From patchwork Thu Jan 23 17:01:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Coly Li X-Patchwork-Id: 11348779 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B17C51398 for ; Thu, 23 Jan 2020 17:03:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9A0C721569 for ; Thu, 23 Jan 2020 17:03:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730040AbgAWRDG (ORCPT ); Thu, 23 Jan 2020 12:03:06 -0500 Received: from mx2.suse.de ([195.135.220.15]:51858 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730037AbgAWRDG (ORCPT ); Thu, 23 Jan 2020 12:03:06 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 87F6CAC50; Thu, 23 Jan 2020 17:03:04 +0000 (UTC) From: colyli@suse.de To: axboe@kernel.dk Cc: linux-bcache@vger.kernel.org, linux-block@vger.kernel.org, Coly Li , stable@vger.kernel.org Subject: [PATCH 14/17] bcache: back to cache all readahead I/Os Date: Fri, 24 Jan 2020 01:01:39 +0800 Message-Id: <20200123170142.98974-15-colyli@suse.de> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20200123170142.98974-1-colyli@suse.de> References: <20200123170142.98974-1-colyli@suse.de> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: Coly Li In year 2007 high performance SSD was still expensive, in order to save more space for real workload or meta data, the readahead I/Os for non-meta data was bypassed and not cached on SSD. In now days, SSD price drops a lot and people can find larger size SSD with more comfortable price. It is unncessary to bypass normal readahead I/Os to save SSD space for now. This patch removes the code which checks REQ_RAHEAD tag of bio in check_should_bypass(), then all readahead I/Os will be cached on SSD. NOTE: this patch still keeps the checking of "REQ_META|REQ_PRIO" in should_writeback(), because we still want to cache meta data I/Os even they are asynchronized. Cc: stable@vger.kernel.org Signed-off-by: Coly Li Acked-by: Eric Wheeler --- drivers/md/bcache/request.c | 9 --------- 1 file changed, 9 deletions(-) diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c index 73478a91a342..acc07c4f27ae 100644 --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -378,15 +378,6 @@ static bool check_should_bypass(struct cached_dev *dc, struct bio *bio) op_is_write(bio_op(bio)))) goto skip; - /* - * Flag for bypass if the IO is for read-ahead or background, - * unless the read-ahead request is for metadata - * (eg, for gfs2 or xfs). - */ - if (bio->bi_opf & (REQ_RAHEAD|REQ_BACKGROUND) && - !(bio->bi_opf & (REQ_META|REQ_PRIO))) - goto skip; - if (bio->bi_iter.bi_sector & (c->sb.block_size - 1) || bio_sectors(bio) & (c->sb.block_size - 1)) { pr_debug("skipping unaligned io");