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Message-ID: <4ac8ed1b-6f2c-5083-fae3-4b6fe9e8cf1b@redhat.com>
Date:   Mon, 24 Oct 2022 14:46:49 -0400
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Subject: Re: [PATCH v4 3/5] locking/rwsem: Change waiter->hanodff_set to a
 handoff_state enum
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To:     john.p.donnelly@oracle.com, Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>,
        Boqun Feng <boqun.feng@gmail.com>
Cc:     linux-kernel@vger.kernel.org, Hillf Danton <hdanton@sina.com>,
        Mukesh Ojha <quic_mojha@quicinc.com>,
        =?UTF-8?B?VGluZzExIFdhbmcg546L5am3?= <wangting11@xiaomi.com>,
        Jack Vogel <jack.vogel@oracle.com>,
        Jorge Lopez <jorge.jo.lopez@oracle.com>,
        Vijayendra Suman <vijayendra.suman@oracle.com>
References: <20221024174418.796468-1-longman@redhat.com>
 <20221024174418.796468-4-longman@redhat.com>
 <e392155b-5c96-11a5-df32-6670139223da@oracle.com>
From:   Waiman Long <longman@redhat.com>
In-Reply-To: <e392155b-5c96-11a5-df32-6670139223da@oracle.com>
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On 10/24/22 14:25, john.p.donnelly@oracle.com wrote:
> On 10/24/22 12:44 PM, Waiman Long wrote:
>> Change the boolean waiter->handoff_set to an enum type so that we can
>> have more states in some later patches. Also use READ_ONCE() outside
>> wait_lock critical sections for read and WRITE_ONCE() inside wait_lock
>> critical sections for write for proper synchronization. There is no
>> functional change.
>
> Hi,
>
> Do we need
>
>
> Fixes: d257cc8cb8d5 ("locking/rwsem: Make handoff bit handling more 
> consistent")
>
> Fixes: 91d2a812dfb9 ("locking/rwsem: Make handoff writer 
> optimistically spin on owner")
>
> Cc: stable@vger.kernel.org
>
>
> clauses added to patches 3,4,5 so they are all picked up in one series ?
>
> Thank you,
>
> John.

I am not planning to do that. The handoff code rewrite represent a 
moderate amount of changes. So I don't want them to be backported to 
stable in case there are some hidden bugs inside. That is why I have 
patch 2 is essentially reverted in patch 4.

Cheers,
Longman