The same event as the one you mentionned (I also checked that it's the same event than the one used by perf mem record)
Setting precise-ip to 0 allows me to open the event and then mmap the result, but I don't have any sample. Manu > Le 29 oct. 2014 à 17:09, Vince Weaver <[email protected]> a écrit : > >> On Wed, 29 Oct 2014, Manuel Selva wrote: >> >> I am trying to setup load latency sampling on a Sandy Bridge processor (Cpu >> familly 6, model 42, model name Intel(R) Core(TM) i5-2520M CPU @ 2.50GHz) >> running a 3.13 linux kernel. >> >> After deep investigations made of reading of the Intel SDM, examples provided >> by the pfm library and the source code of perf, I am still not able to get >> sample. I think for now that my problem is related to the precise_ip >> parameter >> of the perf_event_attr structure. >> >> Any time I change this value from 0 to 1 or from 0 to 2 (2 is the value to >> enable PEBS isn't it ?) the perf_event_open system call failed with a "Not >> supported operation" error. Running perf mem record on this Sandy Bridge >> platform also result in the same error. > > Which event are you trying to use? > > On my Ivybrige machine using 3.14 I am able to get latency values with > pe.config=0x1cd; > pe.config1=3; > pe.precise_ip=2; > > Vince -- To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
