Re: [PATCH] perf/x86: fix load latency/precise store data source issues

From: Andi Kleen
Date: Tue Aug 05 2014 - 17:37:39 EST


On Tue, Aug 05, 2014 at 06:13:33AM +0200, Stephane Eranian wrote:
>
> This patch fixes some issues introduced by Andi's 'Revamp
> PEBS' event selection patch (which is under review right now).
>
> Most of the issues were related to the encoding of the
> data source, for PEBS events in general and load/store
> events on Haswell.
>
> This patchd does:
> - the default of 0 in perf_sample_data_init() was wrong. 0 is not
> a valid value. So defined PERF_MEM_NA (not available)

Looks good.

>
> - On HSW, renamed your precise_store_hsw() to datala_hsw()
> because you are actually processing both loads and stores, except
> the load latency event which goes thru normal function

Pleae don't mix cleanups with bug fixes.

>
> - precise_store_data_hsw() was returning bogus data source for store
> events. dse.mem_lvl instead of dse.val

This was already fixed in the second patch (and it wasn't introduced
by my patch):

commit 57f6c0e81f5b82b341c4c4ddd621531788c50433
Author: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Date: Fri Jul 18 17:41:48 2014 -0700

perf, x86: Fix haswell mem hierarchy flags reporting

This fixes a bug introduced with

commit 722e76e60f2775c21b087ff12c5e678cf0ebcaaf
Author: Stephane Eranian <eranian@xxxxxxxxxx>
Date: Thu May 15 17:56:44 2014 +0200

fix Haswell precise store data source encoding

When returning early we need to return the complete value of the
memory hierarchy, not just the mem_lvl. Otherwise any load/store/na
flags set early get lost.

Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>

-Andi


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