Re: [PATCH] percpu-refcount: support synchronous switch to atomic mode.

From	Shaohua Li <shli@kernel.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH] percpu-refcount: support synchronous switch to atomic mode.
Date	2017-03-23 03:30 +0100
Message-ID	<to0FH-3Ws-9@gated-at.bofh.it> (permalink)
References	<tnDSN-3DX-3@gated-at.bofh.it> <tnQ3E-4lf-25@gated-at.bofh.it>
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On Wed, Mar 22, 2017 at 11:00:29AM -0400, Tejun Heo wrote:
> On Wed, Mar 22, 2017 at 12:50:12PM +1100, NeilBrown wrote:
> > 
> > percpu_ref_switch_to_atomic_sync() schedules the switch
> > to atomic mode, then waits for it to complete.
> > 
> > Also export percpu_ref_switch_to_* so they can be used from modules.
> > 
> > This will be used in md/raid to count the number of pending write
> > requests to an array.
> > We occasionally need to check if the count is zero, but most often
> > we don't care.
> > We always want updates to the counter to be fast, as in some cases
> > we count every 4K page.
> > 
> > Signed-off-by: NeilBrown <neilb@suse.com>
> 
> Acked-by: Tejun Heo <tj@kernel.org>
> 
> Please feel free to route through other patches through md tree.  If
> preferable, I can route it through percpu/for-4.12.

Thanks, Tejun. I applied it to md tree, that will avoid a lot of troubles.

Thanks,
Shaohua

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[PATCH] percpu-refcount: support synchronous switch to atomic mode. NeilBrown <neilb@suse.com> - 2017-03-22 03:10 +0100
  Re: [PATCH] percpu-refcount: support synchronous switch to atomic  mode. Tejun Heo <tj@kernel.org> - 2017-03-22 16:10 +0100
    Re: [PATCH] percpu-refcount: support synchronous switch to atomic  mode. Shaohua Li <shli@kernel.org> - 2017-03-23 03:30 +0100

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