From: Nhat Pham <nphamcs@gmail.com>
To: Kairui Song <ryncsn@gmail.com>
Cc: Zhaoyu Liu <liuzhaoyu.zackary@bytedance.com>,
akpm@linux-foundation.org, ying.huang@intel.com,
songmuchun@bytedance.com, david@redhat.com, willy@infradead.org,
chrisl@kernel.org, yosryahmed@google.com,
guo.ziliang@zte.com.cn, linux-kernel@vger.kernel.org,
linux-mm@kvack.org
Subject: Re: [PATCH] mm: swap: prejudgement swap_has_cache to avoid page allocation
Date: Mon, 1 Apr 2024 08:20:40 -0700 [thread overview]
Message-ID: <CAKEwX=O8_arvHJy7ZUZP+j4zY8Yj=Z4iGEgDh4B-GG0cnHphLw@mail.gmail.com> (raw)
In-Reply-To: <CAMgjq7C-4H5zcbs_-mvSNBBWiGhx__0_sTTG32Nfsz7TnP=i5Q@mail.gmail.com>
On Mon, Apr 1, 2024 at 8:15 AM Kairui Song <ryncsn@gmail.com> wrote:
> eg. If swap_has_cache returns true, then swap cache is freed, and
> skip_if_exists is set to true, __read_swap_cache_async will return
> NULL for an entry that it should be able to alloc and cache, could
> this be a problem (for example, causing zswap writeback to fail with
> ENOMEM due to readahead)?
Yeah the scenario you describe sounds plausible to me. This will make
zswap writeback less efficient - it seems more pages will be
(unnecessarily) skipped because of this check.
next prev parent reply other threads:[~2024-04-01 15:20 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-01 14:09 Zhaoyu Liu
2024-04-01 15:15 ` Kairui Song
2024-04-01 15:20 ` Nhat Pham [this message]
2024-04-02 8:50 ` Zhaoyu Liu
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