From c054a78c66c7a5aa218220d8949ebcf13a86b796 Mon Sep 17 00:00:00 2001 From: Yu Zhao Date: Wed, 31 Jan 2018 16:20:02 -0800 Subject: [PATCH] memcg: refactor mem_cgroup_resize_limit() 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. Link: http://lkml.kernel.org/r/20180108224238.14583-1-yuzhao@google.com Signed-off-by: Yu Zhao Acked-by: Vladimir Davydov Acked-by: Michal Hocko Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 77 +++++++++++++-------------------------------------------- 1 file changed, 17 insertions(+), 60 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 51d398f..695d9f1 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2461,13 +2461,15 @@ 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 @@ -2477,7 +2479,7 @@ 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)) { @@ -2486,73 +2488,28 @@ 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--; @@ -3014,10 +2971,10 @@ 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); -- 2.7.4