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Subject: Re: [PATCH] blktrace: Fix potentail deadlock between delete & sysfs
 ops
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Jens Axboe <axboe@kernel.dk>, Jeff Layton <jlayton@poochiereds.net>,
        "J. Bruce Fields" <bfields@fieldses.org>,
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From: Waiman Long <longman@redhat.com>
Organization: Red Hat
Message-ID: <9e4fa528-8537-0864-d661-62d7e33c5359@redhat.com>
Date: Wed, 16 Aug 2017 15:26:53 -0400
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On 08/16/2017 03:14 PM, Steven Rostedt wrote:
> On Wed, 16 Aug 2017 15:07:25 -0400
> Waiman Long <longman@redhat.com> wrote:
>
>
>> I am thinking about maybe letting a RT task to sleep a tiny amount of
>> time instead of calling schedule(). Hopefully, that will allow a
>> lower-priority task to make forward progress.
> That is actually one of the ugly hacks we have in the PREEMPT_RT patch
> (and one of the things we need to fix before getting it to mainline).
>
> A simple msleep(1).
>
> -- Steve


I am planning to use usleep_range(). That will allow a short sleep in
the us range instead of ms. The documentation suggest that for a
10us-20ms sleep.

Cheers,
Longman