linux-kernel - Re: [PATCH v13 22/22] mm: zswap: Batched zswap_compress() with compress batching of large folios.

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Message-ID: <aTZS4RKR3Zci8d_I@gondor.apana.org.au>
Date: Mon, 8 Dec 2025 12:24:01 +0800
From: Herbert Xu <herbert@...dor.apana.org.au>
To: "Sridhar, Kanchana P" <kanchana.p.sridhar@...el.com>
Cc: Yosry Ahmed <yosry.ahmed@...ux.dev>, SeongJae Park <sj@...nel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-mm@...ck.org" <linux-mm@...ck.org>,
	"hannes@...xchg.org" <hannes@...xchg.org>,
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	"Feghali, Wajdi K" <wajdi.k.feghali@...el.com>,
	"Gopal, Vinodh" <vinodh.gopal@...el.com>
Subject: Re: [PATCH v13 22/22] mm: zswap: Batched zswap_compress() with
 compress batching of large folios.

On Mon, Dec 08, 2025 at 04:17:38AM +0000, Sridhar, Kanchana P wrote:
>
> I see. So the way my patch-set tries to standardize batching in
> zswap_compress() is to call it with a batch of 8 pages, regardless of batching
> or non-batching compressors. In zswap_compress(), I presently iterate
> through each page in the batch for sequential processing for non-batching
> compressors whose batch size is 1. For batching compressors, the iteration
> happens just once: the whole batch is compressed in one call to
> crypto_acomp_compress().

Oh I wasn't aware of this.  In that case there is no need for me
to delay the next step and we can do it straight away.

I had thought that the batch size was to limit the batching size
to acomp.  But if it's not, perhaps we can remove the batch size
exposure altogether.  IOW it would only be visible internally to
the acomp API while the users such as zswap would simply batch
things in whatever size that suits them.

Thanks,
-- 
Email: Herbert Xu <herbert@...dor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
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