_counter_read(&memcg->memory); + oldusage = page_counter_read(counter); do { if (signal_pending(current)) { @@ -2492,73 +2494,28 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, } mutex_lock(&memcg_limit_mutex); - if (limit > memcg->memsw.limit) { - mutex_unlock(&memcg_limit_mutex); - ret = -EINVAL; - break; - } - if (limit > memcg->memory.limit) - enlarge = true; - ret = page_counter_limit(&memcg->memory, limit); - mutex_unlock(&memcg_limit_mutex); - - if (!ret) - break; - - try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, true); - - curusage = page_counter_read(&memcg->memory); - /* Usage is reduced ? */ - if (curusage >= oldusage) - retry_count--; - else - oldusage = curusage; - } while (retry_count); - - if (!ret && enlarge) - memcg_oom_recover(memcg); - - return ret; -} - -static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, - unsigned long limit) -{ - unsigned long curusage; - unsigned long oldusage; - bool enlarge = false; - int retry_count; - int ret; - - /* see mem_cgroup_resize_res_limit */ - retry_count = MEM_CGROUP_RECLAIM_RETRIES * - mem_cgroup_count_children(memcg); - - oldusage = page_counter_read(&memcg->memsw); - - do { - if (signal_pending(current)) { - ret = -EINTR; - break; - } - - mutex_lock(&memcg_limit_mutex); - if (limit < memcg->memory.limit) { + /* + * Make sure that the new limit (memsw or memory limit) doesn't + * break our basic invariant rule memory.limit <= memsw.limit. + */ + limits_invariant = memsw ? limit >= memcg->memory.limit : + limit <= memcg->memsw.limit; + if (!limits_invariant) { mutex_unlock(&memcg_limit_mutex); ret = -EINVAL; break; } - if (limit > memcg->memsw.limit) + if (limit > counter->limit) enlarge = true; - ret = page_counter_limit(&memcg->memsw, limit); + ret = page_counter_limit(counter, limit); mutex_unlock(&memcg_limit_mutex); if (!ret) break; - try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, false); + try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, !memsw); - curusage = page_counter_read(&memcg->memsw); + curusage = page_counter_read(counter); /* Usage is reduced ? */ if (curusage >= oldusage) retry_count--; @@ -3020,10 +2977,10 @@ static ssize_t mem_cgroup_write(struct kernfs_open_file *of, } switch (MEMFILE_TYPE(of_cft(of)->private)) { case _MEM: - ret = mem_cgroup_resize_limit(memcg, nr_pages); + ret = mem_cgroup_resize_limit(memcg, nr_pages, false); break; case _MEMSWAP: - ret = mem_cgroup_resize_memsw_limit(memcg, nr_pages); + ret = mem_cgroup_resize_limit(memcg, nr_pages, true); break; case _KMEM: ret = memcg_update_kmem_limit(memcg, nr_pages); -- 2.16.0.rc0.223.g4a4ac83678-goog -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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