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=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 B70CAC433ED for ; Tue, 6 Apr 2021 03:23:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6D8216124B for ; Tue, 6 Apr 2021 03:23:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240277AbhDFDXK (ORCPT ); Mon, 5 Apr 2021 23:23:10 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:58810 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230364AbhDFDXK (ORCPT ); Mon, 5 Apr 2021 23:23:10 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617679382; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=xZtS9exMV0Q/o8g3fCz5HcTaKQTbu2EFynNJ1+xwKEo=; b=R0NYj4dQpUONDZA7gmL80rxUb4C92HivjMYKHNlwDsOGo5MPt+t8x5rtYnpA5nDrv6gcAp 6c3Z2zWdGHxBrlBS1piwDleSeUiJ6zM2aeGI40WElvwXHyPc9BMJuIc0UHp68sRYpfCRS2 Zi1g0JP3udnxWzCqWS9R0q8LyZis5xY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-445-sn6jPURDMWK-gfw0Pn2mUQ-1; Mon, 05 Apr 2021 23:19:44 -0400 X-MC-Unique: sn6jPURDMWK-gfw0Pn2mUQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E40AC1084C8C; Tue, 6 Apr 2021 03:19:42 +0000 (UTC) Received: from localhost (ovpn-12-144.pek2.redhat.com [10.72.12.144]) by smtp.corp.redhat.com (Postfix) with ESMTP id 21C1E5C729; Tue, 6 Apr 2021 03:19:38 +0000 (UTC) From: Ming Lei To: Jens Axboe Cc: linux-block@vger.kernel.org, Ming Lei , Yanhui Ma , John Garry , Hannes Reinecke Subject: [PATCH] blk-mq: set default elevator as deadline in case of hctx shared tagset Date: Tue, 6 Apr 2021 11:19:33 +0800 Message-Id: <20210406031933.767228-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Yanhui found that write performance is degraded a lot after applying hctx shared tagset on one test machine with megaraid_sas. And turns out it is caused by none scheduler which becomes default elevator caused by hctx shared tagset patchset. Given more scsi HBAs will apply hctx shared tagset, and the similar performance exists for them too. So keep previous behavior by still using default mq-deadline for queues which apply hctx shared tagset, just like before. Fixes: 32bc15afed04 ("blk-mq: Facilitate a shared sbitmap per tagset") Reported-by: Yanhui Ma Cc: John Garry Cc: Hannes Reinecke Signed-off-by: Ming Lei --- block/elevator.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/block/elevator.c b/block/elevator.c index 293c5c81397a..440699c28119 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -621,7 +621,8 @@ static inline bool elv_support_iosched(struct request_queue *q) */ static struct elevator_type *elevator_get_default(struct request_queue *q) { - if (q->nr_hw_queues != 1) + if (q->nr_hw_queues != 1 && + !blk_mq_is_sbitmap_shared(q->tag_set->flags)) return NULL; return elevator_get(q, "mq-deadline", false); -- 2.29.2