lkml.org 
[lkml]   [2019]   [Apr]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 7/7] clocksource/arm_arch_timer: Use arch_timer_read_counter to access stable counters
From
Date
Hi,

On 30/04/2019 16:27, Marc Zyngier wrote:
[...]
>>> @@ -372,6 +392,7 @@ static u32 notrace sun50i_a64_read_cntv_tval_el0(void)
>>> DEFINE_PER_CPU(const struct arch_timer_erratum_workaround *, timer_unstable_counter_workaround);
>>> EXPORT_SYMBOL_GPL(timer_unstable_counter_workaround);
>>>
>>> +static atomic_t timer_unstable_counter_workaround_in_use = ATOMIC_INIT(0);
>>
>> Wouldn't make sense to READ_ONCE / WRITE_ONCE instead of using an atomic?
>
> I don't think *_ONCE says anything about the atomicity of the access. It
> only instruct the compiler that this should only be accessed once, and
> not reloaded/rewritten.

FWIW 7bd3e239d6c6 ("locking: Remove atomicy checks from {READ,WRITE}_ONCE")
points this out.

[...]

\
 
 \ /
  Last update: 2019-04-30 17:40    [W:0.087 / U:0.544 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site