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([2605:e000:100e:8c61:91ff:e31e:f68d:32a9]) by smtp.gmail.com with ESMTPSA id b18sm3380479pfb.116.2020.02.21.08.16.35 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 21 Feb 2020 08:16:36 -0800 (PST) Subject: Re: [PATCH] io_uring: prevent sq_thread from spinning when it should stop To: Stefano Garzarella Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Alexander Viro , Hannes Reinecke , io-uring@vger.kernel.org References: <20200221154216.206367-1-sgarzare@redhat.com> From: Jens Axboe Message-ID: <916f5b1f-1e01-dfe6-7049-113e7175b66a@kernel.dk> Date: Fri, 21 Feb 2020 08:16:33 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20200221154216.206367-1-sgarzare@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/21/20 8:42 AM, Stefano Garzarella wrote: > This patch drops 'cur_mm' before calling cond_resched(), to prevent > the sq_thread from spinning even when the user process is finished. > > Before this patch, if the user process ended without closing the > io_uring fd, the sq_thread continues to spin until the > 'sq_thread_idle' timeout ends. > > In the worst case where the 'sq_thread_idle' parameter is bigger than > INT_MAX, the sq_thread will spin forever. Thanks, applied. -- Jens Axboe