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Subject: Re: [PATCH 3/3] task_work: use TIF_TASKWORK if available
To:     Oleg Nesterov <oleg@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>
Cc:     linux-kernel@vger.kernel.org, io-uring@vger.kernel.org,
        peterz@infradead.org
References: <20201001194208.1153522-1-axboe@kernel.dk>
 <20201001194208.1153522-4-axboe@kernel.dk>
 <20201002151415.GA29066@redhat.com> <871rigejb8.fsf@nanos.tec.linutronix.de>
 <20201002153849.GC29066@redhat.com>
From:   Jens Axboe <axboe@kernel.dk>
Message-ID: <19d2f8cc-320f-a4d1-79e3-fbdef3b44540@kernel.dk>
Date:   Fri, 2 Oct 2020 10:18:15 -0600
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On 10/2/20 9:38 AM, Oleg Nesterov wrote:
> On 10/02, Thomas Gleixner wrote:
>>
>> I think it's fundamentaly wrong that we have several places and several
>> flags which handle task_work_run() instead of having exactly one place
>> and one flag.
> 
> Damn yes, agreed.

As mentioned in the other reply, this is actually a nice step towards
NOT having that be the case. Right now we have TWA_RESUME, which uses
TIF_NOTIFY_RESUME. Once all archs support TIF_NOTIFY_SIGNAL, then we can
totally drop TWA_NOTIFY resume, and use use TWA_SIGNAL as the default
for notify == true task_work users. And we can drop task_work noticing
and running in the signal handling as well, leaving us with only having
tracehook_notify_signal() running the task_work.

-- 
Jens Axboe