From: Thomas Gleixner <tglx@linutronix.de>
To: Peter Zijlstra <peterz@infradead.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Stefan Liebler <stli@linux.ibm.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
Darren Hart <dvhart@infradead.org>,
Ingo Molnar <mingo@kernel.org>
Subject: Re: [patch] futex: Cure exit race
Date: Wed, 19 Dec 2018 14:29:10 +0100 [thread overview]
Message-ID: <539c47359b37a5b6b9177da823be45d6@dl.linutronix.de> (raw)
In-Reply-To: <alpine.DEB.2.21.1812172239090.1660@nanos.tec.linutronix.de>
On 2018-12-18 10:31, Thomas Gleixner wrote:
> On Wed, 12 Dec 2018, Peter Zijlstra wrote:
>> On Mon, Dec 10, 2018 at 06:43:51PM +0100, Thomas Gleixner wrote:
>> @@ -806,6 +806,8 @@ void __noreturn do_exit(long code)
>> * task into the wait for ever nirwana as well.
>> */
>> tsk->flags |= PF_EXITPIDONE;
>> + smp_mb();
>> + wake_up_bit(&tsk->flags, 3 /* PF_EXITPIDONE */);
>
> Using ilog2(PF_EXITPIDONE) spares that horrible inline comment and
> more
> importantly selects the right bit. 0x04 is bit 2 ....
Plus wake_up_bit() and wait_on_bit() want an unsigned long, but
tsk->flags is
unsigned int....
Moar staring....
next prev parent reply other threads:[~2018-12-19 13:29 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-10 15:23 [patch] futex: Cure exit race Thomas Gleixner
2018-12-10 16:02 ` Peter Zijlstra
2018-12-10 17:43 ` Thomas Gleixner
2018-12-12 9:04 ` Peter Zijlstra
2018-12-18 9:31 ` Thomas Gleixner
2018-12-19 13:29 ` Thomas Gleixner [this message]
2018-12-19 19:13 ` Thomas Gleixner
[not found] ` <20181210210920.75EBD20672@mail.kernel.org>
2018-12-10 21:16 ` Thomas Gleixner
2018-12-10 23:01 ` Sasha Levin
2018-12-11 10:29 ` Thomas Gleixner
2018-12-11 8:04 ` Stefan Liebler
2018-12-11 10:32 ` Thomas Gleixner
2018-12-18 22:18 ` [tip:locking/urgent] " tip-bot for Thomas Gleixner
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