[lkml]   [2010]   [Jan]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [RFC] perf_events: support for uncore a.k.a. nest units
On Thu, 2010-01-21 at 09:47 +0100, stephane eranian wrote:
> I don't think that is correct. You can be using the uncore PMU on Nehalem
> without any core PMU event. The only thing to realize is that uncore PMU
> shares the same interrupt vector as core PMU. You need to configure which
> core the uncore is going to interrupt on. This is done via a bitmask, so you
> can interrupt more than one core at a time. Several strategies are possible.

Ah, sharing the IRQ line is no problem. But from reading I got the
impression you need to configure an Offcore counter. See

• EN_PMI_COREn (bit n, n = 0, 3 if four cores are present): When set, processor
core n is programmed to receive an interrupt signal from any interrupt enabled
uncore counter. PMI delivery due to an uncore counter overflow is enabled by
setting IA32_DEBUG_CTL.Offcore_PMI_EN to 1.

Which seems to indicate a link with the off-core response thing.

However I would be very glad to be wrong :-)

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2010-01-21 10:03    [W:0.132 / U:1.236 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site