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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A84BBC4332F for ; Sat, 5 Mar 2022 05:19:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230180AbiCEFU0 (ORCPT ); Sat, 5 Mar 2022 00:20:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55294 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229495AbiCEFU0 (ORCPT ); Sat, 5 Mar 2022 00:20:26 -0500 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB63B120F61; Fri, 4 Mar 2022 21:19:33 -0800 (PST) Received: by verein.lst.de (Postfix, from userid 2407) id BE57B68AFE; Sat, 5 Mar 2022 06:19:29 +0100 (CET) Date: Sat, 5 Mar 2022 06:19:29 +0100 From: Christoph Hellwig To: Dave Chinner Cc: Christoph Hellwig , axboe@kernel.dk, sagi@grimberg.me, kbusch@kernel.org, song@kernel.org, linux-block@vger.kernel.org, linux-raid@vger.kernel.org, linux-nvme@lists.infradead.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 2/2] block: remove the per-bio/request write hint Message-ID: <20220305051929.GA24696@lst.de> References: <20220304175556.407719-1-hch@lst.de> <20220304175556.407719-2-hch@lst.de> <20220304221255.GL3927073@dread.disaster.area> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220304221255.GL3927073@dread.disaster.area> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Sat, Mar 05, 2022 at 09:12:55AM +1100, Dave Chinner wrote: > AFAICT, all the filesystem/IO path passthrough plumbing for hints is > now gone, and no hardware will ever receive hints. Doesn't this > mean that file_write_hint(), file->f_write_hint and iocb->ki_hint > are now completely unused, too? No, for the reason tha you state below. f2fs still uses it. > AFAICT, this patch leaves just the f2fs allocator usage of > inode->i_rw_hint to select a segment to allocate from as the > remaining consumer of this entire plumbing and user API. Is that > used by applications anywhere, or can that be removed and so the > rest of the infrastructure get removed and the fcntl()s no-op'd or > -EOPNOTSUPP? I was told it is used quite heavily in android.