From: Li Zefan <lizefan@huawei.com>
To: "xiaofeng.yan" <xiaofeng.yan@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>, <mingo@redhat.com>,
<linux-kernel@vger.kernel.org>, <xiaofeng.yan2012@gmail.com>,
Juri Lelli <juri.lelli@gmail.com>
Subject: Re: [PATCH] sched/rt: overrun could happen in start_hrtick_dl
Date: Tue, 8 Jul 2014 10:40:19 +0800 [thread overview]
Message-ID: <53BB5A13.1070305@huawei.com> (raw)
In-Reply-To: <53BB4510.5090704@huawei.com>
On 2014/7/8 9:10, xiaofeng.yan wrote:
> On 2014/7/7 16:41, Peter Zijlstra wrote:
>> On Fri, Jul 04, 2014 at 12:02:21PM +0000, xiaofeng.yan wrote:
>>> It could be wrong for the precision of runtime and deadline
>>> when the precision is within microsecond level. For example:
>>> Task runtime deadline period
>>> P1 200us 500us 500us
>>>
>>> This case need enbale HRTICK feature by the next command
>>> PC#echo "HRTICK" > /sys/kernel/debug/sched_features
>>> PC#./schedtool -E -t 200000:500000 -e ./test&
>>> PC#trace-cmd record -e sched_switch
>> Are you actually using HRTICK ?
> yes, If HRTICK is close , then all of runtime and deadline will be wrong.
I think what peter meant is, do you use HRTICK in products or
just use it for testing/experiment?
next prev parent reply other threads:[~2014-07-08 2:40 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-04 12:02 [PATCH] sched/rt: overrun could happen in start_hrtick_dl xiaofeng.yan
2014-07-07 8:41 ` Peter Zijlstra
2014-07-08 1:10 ` xiaofeng.yan
2014-07-08 2:40 ` Li Zefan [this message]
2014-07-08 2:51 ` xiaofeng.yan
2014-07-08 7:49 ` Peter Zijlstra
2014-07-08 8:41 ` xiaofeng.yan
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