linux-kernel - Re: [PATCH] io_uring: prevent sq_thread from spinning when it should stop

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Message-ID: <916f5b1f-1e01-dfe6-7049-113e7175b66a@kernel.dk>
Date:   Fri, 21 Feb 2020 08:16:33 -0800
From:   Jens Axboe <axboe@...nel.dk>
To:     Stefano Garzarella <sgarzare@...hat.com>
Cc:     linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
        Alexander Viro <viro@...iv.linux.org.uk>,
        Hannes Reinecke <hare@...e.com>, io-uring@...r.kernel.org
Subject: Re: [PATCH] io_uring: prevent sq_thread from spinning when it should
 stop

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