On Thu, Feb 11, 2010 at 11:10 PM, Corey Ashford <cjash...@linux.vnet.ibm.com> wrote: > Hi Stephane, > > On 2/11/2010 1:00 PM, stephane eranian wrote: >> >> Gary, >> >> On Thu, Feb 11, 2010 at 9:51 PM,<gary.m...@bull.com> wrote: >>> >>> Hi Stephane >>> >>> Do you happen to know if perf_events has any plans to support Nehalem >>> uncore events ?? >>> >> Well, I don't know if anyone is working on this. But this is definitively >> on >> my list of things to add. I don't like regressions! >> >> As you may have seen I started fixing some of these regressions myself >> by posting patches to LKML. The first priority was correct event -> >> counter >> assignment. This is almost done now (at least on x86-tip). Next step is to >> add the non-standard features, such as PEBS, LBR, uncore, offcore and >> the likes. They will all be implemented because they are important to many >> users. >> > > I'm jazzed to see that you are considering adding support to perf_events for > offcore PMUs. Have you had a chance to think about the fuzzy proposal I > made on LKML regarding the addressing of offcore PMUs, or even uncore PMUs > where there are multiple instances of the same PMU type? > I think the current PMU naming scheme is not flexible enough. Clearly, it does not address PMU beyond the CPU socket. For existing uncore PMU on Nehalem, for instance, we can get by by using the CPU as a hint. But we need something more flexible.
> Peter Zijlstra's idea is to add another field to the perf_event_attr struct, > .pmu_id, which is a (char *) pointing to a pathname in /sys/devices, and > directly at a PMU entry which contains a PMU id which can be used to both > determine which PMU is being referred to and what type it is. Of course, > these new PMU entries in /sys/devices would need to be added. > Yes, you need some enumeration of the available PMUs in sysfs. I would rather pass a file descriptor to the sysfs file rather that the pathname. It makes is easier to handle in the kernel. > Any thoughts, concerns, alternative ideas, etc. would be appreciated, and > I'm interested to hear your take on how to approach this issue. > My choice would be pass a fd to a sysfs file designating the resource. As mentioned, the kernel would have to enumerate all PMUs at boot time, or on hotplug event. ------------------------------------------------------------------------------ SOLARIS 10 is the OS for Data Centers - provides features such as DTrace, Predictive Self Healing and Award Winning ZFS. Get Solaris 10 NOW http://p.sf.net/sfu/solaris-dev2dev _______________________________________________ perfmon2-devel mailing list perfmon2-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/perfmon2-devel
