On 07/31/13 17:20, Timur Tabi wrote: > 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. That's encouraging. It looks like you introduced it to use in interrupt context but then it got shot down[1]? I lost track in all the versions. > > Of course, that assumes that spinning in interrupt context is a good > idea to begin with. Maybe we shouldn't be encouraging it? I read through the v5 discussion and it seems I'm about to walk through some tall grass on the way to Cerulean City. Andrew Morton, I choose you! Use your mind-power move to convince everyone that having a macro for spinning on a register in interrupt context is a good thing. At least it will be more obvious. > >>>> 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 > [1] https://lists.ozlabs.org/pipermail/linuxppc-dev/2009-May/072521.html -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
