From: Michael wang <wangyun@linux.vnet.ibm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>,
Ingo Molnar <mingo@kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: sched: hang in migrate_swap
Date: Wed, 26 Feb 2014 10:32:22 +0800 [thread overview]
Message-ID: <530D5236.8090007@linux.vnet.ibm.com> (raw)
In-Reply-To: <20140225104924.GK9987@twins.programming.kicks-ass.net>
On 02/25/2014 06:49 PM, Peter Zijlstra wrote:
> On Tue, Feb 25, 2014 at 12:47:01PM +0800, Michael wang wrote:
>> On 02/24/2014 09:10 PM, Peter Zijlstra wrote:
>>> On Mon, Feb 24, 2014 at 01:12:18PM +0100, Peter Zijlstra wrote:
>>>> + if (p) {
>>>> + if (unlikely(p == RETRY_TASK))
>>>> + goto again;
>>>
>>> We could even make that: unlikely(p & 1), I think most CPUs can encode
>>> that far better than the full pointer immediate.
>>
>> Agree, unless odd-align stuff appeared...
>
> That shouldn't happen; we rely on u32 alignment all over the place. So
> for general objects we should have at least the lower two bits free to
> play with.
Make sense :)
Regards,
Michael Wang
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next prev parent reply other threads:[~2014-02-26 2:32 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-19 18:08 sched: hang in migrate_swap Sasha Levin
2014-02-20 4:32 ` Michael wang
2014-02-21 16:43 ` Sasha Levin
2014-02-22 1:45 ` Michael wang
2014-02-24 3:23 ` Sasha Levin
2014-02-24 5:19 ` Michael wang
2014-02-24 5:54 ` Sasha Levin
2014-02-24 7:10 ` Peter Zijlstra
2014-02-24 10:14 ` Michael wang
2014-02-24 12:12 ` Peter Zijlstra
2014-02-24 13:10 ` Peter Zijlstra
2014-02-25 4:47 ` Michael wang
2014-02-25 10:49 ` Peter Zijlstra
2014-02-26 2:32 ` Michael wang [this message]
2014-02-24 18:21 ` Sasha Levin
2014-02-25 2:48 ` Michael wang
2014-02-25 11:03 ` Peter Zijlstra
2014-02-25 3:01 ` Michael wang
2014-02-27 13:33 ` [tip:sched/core] sched: Guarantee task priority in pick_next_task () tip-bot for Peter Zijlstra
2014-04-10 3:31 ` sched: hang in migrate_swap Sasha Levin
2014-04-10 6:59 ` Michael wang
2014-04-10 13:38 ` Kirill Tkhai
2014-04-11 14:32 ` Sasha Levin
2014-04-11 15:16 ` Kirill Tkhai
2014-05-12 18:48 ` Sasha Levin
2014-05-14 9:42 ` Kirill Tkhai
2014-05-14 10:13 ` Peter Zijlstra
2014-05-14 10:21 ` Kirill Tkhai
2014-05-14 10:26 ` Peter Zijlstra
2014-05-14 11:20 ` Peter Zijlstra
2015-06-15 19:38 ` Rafael David Tinoco
2015-06-15 19:47 ` Peter Zijlstra
2014-04-18 8:24 ` [tip:sched/urgent] sched: Check for stop task appearance when balancing happens tip-bot for Kirill Tkhai
2014-04-10 7:42 ` sched: hang in migrate_swap Peter Zijlstra
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