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=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 39196C433FF for ; Thu, 8 Aug 2019 17:27:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0B4602089E for ; Thu, 8 Aug 2019 17:27:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b="Ymr7/4FN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404258AbfHHR07 (ORCPT ); Thu, 8 Aug 2019 13:26:59 -0400 Received: from mail-qk1-f182.google.com ([209.85.222.182]:34994 "EHLO mail-qk1-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728020AbfHHR07 (ORCPT ); Thu, 8 Aug 2019 13:26:59 -0400 Received: by mail-qk1-f182.google.com with SMTP id r21so69516096qke.2 for ; Thu, 08 Aug 2019 10:26:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=from:references:in-reply-to:mime-version:thread-index:date :message-id:subject:to:cc; bh=PJEP7gEb1ir827/sFAdb/9iaLt0vvpBXTOPy5U52QpY=; b=Ymr7/4FN7IS6Uiy4y7B9nufR8EOKd0LFps5RujX6jqtAMtsrXjXcD/a1BK4nBK/qAP ST9FeRfNKUmjVjeucDS5dxL4OgOr8oUVLDGoit8DbYXKzgbXRMR6GbwX5+0d1VnuPVMK zPIC+48WLANAqQ9XKJ4ndvBghWMugxAWY/EmM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:references:in-reply-to:mime-version :thread-index:date:message-id:subject:to:cc; bh=PJEP7gEb1ir827/sFAdb/9iaLt0vvpBXTOPy5U52QpY=; b=Y5E9GFIYHjrIgkjkMJt8PxT0tcnIQM1egluZz5uBzBksRLc3xPQqHWcpGvpzyfLO/G ZdKsBGADAcT6S6nAsqautk2CoaL5Cn7rxxbQ7TwClTnhAzx0rtYsFxqlVM5KkLMsPPjE JHX1E4aWBYSOMwkWLhAVUGLLp+URT7ENKZDXnATc3aeUrhipjN2X4oHUdoO3A6vkLHhq hPr6cyZBVHtbq9qH40GOB1iCWl53K5vS4rdxOPcMZwT4Tzk07+wq5OQ5+8c+xLgp/UtP pTIfUbmmDbminzCeqDoBuCg5Ky0w3nKVUcGOQ61bjmzuAxQiwv/EzyCRreB4ndwGiiRE Bw6Q== X-Gm-Message-State: APjAAAVh089rHcWicCJYqFcla2D9J6z8FHxRfhPvA7BOxmM9nMCOIN+7 b7/XK+WH464qV62yMhaHlntSwU5ooci980G0JDoWdw== X-Google-Smtp-Source: APXvYqyih0kPBD1dhOUgNQ+IIiF0gTjskfkI6JPxyvlxt6FEQp2hZHEO6mG/I7/0l6AX5I1YjoJLer3uHY30JiPqOhA= X-Received: by 2002:a37:a48e:: with SMTP id n136mr14853725qke.223.1565285218410; Thu, 08 Aug 2019 10:26:58 -0700 (PDT) From: Chandrakanth Patil References: <20190726073214.23820-1-chandrakanth.patil@broadcom.com> In-Reply-To: MIME-Version: 1.0 X-Mailer: Microsoft Outlook 15.0 Thread-Index: AQJOpmXLT9cDiysBe+k0Ph7wC/nHkgLLBRGXpehppdA= Date: Thu, 8 Aug 2019 22:56:56 +0530 Message-ID: <06139ab3efab799a9d3148b1f04847b0@mail.gmail.com> Subject: RE: [PATCH] megaraid_sas: change sdev queue depth max vs optimal To: "Martin K. Petersen" Cc: linux-scsi@vger.kernel.org, Kashyap Desai , Sumit Saxena , Kiran Kumar Kasturi , Sankar Patra , Sasikumar PC , Shivasharan Srikanteshwara , Anand Lodnoor Content-Type: text/plain; charset="UTF-8" Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Martin, The firmware provided queue depth provides optimum performance in most of the cases/workloads. And this patch provides the option to the user to go with max queue_depth or with optimum queue_depth. -Chandrakanth -----Original Message----- From: Martin K. Petersen [mailto:martin.petersen@oracle.com] Sent: Thursday, August 8, 2019 6:56 AM To: Chandrakanth Patil Cc: linux-scsi@vger.kernel.org; kashyap.desai@broadcom.com; sumit.saxena@broadcom.com; kiran-kumar.kasturi@broadcom.com; sankar.patra@broadcom.com; sasikumar.pc@broadcom.com; shivasharan.srikanteshwara@broadcom.com; anand.lodnoor@broadcom.com Subject: Re: [PATCH] megaraid_sas: change sdev queue depth max vs optimal Chandrakanth, > This patch provides the module parameter and sysfs interface to switch > between the firmware provided (optimal) queue depth and controller > queue depth (can_queue). This smells a bit like a don't-be-broken flag. Why isn't the firmware-provided value optimal? -- Martin K. Petersen Oracle Linux Engineering