Re: [PATCH v5] locking/rwsem: Make handoff bit handling more consistent

From: Greg KH <gregkh@linuxfoundation.org>
To: Waiman Long <longman@redhat.com>
Cc: john.p.donnelly@oracle.com,
	chenguanyou <chenguanyou9338@gmail.com>,
	dave@stgolabs.net, hdanton@sina.com,
	linux-kernel@vger.kernel.org, mazhenhua@xiaomi.com,
	mingo@redhat.com, peterz@infradead.org, quic_aiquny@quicinc.com,
	will@kernel.org, sashal@kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH v5] locking/rwsem: Make handoff bit handling more consistent
Date: Thu, 14 Apr 2022 17:42:12 +0200	[thread overview]
Message-ID: <YlhA1IVb/MIox/Ik@kroah.com> (raw)
In-Reply-To: <d32d3036-a554-624b-0d3f-247539142273@redhat.com>

On Thu, Apr 14, 2022 at 11:18:23AM -0400, Waiman Long wrote:
> On 4/14/22 06:48, Greg KH wrote:
> > On Tue, Apr 12, 2022 at 01:04:05PM -0400, Waiman Long wrote:
> > > The patch has already been in the tip tree. It may not be easy to add a
> > > Fixes tag to it. Anyway, I will encourage stable tree maintainer to take it
> > > as it does fix a problem as shown in your test.
> > I have no idea what you want me to do here.  Please be explicit...
> > 
> I would like the stable trees to include commit 1ee326196c66
> ("locking/rwsem: Always try to wake waiters in out_nolock path") after it is
> merged into the mainline in the v5.19 merge window. It should be applied to
> the stable trees that have incorporated the backport of commit d257cc8cb8d5
> ("locking/rwsem: Make handoff bit handling more consistent") since this
> commit seems to make the missed wakeup problem easier to show up.

Please let us know when this is merged into Linus's tree.  Nothing we
can do until then and I'm not going to remember this in a few months
anyway.

thanks,

greg k-h