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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 2A5B1C433E7 for ; Sun, 18 Oct 2020 19:59:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F00F322269 for ; Sun, 18 Oct 2020 19:59:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603051177; bh=AFKSqP4Sk2XqD1p6XQv5tDp/EspU/W0wAQxsWRRx6is=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=BrMRvBUVx+MDkdQj3X3L5TNgcZE+pyhulBDojvvTjEUFFNs2/rkoI7DvZkL4H/aXa +PG64qg+8ReOPeOPWKVTboD9Tq8UejcMtujqVeKlxlVP61baigxJjCSZo/o0Eg6uAN 5ktNaWqZ+d/QUu0csDqsjVIp5vVrTC7X03yJPuY0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727812AbgJRTSr (ORCPT ); Sun, 18 Oct 2020 15:18:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:56702 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727137AbgJRTSf (ORCPT ); Sun, 18 Oct 2020 15:18:35 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 51F68222C3; Sun, 18 Oct 2020 19:18:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603048715; bh=AFKSqP4Sk2XqD1p6XQv5tDp/EspU/W0wAQxsWRRx6is=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=I/OCeEvLb8KiAJNBuuMw01NrgoG3dor7BeNJsrYY+DZmjGoLf0NQ+IGQ42xnpk20J LayffzL5g+wTI+Wx6x+jPEB4ORLfkmbUCT6mjatnQjHAwGNX91Zxok4Q1B4uPE22dJ +rMslXJitOJyGvb6iQd7bdWhGPBWNXxD5bz563ss= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ming Lei , Christoph Hellwig , Hannes Reinecke , David Milburn , "Ewan D . Milne" , Jens Axboe , Sasha Levin , linux-block@vger.kernel.org Subject: [PATCH AUTOSEL 5.9 022/111] blk-mq: always allow reserved allocation in hctx_may_queue Date: Sun, 18 Oct 2020 15:16:38 -0400 Message-Id: <20201018191807.4052726-22-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201018191807.4052726-1-sashal@kernel.org> References: <20201018191807.4052726-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ming Lei [ Upstream commit 285008501c65a3fcee05d2c2c26cbf629ceff2f0 ] NVMe shares tagset between fabric queue and admin queue or between connect_q and NS queue, so hctx_may_queue() can be called to allocate request for these queues. Tags can be reserved in these tagset. Before error recovery, there is often lots of in-flight requests which can't be completed, and new reserved request may be needed in error recovery path. However, hctx_may_queue() can always return false because there is too many in-flight requests which can't be completed during error handling. Finally, nothing can proceed. Fix this issue by always allowing reserved tag allocation in hctx_may_queue(). This is reasonable because reserved tags are supposed to always be available. Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Cc: David Milburn Cc: Ewan D. Milne Signed-off-by: Ming Lei Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/blk-mq-tag.c | 3 ++- block/blk-mq.c | 5 +++-- 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 32d82e23b0953..a1c1e7c611f7b 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -59,7 +59,8 @@ void __blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx) static int __blk_mq_get_tag(struct blk_mq_alloc_data *data, struct sbitmap_queue *bt) { - if (!data->q->elevator && !hctx_may_queue(data->hctx, bt)) + if (!data->q->elevator && !(data->flags & BLK_MQ_REQ_RESERVED) && + !hctx_may_queue(data->hctx, bt)) return BLK_MQ_NO_TAG; if (data->shallow_depth) diff --git a/block/blk-mq.c b/block/blk-mq.c index cdced4aca2e81..96425e4bd2b2c 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1105,10 +1105,11 @@ static bool __blk_mq_get_driver_tag(struct request *rq) if (blk_mq_tag_is_reserved(rq->mq_hctx->sched_tags, rq->internal_tag)) { bt = &rq->mq_hctx->tags->breserved_tags; tag_offset = 0; + } else { + if (!hctx_may_queue(rq->mq_hctx, bt)) + return false; } - if (!hctx_may_queue(rq->mq_hctx, bt)) - return false; tag = __sbitmap_queue_get(bt); if (tag == BLK_MQ_NO_TAG) return false; -- 2.25.1