Unfortunately, it was never correctly shown..
This is only found when I started to look into making the blocktime feature
more useful (so as to avoid using bpftrace, even though I'm not sure which
one will be harder to use..).
So the old dump would look like this:
Postcopy vCPU Blocktime: 0-1,4,10,21,33,46,48,59
Even though there're actually 40 vcpus, and the string will merge same
elements and also sort them.
To fix it, simply loop over the uint32List manually. Now it looks like:
Postcopy vCPU Blocktime (ms):
[15, 0, 0, 43, 29, 34, 36, 29, 37, 41,
33, 37, 45, 52, 50, 38, 40, 37, 40, 49,
40, 35, 35, 35, 81, 19, 18, 19, 18, 30,
22, 3, 0, 0, 0, 0, 0, 0, 0, 0]
Cc: Dr. David Alan Gilbert <dave@treblig.org>
Cc: Alexey Perevalov <a.perevalov@samsung.com>
Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
migration/migration-hmp-cmds.c | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)
diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c
index 367ff6037f..3cf890b887 100644
--- a/migration/migration-hmp-cmds.c
+++ b/migration/migration-hmp-cmds.c
@@ -208,15 +208,20 @@ void hmp_info_migrate(Monitor *mon, const QDict *qdict)
}
if (info->has_postcopy_vcpu_blocktime) {
- Visitor *v;
- char *str;
- v = string_output_visitor_new(false, &str);
- visit_type_uint32List(v, NULL, &info->postcopy_vcpu_blocktime,
- &error_abort);
- visit_complete(v, &str);
- monitor_printf(mon, "Postcopy vCPU Blocktime: %s\n", str);
- g_free(str);
- visit_free(v);
+ uint32List *item = info->postcopy_vcpu_blocktime;
+ int count = 0;
+
+ monitor_printf(mon, "Postcopy vCPU Blocktime (ms): \n [");
+
+ while (item) {
+ monitor_printf(mon, "%"PRIu32", ", item->value);
+ item = item->next;
+ /* Each line 10 vcpu results, newline if there's more */
+ if ((++count % 10 == 0) && item) {
+ monitor_printf(mon, "\n ");
+ }
+ }
+ monitor_printf(mon, "\b\b]\n");
}
out:
--
2.49.0Peter Xu <peterx@redhat.com> writes:
> Unfortunately, it was never correctly shown..
>
> This is only found when I started to look into making the blocktime feature
> more useful (so as to avoid using bpftrace, even though I'm not sure which
> one will be harder to use..).
>
> So the old dump would look like this:
>
> Postcopy vCPU Blocktime: 0-1,4,10,21,33,46,48,59
>
> Even though there're actually 40 vcpus, and the string will merge same
> elements and also sort them.
>
> To fix it, simply loop over the uint32List manually. Now it looks like:
>
> Postcopy vCPU Blocktime (ms):
> [15, 0, 0, 43, 29, 34, 36, 29, 37, 41,
> 33, 37, 45, 52, 50, 38, 40, 37, 40, 49,
> 40, 35, 35, 35, 81, 19, 18, 19, 18, 30,
> 22, 3, 0, 0, 0, 0, 0, 0, 0, 0]
>
> Cc: Dr. David Alan Gilbert <dave@treblig.org>
> Cc: Alexey Perevalov <a.perevalov@samsung.com>
> Cc: Markus Armbruster <armbru@redhat.com>
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
> migration/migration-hmp-cmds.c | 23 ++++++++++++++---------
> 1 file changed, 14 insertions(+), 9 deletions(-)
>
> diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c
> index 367ff6037f..3cf890b887 100644
> --- a/migration/migration-hmp-cmds.c
> +++ b/migration/migration-hmp-cmds.c
> @@ -208,15 +208,20 @@ void hmp_info_migrate(Monitor *mon, const QDict *qdict)
> }
>
> if (info->has_postcopy_vcpu_blocktime) {
> - Visitor *v;
> - char *str;
> - v = string_output_visitor_new(false, &str);
> - visit_type_uint32List(v, NULL, &info->postcopy_vcpu_blocktime,
> - &error_abort);
> - visit_complete(v, &str);
> - monitor_printf(mon, "Postcopy vCPU Blocktime: %s\n", str);
> - g_free(str);
> - visit_free(v);
> + uint32List *item = info->postcopy_vcpu_blocktime;
> + int count = 0;
> +
> + monitor_printf(mon, "Postcopy vCPU Blocktime (ms): \n [");
> +
> + while (item) {
> + monitor_printf(mon, "%"PRIu32", ", item->value);
> + item = item->next;
> + /* Each line 10 vcpu results, newline if there's more */
The list can be arbitrarily long?
> + if ((++count % 10 == 0) && item) {
> + monitor_printf(mon, "\n ");
> + }
> + }
> + monitor_printf(mon, "\b\b]\n");
Uh, backspace?
I usually do something like
sep = "";
for (...) {
printf("%s...", sep, ...);
sep = ", "
}
To add line breaks, I'd use something like
sep = ... ? ", " : ",\n";
> }
>
> out:
The less the string visitors are used, the happier I am.
* Markus Armbruster (armbru@redhat.com) wrote:
> Peter Xu <peterx@redhat.com> writes:
>
> > Unfortunately, it was never correctly shown..
> >
> > This is only found when I started to look into making the blocktime feature
> > more useful (so as to avoid using bpftrace, even though I'm not sure which
> > one will be harder to use..).
> >
> > So the old dump would look like this:
> >
> > Postcopy vCPU Blocktime: 0-1,4,10,21,33,46,48,59
> >
> > Even though there're actually 40 vcpus, and the string will merge same
> > elements and also sort them.
> >
> > To fix it, simply loop over the uint32List manually. Now it looks like:
> >
> > Postcopy vCPU Blocktime (ms):
> > [15, 0, 0, 43, 29, 34, 36, 29, 37, 41,
> > 33, 37, 45, 52, 50, 38, 40, 37, 40, 49,
> > 40, 35, 35, 35, 81, 19, 18, 19, 18, 30,
> > 22, 3, 0, 0, 0, 0, 0, 0, 0, 0]
> >
> > Cc: Dr. David Alan Gilbert <dave@treblig.org>
> > Cc: Alexey Perevalov <a.perevalov@samsung.com>
> > Cc: Markus Armbruster <armbru@redhat.com>
> > Signed-off-by: Peter Xu <peterx@redhat.com>
> > ---
> > migration/migration-hmp-cmds.c | 23 ++++++++++++++---------
> > 1 file changed, 14 insertions(+), 9 deletions(-)
> >
> > diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c
> > index 367ff6037f..3cf890b887 100644
> > --- a/migration/migration-hmp-cmds.c
> > +++ b/migration/migration-hmp-cmds.c
> > @@ -208,15 +208,20 @@ void hmp_info_migrate(Monitor *mon, const QDict *qdict)
> > }
> >
> > if (info->has_postcopy_vcpu_blocktime) {
> > - Visitor *v;
> > - char *str;
> > - v = string_output_visitor_new(false, &str);
> > - visit_type_uint32List(v, NULL, &info->postcopy_vcpu_blocktime,
> > - &error_abort);
> > - visit_complete(v, &str);
> > - monitor_printf(mon, "Postcopy vCPU Blocktime: %s\n", str);
> > - g_free(str);
> > - visit_free(v);
> > + uint32List *item = info->postcopy_vcpu_blocktime;
> > + int count = 0;
> > +
> > + monitor_printf(mon, "Postcopy vCPU Blocktime (ms): \n [");
> > +
> > + while (item) {
> > + monitor_printf(mon, "%"PRIu32", ", item->value);
> > + item = item->next;
> > + /* Each line 10 vcpu results, newline if there's more */
>
> The list can be arbitrarily long?
One per vCPU, so a small arbitrary.
> > + if ((++count % 10 == 0) && item) {
> > + monitor_printf(mon, "\n ");
> > + }
> > + }
> > + monitor_printf(mon, "\b\b]\n");
>
> Uh, backspace?
Agreed!
Dave
> I usually do something like
>
> sep = "";
> for (...) {
> printf("%s...", sep, ...);
> sep = ", "
> }
>
> To add line breaks, I'd use something like
>
> sep = ... ? ", " : ",\n";
>
> > }
> >
> > out:
>
> The less the string visitors are used, the happier I am.
>
--
-----Open up your eyes, open up your mind, open up your code -------
/ Dr. David Alan Gilbert | Running GNU/Linux | Happy \
\ dave @ treblig.org | | In Hex /
\ _________________________|_____ http://www.treblig.org |_______/
On Wed, May 28, 2025 at 03:08:38PM +0000, Dr. David Alan Gilbert wrote:
> * Markus Armbruster (armbru@redhat.com) wrote:
> > Peter Xu <peterx@redhat.com> writes:
> >
> > > Unfortunately, it was never correctly shown..
> > >
> > > This is only found when I started to look into making the blocktime feature
> > > more useful (so as to avoid using bpftrace, even though I'm not sure which
> > > one will be harder to use..).
> > >
> > > So the old dump would look like this:
> > >
> > > Postcopy vCPU Blocktime: 0-1,4,10,21,33,46,48,59
> > >
> > > Even though there're actually 40 vcpus, and the string will merge same
> > > elements and also sort them.
> > >
> > > To fix it, simply loop over the uint32List manually. Now it looks like:
> > >
> > > Postcopy vCPU Blocktime (ms):
> > > [15, 0, 0, 43, 29, 34, 36, 29, 37, 41,
> > > 33, 37, 45, 52, 50, 38, 40, 37, 40, 49,
> > > 40, 35, 35, 35, 81, 19, 18, 19, 18, 30,
> > > 22, 3, 0, 0, 0, 0, 0, 0, 0, 0]
> > >
> > > Cc: Dr. David Alan Gilbert <dave@treblig.org>
> > > Cc: Alexey Perevalov <a.perevalov@samsung.com>
> > > Cc: Markus Armbruster <armbru@redhat.com>
> > > Signed-off-by: Peter Xu <peterx@redhat.com>
> > > ---
> > > migration/migration-hmp-cmds.c | 23 ++++++++++++++---------
> > > 1 file changed, 14 insertions(+), 9 deletions(-)
> > >
> > > diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c
> > > index 367ff6037f..3cf890b887 100644
> > > --- a/migration/migration-hmp-cmds.c
> > > +++ b/migration/migration-hmp-cmds.c
> > > @@ -208,15 +208,20 @@ void hmp_info_migrate(Monitor *mon, const QDict *qdict)
> > > }
> > >
> > > if (info->has_postcopy_vcpu_blocktime) {
> > > - Visitor *v;
> > > - char *str;
> > > - v = string_output_visitor_new(false, &str);
> > > - visit_type_uint32List(v, NULL, &info->postcopy_vcpu_blocktime,
> > > - &error_abort);
> > > - visit_complete(v, &str);
> > > - monitor_printf(mon, "Postcopy vCPU Blocktime: %s\n", str);
> > > - g_free(str);
> > > - visit_free(v);
> > > + uint32List *item = info->postcopy_vcpu_blocktime;
> > > + int count = 0;
> > > +
> > > + monitor_printf(mon, "Postcopy vCPU Blocktime (ms): \n [");
> > > +
> > > + while (item) {
> > > + monitor_printf(mon, "%"PRIu32", ", item->value);
> > > + item = item->next;
> > > + /* Each line 10 vcpu results, newline if there's more */
> >
> > The list can be arbitrarily long?
>
> One per vCPU, so a small arbitrary.
>
> > > + if ((++count % 10 == 0) && item) {
> > > + monitor_printf(mon, "\n ");
> > > + }
> > > + }
> > > + monitor_printf(mon, "\b\b]\n");
> >
> > Uh, backspace?
>
> Agreed!
Agreed on.. using backspace? :)
>
> Dave
>
> > I usually do something like
> >
> > sep = "";
> > for (...) {
> > printf("%s...", sep, ...);
> > sep = ", "
> > }
> >
> > To add line breaks, I'd use something like
> >
> > sep = ... ? ", " : ",\n";
Thanks for the suggestion! Definitely better..
I'll squash below into this patch when repost, comments on top always
welcomed.
diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c
index 3cf890b887..6c36e202a0 100644
--- a/migration/migration-hmp-cmds.c
+++ b/migration/migration-hmp-cmds.c
@@ -209,19 +209,18 @@ void hmp_info_migrate(Monitor *mon, const QDict *qdict)
if (info->has_postcopy_vcpu_blocktime) {
uint32List *item = info->postcopy_vcpu_blocktime;
+ const char *sep = "";
int count = 0;
monitor_printf(mon, "Postcopy vCPU Blocktime (ms): \n [");
while (item) {
- monitor_printf(mon, "%"PRIu32", ", item->value);
+ monitor_printf(mon, "%s%"PRIu32, sep, item->value);
item = item->next;
/* Each line 10 vcpu results, newline if there's more */
- if ((++count % 10 == 0) && item) {
- monitor_printf(mon, "\n ");
- }
+ sep = ((++count % 10 == 0) && item) ? ",\n " : ", ";
}
- monitor_printf(mon, "\b\b]\n");
+ monitor_printf(mon, "]\n");
}
--
Peter Xu
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