Re: [PATCH 1/1] Fix: trace sched switch start/stop racy updates

[Mathieu Desnoyers]

----- On Aug 16, 2019, at 6:57 PM, Linus Torvalds torvalds@xxxxxxxxxxxxxxxxxxxx wrote:

> So in general, we very much expect the compiler to do sane code
> generation, and not (for example) do store tearing on normal
> word-sized things or add writes that weren't there originally etc.

My understanding of https://lwn.net/Articles/793253/ section "Store tearing"
which points at https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56028 seems
to contradict your expectation at least when writing constants to a
64-bit word without a volatile access.

Thanks,

Mathieu


-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com