Re: [tip: locking/urgent] locking/ww_mutex: Simplify use_ww_ctx & ww_ctx handling

From: Peter Zijlstra
Date: Wed Mar 17 2021 - 09:57:01 EST


On Wed, Mar 17, 2021 at 09:43:20AM -0400, Waiman Long wrote:

> Using gcc 8.4.1, the generated __mutex_lock function has the same size (with
> last instruction at offset +5179) with or without this patch. Well, you can
> say that this patch is an no-op wrt generated code.

OK, then GCC has gotten better. Because back then I tried really hard
but it wouldn't remove the if (ww_ctx) branches unless I had that extra
const bool argument.