Re: [PATCH 1/2] regulator: Fix useless O^2 complexity in suspend/resume

[Marek Szyprowski]

Hi Mark,

On 2018-09-03 17:09, Mark Brown wrote:
> On Mon, Sep 03, 2018 at 04:49:36PM +0200, Marek Szyprowski wrote:
>> regulator_pm_ops with regulator_suspend and regulator_resume functions are
>> assigned to every regulator device registered in the system, so there is no
>> need to iterate over all again in them. Replace class_for_each_device()
>> construction with direct operation on the rdev embedded in the given
>> regulator device. This saves a lots of useless operations in suspend and
>> resume paths.
> This would've been better as the second patch since it's an optimization
> and not so urgent for stable.

Frankly, the slow down caused by this O^2 in case of 40 regulators in the
system (not that unusual in nowadays mobiles) is noticeable and quite
annoying. IMHO this is still a good candidate for stable.

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland