From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2CF89D29DC2 for ; Tue, 13 Jan 2026 04:31:37 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id EEC136B0005; Mon, 12 Jan 2026 23:31:36 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id E99CD6B0089; Mon, 12 Jan 2026 23:31:36 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DA59F6B008A; Mon, 12 Jan 2026 23:31:36 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id CAE196B0005 for ; Mon, 12 Jan 2026 23:31:36 -0500 (EST) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 286D91A74D for ; Tue, 13 Jan 2026 04:31:36 +0000 (UTC) X-FDA: 84325666992.17.45FEABE Received: from abb.hmeau.com (abb.hmeau.com [180.181.231.80]) by imf28.hostedemail.com (Postfix) with ESMTP id 9B834C0010 for ; Tue, 13 Jan 2026 04:31:33 +0000 (UTC) Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=gondor.apana.org.au header.s=h01 header.b=BAkTdP8q; spf=pass (imf28.hostedemail.com: domain of herbert@gondor.apana.org.au designates 180.181.231.80 as permitted sender) smtp.mailfrom=herbert@gondor.apana.org.au; dmarc=pass (policy=quarantine) header.from=apana.org.au ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1768278694; a=rsa-sha256; cv=none; b=XhIBghRQeW8OT53pnBSYJlfF21p3rR/Ikxn/QtaKBUx7T1mdUKUNQko7QCXIjuUBrWbL8O y7JHs1336hE5GXr89CFsNWnuH8VJzkT0/Kjw3D3mjKpS+9Bgun8IBnv8kBi5IE3mQfJeTD GfW8p7tNQBwXjw71HREwnJUY7CB9H1k= ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=pass header.d=gondor.apana.org.au header.s=h01 header.b=BAkTdP8q; spf=pass (imf28.hostedemail.com: domain of herbert@gondor.apana.org.au designates 180.181.231.80 as permitted sender) smtp.mailfrom=herbert@gondor.apana.org.au; dmarc=pass (policy=quarantine) header.from=apana.org.au ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1768278694; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=/pp81rQAMhtIyr/Wtg2fg/qbmVYAdF7/Cz7odtkofXs=; b=6JpuCfrNALZt+wMYLonuTiUG0Q2Ri5Q42MH+ArsbBCa+ZQ/w+bXr56u6V5mSr+JLYfyWjU fdS8Q29Jav0/ulrdcug4wOJM+e3IG8tEzkS+uhiPAFLM9x94DigmocgY8PKjDxaUNNXWl3 +5Z0m19lqT/k1MLfQfCCRuExI9N5F0E= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gondor.apana.org.au; s=h01; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:cc:to:subject:message-id:date: from:content-type:reply-to; bh=/pp81rQAMhtIyr/Wtg2fg/qbmVYAdF7/Cz7odtkofXs=; b=BAkTdP8qpghJLdcrfg0qrzk1VDQjiN1SUNcj+XKOLJV1UZR2nTD/vtJ25qL3/Ficf6nggqrAFRA P78UjgHnZoJ063amkA26uAG5/hW/GMF6wb80xQv/neI+nPNO+MZpxHGQYJnn2wwG9Q8CG13JhLASf M+YXgji5qx3H0rle2JIvZnfMakW5c/dWZ663CHt9xShu09k77ArMcPHQ+f4KUGMfidxNae57GDZ+i OKSpsE/6Z/pYeAoaawIY+bqqcQYQLT5HXfV1W0BipTzOziMEhGyvSuDoskklQY4l00KEAm0zpnIuN bNHBUApGlhS3zX6wHDEnLOl7y406uc8k73Yg==; Received: from loth.rohan.me.apana.org.au ([192.168.167.2]) by formenos.hmeau.com with smtp (Exim 4.96 #2 (Debian)) id 1vfW3V-00GH2y-1T; Tue, 13 Jan 2026 12:30:58 +0800 Received: by loth.rohan.me.apana.org.au (sSMTP sendmail emulation); Tue, 13 Jan 2026 12:30:57 +0800 Date: Tue, 13 Jan 2026 12:30:57 +0800 From: Herbert Xu To: Sergey Senozhatsky Cc: Andrew Morton , Yosry Ahmed , Minchan Kim , Nhat Pham , Johannes Weiner , Brian Geffon , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] zsmalloc: introduce SG-list based object read API Message-ID: References: <20260113034645.2729998-1-senozhatsky@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260113034645.2729998-1-senozhatsky@chromium.org> X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 9B834C0010 X-Stat-Signature: nfxm8633yj86nteenn3ttjzx1kapdrzn X-Rspam-User: X-HE-Tag: 1768278693-708726 X-HE-Meta: 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Jan 13, 2026 at 12:46:45PM +0900, Sergey Senozhatsky wrote: > Currently, zsmalloc performs address linearization on read > (which sometimes requires memcpy() to a local buffer). > Not all zsmalloc users need a linear address. For example, > Crypto API supports SG-list, performing linearization under > the hood, if needed. In addition, some compressors can have > native SG-list support, completely avoiding the linearization > step. > > Provide an SG-list based zsmalloc read API: > - zs_obj_read_sg_begin() > - zs_obj_read_sg_end() > > This API allows callers to obtain an SG representation > of the object (one entry for objects that are contained > in a single page and two entries for spanning objects), > avoiding the need for a bounce buffer and memcpy. > > Signed-off-by: Sergey Senozhatsky > Cc: Herbert Xu > --- > include/linux/zsmalloc.h | 4 +++ > mm/zsmalloc.c | 65 ++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 69 insertions(+) Acked-by: Herbert Xu Thanks, -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt