On Mon, Oct 28, 2024 at 7:11 PM JP Kobryn <inwardvessel@xxxxxxxxx> wrote:
>
> 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.
>
> Signed-off-by: JP Kobryn <inwardvessel@xxxxxxxxx>
Reviewed-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
> ---
> mm/memcontrol.c | 17 ++++++++---------
> 1 file changed, 8 insertions(+), 9 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 18c3f513d766..59f6f247fc13 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -588,8 +588,11 @@ 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);
>
> @@ -613,8 +616,7 @@ 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)
> @@ -630,7 +632,7 @@ 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);
> }
>
> @@ -5281,11 +5283,8 @@ 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;
> --
> 2.47.0
>
