Commit e1479b88 authored by JP Kobryn's avatar JP Kobryn Committed by Andrew Morton
Browse files

memcg: rename do_flush_stats and add force flag 

Patch series "memcg: tracepoint for flushing stats", v3.

This series adds new capability for understanding frequency and circumstances
behind flushing memcg stats.


This patch (of 2):

Change the name to something more consistent with others in the file and
use double unders to signify it is associated with the
mem_cgroup_flush_stats() API call.  Additionally include a new flag that
call sites use to indicate a forced flush; skipping checks and flushing
unconditionally.  There are no changes in functionality.

Link: https://lkml.kernel.org/r/20241029021106.25587-1-inwardvessel@gmail.com
Link: https://lkml.kernel.org/r/20241029021106.25587-2-inwardvessel@gmail.com


Signed-off-by: default avatarJP Kobryn <inwardvessel@gmail.com>
Reviewed-by: default avatarYosry Ahmed <yosryahmed@google.com>
Acked-by: default avatarShakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent ab6e8e74

mm/memcontrol.c

+8 −9
Original line number Diff line number Diff line
@@ -595,8 +595,11 @@ static inline void memcg_rstat_updated(struct mem_cgroup *memcg, int val) 
	}

}



static void do_flush_stats(struct mem_cgroup *memcg)

static void __mem_cgroup_flush_stats(struct mem_cgroup *memcg, bool force)

{

	if (!force && !memcg_vmstats_needs_flush(memcg->vmstats))

		return;



	if (mem_cgroup_is_root(memcg))

		WRITE_ONCE(flush_last_time, jiffies_64);
@@ -620,8 +623,7 @@ void mem_cgroup_flush_stats(struct mem_cgroup *memcg) 
	if (!memcg)

		memcg = root_mem_cgroup;



	if (memcg_vmstats_needs_flush(memcg->vmstats))

		do_flush_stats(memcg);

	__mem_cgroup_flush_stats(memcg, false);

}



void mem_cgroup_flush_stats_ratelimited(struct mem_cgroup *memcg)
@@ -637,7 +639,7 @@ static void flush_memcg_stats_dwork(struct work_struct *w) 
	 * Deliberately ignore memcg_vmstats_needs_flush() here so that flushing

	 * in latency-sensitive paths is as cheap as possible.

	 */

	do_flush_stats(root_mem_cgroup);

	__mem_cgroup_flush_stats(root_mem_cgroup, true);

	queue_delayed_work(system_unbound_wq, &stats_flush_dwork, FLUSH_TIME);

}
@@ -5286,11 +5288,8 @@ bool obj_cgroup_may_zswap(struct obj_cgroup *objcg) 
			break;

		}



		/*

		 * mem_cgroup_flush_stats() ignores small changes. Use

		 * do_flush_stats() directly to get accurate stats for charging.

		 */

		do_flush_stats(memcg);

		/* Force flush to get accurate stats for charging */

		__mem_cgroup_flush_stats(memcg, true);

		pages = memcg_page_state(memcg, MEMCG_ZSWAP_B) / PAGE_SIZE;

		if (pages < max)

			continue;