Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
---
docs/devel/tracing.txt | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/docs/devel/tracing.txt b/docs/devel/tracing.txt
index 07abbb3..6ab32cc 100644
--- a/docs/devel/tracing.txt
+++ b/docs/devel/tracing.txt
@@ -18,7 +18,7 @@ for debugging, profiling, and observing execution.
3. Run the virtual machine to produce a trace file:
- qemu -trace events=/tmp/events ... # your normal QEMU invocation
+ qemu --trace events=/tmp/events ... # your normal QEMU invocation
4. Pretty-print the binary trace file:
--
1.8.3.1
On Tue, Jun 12, 2018 at 23:15:49 -0400, Yaowei Bai wrote: > Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com> > --- > docs/devel/tracing.txt | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/docs/devel/tracing.txt b/docs/devel/tracing.txt > index 07abbb3..6ab32cc 100644 > --- a/docs/devel/tracing.txt > +++ b/docs/devel/tracing.txt > @@ -18,7 +18,7 @@ for debugging, profiling, and observing execution. > > 3. Run the virtual machine to produce a trace file: > > - qemu -trace events=/tmp/events ... # your normal QEMU invocation > + qemu --trace events=/tmp/events ... # your normal QEMU invocation The second dash is not missing; both '-args' and '--args' work. '-args' seems to be favoured though; see `qemu -h' or `qemu --h' :-) Emilio
On Tue, Jun 12, 2018 at 11:50:30PM -0400, Emilio G. Cota wrote: > On Tue, Jun 12, 2018 at 23:15:49 -0400, Yaowei Bai wrote: > > Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com> > > --- > > docs/devel/tracing.txt | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/docs/devel/tracing.txt b/docs/devel/tracing.txt > > index 07abbb3..6ab32cc 100644 > > --- a/docs/devel/tracing.txt > > +++ b/docs/devel/tracing.txt > > @@ -18,7 +18,7 @@ for debugging, profiling, and observing execution. > > > > 3. Run the virtual machine to produce a trace file: > > > > - qemu -trace events=/tmp/events ... # your normal QEMU invocation > > + qemu --trace events=/tmp/events ... # your normal QEMU invocation > > The second dash is not missing; both '-args' and '--args' work. > > '-args' seems to be favoured though; see `qemu -h' or `qemu --h' :-) Oh, you're right. I just checked qemu-nbd/io utilities. Forget about this change. Thanks. :-) > > Emilio
On 06/12/2018 10:50 PM, Emilio G. Cota wrote: > On Tue, Jun 12, 2018 at 23:15:49 -0400, Yaowei Bai wrote: >> Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com> >> --- >> docs/devel/tracing.txt | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/docs/devel/tracing.txt b/docs/devel/tracing.txt >> index 07abbb3..6ab32cc 100644 >> --- a/docs/devel/tracing.txt >> +++ b/docs/devel/tracing.txt >> @@ -18,7 +18,7 @@ for debugging, profiling, and observing execution. >> >> 3. Run the virtual machine to produce a trace file: >> >> - qemu -trace events=/tmp/events ... # your normal QEMU invocation >> + qemu --trace events=/tmp/events ... # your normal QEMU invocation > > The second dash is not missing; both '-args' and '--args' work. > > '-args' seems to be favoured though; see `qemu -h' or `qemu --h' :-) Actually, we're trying to fix that: https://wiki.qemu.org/BiteSizedTasks#Consistent_option_usage_in_documentation The one-vs-two dash usage is only supported in qemu, not in qemu-nbd or qemu-img (that is, qemu acts as if it uses getopt_long_only(), while the others use getopt_long() - except that we hand-rolled the parser in qemu, meaning you might find quirks where it sometimes doesn't even match getopt_long_only()). At any rate, since --trace is an option that is supported across multiple binaries, we SHOULD favor the double-dash spelling in our documentation, so that you can consistently reuse the same --trace invocation without worrying whether the binary parses its arguments with getopt_long() (where double is required) or like getopt_long_only() (where the double is optional but supported). So I'm in favor of this patch, although it may need more of a commit message summarizing the justification I've just pointed you to. Reviewed-by: Eric Blake <eblake@redhat.com> -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org
On Wed, Jun 13, 2018 at 06:27:49AM -0500, Eric Blake wrote: > On 06/12/2018 10:50 PM, Emilio G. Cota wrote: > >On Tue, Jun 12, 2018 at 23:15:49 -0400, Yaowei Bai wrote: > >>Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com> > >>--- > >> docs/devel/tracing.txt | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >>diff --git a/docs/devel/tracing.txt b/docs/devel/tracing.txt > >>index 07abbb3..6ab32cc 100644 > >>--- a/docs/devel/tracing.txt > >>+++ b/docs/devel/tracing.txt > >>@@ -18,7 +18,7 @@ for debugging, profiling, and observing execution. > >> 3. Run the virtual machine to produce a trace file: > >>- qemu -trace events=/tmp/events ... # your normal QEMU invocation > >>+ qemu --trace events=/tmp/events ... # your normal QEMU invocation > > > >The second dash is not missing; both '-args' and '--args' work. > > > >'-args' seems to be favoured though; see `qemu -h' or `qemu --h' :-) > > Actually, we're trying to fix that: > https://wiki.qemu.org/BiteSizedTasks#Consistent_option_usage_in_documentation > > The one-vs-two dash usage is only supported in qemu, not in qemu-nbd > or qemu-img (that is, qemu acts as if it uses getopt_long_only(), > while the others use getopt_long() - except that we hand-rolled the > parser in qemu, meaning you might find quirks where it sometimes > doesn't even match getopt_long_only()). > > At any rate, since --trace is an option that is supported across > multiple binaries, we SHOULD favor the double-dash spelling in our > documentation, so that you can consistently reuse the same --trace > invocation without worrying whether the binary parses its arguments Yes, this patch is inspired by this situation when translating DPRINT into trace for a new qemu utility (much like qemu-nbd) following docs/devel/tracing.txt. The utility complains it don't support -trace option. So i sent this patch after confirming this with qemu-nbd,qemu-io utilities. > with getopt_long() (where double is required) or like > getopt_long_only() (where the double is optional but supported). > > So I'm in favor of this patch, although it may need more of a commit > message summarizing the justification I've just pointed you to. Thanks for your nice explaination. If this patch could be merged i will send V2 with a commit message. > > Reviewed-by: Eric Blake <eblake@redhat.com> Thanks. > > -- > Eric Blake, Principal Software Engineer > Red Hat, Inc. +1-919-301-3266 > Virtualization: qemu.org | libvirt.org
On Wed, Jun 13, 2018 at 10:15:10AM -0400, Yaowei Bai wrote: > On Wed, Jun 13, 2018 at 06:27:49AM -0500, Eric Blake wrote: > > On 06/12/2018 10:50 PM, Emilio G. Cota wrote: > > >On Tue, Jun 12, 2018 at 23:15:49 -0400, Yaowei Bai wrote: > > >>Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com> > > >>--- > > >> docs/devel/tracing.txt | 2 +- > > >> 1 file changed, 1 insertion(+), 1 deletion(-) > > >> > > >>diff --git a/docs/devel/tracing.txt b/docs/devel/tracing.txt > > >>index 07abbb3..6ab32cc 100644 > > >>--- a/docs/devel/tracing.txt > > >>+++ b/docs/devel/tracing.txt > > >>@@ -18,7 +18,7 @@ for debugging, profiling, and observing execution. > > >> 3. Run the virtual machine to produce a trace file: > > >>- qemu -trace events=/tmp/events ... # your normal QEMU invocation > > >>+ qemu --trace events=/tmp/events ... # your normal QEMU invocation > > > > > >The second dash is not missing; both '-args' and '--args' work. > > > > > >'-args' seems to be favoured though; see `qemu -h' or `qemu --h' :-) > > > > Actually, we're trying to fix that: > > https://wiki.qemu.org/BiteSizedTasks#Consistent_option_usage_in_documentation > > > > The one-vs-two dash usage is only supported in qemu, not in qemu-nbd > > or qemu-img (that is, qemu acts as if it uses getopt_long_only(), > > while the others use getopt_long() - except that we hand-rolled the > > parser in qemu, meaning you might find quirks where it sometimes > > doesn't even match getopt_long_only()). > > > > At any rate, since --trace is an option that is supported across > > multiple binaries, we SHOULD favor the double-dash spelling in our > > documentation, so that you can consistently reuse the same --trace > > invocation without worrying whether the binary parses its arguments > > Yes, this patch is inspired by this situation when translating DPRINT into > trace for a new qemu utility (much like qemu-nbd) following docs/devel/tracing.txt. > The utility complains it don't support -trace option. So i sent this > patch after confirming this with qemu-nbd,qemu-io utilities. > > > with getopt_long() (where double is required) or like > > getopt_long_only() (where the double is optional but supported). > > > > So I'm in favor of this patch, although it may need more of a commit > > message summarizing the justification I've just pointed you to. > > Thanks for your nice explaination. If this patch could be merged i will > send V2 with a commit message. Please update the remaining occurrences of the -trace option syntax in v2: $ git grep -- -trace docs/devel/tracing.txt Stefan
On 06/15/2018 12:30 PM, Stefan Hajnoczi wrote: >>> >>> So I'm in favor of this patch, although it may need more of a commit >>> message summarizing the justification I've just pointed you to. >> >> Thanks for your nice explaination. If this patch could be merged i will >> send V2 with a commit message. > > Please update the remaining occurrences of the -trace option syntax in > v2: > > $ git grep -- -trace docs/devel/tracing.txt Also fixing strings in trace/control.[ch] would be appropriate. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org
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