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 AD86CC7619A for ; Wed, 12 Apr 2023 15:32:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1BE63900003; Wed, 12 Apr 2023 11:32:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1488A6B0078; Wed, 12 Apr 2023 11:32:14 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 00F1D900003; Wed, 12 Apr 2023 11:32:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id E1CDB6B0074 for ; Wed, 12 Apr 2023 11:32:13 -0400 (EDT) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id B2316120125 for ; Wed, 12 Apr 2023 15:32:13 +0000 (UTC) X-FDA: 80673130146.15.EECE39A Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf18.hostedemail.com (Postfix) with ESMTP id 56AF01C002B for ; Wed, 12 Apr 2023 15:32:11 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=y5JRgZIJ; spf=none (imf18.hostedemail.com: domain of BATV+76e3400107323edf7514+7171+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+76e3400107323edf7514+7171+infradead.org+hch@bombadil.srs.infradead.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1681313531; 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=jVIUX30CHSeuMRIZ4MbX/VFPgD+9bUpANKvI3RmLVRc=; b=P01XFYNBQiVc/PIMEyJrao8KVAv4fO+hrWypG1tQgflSMOOxb609KehgOy0NmdxJq/G+Pa lUmuAVtyjAgHDr2UCDMHq1UBxTl0KhOazhb2qfOgjf/xi+KfZ6vylXPqbEGRkg46WXKCCf 53y2fcgFvyTy7UAOREn857sbZLADBJM= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=y5JRgZIJ; spf=none (imf18.hostedemail.com: domain of BATV+76e3400107323edf7514+7171+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+76e3400107323edf7514+7171+infradead.org+hch@bombadil.srs.infradead.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1681313531; a=rsa-sha256; cv=none; b=vLRG171OjyS6WdlnypIVONePqdo1rRIIjI3Dckoy7YZZQ/GdVIexflGwx57eZdH1kzFYbq 8D9+kBqYqnxnJ/AIRiclg+xPTxALWXcjSbWl7SF4Kw9ZAXacWmqwP9I+Hjkdm5J2gwiff+ +7hr9Iu//64jXurQvSGHzqhnnNtjmb4= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; 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; bh=jVIUX30CHSeuMRIZ4MbX/VFPgD+9bUpANKvI3RmLVRc=; b=y5JRgZIJ8RY6GdBqYVEE/YVMEp dqmS2vYU/39+lDvSEZChJo8KFFmv8H+CObQ8w7xEEbiDMJhtF/yb+Sl/X5fUSnZLlwk5OQrb+Uu7o ZkIPfe/2ZZeZXXOqAzImp8FRwvcc9X0cS72YSeedaNoOOZNDB5A+r6WbRAOn5ceLv6Me3d41Soyoe BJBLTcoAnPbOOhKgq5tMK0+vkFJBKfg8+/OO9XGGllNz7hfJ5qiiEcg6g9PP3Or4q28T5+OLNIggI i48okYGNvg3shRsABwU6JgMeVEKYWVJtUTT6ZRFivxtjHE15fUaUidKVR+Nc1Uxpghun2l+zXXadg v88nBQMw==; Received: from hch by bombadil.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1pmcRi-003dp9-1Q; Wed, 12 Apr 2023 15:31:42 +0000 Date: Wed, 12 Apr 2023 08:31:42 -0700 From: Christoph Hellwig To: David Howells Cc: netdev@vger.kernel.org, "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Willem de Bruijn , David Ahern , Matthew Wilcox , Al Viro , Christoph Hellwig , Jens Axboe , Jeff Layton , Christian Brauner , Chuck Lever III , Linus Torvalds , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Jeroen de Borst , Catherine Sullivan , Shailend Chand , Felix Fietkau , John Crispin , Sean Wang , Mark Lee , Lorenzo Bianconi , Matthias Brugger , AngeloGioacchino Del Regno , Keith Busch , Jens Axboe , Christoph Hellwig , Sagi Grimberg , Chaitanya Kulkarni , Andrew Morton , linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-nvme@lists.infradead.org Subject: Re: [PATCH net-next v6 04/18] mm: Make the page_frag_cache allocator use per-cpu Message-ID: References: <20230411160902.4134381-1-dhowells@redhat.com> <20230411160902.4134381-5-dhowells@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230411160902.4134381-5-dhowells@redhat.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 56AF01C002B X-Rspam-User: X-Stat-Signature: frwfmyd35ow6976ca5b4a7xeipyfaptw X-HE-Tag: 1681313531-824266 X-HE-Meta: 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 7Ptnf4eg 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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: On Tue, Apr 11, 2023 at 05:08:48PM +0100, David Howells wrote: > Make the page_frag_cache allocator have a separate allocation bucket for > each cpu to avoid racing. This means that no lock is required, other than > preempt disablement, to allocate from it, though if a softirq wants to > access it, then softirq disablement will need to be added. Can you show any performance numbers? > Make the NVMe, mediatek and GVE drivers pass in NULL to page_frag_cache() > and use the default allocation buckets rather than defining their own. Let me ask a third time as I've not got an answer the last two times: why are these callers treated different from the others?