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References: <20231213-zswap-dstmem-v5-0-9382162bbf05@bytedance.com> <20231213-zswap-dstmem-v5-5-9382162bbf05@bytedance.com>
In-Reply-To: <20231213-zswap-dstmem-v5-5-9382162bbf05@bytedance.com>
From: Yosry Ahmed <yosryahmed@google.com>
Date: Thu, 28 Dec 2023 07:19:08 -0800
Message-ID: <CAJD7tkber7UL7F-ZghNvVig=7zoAB9cPMjaQpWm8c6Y9OrmBFQ@mail.gmail.com>
Subject: Re: [PATCH v5 5/5] mm/zswap: change per-cpu mutex and buffer to per-acomp_ctx
To: Chengming Zhou <zhouchengming@bytedance.com>
Cc: Barry Song <21cnbao@gmail.com>, Nhat Pham <nphamcs@gmail.com>, 
	Andrew Morton <akpm@linux-foundation.org>, Dan Streetman <ddstreet@ieee.org>, 
	Vitaly Wool <vitaly.wool@konsulko.com>, Johannes Weiner <hannes@cmpxchg.org>, 
	Chris Li <chriscli@google.com>, Seth Jennings <sjenning@redhat.com>, Chris Li <chrisl@kernel.org>, 
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
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On Thu, Dec 28, 2023 at 1:46=E2=80=AFAM Chengming Zhou
<zhouchengming@bytedance.com> wrote:
>
> First of all, we need to rename acomp_ctx->dstmem field to buffer,
> since we are now using for purposes other than compression.
>
> Then we change per-cpu mutex and buffer to per-acomp_ctx, since
> them belong to the acomp_ctx and are necessary parts when used
> in the compress/decompress contexts.
>
> So we can remove the old per-cpu mutex and dstmem.
>
> Acked-by: Chris Li <chrisl@kernel.org> (Google)
> Reviewed-by: Nhat Pham <nphamcs@gmail.com>
> Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>

Instead of hardcoding PAGE_SIZE * 2 multiple times, can we define a
constant for this and document the need for the buffer size there?
Even better if that constant is based on WORST_COMPR_FACTOR and shared
between zswap and zram -- but this can be a follow up change.