From: Herbert Xu <herbert@gondor.apana.org.au>
To: Yosry Ahmed <yosry.ahmed@linux.dev>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>,
Andrew Morton <akpm@linux-foundation.org>,
Nhat Pham <nphamcs@gmail.com>, Minchan Kim <minchan@kernel.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Brian Geffon <bgeffon@google.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [RFC PATCH 2/2] zsmalloc: chain-length configuration should consider other metrics
Date: Thu, 8 Jan 2026 16:05:14 +0800 [thread overview]
Message-ID: <aV9lOve5tabZqKSt@gondor.apana.org.au> (raw)
In-Reply-To: <yxpn4gan74uryy6huzulsqvqvbsqiehdqe6lu7m3hjf3tjjdop@a6cifoycstso>
On Thu, Jan 08, 2026 at 08:01:20AM +0000, Yosry Ahmed wrote:
>
> IIUC based on Herbert's previous response, crypto and scomp already
> support passing in a discontiguous SG-list. So for zswap, if zsmalloc
> returns an SG-list, it will just be passed as-is to the crypto API.
>
> If zram can also use the SG-list, then we can completely drop the
> memcpy() logic from zsmalloc.
>
> Herbert, please correct me if I am wrong.
You're correct. The SG support has always been there. You can
use that today and scomp will perform the memcpy for you if and
only if it's necessary.
The algorithm-specific SG support would simply be a performance
enhancement that eliminates the memcpy entirely for whichever
algorithm that we choose to implement it for.
Cheers,
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
next prev parent reply other threads:[~2026-01-08 8:05 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-01 1:38 [RFC PATCH 0/2] zsmalloc: size-classes chain-length tunings Sergey Senozhatsky
2026-01-01 1:38 ` [RFC PATCH 1/2] zsmalloc: drop hard limit on the number of size classes Sergey Senozhatsky
2026-01-01 1:38 ` [RFC PATCH 2/2] zsmalloc: chain-length configuration should consider other metrics Sergey Senozhatsky
2026-01-02 18:29 ` Yosry Ahmed
2026-01-05 1:42 ` Sergey Senozhatsky
2026-01-05 7:23 ` Sergey Senozhatsky
2026-01-05 16:01 ` Yosry Ahmed
2026-01-06 4:10 ` Sergey Senozhatsky
2026-01-05 15:58 ` Yosry Ahmed
2026-01-06 4:20 ` Sergey Senozhatsky
2026-01-06 4:22 ` Sergey Senozhatsky
2026-01-06 5:08 ` Herbert Xu
2026-01-06 16:24 ` Yosry Ahmed
2026-01-07 5:25 ` Herbert Xu
2026-01-07 5:39 ` Yosry Ahmed
2026-01-07 5:42 ` Herbert Xu
2026-01-07 5:43 ` Sergey Senozhatsky
2026-01-07 17:12 ` Yosry Ahmed
2026-01-08 7:37 ` Sergey Senozhatsky
2026-01-08 8:01 ` Yosry Ahmed
2026-01-08 8:05 ` Herbert Xu [this message]
2026-01-09 3:29 ` Sergey Senozhatsky
2026-01-06 9:47 ` Sergey Senozhatsky
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