Messages in this thread | ![/](/images/icornerl.gif) | | From | Francis Moreau <> | Subject | Re: perf tools miscellaneous questions | Date | Thu, 04 Nov 2010 21:58:32 +0100 |
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Francis Moreau <francis.moro@gmail.com> writes:
> Francis Moreau <francis.moro@gmail.com> writes: >
[...]
>> >> How could I know the number of cache level on my cpu ? >> >> I tried: >> >> $ perf stat -e cache-misses:u,l1d-loads-misses:u true >> >> Performance counter stats for 'true': >> >> 802 cache-misses >> 937 L1-dcache-load-misses >> >> 0.000996578 seconds time elapsed >> >> $ perf stat -e cache-misses:u,L2-loads-misses:u true >> >> Performance counter stats for 'true': >> >> 788 cache-misses >> 95 LLC-load-misses >> >> 0.001025423 seconds time elapsed >> >> So it looks like you're right: in my case I have this cache >> configuration: >> > > oops sorry, I replied too early... > > so my cache configuration is: > > L1 -> L2 -> LLC > > where L2 misses is given by: 'cache-misses' - 'LLC-load-misses' > > Is that correct ? > > If so, I found 'cache-misses' term very not intuitive IMHO, probably > because I'm not an expert in cpu caches...
Well thinking more about it, the above is wrong and I'm lost.
If 'cache-misses' is the last level cache misses then how to interpret these results ?
$ perf stat -e llc-load-misses:u,llc-store-misses:u true
Performance counter stats for 'true':
94 LLC-load-misses 0 LLC-store-misses
0.000981840 seconds time elapsed
$ perf stat -e cache-misses:u true
Performance counter stats for 'true':
796 cache-misses
0.001345136 seconds time elapsed
Here 'cache-misses' value is much more than llc misses one...
-- Francis
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