Messages in this thread | | | Date | Mon, 19 Jul 2010 12:04:33 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: perf can't keep up with mmap data |
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Em Mon, Jul 19, 2010 at 09:48:13AM +0200, Christoph Hellwig escreveu: > When running current -tip perf in my 32-bit x86 kvm guest I get lots > of messages like: > > WARNING: failed to keep up with mmap data. > > when starting perf top, and still quite a few everytime it refreshes the > display.
Should be better reported, probably with a message suggesting to use:
perf top -r RTPRIO
or to reduce the sampling frequency:
perf top -F 500
to have:
PerfTop: 287 irqs/sec kernel:40.8% exact: 0.0% [500Hz cycles], (all, 2 CPUs)
Instead of the default:
PerfTop: 35 irqs/sec kernel:25.7% exact: 0.0% [1000Hz cycles], (all, 2 CPUs)
- Arnaldo
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