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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 19740C433EF for ; Tue, 15 Mar 2022 10:49:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347623AbiCOKuh (ORCPT ); Tue, 15 Mar 2022 06:50:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33460 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347604AbiCOKsA (ORCPT ); Tue, 15 Mar 2022 06:48:00 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C3240522D6; Tue, 15 Mar 2022 03:45:02 -0700 (PDT) Received: from fraeml741-chm.china.huawei.com (unknown [172.18.147.226]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4KHqlb4ryTz6809b; Tue, 15 Mar 2022 18:44:11 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by fraeml741-chm.china.huawei.com (10.206.15.222) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 15 Mar 2022 11:44:56 +0100 Received: from localhost.localdomain (10.69.192.58) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Tue, 15 Mar 2022 10:44:53 +0000 From: John Garry To: , , , , , , CC: , , , , John Garry Subject: [PATCH 0/2] scsi/libata: A potential tagging fix and improvement Date: Tue, 15 Mar 2022 18:39:04 +0800 Message-ID: <1647340746-17600-1-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-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Two loosely related patches are included: - Fix for scsi_realloc_sdev_budget_map(). I noticed that the budget token for scsi commands was way in excess of the device queue depth, so I think we need to fix the sbitmap depth. I need to test this more. - libata change to use scsi command budget token for qc tag for SAS host. I marked this as RFC as for SAS hosts I don't see anything which guarantees that the budget size is <= 32 always. For libsas hosts we resize the device depth to 32 in the slave configure callback, but this seems an unreliable approach since not all hosts may call this. In addition, I am worried that even if we resize the device depth properly in the slave config callback, we may still try to alloc qc tag prior to this - in lun scan, for example. So we need a way to guarantee that the device queue depth is <= 32 always, which I would be open to suggestions for. John Garry (2): scsi: core: Fix sbitmap depth in scsi_realloc_sdev_budget_map() libata: Use scsi cmnd budget token for qc tag for SAS host drivers/ata/libata-core.c | 5 +++-- drivers/ata/libata-sata.c | 21 ++++----------------- drivers/ata/libata-scsi.c | 2 +- drivers/ata/libata.h | 4 ++-- drivers/scsi/scsi_scan.c | 5 +++++ include/linux/libata.h | 1 - 6 files changed, 15 insertions(+), 23 deletions(-) -- 2.26.2