linux-kernel - Re: [PATCH] sched/deadline: Zero out positive runtime after throttling constrained tasks

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <59254990.4060008@redhat.com>
Date:   Wed, 24 May 2017 16:51:28 +0800
From:   Xunlei Pang <xpang@...hat.com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     Daniel Bristot de Oliveira <bristot@...hat.com>,
        Xunlei Pang <xlpang@...hat.com>, linux-kernel@...r.kernel.org,
        Juri Lelli <juri.lelli@....com>,
        Ingo Molnar <mingo@...hat.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Luca Abeni <luca.abeni@...tannapisa.it>
Subject: Re: [PATCH] sched/deadline: Zero out positive runtime after
 throttling constrained tasks

Hi Peter,

On 05/11/2017 at 10:35 PM, Daniel Bristot de Oliveira wrote:
> On 05/10/2017 03:03 PM, Xunlei Pang wrote:
>> When a contrained task is throttled by dl_check_constrained_dl(),
>> it may carry the remaining positive runtime, as a result when
>> dl_task_timer() fires and calls replenish_dl_entity(), it will
>> not be replenished correctly due to the positive dl_se->runtime.
>>
>> This patch assigns its runtime to 0 if positive after throttling.
>>
>> Fixes: df8eac8cafce ("sched/deadline: Throttle a constrained deadline task activated after the deadline)
>> Cc: Daniel Bristot de Oliveira <bristot@...hat.com>
>> Signed-off-by: Xunlei Pang <xlpang@...hat.com>
>> ---
>>  kernel/sched/deadline.c | 2 ++
>>  1 file changed, 2 insertions(+)
>>
>> diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
>> index a2ce590..d3d291e 100644
>> --- a/kernel/sched/deadline.c
>> +++ b/kernel/sched/deadline.c
>> @@ -723,6 +723,8 @@ static inline void dl_check_constrained_dl(struct sched_dl_entity *dl_se)
>>  		if (unlikely(dl_se->dl_boosted || !start_dl_timer(p)))
>>  			return;
>>  		dl_se->dl_throttled = 1;
>> +		if (dl_se->runtime > 0)
>> +			dl_se->runtime = 0;
>>  	}
>>  }
> Acked-by: Daniel Bristot de Oliveira <bristot@...hat.com>

Could you please have this one? Thanks!

Regards,
Xunlei