Messages in this thread |  | | | Date | Fri, 17 Jun 2011 10:06:18 +0200 | | From | Ingo Molnar <> | | Subject | Re: [PATCH] oprofile, x86: Fix race in nmi handler while starting |
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* Robert Richter <robert.richter@amd.com> wrote:
> On 09.06.11 03:18:54, Ingo Molnar wrote: > > > > * Robert Richter <robert.richter@amd.com> wrote: > > > > > In some rare cases, nmis are generated immediately after the > > > nmi handler of the cpu was started. This causes the counter not > > > to be enabled. Before enabling the nmi handlers we need to set > > > variable ctr_running first and make sure its value is written > > > to memory. > > > > > > Also, the patch makes all existing barriers a memory barrier > > > instead of a compiler barrier only. > > > > Could we *PLEASE* just do the obvious and turn oprofile into a > > perf user on x86 too, like ARM already does? Two years down the > > line and there's zero progress in that area. We want to obsolete > > the Oprofile PMU bits on x86, the infrastructure duplication > > causes non-trivial problems like this one. > > Ingo, > > I would rather prefer to spend the effort to add full pmu support > to perf. AMD features missing are still IBS and nb performance > counters for family 15h. The oprofile kernel driver would become > obsolete at all with a new daemon using the perf syscall interface.
Agreed - i just don't see *any* progress on the IBS front: more time seems to be spent on fixing and sometimes even extending oprofile than on any IBS work.
Thanks,
Ingo
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