* How to recheck 'maxactive' ?
@ 2020-03-22 14:06 Taeung Song
2020-03-23 6:47 ` Masami Hiramatsu
0 siblings, 1 reply; 5+ messages in thread
From: Taeung Song @ 2020-03-22 14:06 UTC (permalink / raw)
To: linux-trace-users; +Cc: Masami Hiramatsu, David S. Miller
Hi,
After setting 'maxactive' for kretprobe,
how can I recheck the value of 'maxactive' ?
For example, in order to distinguish the difference
between two kretprobe events
(kmem_cache_alloc_node and kmem_cache_alloc_node10)
$ cd /sys/kernel/debug/tracing
$ echo 'r:kmem_cache_alloc_node kmem_cache_alloc_node' >> kprobe_events
$ echo 'r10:kmem_cache_alloc_node10 kmem_cache_alloc_node' >>
kprobe_events
$ cat kprobe_events
r:kprobes/kmem_cache_alloc_node kmem_cache_alloc_node
r:kprobes/kmem_cache_alloc_node10 kmem_cache_alloc_node
Thanks,
Taeung
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: How to recheck 'maxactive' ?
2020-03-22 14:06 How to recheck 'maxactive' ? Taeung Song
@ 2020-03-23 6:47 ` Masami Hiramatsu
2020-03-23 12:54 ` Taeung Song
2020-03-23 13:04 ` Steven Rostedt
0 siblings, 2 replies; 5+ messages in thread
From: Masami Hiramatsu @ 2020-03-23 6:47 UTC (permalink / raw)
To: Taeung Song; +Cc: linux-trace-users, Masami Hiramatsu, David S. Miller
Hi Taeung,
On Sun, 22 Mar 2020 23:06:20 +0900
Taeung Song <treeze.taeung@gmail.com> wrote:
> Hi,
>
> After setting 'maxactive' for kretprobe,
> how can I recheck the value of 'maxactive' ?
> For example, in order to distinguish the difference
> between two kretprobe events
> (kmem_cache_alloc_node and kmem_cache_alloc_node10)
>
> $ cd /sys/kernel/debug/tracing
> $ echo 'r:kmem_cache_alloc_node kmem_cache_alloc_node' >> kprobe_events
> $ echo 'r10:kmem_cache_alloc_node10 kmem_cache_alloc_node' >>
> kprobe_events
>
> $ cat kprobe_events
> r:kprobes/kmem_cache_alloc_node kmem_cache_alloc_node
> r:kprobes/kmem_cache_alloc_node10 kmem_cache_alloc_node
Oops! good catch. That must be a bug, since the kprobe_events design policy
is to support following operation.
$ cat kprobe_events > /etc/event_setting
(reboot)
$ cat /etc/event_setting > kprobe_events
What about below patch?
From 935ed56819f2bfb7ac977f5c63273c9a6e3dfb42 Mon Sep 17 00:00:00 2001
From: Masami Hiramatsu <mhiramat@kernel.org>
Date: Mon, 23 Mar 2020 10:57:48 +0900
Subject: [PATCH] ftrace/kprobe: Show the maxactive number on kprobe_events
Show maxactive parameter on kprobe_events.
This allows user to save the current configuration and
restore it without losing maxactive parameter.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
kernel/trace/trace_kprobe.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 362cca52f5de..d0568af4a0ef 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1078,6 +1078,8 @@ static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev)
int i;
seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
+ if (trace_kprobe_is_return(tk) && tk->rp.maxactive)
+ seq_printf(m, "%d", tk->rp.maxactive);
seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp),
trace_probe_name(&tk->tp));
--
2.20.1
Thank you,
--
Masami Hiramatsu <mhiramat@kernel.org>
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: How to recheck 'maxactive' ?
2020-03-23 6:47 ` Masami Hiramatsu
@ 2020-03-23 12:54 ` Taeung Song
2020-03-23 13:04 ` Steven Rostedt
1 sibling, 0 replies; 5+ messages in thread
From: Taeung Song @ 2020-03-23 12:54 UTC (permalink / raw)
To: Masami Hiramatsu; +Cc: linux-trace-users, David S. Miller
Hi Masami,
Thank you for the reply!
And your patch looks great.
Thanks,
Taeung
On 3/23/20 3:47 PM, Masami Hiramatsu wrote:
> Hi Taeung,
>
> On Sun, 22 Mar 2020 23:06:20 +0900
> Taeung Song <treeze.taeung@gmail.com> wrote:
>
>> Hi,
>>
>> After setting 'maxactive' for kretprobe,
>> how can I recheck the value of 'maxactive' ?
>> For example, in order to distinguish the difference
>> between two kretprobe events
>> (kmem_cache_alloc_node and kmem_cache_alloc_node10)
>>
>> $ cd /sys/kernel/debug/tracing
>> $ echo 'r:kmem_cache_alloc_node kmem_cache_alloc_node' >> kprobe_events
>> $ echo 'r10:kmem_cache_alloc_node10 kmem_cache_alloc_node' >>
>> kprobe_events
>>
>> $ cat kprobe_events
>> r:kprobes/kmem_cache_alloc_node kmem_cache_alloc_node
>> r:kprobes/kmem_cache_alloc_node10 kmem_cache_alloc_node
>
> Oops! good catch. That must be a bug, since the kprobe_events design policy
> is to support following operation.
>
> $ cat kprobe_events > /etc/event_setting
> (reboot)
> $ cat /etc/event_setting > kprobe_events
>
> What about below patch?
>
> From 935ed56819f2bfb7ac977f5c63273c9a6e3dfb42 Mon Sep 17 00:00:00 2001
> From: Masami Hiramatsu <mhiramat@kernel.org>
> Date: Mon, 23 Mar 2020 10:57:48 +0900
> Subject: [PATCH] ftrace/kprobe: Show the maxactive number on kprobe_events
>
> Show maxactive parameter on kprobe_events.
> This allows user to save the current configuration and
> restore it without losing maxactive parameter.
>
> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
> ---
> kernel/trace/trace_kprobe.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> index 362cca52f5de..d0568af4a0ef 100644
> --- a/kernel/trace/trace_kprobe.c
> +++ b/kernel/trace/trace_kprobe.c
> @@ -1078,6 +1078,8 @@ static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev)
> int i;
>
> seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
> + if (trace_kprobe_is_return(tk) && tk->rp.maxactive)
> + seq_printf(m, "%d", tk->rp.maxactive);
> seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp),
> trace_probe_name(&tk->tp));
>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: How to recheck 'maxactive' ?
2020-03-23 6:47 ` Masami Hiramatsu
2020-03-23 12:54 ` Taeung Song
@ 2020-03-23 13:04 ` Steven Rostedt
2020-03-24 6:40 ` Masami Hiramatsu
1 sibling, 1 reply; 5+ messages in thread
From: Steven Rostedt @ 2020-03-23 13:04 UTC (permalink / raw)
To: Masami Hiramatsu; +Cc: Taeung Song, linux-trace-users, David S. Miller
On Mon, 23 Mar 2020 15:47:41 +0900
Masami Hiramatsu <mhiramat@kernel.org> wrote:
> Hi Taeung,
>
> On Sun, 22 Mar 2020 23:06:20 +0900
> Taeung Song <treeze.taeung@gmail.com> wrote:
>
> > Hi,
> >
> > After setting 'maxactive' for kretprobe,
> > how can I recheck the value of 'maxactive' ?
> > For example, in order to distinguish the difference
> > between two kretprobe events
> > (kmem_cache_alloc_node and kmem_cache_alloc_node10)
> >
> > $ cd /sys/kernel/debug/tracing
> > $ echo 'r:kmem_cache_alloc_node kmem_cache_alloc_node' >> kprobe_events
> > $ echo 'r10:kmem_cache_alloc_node10 kmem_cache_alloc_node' >>
> > kprobe_events
> >
> > $ cat kprobe_events
> > r:kprobes/kmem_cache_alloc_node kmem_cache_alloc_node
> > r:kprobes/kmem_cache_alloc_node10 kmem_cache_alloc_node
>
> Oops! good catch. That must be a bug, since the kprobe_events design policy
> is to support following operation.
>
> $ cat kprobe_events > /etc/event_setting
> (reboot)
> $ cat /etc/event_setting > kprobe_events
>
> What about below patch?
>
> >From 935ed56819f2bfb7ac977f5c63273c9a6e3dfb42 Mon Sep 17 00:00:00 2001
> From: Masami Hiramatsu <mhiramat@kernel.org>
> Date: Mon, 23 Mar 2020 10:57:48 +0900
> Subject: [PATCH] ftrace/kprobe: Show the maxactive number on kprobe_events
>
> Show maxactive parameter on kprobe_events.
> This allows user to save the current configuration and
> restore it without losing maxactive parameter.
>
Hi Masami,
Can you resend this patch as a stand alone (so that it shows up as a patch
on the mailing lists).
Thanks!
-- Steve
> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
> ---
> kernel/trace/trace_kprobe.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> index 362cca52f5de..d0568af4a0ef 100644
> --- a/kernel/trace/trace_kprobe.c
> +++ b/kernel/trace/trace_kprobe.c
> @@ -1078,6 +1078,8 @@ static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev)
> int i;
>
> seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
> + if (trace_kprobe_is_return(tk) && tk->rp.maxactive)
> + seq_printf(m, "%d", tk->rp.maxactive);
> seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp),
> trace_probe_name(&tk->tp));
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: How to recheck 'maxactive' ?
2020-03-23 13:04 ` Steven Rostedt
@ 2020-03-24 6:40 ` Masami Hiramatsu
0 siblings, 0 replies; 5+ messages in thread
From: Masami Hiramatsu @ 2020-03-24 6:40 UTC (permalink / raw)
To: Steven Rostedt; +Cc: Taeung Song, linux-trace-users, David S. Miller
On Mon, 23 Mar 2020 09:04:01 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:
> On Mon, 23 Mar 2020 15:47:41 +0900
> Masami Hiramatsu <mhiramat@kernel.org> wrote:
>
> > Hi Taeung,
> >
> > On Sun, 22 Mar 2020 23:06:20 +0900
> > Taeung Song <treeze.taeung@gmail.com> wrote:
> >
> > > Hi,
> > >
> > > After setting 'maxactive' for kretprobe,
> > > how can I recheck the value of 'maxactive' ?
> > > For example, in order to distinguish the difference
> > > between two kretprobe events
> > > (kmem_cache_alloc_node and kmem_cache_alloc_node10)
> > >
> > > $ cd /sys/kernel/debug/tracing
> > > $ echo 'r:kmem_cache_alloc_node kmem_cache_alloc_node' >> kprobe_events
> > > $ echo 'r10:kmem_cache_alloc_node10 kmem_cache_alloc_node' >>
> > > kprobe_events
> > >
> > > $ cat kprobe_events
> > > r:kprobes/kmem_cache_alloc_node kmem_cache_alloc_node
> > > r:kprobes/kmem_cache_alloc_node10 kmem_cache_alloc_node
> >
> > Oops! good catch. That must be a bug, since the kprobe_events design policy
> > is to support following operation.
> >
> > $ cat kprobe_events > /etc/event_setting
> > (reboot)
> > $ cat /etc/event_setting > kprobe_events
> >
> > What about below patch?
> >
> > >From 935ed56819f2bfb7ac977f5c63273c9a6e3dfb42 Mon Sep 17 00:00:00 2001
> > From: Masami Hiramatsu <mhiramat@kernel.org>
> > Date: Mon, 23 Mar 2020 10:57:48 +0900
> > Subject: [PATCH] ftrace/kprobe: Show the maxactive number on kprobe_events
> >
> > Show maxactive parameter on kprobe_events.
> > This allows user to save the current configuration and
> > restore it without losing maxactive parameter.
> >
>
> Hi Masami,
>
> Can you resend this patch as a stand alone (so that it shows up as a patch
> on the mailing lists).
Yes I'll do.
Thank you!
>
> Thanks!
>
> -- Steve
>
>
> > Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
> > ---
> > kernel/trace/trace_kprobe.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> > index 362cca52f5de..d0568af4a0ef 100644
> > --- a/kernel/trace/trace_kprobe.c
> > +++ b/kernel/trace/trace_kprobe.c
> > @@ -1078,6 +1078,8 @@ static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev)
> > int i;
> >
> > seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
> > + if (trace_kprobe_is_return(tk) && tk->rp.maxactive)
> > + seq_printf(m, "%d", tk->rp.maxactive);
> > seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp),
> > trace_probe_name(&tk->tp));
> >
>
--
Masami Hiramatsu <mhiramat@kernel.org>
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2020-03-24 6:40 UTC | newest]
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2020-03-22 14:06 How to recheck 'maxactive' ? Taeung Song
2020-03-23 6:47 ` Masami Hiramatsu
2020-03-23 12:54 ` Taeung Song
2020-03-23 13:04 ` Steven Rostedt
2020-03-24 6:40 ` Masami Hiramatsu
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