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authorNhat Pham <nphamcs@gmail.com>2023-11-30 22:40:19 +0300
committerAndrew Morton <akpm@linux-foundation.org>2023-12-12 21:57:01 +0300
commitfdc4161ff6a5e96222e159c1f1b28d31a985130d (patch)
tree6fc5bc06c0cf404cf273383504156de9ba0941b5 /include/linux/memcontrol.h
parent0a97c01cd20bb96359d8c9dedad92a061ed34e0b (diff)
downloadlinux-fdc4161ff6a5e96222e159c1f1b28d31a985130d.tar.xz
memcontrol: implement mem_cgroup_tryget_online()
This patch implements a helper function that try to get a reference to an memcg's css, as well as checking if it is online. This new function is almost exactly the same as the existing mem_cgroup_tryget(), except for the onlineness check. In the !CONFIG_MEMCG case, it always returns true, analogous to mem_cgroup_tryget(). This is useful for e.g to the new zswap writeback scheme, where we need to select the next online memcg as a candidate for the global limit reclaim. Link: https://lkml.kernel.org/r/20231130194023.4102148-3-nphamcs@gmail.com Signed-off-by: Nhat Pham <nphamcs@gmail.com> Tested-by: Bagas Sanjaya <bagasdotme@gmail.com> Reviewed-by: Yosry Ahmed <yosryahmed@google.com> Cc: Chris Li <chrisl@kernel.org> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Seth Jennings <sjenning@redhat.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include/linux/memcontrol.h')
-rw-r--r--include/linux/memcontrol.h10
1 files changed, 10 insertions, 0 deletions
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 7bdcf3020d7a..2bd7d14ace78 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -821,6 +821,11 @@ static inline bool mem_cgroup_tryget(struct mem_cgroup *memcg)
return !memcg || css_tryget(&memcg->css);
}
+static inline bool mem_cgroup_tryget_online(struct mem_cgroup *memcg)
+{
+ return !memcg || css_tryget_online(&memcg->css);
+}
+
static inline void mem_cgroup_put(struct mem_cgroup *memcg)
{
if (memcg)
@@ -1349,6 +1354,11 @@ static inline bool mem_cgroup_tryget(struct mem_cgroup *memcg)
return true;
}
+static inline bool mem_cgroup_tryget_online(struct mem_cgroup *memcg)
+{
+ return true;
+}
+
static inline void mem_cgroup_put(struct mem_cgroup *memcg)
{
}