Re: [PATCH 1/3] arm/pmu: Reject groups spanning multiple hardware PMUs

From: Suzuki K. Poulose
Date: Tue Mar 10 2015 - 08:01:00 EST

On 10/03/15 11:27, Peter Zijlstra wrote:
On Mon, Mar 09, 2015 at 12:46:30PM +0000, Suzuki K. Poulose wrote:
From: "Suzuki K. Poulose" <suzuki.poulose@xxxxxxx>

Don't allow grouping hardware events from different PMUs
(eg. CCI + CPU).

Uhm, how does this work? If we have multiple hardware PMUs we'll stop
scheduling events after the first failed event schedule. This can leave
one of the PMUs severely under utilized.
This is done from pmu->event_init(), where we haven't scheduled an
event yet. Do you think we need to solve it using a different approach
? What is the best way to handle this situation ? Is it OK
to allow different PMUs in the group ?


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