From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965080AbeBMOm0 (ORCPT ); Tue, 13 Feb 2018 09:42:26 -0500 Received: from mail-pg0-f45.google.com ([74.125.83.45]:43642 "EHLO mail-pg0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935370AbeBMOmY (ORCPT ); Tue, 13 Feb 2018 09:42:24 -0500 X-Google-Smtp-Source: AH8x224TNGYhfhwwWmiU64cLULT0WNO+xlrusPPTKLYIV9A+nYXQLTP90LSbTvkhEo/WNDm9pszkcg== Subject: Re: [PATCH v2 RESENT] blk: optimization for classic polling To: Nitesh Shetty , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Cc: linux-nvme@lists.infradead.org, joshi.k@samsung.com References: <3578876466-3733-1-git-send-email-nj.shetty@samsung.com> <1518548206-4766-1-git-send-email-nj.shetty@samsung.com> From: Jens Axboe Message-ID: <620867e2-2a0c-5c32-10c6-7cc5268ac944@kernel.dk> Date: Tue, 13 Feb 2018 07:42:20 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:58.0) Gecko/20100101 Thunderbird/58.0 MIME-Version: 1.0 In-Reply-To: <1518548206-4766-1-git-send-email-nj.shetty@samsung.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/13/18 11:56 AM, Nitesh Shetty wrote: > This removes the dependency on interrupts to wake up task. Set task > state as TASK_RUNNING, if need_resched() returns true, > while polling for IO completion. > Earlier, polling task used to sleep, relying on interrupt to wake it up. > This made some IO take very long when interrupt-coalescing is enabled in > NVMe. __set_current_state() should suffice here. -- Jens Axboe