lkml.org 
[lkml]   [2016]   [Feb]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH 1/2] cpufreq: governor: Fix race in dbs_update_util_handler()
From
On Mon, Feb 22, 2016 at 2:04 PM, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> On 22-02-16, 13:26, Rafael J. Wysocki wrote:
>> On Mon, Feb 22, 2016 at 6:23 AM, Viresh Kumar <viresh.kumar@linaro.org> wrote:
>> > On 21-02-16, 03:14, Rafael J. Wysocki wrote:
>> >> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

[cut]

>> > I think we should be doing this here:
>> >
>> > delta_ns = time - ACCESS_ONCE(policy_dbs->last_sample_time);
>> > if ((s64)delta_ns < policy_dbs->sample_delay_ns) {
>> > atomic_set(&policy_dbs->work_count, 0);
>> > return;
>> > }
>> >
>> > There is no point running the routine again, we already have ->work_count
>> > incremented for us, lets do the check right now.
>>
>> No, we need to check work_in_progress too.
>
> Then maybe move first half of this routine into a separate function
> and call it from the beginning and here ?

That won't help. The time value is still going to be stale.

Thanks,
Rafael

\
 
 \ /
  Last update: 2016-02-22 15:01    [W:0.047 / U:1.260 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site