perf can't keep up with mmap data
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From: Arnaldo Carvalho de Melo on 19 Jul 2010 11:10 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |