PC Processors

[111alan]

Was trying to get some basic performance data in uprof. My question is, how to calculate the actual hit rate of uop/L1/L2/L3 cache? The results of simply making divisions between the DC_refill_L2/CCX/dram values doesn't seem to make sense(too high).

And what does function "%data cache miss" actually mean? Is it the proportion of accesses that missed all levels of caches, or it's just the percentage that missed the L1D?

Thank you.

[swarup · Accepted solution]

Hi 111alan‌,

L1D Hit rate can be calculated from (L1) DC Miss rate (event 0x60, umask 0xC8). DC Miss rate can be seen by selecting "View" dropdown box > "Data access assessment".
L2 Hits can be calculated by profiling the event 0x64, umask=0xF6.
As L3 is shared among group of cores, uProf does not support L3 specific events. For that, you may need to use AMDPcm tool packed along with uProf.

"%data cache miss" :  It is the percentage that missed the L1D.

[111alan]

Thank you for helping, I'll give these a try soon.