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]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5E78DC021B8 for ; Sat, 1 Mar 2025 07:04:08 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B2D856B007B; Sat, 1 Mar 2025 02:04:07 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id ADD0F6B0082; Sat, 1 Mar 2025 02:04:07 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9CB616B0083; Sat, 1 Mar 2025 02:04:07 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 7FB7E6B007B for ; Sat, 1 Mar 2025 02:04:07 -0500 (EST) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id DF81B81B2B for ; Sat, 1 Mar 2025 07:04:06 +0000 (UTC) X-FDA: 83172092892.22.417099F Received: from abb.hmeau.com (abb.hmeau.com [144.6.53.87]) by imf02.hostedemail.com (Postfix) with ESMTP id BF1B680005 for ; Sat, 1 Mar 2025 07:04:04 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=hmeau.com header.s=formenos header.b=q8hA7oPL; dmarc=pass (policy=quarantine) header.from=apana.org.au; spf=pass (imf02.hostedemail.com: domain of herbert@gondor.apana.org.au designates 144.6.53.87 as permitted sender) smtp.mailfrom=herbert@gondor.apana.org.au ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1740812645; 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=/wZMqZ2Ju9nv88CrsTXF+I4+HMBtyCzE6QMvTsRE1Ao=; b=HjZKnW3s4Zo7Jd3jvWF5eHXL+jsCheLoBSAdIiWabzlettDYUdrqcLvMZ1bFH1DNyLupcj osKeZNIZF32by6U/tS/MpBf+hLYhL4umVTTI57b54H25WpG0AALlJv6hOlVABEA2oNgU0F yrK7/owRpy25l6DYQxyoMT5GwkL2j04= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1740812645; a=rsa-sha256; cv=none; b=EcKDvhe+Tbllbl5WqWL+4VtPd4WLA2RiTDt0fLRNLl/LfDneVnpWj+WAeQwYPY6qkMINzN Q8aqZMJpl7SN7LrAE0xg95gOG3aDpkpQOtoVOAnGOZFX4MFwOptuAhQmoTB0yOSGL6aGm0 8nEndG44gc6MkoiKHmNCsduuERf0FTg= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=hmeau.com header.s=formenos header.b=q8hA7oPL; dmarc=pass (policy=quarantine) header.from=apana.org.au; spf=pass (imf02.hostedemail.com: domain of herbert@gondor.apana.org.au designates 144.6.53.87 as permitted sender) smtp.mailfrom=herbert@gondor.apana.org.au DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=hmeau.com; s=formenos; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=/wZMqZ2Ju9nv88CrsTXF+I4+HMBtyCzE6QMvTsRE1Ao=; b=q8hA7oPLlauPwKQL5mD0rFaWH9 kroWWQ9yCZ+M1Y/VKeW3LB418ZLIo5wDeRwjb1j9s2hOYvhHOMZq1IM5hP23oeSPZ/RxwIAouUjl6 eh86LRzTkgQAjSaBmpU4yAkd/rm89iJ33Sd33oojyI0IjHU11QkuUu1lTCElWVqV7mW19//JdH+Qe Ml8vLXQyT4d9KalJvWgOS0FokOFgMP07q0kLCIltrJWgXQzIUACcmTlKXsLJ9ywXzdj7btSxxO2pV QQdIa15ZSgow91z1JRDYCC99y9ddWTXDJhq+4JWCS1yKn08NOo0hpgt/QGcEYQhf5pmtaY8uWhE/l 0QsbPj7A==; Received: from loth.rohan.me.apana.org.au ([192.168.167.2]) by formenos.hmeau.com with smtp (Exim 4.96 #2 (Debian)) id 1toGt2-002mQP-2o; Sat, 01 Mar 2025 15:03:49 +0800 Received: by loth.rohan.me.apana.org.au (sSMTP sendmail emulation); Sat, 01 Mar 2025 15:03:48 +0800 Date: Sat, 1 Mar 2025 15:03:48 +0800 From: Herbert Xu To: Yosry Ahmed Cc: Eric Biggers , Linux Crypto Mailing List , linux-mm@kvack.org Subject: Re: [RFC PATCH 7/7] mm: zswap: Use acomp virtual address interface Message-ID: References: <153c340a52090f2ff82f8f066203186a932d3f99.1740651138.git.herbert@gondor.apana.org.au> <20250227183847.GB1613@sol.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: BF1B680005 X-Stat-Signature: k16inmnwijafn51pzhby4jkoa933dy9o X-HE-Tag: 1740812644-986446 X-HE-Meta: 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 iCfYD/kl Kn20T+mOjPPvgqIQePE0rrWL8qoavZobzk0YXS3zOyD9v9u7OBncvHnXJQk0Eb6GRHVW3m/OnIIUkzwhI5XhKu5ZAKqtZ13HqCZH9qBrg4hFMxzJQ2LXtpk2kKhg4W+/Rw3j5ptH6yhawKzL/iWskjVG5tTVbm3LV4IK87+YP/FVuwIPTrs+B0ditNA8YKHNw5h4nL1LrXI9Nwa4ZWZ27ZUCAInqNwRc/KVSB2JoUKMaQzxztJ/aLsC4AaVUnvPg4NYKMSbqdx6+HsDg= 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 Sat, Mar 01, 2025 at 02:36:50PM +0800, Herbert Xu wrote: > > I thought this was a lot more complicated and you had some weird > arbtirary pointer from an unknown source. But if it's just highmem > I can get rid of the memcpy for you right now. So it appears that your highmem usage is coming from zsmalloc. In that case you don't want virtual addresses at all, you want an SG list. In fact you've already gone through a totally unnecessary copy in _zs_map_object. Had it simply given us a 2-entry SG list, the Crypto API can process the data directly with no copies at all. The whole point of SG lists is to deal with memory fragmentation. When your object is too big to fit in a single page, you need an SG list to describe it. Forcing virtual addresses just leads to an unnecessary copy. Chers, -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt