From: "Daniel P. Berrangé" <berrange@redhat.com>
To: Gerd Hoffmann <kraxel@redhat.com>
Cc: qemu-devel@nongnu.org,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
Markus Armbruster <armbru@redhat.com>
Subject: Re: [PATCH v3 0/8] [RfC] fix tracing for modules
Date: Fri, 9 Apr 2021 14:17:13 +0100 [thread overview]
Message-ID: <YHBT2ZLdIesZOR4Q@redhat.com> (raw)
In-Reply-To: <20210409131245.oqeu4ooueazqfcir@sirius.home.kraxel.org>
On Fri, Apr 09, 2021 at 03:12:45PM +0200, Gerd Hoffmann wrote:
> Hi,
>
> > eg a trace point "dma_map_wait" gets mapped to probes in many
> > .stp files, once per target, because we need to match based on
> > the executable path:
> >
> > probe qemu.system.x86_64.dma_map_wait = process("/usr/libexec/qemu-system-x86_64").mark("dma_map_wait")
>
> So, that changes with modules, we need the module name now, i.e.
>
> probe qemu.system.x86_64.qxl_soft_reset = \
> process("/home/kraxel/qemu-install/lib/qemu/hw-display-qxl.so").mark("qxl_soft_reset")
>
> We could repeat that in every qemu-system-$arch.stp file.
This would have the surprise the 'qemu.system.x86_64.qxl_soft_reset'
probes will fire even for qemu-system-ppc64 / qemu-system-xxxxx etc
because we've not restricted the scope as the original probe did.
If we can't fix that, then we must use the second option to avoid
the surprise IMHO
> We could also have one stp file per module, with probes like this:
>
> probe qemu.modules.qxl_soft_reset = \
> process("/home/kraxel/qemu-install/lib/qemu/hw-display-qxl.so").mark("qxl_soft_reset")
>
> The later looks like a better fit to me, but has the drawback that the
> tracepoints have different names in modular and non-modular builds ...
Regards,
Daniel
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next prev parent reply other threads:[~2021-04-09 13:18 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-21 12:50 [PATCH v3 0/8] [RfC] fix tracing for modules Gerd Hoffmann
2021-01-21 12:50 ` [PATCH v3 1/8] meson: add trace_events_config[] Gerd Hoffmann
2021-01-27 14:48 ` Stefan Hajnoczi
2021-01-21 12:50 ` [PATCH v3 2/8] meson: move up hw subdir (specifically before trace subdir) Gerd Hoffmann
2021-01-27 14:49 ` Stefan Hajnoczi
2021-01-21 12:50 ` [PATCH v3 3/8] meson: add module_trace & module_trace_src Gerd Hoffmann
2021-01-27 15:03 ` Stefan Hajnoczi
2021-01-21 12:50 ` [PATCH v3 4/8] meson: move qxl trace events to separate file Gerd Hoffmann
2021-01-27 15:33 ` Stefan Hajnoczi
2021-03-22 11:43 ` Daniel P. Berrangé
2021-01-21 12:50 ` [PATCH v3 5/8] trace: iter init tweaks Gerd Hoffmann
2021-02-03 16:13 ` Stefan Hajnoczi
2021-01-21 12:50 ` [PATCH v3 6/8] trace: add trace_event_iter_init_group Gerd Hoffmann
2021-02-03 16:16 ` Stefan Hajnoczi
2021-01-21 12:50 ` [PATCH v3 7/8] trace/simple: pass iter to st_write_event_mapping Gerd Hoffmann
2021-02-03 16:17 ` Stefan Hajnoczi
2021-01-21 12:50 ` [PATCH v3 8/8] trace/simple: add st_init_group Gerd Hoffmann
2021-02-03 16:22 ` Stefan Hajnoczi
2021-02-03 16:32 ` [PATCH v3 0/8] [RfC] fix tracing for modules Stefan Hajnoczi
2021-02-22 15:13 ` Gerd Hoffmann
2021-03-22 11:36 ` Stefan Hajnoczi
2021-03-22 11:46 ` Daniel P. Berrangé
2021-03-29 16:32 ` Stefan Hajnoczi
2021-03-22 12:03 ` Daniel P. Berrangé
2021-03-26 12:47 ` Gerd Hoffmann
2021-03-29 9:23 ` Daniel P. Berrangé
2021-03-29 9:48 ` Gerd Hoffmann
2021-03-29 10:02 ` Daniel P. Berrangé
2021-03-31 10:55 ` Gerd Hoffmann
2021-04-09 9:10 ` Gerd Hoffmann
2021-04-09 13:12 ` Gerd Hoffmann
2021-04-09 13:17 ` Daniel P. Berrangé [this message]
2021-04-12 13:07 ` Gerd Hoffmann
2021-04-15 13:10 ` Daniel P. Berrangé
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