https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82602
Bernd Edlinger <bernd.edlinger at hotmail dot de> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |bernd.edlinger at hotmail dot
de
--- Comment #5 from Bernd Edlinger <bernd.edlinger at hotmail dot de> ---
(In reply to Xi Ruoyao from comment #3)
> I'm still not convinced this is a bug. For example, all kernel code
> uses `asm volatile ("" ::: "memory")` as barrier to stop GCC to reorder code
> through it, not `asm volatile ("" :::)`. So the developers have been aware
> a "asm volatile" does NOT mean a barrier. If we change this behaviour and
> stop reordering through all "asm volatile"s, the generated code could be
> slower.
Yes, spin locks need to have a "memory" clobber.
I agree it will only work by chance without.
