From: "Alex Bennée" <alex.bennee@linaro.org>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: mohamad.gebai@gmail.com, qemu-devel@nongnu.org,
stefanha@redhat.com, "Andreas Färber" <afaerber@suse.de>
Subject: Re: [Qemu-devel] [PATCH v2 3/3] trace: instrument and trace tcg tb flush activity
Date: Tue, 15 Jul 2014 15:16:26 +0100 [thread overview]
Message-ID: <871ttmyabr.fsf@linaro.org> (raw)
In-Reply-To: <53C52A66.5000906@redhat.com>
Paolo Bonzini writes:
> Il 15/07/2014 13:42, Alex Bennée ha scritto:
>> + trace_inc_counter(&cpu->tb_jmp_cache_stats.misses);
>> tb = tb_find_slow(env, pc, cs_base, flags);
>> + } else {
>> + trace_inc_counter(&cpu->tb_jmp_cache_stats.hits);
>> }
>
> I think this is premature optimization...
How do you mean? It's not really an optimization as much as an
instrumentation. It should compile away to nothing if you don't have
tracing enabled in your build.
OTOH the numbers I'm seeing are very interesting in so far as the fast
path could be a potential waste of code in a lot of cases.
--
Alex Bennée
next prev parent reply other threads:[~2014-07-15 14:17 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-15 11:42 [Qemu-devel] [PATCH v2 0/3] some TCG related trace patches Alex Bennée
2014-07-15 11:42 ` [Qemu-devel] [PATCH v2 1/3] trace: teach lttng backend to use format strings Alex Bennée
2014-08-01 9:05 ` Alex Bennée
2014-08-01 12:54 ` Stefan Hajnoczi
2014-07-15 11:42 ` [Qemu-devel] [PATCH v2 2/3] trace: add some tcg tracing support Alex Bennée
2014-07-15 11:42 ` [Qemu-devel] [PATCH v2 3/3] trace: instrument and trace tcg tb flush activity Alex Bennée
2014-07-15 12:15 ` Andreas Färber
2014-07-15 13:12 ` Alex Bennée
2014-07-15 12:23 ` Peter Maydell
2014-07-15 13:07 ` Peter Maydell
2014-07-15 13:10 ` Alex Bennée
2014-07-15 13:19 ` Paolo Bonzini
2014-07-15 14:16 ` Alex Bennée [this message]
2014-07-15 20:11 ` Paolo Bonzini
2014-07-15 20:29 ` Peter Maydell
2014-07-15 20:38 ` Paolo Bonzini
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