Re: Link between Intel documentation events and perf list events

[Andi Kleen <andi@firstfloor.org>]

On Tue, Jul 02, 2013 at 03:33:18PM +0200, Manuel Selva wrote:
> Thanks again for the help.Your answer suggests that events listed as
> Hardware event by perf listare what is called Architecural Events
> for Intel processors, isn't it ?

perf uses a superset of the architectural events
(but only a small subset of a full Intel event list)

Also it supports setting the other events in raw form
(or various add-on tools exist to provide them as names)

> On my Sandy Bridge core i5-2520M, perf list reports 10 hardware
> events, where as they are only 7 entriesin the table 18-1 of Intel
> documentation you mentioned. So I am wondering what are these 3
> additional events;

Not all events supported by perf are in sysfs.

> 
> event=0x00,umask=0x03 (ref-cycles)
> event=0xb1,umask=0x01,inv,cmask=0x01 (stalled-cycles-backend)
> event=0x0e,umask=0x01,inv,cmask=0x01 (stalled-cycles-frontend)
> 
> Looking at table 19-7 in the same Intel document, I can see non
> architectural events for my core i5-2xxx. In this table I can see
> that:
> 
> ref-cycles                       ==> Can't find it

This is typically called CPU_CLK_UNHALTED.REF_TSC or so
in the Intel documentation.

> stalled-cycles-backend ==> Counts total number of uops to be
> dispatched per- thread each cycle. Set Cmask = 1, INV =1 to count
> stall cycles.
> stalled-cycles-frontend ==> Increments each cycle the # of Uops
> issued by the RAT to RS.Set Cmask = 1, Inv = 1, Any= 1to count
> stalled cycles of this core.

These two are very broken. Just ignore them.

-Andi