Cc: Christoph Hellwig <hch@...>, Paul Mackerras <paulus@...>, Andrew Morton <akpm@...>, Greg KH <gregkh@...>, Philip Mucci <mucci@...>, <eranian@...>, William Cohen <wcohen@...>, Robert Richter <robert.richter@...>, <linux-kernel@...>, Perfmon <perfmon@...>, <perfmon2-devel@...>, OSPAT devel <ospat-devel@...>, papi list <ptools-perfapi@...>
actually multiplexing is the main feature i am in need of. there are an
insufficient number of counters (even on k8 with 4 counters) to do
complete stall accounting or to get a general overview of L1d/L1i/L2 cache
hit rates, average miss latency, time spent in various stalls, and the
memory system utilization (or HT bus utilization). this runs out to
something like 30 events which are interesting... and re-running a
benchmark over and over just to get around the lack of multiplexing is a
royal pain in the ass.
it's not a "far away non-essential feature" to me. it's something i would
use daily if i had all the pieces together now (and i'm constrained
because i cannot add an out-of-tree patch which adds unofficial syscalls
to the kernel i use).
-dean
-
