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 7490AC433EF for ; Sat, 5 Mar 2022 05:19:49 +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=eYIf0CTh3souYhHSw2zpj9pEs2fEKkD4At2691RpuEc=; b=GhYuuXkmgS+AlHsQGwGS/FhW66 JCCfqsatu8cR0Xx5Xn+DqJ+55QrFl62XuBhU6rE3A1CxucL11ycuAAKQAEEeQS2xGYDer4Qzobbgv pX8soHEeJmb/tRqO3IuH5LZfTMYumpVc3O8BE3L8Q9Dbh7YCOdgtT5JUTzUCUnZduL4NuCbZdunAX iCkF/XhZvz1TQIaujBaRKI2V0FdkGWxg/E3PT1omIx1L2YUVBHzGa32pVhg7ppU1K8Fb1cBJxR07B lGEnipu0kdN4iwfwfi3ZHEaH0Jn0t0FG9G9Lz1Kph4KboM5b1sZPiMbzf7Qw/S96Al//q6FoUVfeb yhdXjuLQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nQMpS-00CmFd-Ha; Sat, 05 Mar 2022 05:19:42 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nQMpL-00CmFB-04 for linux-nvme@lists.infradead.org; Sat, 05 Mar 2022 05:19:36 +0000 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) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220304_211935_236306_0869AA5A X-CRM114-Status: GOOD ( 15.21 ) X-BeenThere: linux-nvme@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-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.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.