Re: [PATCH 2/3] powerpc: Instrument Hypervisor Calls: add wrappers

Mike Kravetz wrote:

On Fri, Jul 14, 2006 at 07:15:45PM -0500, Nathan Lynch wrote:

quoted

Hmm, isn't it possible that the stats could be corrupted if we process
an interrupt/softirq which does an hcall while the stats are being
updated?  Maybe it's not a show-stopper, but it seems to me that
accuracy could suffer under some workloads.

Yes, they can become inaccurate.  Is this what you mean by 'corrupted' or
you thinking of something worse?

Yes, "corrupted" was perhaps too strong, but we could lose the
accounting for hcalls from interrupts that we take at exactly the
wrong time.  I guess it's a pretty tiny risk.

I just wanted to make sure this had been considered, but if you're
comfortable with the overhead/accuracy tradeoff, then okay.