Re: [PATCH 3/3] perf_events: add Intel Sandy Bridge offcore_response low-level support (v3)

[Peter Zijlstra <peterz@infradead.org>]

On Mon, 2011-05-23 at 18:12 +0200, Stephane Eranian wrote:
> This patch adds Intel Sandy Bridge offcore_response support by
> providing the low-level constraint table for those events.
>     
> On Sandy Bridge, there are two offcore_response events. Each uses
> its own dedictated extra register. But those registers are NOT shared
> between sibling CPUs when HT is on unlike Nehalem/Westmere. They are
> always private to each CPU. But they still need to be controlled within
> an event group. All events within an event group must use the same
> value for the extra MSR. That's not controlled by the second patch in
> this series.
>     
> Furthermore on Sandy Bridge, the offcore_response events have NO
> counter constraints contrary to what the official documentation
> indicates, so drop the events from the contraint table.

You sending this suggests you actually have a SNB machine, do you also
happen to know how to use those SNB RSP MSRs? Lin Ming and I were
wondering how to fill out the extra-regs for
snb_hw_cache_events_jds[C(LL)].