Re: [PATCH v2 00/15] timers: Cleanup delay/sleep related mess

[Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>]

Le 11/09/2024 à 07:13, Anna-Maria Behnsen a écrit :
> Hi,
>
> a question about which sleeping function should be used in acpi_os_sleep()
> started a discussion and examination about the existing documentation and
> implementation of functions which insert a sleep/delay.
>
> The result of the discussion was, that the documentation is outdated and
> the implemented fsleep() reflects the outdated documentation but doesn't
> help to reflect reality which in turns leads to the queue which covers the
> following things:
>
> - Split out all timeout and sleep related functions from hrtimer.c and timer.c
>    into a separate file
>
> - Update function descriptions of sleep related functions
>
> - Change fsleep() to reflect reality
>
> - Rework all comments or users which obviously rely on the outdated
>    documentation as they reference "Documentation/timers/timers-howto.rst"
>
> - Last but not least (as there are no more references): Update the outdated
>    documentation and move it into a file with a self explaining file name
>
> The queue is available here and applies on top of tip/timers/core:
>
>    git://git.kernel.org/pub/scm/linux/kernel/git/anna-maria/linux-devel.git timers/misc
>
> Signed-off-by: Anna-Maria Behnsen <anna-maria@xxxxxxxxxxxxx>

Hi,

not directly related to your serie, but some time ago I sent a patch to 
micro-optimize Optimize usleep_range(). (See [1])

The idea is that the 2 parameters of usleep_range() are usually 
constants and some code reordering could easily let the compiler compute 
a few things at compilation time.

There was consensus on the value of the change (see [2]), but as you are 
touching things here, maybe it makes sense now to save a few cycles at 
runtime and a few bytes of code?

CJ

[1]: 
https://lore.kernel.org/all/f0361b83a0a0b549f8ec5ab8134905001a6f2509.1659126514.git.christophe.jaillet@xxxxxxxxxx/

[2]: 
https://lore.kernel.org/all/03c2bbe795fe4ddcab66eb852bae3715@xxxxxxxxxxxxxxxx/