From: Paolo Bonzini <pbonzini@redhat.com>
To: qemu-devel@nongnu.org, "Blue Swirl" <blauwirbel@gmail.com>,
"Riku Voipio" <riku.voipio@iki.fi>,
"Eduardo Habkost" <ehabkost@redhat.com>,
"Stefan Hajnoczi" <stefanha@redhat.com>,
"Andreas Färber" <afaerber@suse.de>
Subject: Re: [Qemu-devel] [PATCH 4/6] trace: Add per-vCPU tracing states for events with the 'vcpu' property
Date: Mon, 13 Jun 2016 16:08:50 +0200 [thread overview]
Message-ID: <fcfedbc2-67a9-4911-6d5a-6079bd7c1b6f@redhat.com> (raw)
In-Reply-To: <87lh29cmip.fsf@fimbulvetr.bsc.es>
On 13/06/2016 14:15, Lluís Vilanova wrote:
> > That said, I am skeptical about the benefit of the interfaces you are
> > adding. They add a lot of complication and overhead (especially
> > regarding the memory/cache overhead of the dstate array) without a clear
> > use case, in my opinion; all the processing you do at run-time is just
> > as well suited for later filtering.
>
> This should make tracing faster on the future with multi-threaded TCG, as well
> as trace files much smaller if you're tracing something like memory
> accesses. Also, bear in mind this series was split from a much larger one for
> simplicity. The follow-up one provides much larger performance benefits by
> avoiding the generation of TCG code to call the tracing backend when a vCPU is
> not traced.
This still assumes that tracing only some VCPUs is a common use case.
Is it?...
Paolo
next prev parent reply other threads:[~2016-06-13 14:09 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-25 15:02 [Qemu-devel] [PATCH0/6] trace: Per-vCPU tracing states Lluís Vilanova
2016-02-25 15:02 ` [Qemu-devel] [PATCH 1/6] trace: Identify events with the 'vcpu' property Lluís Vilanova
2016-06-09 12:11 ` Stefan Hajnoczi
2016-02-25 15:02 ` [Qemu-devel] [PATCH 2/6] disas: Remove unused macro '_' Lluís Vilanova
2016-06-09 8:18 ` Stefan Hajnoczi
2016-06-09 10:34 ` Lluís Vilanova
2016-02-25 15:03 ` [Qemu-devel] [PATCH 3/6] [trivial] trace: Cosmetic changes on fast-path tracing Lluís Vilanova
2016-06-09 12:11 ` Stefan Hajnoczi
2016-06-13 9:04 ` Paolo Bonzini
2016-06-13 13:39 ` Lluís Vilanova
2016-02-25 15:03 ` [Qemu-devel] [PATCH 4/6] trace: Add per-vCPU tracing states for events with the 'vcpu' property Lluís Vilanova
2016-06-09 12:07 ` Stefan Hajnoczi
2016-06-09 14:17 ` Lluís Vilanova
2016-06-10 16:25 ` Stefan Hajnoczi
2016-06-10 17:52 ` Lluís Vilanova
2016-06-13 8:38 ` Paolo Bonzini
2016-06-13 12:17 ` Lluís Vilanova
2016-06-13 9:13 ` Paolo Bonzini
2016-06-13 12:15 ` Lluís Vilanova
2016-06-13 14:08 ` Paolo Bonzini [this message]
2016-06-13 16:39 ` Lluís Vilanova
2016-06-14 8:39 ` Stefan Hajnoczi
2016-06-14 9:13 ` Paolo Bonzini
2016-06-14 12:17 ` Lluís Vilanova
2016-06-13 14:38 ` Lluís Vilanova
2016-02-25 15:03 ` [Qemu-devel] [PATCH 5/6] trace: Conditionally trace events based on their per-vCPU state Lluís Vilanova
2016-06-09 12:09 ` Stefan Hajnoczi
2016-02-25 15:03 ` [Qemu-devel] [PATCH 6/6] trace: Add QAPI/QMP interfaces to query and control per-vCPU tracing state Lluís Vilanova
2016-06-09 12:10 ` Stefan Hajnoczi
2016-03-07 19:35 ` [Qemu-devel] [PATCH0/6] trace: Per-vCPU tracing states Lluís Vilanova
2016-06-01 12:14 ` Lluís Vilanova
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