* 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] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 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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