| Message ID | 20220421234426.3494842-2-yosryahmed@google.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | memcg: introduce per-memcg proactive reclaim | expand |
On Thu, Apr 21, 2022 at 11:44:23PM +0000, Yosry Ahmed wrote: > From: Shakeel Butt <shakeelb@google.com> [...] > > [yosryahmed@google.com: refreshed to current master, updated commit > message based on recent discussions and use cases] > Signed-off-by: Shakeel Butt <shakeelb@google.com> > Signed-off-by: Yosry Ahmed <yosryahmed@google.com> You should add "Co-developed-by" tag for yourself here. > Acked-by: Johannes Weiner <hannes@cmpxchg.org> > Acked-by: Michal Hocko <mhocko@suse.com> > Acked-by: Wei Xu <weixugc@google.com> > Acked-by: Roman Gushchin <roman.gushchin@linux.dev> > --- > [...] > +static ssize_t memory_reclaim(struct kernfs_open_file *of, char *buf, > + size_t nbytes, loff_t off) > +{ > + struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); > + unsigned int nr_retries = MAX_RECLAIM_RETRIES; > + unsigned long nr_to_reclaim, nr_reclaimed = 0; > + int err; > + > + buf = strstrip(buf); > + err = page_counter_memparse(buf, "", &nr_to_reclaim); > + if (err) > + return err; > + > + while (nr_reclaimed < nr_to_reclaim) { > + unsigned long reclaimed; > + > + if (signal_pending(current)) > + return -EINTR; > + > + /* This is the final attempt, drain percpu lru caches in the Fix the comment format. "/*" should be on its own line. > + * hope of introducing more evictable pages for > + * try_to_free_mem_cgroup_pages(). > + */ No need to send a new version if Andrew can fix these in the mm tree.
On Sat, Apr 23, 2022 at 6:30 AM Shakeel Butt <shakeelb@google.com> wrote: > > On Thu, Apr 21, 2022 at 11:44:23PM +0000, Yosry Ahmed wrote: > > From: Shakeel Butt <shakeelb@google.com> > [...] > > > > [yosryahmed@google.com: refreshed to current master, updated commit > > message based on recent discussions and use cases] > > Signed-off-by: Shakeel Butt <shakeelb@google.com> > > Signed-off-by: Yosry Ahmed <yosryahmed@google.com> > > You should add "Co-developed-by" tag for yourself here. > > > Acked-by: Johannes Weiner <hannes@cmpxchg.org> > > Acked-by: Michal Hocko <mhocko@suse.com> > > Acked-by: Wei Xu <weixugc@google.com> > > Acked-by: Roman Gushchin <roman.gushchin@linux.dev> > > --- > > > [...] > > +static ssize_t memory_reclaim(struct kernfs_open_file *of, char *buf, > > + size_t nbytes, loff_t off) > > +{ > > + struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); > > + unsigned int nr_retries = MAX_RECLAIM_RETRIES; > > + unsigned long nr_to_reclaim, nr_reclaimed = 0; > > + int err; > > + > > + buf = strstrip(buf); > > + err = page_counter_memparse(buf, "", &nr_to_reclaim); > > + if (err) > > + return err; > > + > > + while (nr_reclaimed < nr_to_reclaim) { > > + unsigned long reclaimed; > > + > > + if (signal_pending(current)) > > + return -EINTR; > > + > > + /* This is the final attempt, drain percpu lru caches in the > > Fix the comment format. "/*" should be on its own line. > > > + * hope of introducing more evictable pages for > > + * try_to_free_mem_cgroup_pages(). > > + */ > > No need to send a new version if Andrew can fix these in the mm tree. I will be sending v5 anyway to address your review comments on the last patch. I will fix these as well. Thanks!
diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 69d7a6983f78..19bcd73cad03 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -1208,6 +1208,27 @@ PAGE_SIZE multiple when read back. high limit is used and monitored properly, this limit's utility is limited to providing the final safety net. + memory.reclaim + A write-only nested-keyed file which exists for all cgroups. + + This is a simple interface to trigger memory reclaim in the + target cgroup. + + This file accepts a single key, the number of bytes to reclaim. + No nested keys are currently supported. + + Example:: + + echo "1G" > memory.reclaim + + The interface can be later extended with nested keys to + configure the reclaim behavior. For example, specify the + type of memory to reclaim from (anon, file, ..). + + Please note that the kernel can over or under reclaim from + the target cgroup. If less bytes are reclaimed than the + specified amount, -EAGAIN is returned. + memory.oom.group A read-write single value file which exists on non-root cgroups. The default value is "0". diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 725f76723220..041c17847769 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -6355,6 +6355,45 @@ static ssize_t memory_oom_group_write(struct kernfs_open_file *of, return nbytes; } +static ssize_t memory_reclaim(struct kernfs_open_file *of, char *buf, + size_t nbytes, loff_t off) +{ + struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); + unsigned int nr_retries = MAX_RECLAIM_RETRIES; + unsigned long nr_to_reclaim, nr_reclaimed = 0; + int err; + + buf = strstrip(buf); + err = page_counter_memparse(buf, "", &nr_to_reclaim); + if (err) + return err; + + while (nr_reclaimed < nr_to_reclaim) { + unsigned long reclaimed; + + if (signal_pending(current)) + return -EINTR; + + /* This is the final attempt, drain percpu lru caches in the + * hope of introducing more evictable pages for + * try_to_free_mem_cgroup_pages(). + */ + if (!nr_retries) + lru_add_drain_all(); + + reclaimed = try_to_free_mem_cgroup_pages(memcg, + nr_to_reclaim - nr_reclaimed, + GFP_KERNEL, true); + + if (!reclaimed && !nr_retries--) + return -EAGAIN; + + nr_reclaimed += reclaimed; + } + + return nbytes; +} + static struct cftype memory_files[] = { { .name = "current", @@ -6413,6 +6452,11 @@ static struct cftype memory_files[] = { .seq_show = memory_oom_group_show, .write = memory_oom_group_write, }, + { + .name = "reclaim", + .flags = CFTYPE_NS_DELEGATABLE, + .write = memory_reclaim, + }, { } /* terminate */ };