Re: [PATCH 6/7] perf kvm: move perf_kvm__mmap_read into session utils

From: David Ahern
Date: Mon Jun 23 2014 - 10:06:27 EST

On 6/20/14, 8:44 AM, Arnaldo Carvalho de Melo wrote:
Em Fri, Jun 20, 2014 at 02:49:48PM +0400, Stanislav Fomichev escreveu:
It will be reused by perf trace in the following commit.

I know this is needed, but one of the goals when I started builtin-trace
was not to use perf_session at all, as it initially was just about the
live mode.

record/replay came later and ended up needing it,

perf-kvm does not use the session code because I kept tripping over the out of order timestamp problem. By limiting the number of events read in a single pass I was able to smooth out the load and avoided hitting it as often. As I mentioned before the final piece was using the perf_clock timestamp at the start of the round to ensure I never hit it.

Stanislav: are you seeing out of order timestamp errors or just trying to reuse the live code from perf-kvm?

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