Re: perf events (node-loads, node-load-misses, ...)

[Andi Kleen <andi@firstfloor.org>]

Hyojong Kim <hkim606@gmail.com> writes:

> Hello,
>
> My processor has several hardware cache events, of which I am
> interested in node-loads, node-load-misses, node-stores,
> node-store-misses. I think it is kind of obvious that node-loads and
> node-stores represent references to local memory (memory physically
> attached to a processor package). However, I have no clue as to what
> the rest represents. I have some theory that "node-load-misses"
> represent the number of misses in local memory, or the number of
> accesses to disk. Based on the profiled results I have
> (page-faults:16M << node-load-misses+node-store-misses:748M), however,
> this cannot be the raw number of disk accesses. Maybe some kind of
> piggybacking mechanism (by some MSHR kind of structure in memory?)
> could be the reason behind this discrepancy, but no clue. If anyone
> has some idea on this, please share it with me.

node-loads is the number of memory reads served by the local NUMA node.
node-loads-misses is the number of reads served by a remote NUMA node.
Similar for stores.

It has nothing to do with the disk.

-Andi