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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 04664C7619A for ; Wed, 5 Apr 2023 15:05:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=48zfX+R4D/KjMsx+hDA/cvkhA+0xsbJ5NdemC9lhYPY=; b=DvUvDdFKdN0w4Jb24t0LMz4IZ5 HcMlUbkbgNywXTg8uBFtN6YNwgCtZ5EwOKbywHM+mLdO1aIrlEaLs6ck3Hp7XtacmiMCO+rlg2dD3 2MkmqZ6YBY/1AyH74EWT0Pl2T4gurPpkcobuh3LqFp5jEtBtO/MQFiCx3eSJb3BDLO08O2csSXCac 6cOef3Uq9oxv7XVDWwZcfaXfXz3sVyt5HbJdmHPuUOEm1rVeb9a7O7X4pwbqgAsLfgpwCTsSS8VkI iORBLaCXcVI30yqQHTb2+Ejhc06ast3gbvtO8SevAUkbwn0vkkvmcOu/El7zikX6C6hJOb1PkgU+Q ObFLiT0A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pk4h1-004kwe-2S; Wed, 05 Apr 2023 15:04:59 +0000 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-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org 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?