From: Yosry Ahmed <yosryahmed@google.com>
To: Chengming Zhou <zhouchengming@bytedance.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Nhat Pham <nphamcs@gmail.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] mm/zswap: change zswap_pool kref to percpu_ref
Date: Mon, 12 Feb 2024 14:42:09 -0800 [thread overview]
Message-ID: <CAJD7tkYdEWrrQj+MFNpDR6FHc60czXcuawh3dd1rSF=QQm6+yg@mail.gmail.com> (raw)
In-Reply-To: <20240210-zswap-global-lru-v1-2-853473d7b0da@bytedance.com>
On Sun, Feb 11, 2024 at 5:58 AM Chengming Zhou
<zhouchengming@bytedance.com> wrote:
>
> All zswap entries will take a reference of zswap_pool when
> zswap_store(), and drop it when free. Change it to use the
> percpu_ref is better for scalability performance.
>
> Testing kernel build in tmpfs with memory.max=2GB
> (zswap shrinker and writeback enabled with one 50GB swapfile).
>
> mm-unstable zswap-global-lru
> real 63.20 63.12
> user 1061.75 1062.95
> sys 268.74 264.44
Are these numbers from a single run or the average of multiple runs?
It just seems that the improvement is small, and percpu refcnt is
slightly less intuitive (and uses a bit more memory), so let's make
sure there is a real performance gain first.
It would also be useful to mention how many threads/CPUs are being used here.
next prev parent reply other threads:[~2024-02-12 22:42 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-11 13:57 [PATCH 0/2] mm/zswap: optimize for dynamic zswap_pools Chengming Zhou
2024-02-11 13:57 ` [PATCH 1/2] mm/zswap: global lru and shrinker shared by all zswap_pools Chengming Zhou
2024-02-11 19:01 ` kernel test robot
2024-02-12 13:17 ` Chengming Zhou
2024-02-11 21:04 ` Nhat Pham
2024-02-12 13:20 ` Chengming Zhou
2024-02-11 22:05 ` kernel test robot
2024-02-13 12:57 ` Yosry Ahmed
2024-02-13 14:20 ` Chengming Zhou
2024-02-13 17:43 ` Yosry Ahmed
2024-02-11 13:57 ` [PATCH 2/2] mm/zswap: change zswap_pool kref to percpu_ref Chengming Zhou
2024-02-11 21:21 ` Nhat Pham
2024-02-12 13:29 ` Chengming Zhou
2024-02-12 18:53 ` Nhat Pham
2024-02-13 14:22 ` Chengming Zhou
2024-02-12 22:42 ` Yosry Ahmed [this message]
2024-02-13 14:31 ` Chengming Zhou
2024-02-13 17:45 ` Yosry Ahmed
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