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Re: [PATCH v3 0/8] [RfC] fix tracing for modules
From: |
Gerd Hoffmann |
Subject: |
Re: [PATCH v3 0/8] [RfC] fix tracing for modules |
Date: |
Mon, 29 Mar 2021 11:48:18 +0200 |
On Mon, Mar 29, 2021 at 10:23:42AM +0100, Daniel P. Berrangé wrote:
> On Fri, Mar 26, 2021 at 01:47:00PM +0100, 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")
> > > probe qemu.system.x86_64.dma_map_wait =
> > > process("/usr/libexec/qemu-system-ppc64").mark("dma_map_wait")
> >
> > Probe qemu.system.ppc64.dma_map_wait = ...
> >
> > Can I trace qemu started from build directory?
> > Seems scripts/qemu-trace-stap doesn't support that.
>
> We should really generate extra equiv .stp files just for running from
> the build.
Well, "make install" with --prefix=$HOME/qemu-install fixed that for the time
being.
Now I have this:
kraxel@sirius ~/qemu-install/bin# sudo ./qemu-trace-stap -v run
./qemu-system-x86_64 "qxl_soft_reset"
Using tapset dir '/home/kraxel/qemu-install/share/systemtap/tapset' for binary
'./qemu-system-x86_64'
Compiling script 'probe qemu.system.x86_64.log.qxl_soft_reset {}'
semantic error: unresolved function pid: identifier 'pid' at
/home/kraxel/qemu-install/share/systemtap/tapset/qemu-system-x86_64-log.stp:5451:41
source: printf("%d@%d qxl_soft_reset %d\n", pid(),
gettimeofday_ns(), qid)
^
Pass 2: analysis failed. [man error::pass2]
Any clue why pid() isn't known?
thanks,
Gerd