Message-ID: <8eea871c-eed0-cb4b-1b81-3a6b502c3c34@redhat.com>
Date:   Sun, 22 Jan 2023 22:40:22 -0500
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Subject: Re: [PATCH v6 0/6] lockinig/rwsem: Fix rwsem bugs & enable true lock
 handoff
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To:     Peter Zijlstra <peterz@infradead.org>
Cc:     Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>,
        Boqun Feng <boqun.feng@gmail.com>,
        linux-kernel@vger.kernel.org, john.p.donnelly@oracle.com,
        Hillf Danton <hdanton@sina.com>,
        Mukesh Ojha <quic_mojha@quicinc.com>,
        =?UTF-8?B?VGluZzExIFdhbmcg546L5am3?= <wangting11@xiaomi.com>
References: <20221118022016.462070-1-longman@redhat.com>
 <Y80+SLxrdEVyJHMo@hirez.programming.kicks-ass.net>
From:   Waiman Long <longman@redhat.com>
In-Reply-To: <Y80+SLxrdEVyJHMo@hirez.programming.kicks-ass.net>
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On 1/22/23 08:46, Peter Zijlstra wrote:
> On Thu, Nov 17, 2022 at 09:20:10PM -0500, Waiman Long wrote:
>
>> Waiman Long (6):
>>    locking/rwsem: Prevent non-first waiter from spinning in down_write() slowpath
>>    locking/rwsem: Disable preemption at all down_read*() and up_read() code paths
>>    locking/rwsem: Disable preemption at all down_write*() and up_write() code paths
>>    locking/rwsem: Change waiter->hanodff_set to a handoff_state enum
> After all these we still have down_read_non_owner() using
> __rwsem_set_reader_owner() outside of the preempt_disable() region.
>
> Now, let me go stare at this one:

Thanks for spotting that. I kind of overlook the fact we have a 
down_read_non_owner(). Will update that as well.

Cheers,
Longman

>>    locking/rwsem: Enable direct rwsem lock handoff
>