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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ABA62C32767 for ; Sat, 4 Jan 2020 07:03:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7D26A20848 for ; Sat, 4 Jan 2020 07:03:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725836AbgADG6J (ORCPT ); Sat, 4 Jan 2020 01:58:09 -0500 Received: from mx2.suse.de ([195.135.220.15]:48930 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725790AbgADG6J (ORCPT ); Sat, 4 Jan 2020 01:58:09 -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 F1808AD5F; Sat, 4 Jan 2020 06:58:07 +0000 (UTC) From: Coly Li To: linux-bcache@vger.kernel.org Cc: Coly Li , stable@vger.kernel.org, Eric Wheeler Subject: [PATCH] bcache: back to cache all readahead I/Os Date: Sat, 4 Jan 2020 14:58:02 +0800 Message-Id: <20200104065802.113137-1-colyli@suse.de> X-Mailer: git-send-email 2.16.4 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 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 Cc: 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"); -- 2.16.4