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, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 A0595C55178 for ; Mon, 26 Oct 2020 10:52:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4D965222B9 for ; Mon, 26 Oct 2020 10:52:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1771887AbgJZKwY (ORCPT ); Mon, 26 Oct 2020 06:52:24 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:3488 "EHLO szxga06-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1771850AbgJZKwV (ORCPT ); Mon, 26 Oct 2020 06:52:21 -0400 Received: from DGGEMS407-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga06-in.huawei.com (SkyGuard) with ESMTP id 4CKWr81nlhzhZ37; Mon, 26 Oct 2020 18:52:24 +0800 (CST) Received: from localhost.localdomain (10.69.192.58) by DGGEMS407-HUB.china.huawei.com (10.3.19.207) with Microsoft SMTP Server id 14.3.487.0; Mon, 26 Oct 2020 18:52:09 +0800 From: John Garry To: , CC: , , , John Garry Subject: [RESEND PATCH] scsi: hisi_sas: Stop using queue #0 always for v2 hw Date: Mon, 26 Oct 2020 18:48:33 +0800 Message-ID: <1603709313-185482-1-git-send-email-john.garry@huawei.com> X-Mailer: git-send-email 2.8.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.69.192.58] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In commit 8d98416a55eb ("scsi: hisi_sas: Switch v3 hw to MQ"), the dispatch function was changed to choose the delivery queue based on the request tag HW queue index. This heavily degrades performance for v2 hw, since the HW queues are not exposed there, and, as such, HW queue #0 is used for every command. Revert to previous behaviour for when nr_hw_queues is not set, that being to choose the HW queue based on target device index. Fixes: 8d98416a55eb ("scsi: hisi_sas: Switch v3 hw to MQ") Signed-off-by: John Garry --- Please include as a v5.10 fix, thanks! diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c index a994c7b8d26f..fd980a86aa21 100644 --- a/drivers/scsi/hisi_sas/hisi_sas_main.c +++ b/drivers/scsi/hisi_sas/hisi_sas_main.c @@ -444,7 +444,7 @@ static int hisi_sas_task_prep(struct sas_task *task, } } - if (scmd) { + if (scmd && hisi_hba->shost->nr_hw_queues) { unsigned int dq_index; u32 blk_tag; -- 2.26.2