Received-SPF: softfail (google.com: domain of transitioning linux-kernel-owner@vger.kernel.org does not designate 23.128.96.19 as permitted sender) client-ip=23.128.96.19;
Message-ID: <d32d3036-a554-624b-0d3f-247539142273@redhat.com>
Date:   Thu, 14 Apr 2022 11:18:23 -0400
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.5.0
Subject: Re: [PATCH v5] locking/rwsem: Make handoff bit handling more
 consistent
Content-Language: en-US
To:     Greg KH <gregkh@linuxfoundation.org>
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
References: <20211116012912.723980-1-longman@redhat.com>
 <20220214154741.12399-1-chenguanyou@xiaomi.com>
 <3f02975c-1a9d-be20-32cf-f1d8e3dfafcc@oracle.com>
 <e873727e-22db-3330-015d-bd6581a2937a@redhat.com>
 <31178c33-e25c-c3e8-35e2-776b5211200c@oracle.com>
 <161c2e25-3d26-4dd7-d378-d1741f7bcca8@redhat.com>
 <2b6ed542-b3e0-1a87-33ac-d52fc0e0339c@oracle.com>
 <b3620b7b-c66a-65f8-b10b-c3669b2f82ec@redhat.com>
 <Ylf78yGuXdXWugpn@kroah.com>
From:   Waiman Long <longman@redhat.com>
In-Reply-To: <Ylf78yGuXdXWugpn@kroah.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

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.

Cheers,
Longman