Re: [PATCH] trace-cmd: fix kvm_mmu_prepare_zap_page even name and kvm_mmu_get_page event output in kvm plugin
On Wed, Dec 26, 2012 at 09:22:32AM -0500, Steven Rostedt wrote:
> On Wed, 2012-12-26 at 16:13 +0200, Gleb Natapov wrote:
> > On Wed, Dec 26, 2012 at 08:58:30AM -0500, Steven Rostedt wrote:
> > > On Tue, 2012-12-25 at 13:46 +0200, Gleb Natapov wrote:
> > > > kvm_mmu_zap_page even was renamed to kvm_mmu_prepare_zap_page.
> > > > Print out created field for kvm_mmu_get_page event.
> > >
> > > trace-cmd needs to be backward compatible with older kernels. If older
> > > kernels used kvm_mmu_zap_page, then please add a check for that and have
> > > the plugin cope with either one.
> > >
> > Something like this?
> >
> > if (pevent_find_event_by_name(pevent, "kvmmmu",
> > "kvm_mmu_prepare_zap_page"))
> > pevent_register_event_handler(pevent, -1, "kvmmmu",
> > "kvm_mmu_prepare_zap_page",
> > kvm_mmu_print_role,
> > NULL);
> > else
> > pevent_register_event_handler(pevent, -1, "kvmmmu",
> > "kvm_mmu_zap_page", kvm_mmu_print_role,
> > NULL);
>
> Sure, if it works.
>
Well, it isn't and if it were it would have prevented tarce-cmd running
on new kernel from reading traces generated on older kernels. I will
register both.
> >
> > Also when trace-cmd encounters an event it does not recognize it prints
> > mysterious message:
> >
> > trace-cmd: No such file or directory
> > bad op token {
> >
> > Is this a bug?
> >
>
> Yes and no ;-)
>
> I need to get rid of the "perror" part, for errors that don't set errno.
> That's been on my todo list for a long time. Maybe when I come back to
> work next week I'll fix that.
>
> The 'bad op token {' happens when it tries to parse an event and it
> comes across something that it doesn't recognize. In this case a '{'.
>
> The kvm events are notorious with having extremely complex "print_fmt"
> fields in their event format files. When no event handler is registered
> for an event, trace-cmd uses the print_fmt to figure out how to print
> it. This was never meant to be too complex of a parser. For example,
> looking at my kvm_mmu_prepare_zap_page, we have:
>
> print fmt: "%s", ({ const char *ret = p->buffer + p->len; static const char
> *access_str[] =
> { "---", "--x", "w--", "w-x", "-u-", "-ux", "wu-", "wux" }; union
> kvm_mmu_page_role role;
> role.word = REC->role; trace_seq_printf(p, "sp gfn %llx %u%s q%u%s %s%s" "
> %snxe root %u
> %s%c", REC->gfn, role.level, role.cr4_pae ? " pae" : "", role.quadrant,
> role.direct ? "
> direct" : "", access_str[role.access], role.invalid ? " invalid" : "",
> role.nxe ? "" : "!",
> REC->root_count, REC->unsync ? "unsync" : "sync", 0); ret; })
>
> trace-cmd has no idea on how to parse "({ const char *ret ..." in fact
> it dies on that first "{" because trace-cmd is not a full C parser.
>
> This was why the plugins were created in the first place. To handle
> various events that have too complex print_fmts for trace-cmd to
> understand.
>
> Most events are simple print_fmts and do not need plugins. Like
> sock_rcvqueue_full:
>
> print fmt: "rmem_alloc=%d truesize=%u sk_rcvbuf=%d", REC->rmem_alloc,
> REC->truesize, REC->sk_rcvbuf
>
> trace-cmd has no problem parsing events like that.
>
Got it.
--
Gleb.
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Re: [PATCH] trace-cmd: fix kvm_mmu_prepare_zap_page even name and kvm_mmu_get_page event output in kvm plugin
On Wed, 2012-12-26 at 16:13 +0200, Gleb Natapov wrote:
> On Wed, Dec 26, 2012 at 08:58:30AM -0500, Steven Rostedt wrote:
> > On Tue, 2012-12-25 at 13:46 +0200, Gleb Natapov wrote:
> > > kvm_mmu_zap_page even was renamed to kvm_mmu_prepare_zap_page.
> > > Print out created field for kvm_mmu_get_page event.
> >
> > trace-cmd needs to be backward compatible with older kernels. If older
> > kernels used kvm_mmu_zap_page, then please add a check for that and have
> > the plugin cope with either one.
> >
> Something like this?
>
> if (pevent_find_event_by_name(pevent, "kvmmmu",
> "kvm_mmu_prepare_zap_page"))
> pevent_register_event_handler(pevent, -1, "kvmmmu",
> "kvm_mmu_prepare_zap_page",
> kvm_mmu_print_role,
> NULL);
> else
> pevent_register_event_handler(pevent, -1, "kvmmmu",
> "kvm_mmu_zap_page", kvm_mmu_print_role, NULL);
Sure, if it works.
>
> Also when trace-cmd encounters an event it does not recognize it prints
> mysterious message:
>
> trace-cmd: No such file or directory
> bad op token {
>
> Is this a bug?
>
Yes and no ;-)
I need to get rid of the "perror" part, for errors that don't set errno.
That's been on my todo list for a long time. Maybe when I come back to
work next week I'll fix that.
The 'bad op token {' happens when it tries to parse an event and it
comes across something that it doesn't recognize. In this case a '{'.
The kvm events are notorious with having extremely complex "print_fmt"
fields in their event format files. When no event handler is registered
for an event, trace-cmd uses the print_fmt to figure out how to print
it. This was never meant to be too complex of a parser. For example,
looking at my kvm_mmu_prepare_zap_page, we have:
print fmt: "%s", ({ const char *ret = p->buffer + p->len; static const char
*access_str[] =
{ "---", "--x", "w--", "w-x", "-u-", "-ux", "wu-", "wux" }; union
kvm_mmu_page_role role;
role.word = REC->role; trace_seq_printf(p, "sp gfn %llx %u%s q%u%s %s%s" "
%snxe root %u
%s%c", REC->gfn, role.level, role.cr4_pae ? " pae" : "", role.quadrant,
role.direct ? "
direct" : "", access_str[role.access], role.invalid ? " invalid" : "", role.nxe
? "" : "!",
REC->root_count, REC->unsync ? "unsync" : "sync", 0); ret; })
trace-cmd has no idea on how to parse "({ const char *ret ..." in fact
it dies on that first "{" because trace-cmd is not a full C parser.
This was why the plugins were created in the first place. To handle
various events that have too complex print_fmts for trace-cmd to
understand.
Most events are simple print_fmts and do not need plugins. Like
sock_rcvqueue_full:
print fmt: "rmem_alloc=%d truesize=%u sk_rcvbuf=%d", REC->rmem_alloc,
REC->truesize, REC->sk_rcvbuf
trace-cmd has no problem parsing events like that.
-- Steve
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Re: [PATCH] trace-cmd: fix kvm_mmu_prepare_zap_page even name and kvm_mmu_get_page event output in kvm plugin
On Wed, Dec 26, 2012 at 08:58:30AM -0500, Steven Rostedt wrote:
> On Tue, 2012-12-25 at 13:46 +0200, Gleb Natapov wrote:
> > kvm_mmu_zap_page even was renamed to kvm_mmu_prepare_zap_page.
> > Print out created field for kvm_mmu_get_page event.
>
> trace-cmd needs to be backward compatible with older kernels. If older
> kernels used kvm_mmu_zap_page, then please add a check for that and have
> the plugin cope with either one.
>
Something like this?
if (pevent_find_event_by_name(pevent, "kvmmmu",
"kvm_mmu_prepare_zap_page"))
pevent_register_event_handler(pevent, -1, "kvmmmu",
"kvm_mmu_prepare_zap_page", kvm_mmu_print_role,
NULL);
else
pevent_register_event_handler(pevent, -1, "kvmmmu",
"kvm_mmu_zap_page", kvm_mmu_print_role, NULL);
Also when trace-cmd encounters an event it does not recognize it prints
mysterious message:
trace-cmd: No such file or directory
bad op token {
Is this a bug?
> Thanks,
>
> -- Steve
>
> >
> > Signed-off-by: Gleb Natapov
> > diff --git a/plugin_kvm.c b/plugin_kvm.c
> > index 55812ef..adc5694 100644
> > --- a/plugin_kvm.c
> > +++ b/plugin_kvm.c
> > @@ -382,7 +382,7 @@ static int kvm_mmu_print_role(struct trace_seq *s,
> > struct pevent_record *record,
> > } else
> > trace_seq_printf(s, "WORD: %08x", role.word);
> >
> > - pevent_print_num_field(s, " root %u", event,
> > + pevent_print_num_field(s, " root %u ", event,
> >"root_count", record, 1);
> >
> > if (pevent_get_field_val(s, event, "unsync", record, &val, 1) < 0)
> > @@ -397,6 +397,11 @@ static int kvm_mmu_get_page_handler(struct trace_seq
> > *s, struct pevent_record *r
> > {
> > unsigned long long val;
> >
> > + if (pevent_get_field_val(s, event, "created", record, &val, 1) < 0)
> > + return -1;
> > +
> > + trace_seq_printf(s, "%s ", val ? "new" : "existing");
> > +
> > if (pevent_get_field_val(s, event, "gfn", record, &val, 1) < 0)
> > return -1;
> >
> > @@ -430,7 +435,7 @@ int PEVENT_PLUGIN_LOADER(struct pevent *pevent)
> > pevent_register_event_handler(pevent, -1, "kvmmmu",
> > "kvm_mmu_unsync_page",
> > kvm_mmu_print_role, NULL);
> >
> > - pevent_register_event_handler(pevent, -1, "kvmmmu", "kvm_mmu_zap_page",
> > + pevent_register_event_handler(pevent, -1, "kvmmmu",
> > "kvm_mmu_prepare_zap_page",
> > kvm_mmu_print_role, NULL);
> >
> > return 0;
> > --
> > Gleb.
>
--
Gleb.
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Re: [PATCH] trace-cmd: fix kvm_mmu_prepare_zap_page even name and kvm_mmu_get_page event output in kvm plugin
On Tue, 2012-12-25 at 13:46 +0200, Gleb Natapov wrote:
> kvm_mmu_zap_page even was renamed to kvm_mmu_prepare_zap_page.
> Print out created field for kvm_mmu_get_page event.
trace-cmd needs to be backward compatible with older kernels. If older
kernels used kvm_mmu_zap_page, then please add a check for that and have
the plugin cope with either one.
Thanks,
-- Steve
>
> Signed-off-by: Gleb Natapov
> diff --git a/plugin_kvm.c b/plugin_kvm.c
> index 55812ef..adc5694 100644
> --- a/plugin_kvm.c
> +++ b/plugin_kvm.c
> @@ -382,7 +382,7 @@ static int kvm_mmu_print_role(struct trace_seq *s, struct
> pevent_record *record,
> } else
> trace_seq_printf(s, "WORD: %08x", role.word);
>
> - pevent_print_num_field(s, " root %u", event,
> + pevent_print_num_field(s, " root %u ", event,
> "root_count", record, 1);
>
> if (pevent_get_field_val(s, event, "unsync", record, &val, 1) < 0)
> @@ -397,6 +397,11 @@ static int kvm_mmu_get_page_handler(struct trace_seq *s,
> struct pevent_record *r
> {
> unsigned long long val;
>
> + if (pevent_get_field_val(s, event, "created", record, &val, 1) < 0)
> + return -1;
> +
> + trace_seq_printf(s, "%s ", val ? "new" : "existing");
> +
> if (pevent_get_field_val(s, event, "gfn", record, &val, 1) < 0)
> return -1;
>
> @@ -430,7 +435,7 @@ int PEVENT_PLUGIN_LOADER(struct pevent *pevent)
> pevent_register_event_handler(pevent, -1, "kvmmmu",
> "kvm_mmu_unsync_page",
> kvm_mmu_print_role, NULL);
>
> - pevent_register_event_handler(pevent, -1, "kvmmmu", "kvm_mmu_zap_page",
> + pevent_register_event_handler(pevent, -1, "kvmmmu",
> "kvm_mmu_prepare_zap_page",
> kvm_mmu_print_role, NULL);
>
> return 0;
> --
> Gleb.
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[PATCH] trace-cmd: fix kvm_mmu_prepare_zap_page even name and kvm_mmu_get_page event output in kvm plugin
kvm_mmu_zap_page even was renamed to kvm_mmu_prepare_zap_page.
Print out created field for kvm_mmu_get_page event.
Signed-off-by: Gleb Natapov
diff --git a/plugin_kvm.c b/plugin_kvm.c
index 55812ef..adc5694 100644
--- a/plugin_kvm.c
+++ b/plugin_kvm.c
@@ -382,7 +382,7 @@ static int kvm_mmu_print_role(struct trace_seq *s, struct
pevent_record *record,
} else
trace_seq_printf(s, "WORD: %08x", role.word);
- pevent_print_num_field(s, " root %u", event,
+ pevent_print_num_field(s, " root %u ", event,
"root_count", record, 1);
if (pevent_get_field_val(s, event, "unsync", record, &val, 1) < 0)
@@ -397,6 +397,11 @@ static int kvm_mmu_get_page_handler(struct trace_seq *s,
struct pevent_record *r
{
unsigned long long val;
+ if (pevent_get_field_val(s, event, "created", record, &val, 1) < 0)
+ return -1;
+
+ trace_seq_printf(s, "%s ", val ? "new" : "existing");
+
if (pevent_get_field_val(s, event, "gfn", record, &val, 1) < 0)
return -1;
@@ -430,7 +435,7 @@ int PEVENT_PLUGIN_LOADER(struct pevent *pevent)
pevent_register_event_handler(pevent, -1, "kvmmmu",
"kvm_mmu_unsync_page",
kvm_mmu_print_role, NULL);
- pevent_register_event_handler(pevent, -1, "kvmmmu", "kvm_mmu_zap_page",
+ pevent_register_event_handler(pevent, -1, "kvmmmu",
"kvm_mmu_prepare_zap_page",
kvm_mmu_print_role, NULL);
return 0;
--
Gleb.
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