From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 MIME-Version: 1.0 In-Reply-To: <1518548206-4766-1-git-send-email-nj.shetty@samsung.com> Content-Type: text/plain; charset=utf-8 List-ID: 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: axboe@kernel.dk (Jens Axboe) Date: Tue, 13 Feb 2018 07:42:20 -0700 Subject: [PATCH v2 RESENT] blk: optimization for classic polling In-Reply-To: <1518548206-4766-1-git-send-email-nj.shetty@samsung.com> References: <3578876466-3733-1-git-send-email-nj.shetty@samsung.com> <1518548206-4766-1-git-send-email-nj.shetty@samsung.com> Message-ID: <620867e2-2a0c-5c32-10c6-7cc5268ac944@kernel.dk> 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