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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,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 42D59C04E87 for ; Wed, 15 May 2019 11:21:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 148902084F for ; Wed, 15 May 2019 11:21:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557919264; bh=MZRiXjlFB0iLsVLyMXCmZlsFOOeWxK7ZzekLNQppy5U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=AlzIrFc0n+NMRmEXMgAS1YJjCdClRyfwM4eiuR7YdxIRBQh7R6Xoka9YxSkbZIb5V wg2nM8a3m6673yKEEBy48UdkBdqKAhqUHzQohL3/1DAa8w0PmII2eFky1sBZo8iqow 49ooOq1aZUJ0ORXjGAvleUXdKGQmk+2F4wFfn/RA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731173AbfEOLVD (ORCPT ); Wed, 15 May 2019 07:21:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:58888 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731196AbfEOLVC (ORCPT ); Wed, 15 May 2019 07:21:02 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4D964206BF; Wed, 15 May 2019 11:21:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557919261; bh=MZRiXjlFB0iLsVLyMXCmZlsFOOeWxK7ZzekLNQppy5U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BL4wVPHShzmfVOKC+uPayhm8HRf21uBbsLtHRffRn7sU/f9YgS2bLLZsXqmE4JDDx nGphKgIVkqP+UD2JvueF442O59eVjjmrpRi2SnZ9yzNC29d2qwV1WOBz7AqbuIACJn b49NlzF/mncbE4JtYYB9E3WpcshHkEnvIvGALScI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Wheeler , Kai Krakow , Paolo Valente , Jens Axboe , Sasha Levin Subject: [PATCH 4.19 001/113] bfq: update internal depth state when queue depth changes Date: Wed, 15 May 2019 12:54:52 +0200 Message-Id: <20190515090652.818865774@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190515090652.640988966@linuxfoundation.org> References: <20190515090652.640988966@linuxfoundation.org> User-Agent: quilt/0.66 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org commit 77f1e0a52d26242b6c2dba019f6ebebfb9ff701e upstream A previous commit moved the shallow depth and BFQ depth map calculations to be done at init time, moving it outside of the hotter IO path. This potentially causes hangs if the users changes the depth of the scheduler map, by writing to the 'nr_requests' sysfs file for that device. Add a blk-mq-sched hook that allows blk-mq to inform the scheduler if the depth changes, so that the scheduler can update its internal state. Signed-off-by: Eric Wheeler Tested-by: Kai Krakow Reported-by: Paolo Valente Fixes: f0635b8a416e ("bfq: calculate shallow depths at init time") Signed-off-by: Jens Axboe Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin --- block/bfq-iosched.c | 8 +++++++- block/blk-mq.c | 2 ++ include/linux/elevator.h | 1 + 3 files changed, 10 insertions(+), 1 deletion(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index c5e2c5a011826..15e8c9955b793 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -5226,7 +5226,7 @@ static unsigned int bfq_update_depths(struct bfq_data *bfqd, return min_shallow; } -static int bfq_init_hctx(struct blk_mq_hw_ctx *hctx, unsigned int index) +static void bfq_depth_updated(struct blk_mq_hw_ctx *hctx) { struct bfq_data *bfqd = hctx->queue->elevator->elevator_data; struct blk_mq_tags *tags = hctx->sched_tags; @@ -5234,6 +5234,11 @@ static int bfq_init_hctx(struct blk_mq_hw_ctx *hctx, unsigned int index) min_shallow = bfq_update_depths(bfqd, &tags->bitmap_tags); sbitmap_queue_min_shallow_depth(&tags->bitmap_tags, min_shallow); +} + +static int bfq_init_hctx(struct blk_mq_hw_ctx *hctx, unsigned int index) +{ + bfq_depth_updated(hctx); return 0; } @@ -5656,6 +5661,7 @@ static struct elevator_type iosched_bfq_mq = { .requests_merged = bfq_requests_merged, .request_merged = bfq_request_merged, .has_work = bfq_has_work, + .depth_updated = bfq_depth_updated, .init_hctx = bfq_init_hctx, .init_sched = bfq_init_queue, .exit_sched = bfq_exit_queue, diff --git a/block/blk-mq.c b/block/blk-mq.c index 414656796ecfc..4e563ee462cb6 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2887,6 +2887,8 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) } if (ret) break; + if (q->elevator && q->elevator->type->ops.mq.depth_updated) + q->elevator->type->ops.mq.depth_updated(hctx); } if (!ret) diff --git a/include/linux/elevator.h b/include/linux/elevator.h index a02deea301857..a2bf4a6b9316d 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -99,6 +99,7 @@ struct elevator_mq_ops { void (*exit_sched)(struct elevator_queue *); int (*init_hctx)(struct blk_mq_hw_ctx *, unsigned int); void (*exit_hctx)(struct blk_mq_hw_ctx *, unsigned int); + void (*depth_updated)(struct blk_mq_hw_ctx *); bool (*allow_merge)(struct request_queue *, struct request *, struct bio *); bool (*bio_merge)(struct blk_mq_hw_ctx *, struct bio *); -- 2.20.1