Re: [PATCH] iopoll: use fsleep() instead of usleep_range()

[Jani Nikula <jani.nikula@intel.com>]

On Wed, 02 Jul 2025, Andi Shyti <andi.shyti@kernel.org> wrote:
> Hi Jani,
>
> On Thu, Jun 26, 2025 at 05:51:19PM +0300, Jani Nikula wrote:
>> Sometimes it's necessary to poll with long sleeps, and the accuracy of
>> usleep_range() is overkill. Use the flexible sleep helper fsleep() for
>> sleeping in the read_poll_timeout() family of macros to automatically
>> choose the appropriate method of waiting.
>> 
>> Functionally there are a few consequences for existing users:
>> 
>> - 10 us and shorter sleeps will use usleep() instead of
>>   usleep_range(). Presumably this will not be an issue.
>> 
>> - When it leads to a slack of less than 25%, msleep() will be used
>>   instead of usleep_range(). Presumably this will not be an issue, given
>>   the sleeps will be longer in this case.
>> 
>> - Otherwise, the usleep_range() slack gets switched from the begin of
>>   the range to the end of the range, i.e. [sleep/2+1..sleep] ->
>>   [sleep..sleep+sleep/2]. In theory, this could be an issue in some
>>   cases, but difficult to determine before this hits the real world.
>> 
>> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>
> this patch makes sense to me even with the fixes in the commit
> message suggested byt Geert.
>
> Reviewed-by: Andi Shyti <andi.shyti@kernel.org>

Thanks! However I think Ville's series [1] should have more priority
here. It's mostly orthogonal, but IMO it's more important and should go
first. I can follow up with this one afterwards.

BR,
Jani.


[1] https://lore.kernel.org/r/20250702223439.19752-1-ville.syrjala@linux.intel.com

-- 
Jani Nikula, Intel