* Re: [PATCH] tracing: fix trace_print_seq()
2009-07-01 8:50 [PATCH] tracing: fix trace_print_seq() Xiao Guangrong
@ 2009-07-01 14:01 ` Frederic Weisbecker
2009-07-02 5:57 ` Li Zefan
2009-07-01 14:06 ` [tip:tracing/urgent] tracing: Fix trace_print_seq() tip-bot for Xiao Guangrong
` (2 subsequent siblings)
3 siblings, 1 reply; 7+ messages in thread
From: Frederic Weisbecker @ 2009-07-01 14:01 UTC (permalink / raw)
To: Xiao Guangrong
Cc: Ingo Molnar, Eduard - Gabriel Munteanu, Steven Rostedt, LKML
On Wed, Jul 01, 2009 at 04:50:25PM +0800, Xiao Guangrong wrote:
> We will lose something if trace_seq->buffer[0] is 0, because the copy length
> is calculated by strlen() in seq_puts(), so using seq_write() instead of
> seq_puts().
>
> There have a example:
> after reboot:
> # echo kmemtrace > current_tracer
> # echo 0 > options/kmem_minimalistic
> # cat trace
> # tracer: kmemtrace
> #
> #
> Nothing is exported, because the first byte of trace_seq->buffer[ ]
> is KMEMTRACE_USER_ALLOC.
> ( the value of KMEMTRACE_USER_ALLOC is zero, seeing
> kmemtrace_print_alloc_user() in kernel/trace/kmemtrace.c)
>
> Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
> ---
> kernel/trace/trace_output.c | 3 +--
> 1 files changed, 1 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
> index 7938f3a..e0c2545 100644
> --- a/kernel/trace/trace_output.c
> +++ b/kernel/trace/trace_output.c
> @@ -27,8 +27,7 @@ void trace_print_seq(struct seq_file *m, struct trace_seq *s)
> {
> int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;
>
> - s->buffer[len] = 0;
> - seq_puts(m, s->buffer);
> + seq_write(m, s->buffer, len);
>
> trace_seq_init(s);
> }
> --
> 1.6.1.2
>
Looks good, thanks.
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
But having a '\0' in a non binary trace looks weird. Why do
we have such plain KMEMTRACE_USER_ALLOC whereas binary tracing
is not set, as your example shows it?
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH] tracing: fix trace_print_seq()
2009-07-01 14:01 ` Frederic Weisbecker
@ 2009-07-02 5:57 ` Li Zefan
0 siblings, 0 replies; 7+ messages in thread
From: Li Zefan @ 2009-07-02 5:57 UTC (permalink / raw)
To: Frederic Weisbecker
Cc: Xiao Guangrong, Ingo Molnar, Eduard - Gabriel Munteanu,
Steven Rostedt, LKML
>> There have a example:
>> after reboot:
>> # echo kmemtrace > current_tracer
>> # echo 0 > options/kmem_minimalistic
>> # cat trace
>> # tracer: kmemtrace
>> #
>> #
>> Nothing is exported, because the first byte of trace_seq->buffer[ ]
>> is KMEMTRACE_USER_ALLOC.
>> ( the value of KMEMTRACE_USER_ALLOC is zero, seeing
>> kmemtrace_print_alloc_user() in kernel/trace/kmemtrace.c)
>>
...
> Looks good, thanks.
>
> Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
>
> But having a '\0' in a non binary trace looks weird. Why do
> we have such plain KMEMTRACE_USER_ALLOC whereas binary tracing
> is not set, as your example shows it?
>
Because of this commit:
| commit 42af9054c0eeed09ec58d13ec8bf52d225ebcfcc
| Author: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
| Date: Mon Mar 23 15:12:26 2009 +0200
|
| kmemtrace: restore original tracing data binary format, improve ABI
I think we should change it to use trace_event->binary() interface for
binary trace.
^ permalink raw reply [flat|nested] 7+ messages in thread
* [tip:tracing/urgent] tracing: Fix trace_print_seq()
2009-07-01 8:50 [PATCH] tracing: fix trace_print_seq() Xiao Guangrong
2009-07-01 14:01 ` Frederic Weisbecker
@ 2009-07-01 14:06 ` tip-bot for Xiao Guangrong
2009-07-01 14:15 ` Pekka Enberg
2009-07-01 14:42 ` tip-bot for Xiao Guangrong
2009-07-02 6:54 ` tip-bot for Xiao Guangrong
3 siblings, 1 reply; 7+ messages in thread
From: tip-bot for Xiao Guangrong @ 2009-07-01 14:06 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, hpa, mingo, penberg, eduard.munteanu, xiaoguangrong,
fweisbec, rostedt, tglx, mingo
Commit-ID: 5c37f525657e879a17a27c83021602cd55837531
Gitweb: http://git.kernel.org/tip/5c37f525657e879a17a27c83021602cd55837531
Author: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
AuthorDate: Wed, 1 Jul 2009 16:50:25 +0800
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 1 Jul 2009 16:03:50 +0200
tracing: Fix trace_print_seq()
We will lose something if trace_seq->buffer[0] is 0, because the copy length
is calculated by strlen() in seq_puts(), so using seq_write() instead of
seq_puts().
There have a example:
after reboot:
# echo kmemtrace > current_tracer
# echo 0 > options/kmem_minimalistic
# cat trace
# tracer: kmemtrace
#
#
Nothing is exported, because the first byte of trace_seq->buffer[ ]
is KMEMTRACE_USER_ALLOC.
( the value of KMEMTRACE_USER_ALLOC is zero, seeing
kmemtrace_print_alloc_user() in kernel/trace/kmemtrace.c)
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <4A4B2351.5010300@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
kernel/trace/trace_output.c | 3 +--
1 files changed, 1 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 7938f3a..e0c2545 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -27,8 +27,7 @@ void trace_print_seq(struct seq_file *m, struct trace_seq *s)
{
int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;
- s->buffer[len] = 0;
- seq_puts(m, s->buffer);
+ seq_write(m, s->buffer, len);
trace_seq_init(s);
}
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [tip:tracing/urgent] tracing: Fix trace_print_seq()
2009-07-01 14:06 ` [tip:tracing/urgent] tracing: Fix trace_print_seq() tip-bot for Xiao Guangrong
@ 2009-07-01 14:15 ` Pekka Enberg
0 siblings, 0 replies; 7+ messages in thread
From: Pekka Enberg @ 2009-07-01 14:15 UTC (permalink / raw)
To: mingo, hpa, linux-kernel, eduard.munteanu, xiaoguangrong,
fweisbec, rostedt, tglx, mingo
Cc: linux-tip-commits
On Wed, 2009-07-01 at 14:06 +0000, tip-bot for Xiao Guangrong wrote:
> Commit-ID: 5c37f525657e879a17a27c83021602cd55837531
> Gitweb: http://git.kernel.org/tip/5c37f525657e879a17a27c83021602cd55837531
> Author: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
> AuthorDate: Wed, 1 Jul 2009 16:50:25 +0800
> Committer: Ingo Molnar <mingo@elte.hu>
> CommitDate: Wed, 1 Jul 2009 16:03:50 +0200
>
> tracing: Fix trace_print_seq()
>
> We will lose something if trace_seq->buffer[0] is 0, because the copy length
> is calculated by strlen() in seq_puts(), so using seq_write() instead of
> seq_puts().
>
> There have a example:
> after reboot:
>
> # echo kmemtrace > current_tracer
> # echo 0 > options/kmem_minimalistic
> # cat trace
> # tracer: kmemtrace
> #
> #
>
> Nothing is exported, because the first byte of trace_seq->buffer[ ]
> is KMEMTRACE_USER_ALLOC.
>
> ( the value of KMEMTRACE_USER_ALLOC is zero, seeing
> kmemtrace_print_alloc_user() in kernel/trace/kmemtrace.c)
>
> Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
> Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Pekka Enberg <penberg@cs.helsinki.fi>
> LKML-Reference: <4A4B2351.5010300@cn.fujitsu.com>
> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Nice catch!
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
^ permalink raw reply [flat|nested] 7+ messages in thread
* [tip:tracing/urgent] tracing: Fix trace_print_seq()
2009-07-01 8:50 [PATCH] tracing: fix trace_print_seq() Xiao Guangrong
2009-07-01 14:01 ` Frederic Weisbecker
2009-07-01 14:06 ` [tip:tracing/urgent] tracing: Fix trace_print_seq() tip-bot for Xiao Guangrong
@ 2009-07-01 14:42 ` tip-bot for Xiao Guangrong
2009-07-02 6:54 ` tip-bot for Xiao Guangrong
3 siblings, 0 replies; 7+ messages in thread
From: tip-bot for Xiao Guangrong @ 2009-07-01 14:42 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, hpa, mingo, penberg, eduard.munteanu, xiaoguangrong,
fweisbec, rostedt, tglx, mingo
Commit-ID: 393ab9a2a6cf958c9549e35bd88c03b9b3eae64e
Gitweb: http://git.kernel.org/tip/393ab9a2a6cf958c9549e35bd88c03b9b3eae64e
Author: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
AuthorDate: Wed, 1 Jul 2009 16:50:25 +0800
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 1 Jul 2009 16:41:31 +0200
tracing: Fix trace_print_seq()
We will lose something if trace_seq->buffer[0] is 0, because the copy length
is calculated by strlen() in seq_puts(), so using seq_write() instead of
seq_puts().
There have a example:
after reboot:
# echo kmemtrace > current_tracer
# echo 0 > options/kmem_minimalistic
# cat trace
# tracer: kmemtrace
#
#
Nothing is exported, because the first byte of trace_seq->buffer[ ]
is KMEMTRACE_USER_ALLOC.
( the value of KMEMTRACE_USER_ALLOC is zero, seeing
kmemtrace_print_alloc_user() in kernel/trace/kmemtrace.c)
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4A4B2351.5010300@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
kernel/trace/trace_output.c | 3 +--
1 files changed, 1 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 7938f3a..e0c2545 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -27,8 +27,7 @@ void trace_print_seq(struct seq_file *m, struct trace_seq *s)
{
int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;
- s->buffer[len] = 0;
- seq_puts(m, s->buffer);
+ seq_write(m, s->buffer, len);
trace_seq_init(s);
}
^ permalink raw reply related [flat|nested] 7+ messages in thread* [tip:tracing/urgent] tracing: Fix trace_print_seq()
2009-07-01 8:50 [PATCH] tracing: fix trace_print_seq() Xiao Guangrong
` (2 preceding siblings ...)
2009-07-01 14:42 ` tip-bot for Xiao Guangrong
@ 2009-07-02 6:54 ` tip-bot for Xiao Guangrong
3 siblings, 0 replies; 7+ messages in thread
From: tip-bot for Xiao Guangrong @ 2009-07-02 6:54 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, hpa, mingo, penberg, eduard.munteanu, xiaoguangrong,
fweisbec, rostedt, tglx, mingo
Commit-ID: e1af3aec3e2e7d21d4b3054323779d478c19d907
Gitweb: http://git.kernel.org/tip/e1af3aec3e2e7d21d4b3054323779d478c19d907
Author: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
AuthorDate: Wed, 1 Jul 2009 16:50:25 +0800
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Thu, 2 Jul 2009 08:51:13 +0200
tracing: Fix trace_print_seq()
We will lose something if trace_seq->buffer[0] is 0, because the copy length
is calculated by strlen() in seq_puts(), so using seq_write() instead of
seq_puts().
There have a example:
after reboot:
# echo kmemtrace > current_tracer
# echo 0 > options/kmem_minimalistic
# cat trace
# tracer: kmemtrace
#
#
Nothing is exported, because the first byte of trace_seq->buffer[ ]
is KMEMTRACE_USER_ALLOC.
( the value of KMEMTRACE_USER_ALLOC is zero, seeing
kmemtrace_print_alloc_user() in kernel/trace/kmemtrace.c)
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4A4B2351.5010300@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
kernel/trace/trace_output.c | 3 +--
1 files changed, 1 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 7938f3a..e0c2545 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -27,8 +27,7 @@ void trace_print_seq(struct seq_file *m, struct trace_seq *s)
{
int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;
- s->buffer[len] = 0;
- seq_puts(m, s->buffer);
+ seq_write(m, s->buffer, len);
trace_seq_init(s);
}
^ permalink raw reply related [flat|nested] 7+ messages in thread