Re: re-enable Nehalem raw Offcore-Events support

From: Ingo Molnar
Date: Sun May 01 2011 - 14:01:20 EST



* Andi Kleen <ak@xxxxxxxxxxxxxxx> wrote:

> > I would say that most if not all of the events are not generalizable
> > in the sense that you are talking about; the events are very
> > specific to the Torrent chip. For example, the Torrent chip
>
> It's similar also on Intel chips. [...]

You seem to be seriously misinformed about Intel CPUs.

There are a fair number of events on Intel CPUs that can be generalized and
which we have already generalized. Here's a selection:

Performance counter stats for './fill_1b':

2829.562519 task-clock # 0.994 CPUs utilized
27 context-switches # 0.000 M/sec
52 CPU-migrations # 0.000 M/sec
99 page-faults # 0.000 M/sec
8,559,062,611 cycles # 3.025 GHz (20.02%)
2,530,761,381 stalled-cycles-frontend # 29.57% frontend cycles idle (30.03%)
423,070,037 stalled-cycles-backend # 4.94% backend cycles idle (40.04%)
18,043,436,126 instructions # 2.11 insns per cycle
# 0.14 stalled cycles per insn (50.04%)
1,007,704,770 branches # 356.134 M/sec (60.04%)
521,894 branch-misses # 0.05% of all branches (60.02%)
9,424,849 L1-dcache-loads # 3.331 M/sec (50.03%)
1,028,884 L1-dcache-load-misses # 10.92% of all L1-dcache hits (50.02%)
490,266 LLC-loads # 0.173 M/sec (39.99%)
133,226 LLC-load-misses # 0.047 M/sec (10.01%)

2.846836822 seconds time elapsed

Thanks,

Ingo
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