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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 C5B25C55178 for ; Tue, 27 Oct 2020 16:33:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7D1D3218AC for ; Tue, 27 Oct 2020 16:33:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603816396; bh=EO+sVCLZuPtH9lMAYoB1dKEjFQdyQRcZ0CKObM1UlvY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=i8BzHqyulLpro/Sh7Ul9qdiDYdkmAMBPGQcYOOb/MhXvQ0P+e/nOmXqmqY0l9Tpou OK+/YUt8koIYOnIvmKj9ka9KWLqTaXqOnfFJ15cYjTNw7z90LBPTY+klBNMNhb/mu0 HpxiaUO2RBE7cvTo4qd210lE5Uu2F8HEYi2mClNk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1810054AbgJ0QdP (ORCPT ); Tue, 27 Oct 2020 12:33:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:48682 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1802486AbgJ0Pth (ORCPT ); Tue, 27 Oct 2020 11:49:37 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 6A26C223C6; Tue, 27 Oct 2020 15:49:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603813764; bh=EO+sVCLZuPtH9lMAYoB1dKEjFQdyQRcZ0CKObM1UlvY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jqfnLyi7oEIcERunfCOCupJG3pcZFOiPe7K+Be9pmEpUsWMW5CgbMkeaeZArlkw/W MhUjfESunfBxXV9aaDC2cmDmcXbbiKkbLrOBn6YOuJ1m0pEt2IDIM4AFWSMgbneAIy SJ5X5eSB/psHkbwqni10wL8FF7E9qnxXcL+i4+L4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christoph Hellwig , Hannes Reinecke , David Milburn , "Ewan D. Milne" , Ming Lei , Jens Axboe , Sasha Levin Subject: [PATCH 5.9 662/757] blk-mq: always allow reserved allocation in hctx_may_queue Date: Tue, 27 Oct 2020 14:55:12 +0100 Message-Id: <20201027135521.592311582@linuxfoundation.org> X-Mailer: git-send-email 2.29.1 In-Reply-To: <20201027135450.497324313@linuxfoundation.org> References: <20201027135450.497324313@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 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 c27a61029cdd0..94a53d779c12b 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