Re: [PATCH 1/4] x86, mm: Trace when an IPI is about to be sent

[Mel Gorman]

On Thu, Apr 16, 2015 at 09:55:43AM -0700, Dave Hansen wrote:
> On 04/16/2015 03:22 AM, Mel Gorman wrote:
> > It is easy to trace when an IPI is received to flush a TLB but harder to
> > detect what event sent it. This patch makes it easy to identify the source
> > of IPIs being transmitted for TLB flushes on x86.
> 
> Looks fine to me.  I think I even thought about adding this but didn't
> see an immediate need for it.  I guess this does let you see how many
> IPIs are sent vs. received.
> 

It would but that's not why I wanted it. I wanted a stack track of who
was sending the IPI and I can't get that on the receive side. I could
have used perf probe and some hackery but this seemed useful in itself.

> Reviewed-by: Dave Hansen <dave.hansen@xxxxxxxxx>

Thanks.

-- 
Mel Gorman
SUSE Labs
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