[PATCH 2/2] Convert PowerPC macro spin_event_timeout() to architecture independent macro

Timur Tabi timur at tabi.org
Wed Jul 31 20:20:29 EDT 2013


On 07/31/2013 07:16 PM, Stephen Boyd wrote:
> cpu_relax() is usually just a compiler barrier or an instruction hint to
> the cpu that it should cool down because we're spinning in a tight loop.
> It certainly shouldn't be calling into the  scheduler.

Ah yes, I remember now.  So it does seem that if we can fix the problem
of non-incrementing 'jiffies', then this macro can be used in interrupts.

Of course, that assumes that spinning in interrupt context is a good
idea to begin with.  Maybe we shouldn't be encouraging it?

>> > FYI, you might want to look at the code reviews for spin_event_timeout()
>> > on the linuxppc-dev mailing list, back in March 2009.
>> >
> Sure. Any pointers? Otherwise I'll go digging around the archives.

https://lists.ozlabs.org/pipermail/linuxppc-dev/2009-March/thread.html

-- 
Timur Tabi



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