Re: [PATCH v2] locking/rwsem: Add __always_inline annotation to __down_read_common()

From: Peter Zijlstra
Date: Mon Apr 17 2023 - 07:22:46 EST


On Wed, Apr 12, 2023 at 03:59:05AM +0000, John Stultz wrote:
> Apparently despite it being marked inline, the compiler
> may not inline __down_read_common() which makes it difficult
> to identify the cause of lock contention, as the blocked
> function will always be listed as __down_read_common().
>
> So this patch adds __always_inline annotation to the
> function to force it to be inlines so the calling function
> will be listed.

I'm a wee bit confused; what are you looking at? Wchan? What is stopping
the compiler from now handing you
__down_read{,_interruptible,_killable}() instead? Is that fine?