When used together with -m, this allows us to benchmark the
profiler's performance impact on qemu_mutex_lock.
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This allows us to use atomic-add-bench as a microbenchmark
for evaluating qemu_mutex_lock's performance.
Signed-off-by: Emilio G. Cota <cota@braap.org>
[cherry picked from https://github.com/cota/qemu/commit/f04f34df]
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20180425025459.5258-2-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
With this microbenchmark we can measure the overhead of emulating atomic
instructions with a configurable degree of contention.
The benchmark spawns $n threads, each performing $o atomic ops (additions)
in a loop. Each atomic operation is performed on a different cache line
(assuming lines are 64b long) that is randomly selected from a range [0, $r).
[ Note: each $foo corresponds to a -foo flag ]
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1467054136-10430-20-git-send-email-cota@braap.org>
Emilio G. Cota