Fabio Fantoni
2013-Sep-27 14:00 UTC
[PATCH] tools: adds tracer on qemu-xen debug configure options
When building tools in debug mode (debug=y), pass also --enable-trace-backend=stderr when configuring qemu-xen. Useful to improve debug. Signed-off-by: Fabio Fantoni <fabio.fantoni@m2r.biz> --- tools/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/Makefile b/tools/Makefile index e7a983b..77a3522 100644 --- a/tools/Makefile +++ b/tools/Makefile @@ -174,7 +174,7 @@ qemu-xen-dir-force-update: fi ifeq ($(debug),y) -QEMU_XEN_ENABLE_DEBUG := --enable-debug +QEMU_XEN_ENABLE_DEBUG := --enable-debug --enable-trace-backend=stderr else QEMU_XEN_ENABLE_DEBUG : endif -- 1.7.9.5
Stefano Stabellini
2013-Sep-30 11:21 UTC
Re: [PATCH] tools: adds tracer on qemu-xen debug configure options
On Fri, 27 Sep 2013, Fabio Fantoni wrote:> When building tools in debug mode (debug=y), pass also > --enable-trace-backend=stderr when configuring qemu-xen. > Useful to improve debug. > > Signed-off-by: Fabio Fantoni <fabio.fantoni@m2r.biz>Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>> tools/Makefile | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/Makefile b/tools/Makefile > index e7a983b..77a3522 100644 > --- a/tools/Makefile > +++ b/tools/Makefile > @@ -174,7 +174,7 @@ qemu-xen-dir-force-update: > fi > > ifeq ($(debug),y) > -QEMU_XEN_ENABLE_DEBUG := --enable-debug > +QEMU_XEN_ENABLE_DEBUG := --enable-debug --enable-trace-backend=stderr > else > QEMU_XEN_ENABLE_DEBUG :> endif > -- > 1.7.9.5 >
Ian Campbell
2013-Oct-03 13:08 UTC
Re: [PATCH] tools: adds tracer on qemu-xen debug configure options
On Fri, 2013-09-27 at 16:00 +0200, Fabio Fantoni wrote:> When building tools in debug mode (debug=y), pass also > --enable-trace-backend=stderr when configuring qemu-xen. > Useful to improve debug.What does this actually do in practice? More logging in /var/log/xen/qemu-dm-$dom.log or something else?> > Signed-off-by: Fabio Fantoni <fabio.fantoni@m2r.biz> > --- > tools/Makefile | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/Makefile b/tools/Makefile > index e7a983b..77a3522 100644 > --- a/tools/Makefile > +++ b/tools/Makefile > @@ -174,7 +174,7 @@ qemu-xen-dir-force-update: > fi > > ifeq ($(debug),y) > -QEMU_XEN_ENABLE_DEBUG := --enable-debug > +QEMU_XEN_ENABLE_DEBUG := --enable-debug --enable-trace-backend=stderr > else > QEMU_XEN_ENABLE_DEBUG :> endif
Fabio Fantoni
2013-Oct-03 13:35 UTC
Re: [PATCH] tools: adds tracer on qemu-xen debug configure options
Il 03/10/2013 15:08, Ian Campbell ha scritto:> On Fri, 2013-09-27 at 16:00 +0200, Fabio Fantoni wrote: >> When building tools in debug mode (debug=y), pass also >> --enable-trace-backend=stderr when configuring qemu-xen. >> Useful to improve debug. > What does this actually do in practice? More logging > in /var/log/xen/qemu-dm-$dom.log or something else?Yes, I think that stderr backend is good because the log will go on /var/log/xen/qemu-dm-$dom.log (easy and fast). To use it must be configured with some qemu parameters, containing the type of events to log. Setting it with "device_model_args" should be sufficent instead adding other libxl option, and this should be used only on some debug case. All details here: http://git.qemu.org/?p=qemu.git;a=blob;f=docs/tracing.txt> >> Signed-off-by: Fabio Fantoni <fabio.fantoni@m2r.biz> >> --- >> tools/Makefile | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/tools/Makefile b/tools/Makefile >> index e7a983b..77a3522 100644 >> --- a/tools/Makefile >> +++ b/tools/Makefile >> @@ -174,7 +174,7 @@ qemu-xen-dir-force-update: >> fi >> >> ifeq ($(debug),y) >> -QEMU_XEN_ENABLE_DEBUG := --enable-debug >> +QEMU_XEN_ENABLE_DEBUG := --enable-debug --enable-trace-backend=stderr >> else >> QEMU_XEN_ENABLE_DEBUG :>> endif >
Fabio Fantoni
2013-Oct-10 08:14 UTC
Re: [PATCH] tools: adds tracer on qemu-xen debug configure options
Il 03/10/2013 15:35, Fabio Fantoni ha scritto:> Il 03/10/2013 15:08, Ian Campbell ha scritto: >> On Fri, 2013-09-27 at 16:00 +0200, Fabio Fantoni wrote: >>> When building tools in debug mode (debug=y), pass also >>> --enable-trace-backend=stderr when configuring qemu-xen. >>> Useful to improve debug. >> What does this actually do in practice? More logging >> in /var/log/xen/qemu-dm-$dom.log or something else? > > Yes, I think that stderr backend is good because the log will go on > /var/log/xen/qemu-dm-$dom.log (easy and fast). > To use it must be configured with some qemu parameters, containing the > type of events to log. Setting it with "device_model_args" should be > sufficent instead adding other libxl option, and this should be used > only on some debug case. > All details here: > http://git.qemu.org/?p=qemu.git;a=blob;f=docs/tracing.txt >Any hints on this?>> >>> Signed-off-by: Fabio Fantoni <fabio.fantoni@m2r.biz> >>> --- >>> tools/Makefile | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/tools/Makefile b/tools/Makefile >>> index e7a983b..77a3522 100644 >>> --- a/tools/Makefile >>> +++ b/tools/Makefile >>> @@ -174,7 +174,7 @@ qemu-xen-dir-force-update: >>> fi >>> ifeq ($(debug),y) >>> -QEMU_XEN_ENABLE_DEBUG := --enable-debug >>> +QEMU_XEN_ENABLE_DEBUG := --enable-debug --enable-trace-backend=stderr >>> else >>> QEMU_XEN_ENABLE_DEBUG :>>> endif >> >
Ian Campbell
2013-Oct-10 08:52 UTC
Re: [PATCH] tools: adds tracer on qemu-xen debug configure options
On Thu, 2013-10-10 at 10:14 +0200, Fabio Fantoni wrote:> Il 03/10/2013 15:35, Fabio Fantoni ha scritto: > > Il 03/10/2013 15:08, Ian Campbell ha scritto: > >> On Fri, 2013-09-27 at 16:00 +0200, Fabio Fantoni wrote: > >>> When building tools in debug mode (debug=y), pass also > >>> --enable-trace-backend=stderr when configuring qemu-xen. > >>> Useful to improve debug. > >> What does this actually do in practice? More logging > >> in /var/log/xen/qemu-dm-$dom.log or something else? > > > > Yes, I think that stderr backend is good because the log will go on > > /var/log/xen/qemu-dm-$dom.log (easy and fast). > > To use it must be configured with some qemu parameters, containing the > > type of events to log. Setting it with "device_model_args" should be > > sufficent instead adding other libxl option, and this should be used > > only on some debug case. > > All details here: > > http://git.qemu.org/?p=qemu.git;a=blob;f=docs/tracing.txt > > > > Any hints on this?I missed Stefano''s ack and was waiting for a qemu person to chime in, sorry. There was some previous discussion about whether this kind tracing was the right solution: http://thread.gmane.org/gmane.comp.emulators.xen.devel/164858/focus=165379 I guess however that enabling this in our own debug builds of qemu (i.e. this patch) is OK, but long term something which can work for distro qemu builds would be better.
Stefano Stabellini
2013-Oct-10 10:36 UTC
Re: [PATCH] tools: adds tracer on qemu-xen debug configure options
On Thu, 10 Oct 2013, Ian Campbell wrote:> On Thu, 2013-10-10 at 10:14 +0200, Fabio Fantoni wrote: > > Il 03/10/2013 15:35, Fabio Fantoni ha scritto: > > > Il 03/10/2013 15:08, Ian Campbell ha scritto: > > >> On Fri, 2013-09-27 at 16:00 +0200, Fabio Fantoni wrote: > > >>> When building tools in debug mode (debug=y), pass also > > >>> --enable-trace-backend=stderr when configuring qemu-xen. > > >>> Useful to improve debug. > > >> What does this actually do in practice? More logging > > >> in /var/log/xen/qemu-dm-$dom.log or something else? > > > > > > Yes, I think that stderr backend is good because the log will go on > > > /var/log/xen/qemu-dm-$dom.log (easy and fast). > > > To use it must be configured with some qemu parameters, containing the > > > type of events to log. Setting it with "device_model_args" should be > > > sufficent instead adding other libxl option, and this should be used > > > only on some debug case. > > > All details here: > > > http://git.qemu.org/?p=qemu.git;a=blob;f=docs/tracing.txt > > > > > > > Any hints on this? > > I missed Stefano''s ack and was waiting for a qemu person to chime in, > sorry. > > There was some previous discussion about whether this kind tracing was > the right solution: > http://thread.gmane.org/gmane.comp.emulators.xen.devel/164858/focus=165379 > > I guess however that enabling this in our own debug builds of qemu (i.e. > this patch) is OK, but long term something which can work for distro > qemu builds would be better.Passing --enable-trace-backend=stderr is a good idea. Ack for this patch.
Anthony PERARD
2013-Oct-10 11:27 UTC
Re: [PATCH] tools: adds tracer on qemu-xen debug configure options
On Thu, Oct 10, 2013 at 09:52:16AM +0100, Ian Campbell wrote:> On Thu, 2013-10-10 at 10:14 +0200, Fabio Fantoni wrote: > > Il 03/10/2013 15:35, Fabio Fantoni ha scritto: > > > Il 03/10/2013 15:08, Ian Campbell ha scritto: > > >> On Fri, 2013-09-27 at 16:00 +0200, Fabio Fantoni wrote: > > >>> When building tools in debug mode (debug=y), pass also > > >>> --enable-trace-backend=stderr when configuring qemu-xen. > > >>> Useful to improve debug. > > >> What does this actually do in practice? More logging > > >> in /var/log/xen/qemu-dm-$dom.log or something else? > > > > > > Yes, I think that stderr backend is good because the log will go on > > > /var/log/xen/qemu-dm-$dom.log (easy and fast). > > > To use it must be configured with some qemu parameters, containing the > > > type of events to log. Setting it with "device_model_args" should be > > > sufficent instead adding other libxl option, and this should be used > > > only on some debug case. > > > All details here: > > > http://git.qemu.org/?p=qemu.git;a=blob;f=docs/tracing.txt > > > > > > > Any hints on this? > > I missed Stefano''s ack and was waiting for a qemu person to chime in, > sorry. > > There was some previous discussion about whether this kind tracing was > the right solution: > http://thread.gmane.org/gmane.comp.emulators.xen.devel/164858/focus=165379The discussion was for a particular case, and was not about qemu trace itself.> I guess however that enabling this in our own debug builds of qemu (i.e. > this patch) is OK, but long term something which can work for distro > qemu builds would be better.Having trace compiled in for debug purpose is a good idee, it make it possible to enable some extra debug print without recompiling qemu. And by default, they won''t be any extra debug print in the logs. So ACK to add --enable-trace... to a debug build. -- Anthony PERARD
Ian Campbell
2013-Oct-10 11:42 UTC
Re: [PATCH] tools: adds tracer on qemu-xen debug configure options
On Thu, 2013-10-10 at 11:36 +0100, Stefano Stabellini wrote:> On Thu, 10 Oct 2013, Ian Campbell wrote: > > On Thu, 2013-10-10 at 10:14 +0200, Fabio Fantoni wrote: > > > Il 03/10/2013 15:35, Fabio Fantoni ha scritto: > > > > Il 03/10/2013 15:08, Ian Campbell ha scritto: > > > >> On Fri, 2013-09-27 at 16:00 +0200, Fabio Fantoni wrote: > > > >>> When building tools in debug mode (debug=y), pass also > > > >>> --enable-trace-backend=stderr when configuring qemu-xen. > > > >>> Useful to improve debug. > > > >> What does this actually do in practice? More logging > > > >> in /var/log/xen/qemu-dm-$dom.log or something else? > > > > > > > > Yes, I think that stderr backend is good because the log will go on > > > > /var/log/xen/qemu-dm-$dom.log (easy and fast). > > > > To use it must be configured with some qemu parameters, containing the > > > > type of events to log. Setting it with "device_model_args" should be > > > > sufficent instead adding other libxl option, and this should be used > > > > only on some debug case. > > > > All details here: > > > > http://git.qemu.org/?p=qemu.git;a=blob;f=docs/tracing.txt > > > > > > > > > > Any hints on this? > > > > I missed Stefano''s ack and was waiting for a qemu person to chime in, > > sorry. > > > > There was some previous discussion about whether this kind tracing was > > the right solution: > > http://thread.gmane.org/gmane.comp.emulators.xen.devel/164858/focus=165379 > > > > I guess however that enabling this in our own debug builds of qemu (i.e. > > this patch) is OK, but long term something which can work for distro > > qemu builds would be better. > > Passing --enable-trace-backend=stderr is a good idea. > Ack for this patch.applied.
Ian Jackson
2013-Oct-11 18:08 UTC
Re: [PATCH] tools: adds tracer on qemu-xen debug configure options
Fabio Fantoni writes ("[PATCH] tools: adds tracer on qemu-xen debug
configure options"):> When building tools in debug mode (debug=y), pass also
> --enable-trace-backend=stderr when configuring qemu-xen.
> Useful to improve debug.
This sounds plausible to me but Stefano may disagree ?
Ian.
Fabio Fantoni
2013-Oct-11 18:17 UTC
Re: [PATCH] tools: adds tracer on qemu-xen debug configure options
2013/10/11 Ian Jackson <Ian.Jackson@eu.citrix.com>> Fabio Fantoni writes ("[PATCH] tools: adds tracer on qemu-xen debug > configure options"): > > When building tools in debug mode (debug=y), pass also > > --enable-trace-backend=stderr when configuring qemu-xen. > > Useful to improve debug. > > This sounds plausible to me but Stefano may disagree ? >Stefano had already ack it: http://lists.xen.org/archives/html/xen-devel/2013-10/msg00786.html And the patch is already on git now.> > Ian. >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel