From: Nhat Pham <nphamcs@gmail.com>
To: Yosry Ahmed <yosryahmed@google.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>,
Jesper Dangaard Brouer <hawk@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>,
Roman Gushchin <roman.gushchin@linux.dev>,
Muchun Song <muchun.song@linux.dev>, Yu Zhao <yuzhao@google.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Meta kernel team <kernel-team@meta.com>,
cgroups@vger.kernel.org
Subject: Re: [PATCH v2] memcg: use ratelimited stats flush in the reclaim
Date: Wed, 14 Aug 2024 17:19:35 -0700 [thread overview]
Message-ID: <CAKEwX=M7sWx94nJ0zK-46Xn8ZZHhcHQtb37qR0Jxit+8sAaQWg@mail.gmail.com> (raw)
In-Reply-To: <CAJD7tkaBfWWS32VYAwkgyfzkD_WbUUbx+rrK-Cc6OT7UN27DYA@mail.gmail.com>
On Wed, Aug 14, 2024 at 4:49 PM Yosry Ahmed <yosryahmed@google.com> wrote:
>
>
> We can also use such atomic counters in obj_cgroup_may_zswap() and
> eliminate the rstat flush there as well. Same for zswap_current_read()
> probably.
zswap/zswapped are subtree-cumulative counters. Would that be a problem?
>
> Most in-kernel flushers really only need a few stats, so I am
> wondering if it's better to incrementally move these ones outside of
> the rstat framework and completely eliminate in-kernel flushers. For
> instance, MGLRU does not require the flush that reclaim does as
> Shakeel pointed out.
>
> This will solve so many scalability problems that all of us have
> observed at some point or another and tried to optimize. I believe
> using rstat for userspace reads was the original intention anyway.
But yeah, the fewer in-kernel flushers we have, the fewer
scalability/lock contention issues there will be. Not an expert in
this area, but sounds like a worthwhile direction to pursue.
next prev parent reply other threads:[~2024-08-15 0:19 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-13 21:53 Shakeel Butt
2024-08-13 21:58 ` Yosry Ahmed
2024-08-13 22:30 ` Shakeel Butt
2024-08-14 12:57 ` Jesper Dangaard Brouer
2024-08-14 16:32 ` Shakeel Butt
2024-08-14 23:03 ` Nhat Pham
2024-08-14 23:42 ` Shakeel Butt
2024-08-14 23:48 ` Yosry Ahmed
2024-08-15 0:19 ` Nhat Pham [this message]
2024-08-15 0:22 ` Yosry Ahmed
2024-08-15 0:29 ` Shakeel Butt
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