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 DBD56C77B6C for ; Wed, 5 Apr 2023 15:05:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 28EE46B0072; Wed, 5 Apr 2023 11:05:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 217FF6B0074; Wed, 5 Apr 2023 11:05:23 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0B9FD6B0075; Wed, 5 Apr 2023 11:05:23 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id EDA986B0072 for ; Wed, 5 Apr 2023 11:05:22 -0400 (EDT) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id BC1671A118C for ; Wed, 5 Apr 2023 15:05:22 +0000 (UTC) X-FDA: 80647660884.10.9B35791 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf24.hostedemail.com (Postfix) with ESMTP id 5D56F180026 for ; Wed, 5 Apr 2023 15:05:19 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=B02mlYlJ; spf=none (imf24.hostedemail.com: domain of BATV+46b8a92f13ae362fdcdf+7164+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+46b8a92f13ae362fdcdf+7164+infradead.org+hch@bombadil.srs.infradead.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1680707120; a=rsa-sha256; cv=none; b=RLfT7JpHlrYor11zPM0uqNrnDqHqYimeHor8B7vBFrXUKYtbo0vKoEdujUJhpOUYI6tj5U QV8vdf3vBTcatOs9NKXLeEYGRFw1sc1+pMBBj7LH0dc2vOesLUZlPWXferB1mUXFePpVWK uYSE3eo6trBeggUJZ/ocwWfjhEyt2uk= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=B02mlYlJ; spf=none (imf24.hostedemail.com: domain of BATV+46b8a92f13ae362fdcdf+7164+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+46b8a92f13ae362fdcdf+7164+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=1680707120; 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=48zfX+R4D/KjMsx+hDA/cvkhA+0xsbJ5NdemC9lhYPY=; b=nxAYnBkbAaa/DsBwFVhwTIZzoGTRb9WlcX+vO+isYBT7px9XcWIRwEvxw6cbU67ksPoBOj PLImsw8z3KNHD9uJmynqo2maacYnpHBnr8vQhuBg1eVnqAvpuukPKetQFZ1w9PxODZq9sf NM3efeKl1SkGZfWDNJADSAmguzCvq/k= 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=48zfX+R4D/KjMsx+hDA/cvkhA+0xsbJ5NdemC9lhYPY=; b=B02mlYlJo8YnMyQr/pWc9OnEnq vEJIGspvLVhFvrfqZuBhFZHYfgv7nUd/IPKRXT9kbgCspMF2tMgWY0+bN3DfUsk/13eXXorMhzvmV 7ntFHGEVgjLr8cf4FiuTOtAXT59DJ4KFaYmyDbti6ZboZJRfRoXeAW/d3H6CudDLC5+nCdO24mnNR UfohHx/9mrphbQjnBPzo1WAs2C36jcLVaNglLHuXQ/ABCkjwzCKDifjQJ9P885VG0STzpw4Ib+raR tdyvGBLga1M53Hj0uKOomN1uzFQFf/13OisHdpxe4VkTj//an2R3WqqmRoE1A+0h4rMALfGY/ZdiR oVVnJqpA==; Received: from hch by bombadil.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1pk4gy-004kve-08; Wed, 05 Apr 2023 15:04:56 +0000 Date: Wed, 5 Apr 2023 08:04:56 -0700 From: Christoph Hellwig To: David Howells Cc: Matthew Wilcox , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Al Viro , Christoph Hellwig , Jens Axboe , Jeff Layton , Christian Brauner , Chuck Lever III , Linus Torvalds , netdev@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Lorenzo Bianconi , Felix Fietkau , John Crispin , Sean Wang , Mark Lee , Keith Busch , Christoph Hellwig , Sagi Grimberg , Chaitanya Kulkarni , linux-nvme@lists.infradead.org, linux-mediatek@lists.infradead.org Subject: Re: [PATCH v3 06/55] mm: Make the page_frag_cache allocator use per-cpu Message-ID: References: <20230331160914.1608208-1-dhowells@redhat.com> <20230331160914.1608208-7-dhowells@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230331160914.1608208-7-dhowells@redhat.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html X-Rspam-User: X-Rspamd-Queue-Id: 5D56F180026 X-Rspamd-Server: rspam01 X-Stat-Signature: f9o4fhpxwntb6z3cgiyh55p6nwbad6hz X-HE-Tag: 1680707119-815989 X-HE-Meta: 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 DVPGcP73 p1AHulJLAvcJQfAwTQXc+yGXYaBgyd2l23r/Q2MqHhj4Hz0mTZ8RxC/NqyM914cxbuf3rp6AihlKfZHKpBMo9PPBdeO/ZFH5VF3OabK6DWBrxzBN1H4IYULaS37Aq/XEAGSiprhREssjkse2jVeX+vzWyyRE+KIeYSOyTHMOjU5FYCnWgriTi1JtIO+ln64/cNi07+UviisXPabh2oIZAGRan/z7Uym/CMrMjEAi6svMdEhUSRsTdpq/4pyc+KsBlu8xx1Iz/Gie2MaNCEISQBGx5aFraDf+UEEzSORVZKjKqzhPVJaG+Hfas8VjUUc32sNdoOunJmapH2jz5mNPsl60bS5XFHa2U0dbexIEgpE3JxL9ZWaJZIBXCiK0k8QYdkZzRyhExgjRAucgRbVM5ORI9vYGyr8fsAlbDTkfBD+jmvslY14lTxDH0gCmVZCruTjnH4m77t1ZS/cw+wnxd7i5GmLAW6xnl9Sac 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 Fri, Mar 31, 2023 at 05:08:25PM +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 split this into a separte series? Right now I only see this patch in mbox and miss the context on why wed want this. > Make the NVMe and mediatek drivers pass in NULL to page_frag_cache() and > use the default allocation buckets rather than defining their own. Can you explain why?