2013-05-26 08:52:19

by Wang YanQing

Subject: [PATCH] tracing: Fix file mode of free_buffer

Commit 4f271a2a60c748599b30bb4dafff30d770439b96
(tracing: Add a proc file to stop tracing and free buffer)
implement a method to free up ring buffer in kernel memory
in the release code path of free_buffer's fd.

Then we don't need read/write support for free_buffer,
indeed we just have a dummy write fop, and don't implement read fop.

So the 0200 is more reasonable file mode for free_buffer than
the current file mode 0644.

Signed-off-by: Wang YanQing <[email protected]>
---
kernel/trace/trace.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index ae6fa2d..02d9875 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5927,7 +5927,7 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
trace_create_file("buffer_total_size_kb", 0444, d_tracer,
tr, &tracing_total_entries_fops);

- trace_create_file("free_buffer", 0644, d_tracer,
+ trace_create_file("free_buffer", 0200, d_tracer,
tr, &tracing_free_buffer_fops);

trace_create_file("trace_marker", 0220, d_tracer,
--
1.7.12.4.dirty

2013-05-28 19:32:00

by Steven Rostedt

Subject: Re: [PATCH] tracing: Fix file mode of free_buffer

David, Vaibhav,

Any comments on this patch?

-- Steve


On Sun, 2013-05-26 at 16:52 +0800, Wang YanQing wrote:
> Commit 4f271a2a60c748599b30bb4dafff30d770439b96
> (tracing: Add a proc file to stop tracing and free buffer)
> implement a method to free up ring buffer in kernel memory
> in the release code path of free_buffer's fd.
>
> Then we don't need read/write support for free_buffer,
> indeed we just have a dummy write fop, and don't implement read fop.
>
> So the 0200 is more reasonable file mode for free_buffer than
> the current file mode 0644.
>
> Signed-off-by: Wang YanQing <[email protected]>
> ---
> kernel/trace/trace.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index ae6fa2d..02d9875 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -5927,7 +5927,7 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
> trace_create_file("buffer_total_size_kb", 0444, d_tracer,
> tr, &tracing_total_entries_fops);
>
> - trace_create_file("free_buffer", 0644, d_tracer,
> + trace_create_file("free_buffer", 0200, d_tracer,
> tr, &tracing_free_buffer_fops);
>
> trace_create_file("trace_marker", 0220, d_tracer,

2013-05-28 19:34:56

by Vaibhav Nagarnaik

Subject: Re: [PATCH] tracing: Fix file mode of free_buffer

On Sun, May 26, 2013 at 1:52 AM, Wang YanQing <[email protected]> wrote:
> Commit 4f271a2a60c748599b30bb4dafff30d770439b96
> (tracing: Add a proc file to stop tracing and free buffer)
> implement a method to free up ring buffer in kernel memory
> in the release code path of free_buffer's fd.
>
> Then we don't need read/write support for free_buffer,
> indeed we just have a dummy write fop, and don't implement read fop.
>
> So the 0200 is more reasonable file mode for free_buffer than
> the current file mode 0644.
>
> Signed-off-by: Wang YanQing <[email protected]>

Acked-by: Vaibhav Nagarnaik <[email protected]>

Vaibhav Nagarnaik


> ---
> kernel/trace/trace.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index ae6fa2d..02d9875 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -5927,7 +5927,7 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
> trace_create_file("buffer_total_size_kb", 0444, d_tracer,
> tr, &tracing_total_entries_fops);
>
> - trace_create_file("free_buffer", 0644, d_tracer,
> + trace_create_file("free_buffer", 0200, d_tracer,
> tr, &tracing_free_buffer_fops);
>
> trace_create_file("trace_marker", 0220, d_tracer,
> --
> 1.7.12.4.dirty

2013-05-28 20:14:45

by David Sharp

Subject: Re: [PATCH] tracing: Fix file mode of free_buffer

On Tue, May 28, 2013 at 12:34 PM, Vaibhav Nagarnaik
<[email protected]> wrote:
> On Sun, May 26, 2013 at 1:52 AM, Wang YanQing <[email protected]> wrote:
>> Commit 4f271a2a60c748599b30bb4dafff30d770439b96
>> (tracing: Add a proc file to stop tracing and free buffer)
>> implement a method to free up ring buffer in kernel memory
>> in the release code path of free_buffer's fd.
>>
>> Then we don't need read/write support for free_buffer,
>> indeed we just have a dummy write fop, and don't implement read fop.
>>
>> So the 0200 is more reasonable file mode for free_buffer than
>> the current file mode 0644.
>>
>> Signed-off-by: Wang YanQing <[email protected]>
>
> Acked-by: Vaibhav Nagarnaik <[email protected]>

Acked-by: David Sharp <[email protected]>

>
> Vaibhav Nagarnaik
>
>
>> ---
>> kernel/trace/trace.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
>> index ae6fa2d..02d9875 100644
>> --- a/kernel/trace/trace.c
>> +++ b/kernel/trace/trace.c
>> @@ -5927,7 +5927,7 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
>> trace_create_file("buffer_total_size_kb", 0444, d_tracer,
>> tr, &tracing_total_entries_fops);
>>
>> - trace_create_file("free_buffer", 0644, d_tracer,
>> + trace_create_file("free_buffer", 0200, d_tracer,
>> tr, &tracing_free_buffer_fops);
>>
>> trace_create_file("trace_marker", 0220, d_tracer,
>> --
>> 1.7.12.4.dirty
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/

2013-05-29 00:04:39

by Steven Rostedt

Subject: Re: [PATCH] tracing: Fix file mode of free_buffer

On Tue, 2013-05-28 at 13:14 -0700, David Sharp wrote:
> On Tue, May 28, 2013 at 12:34 PM, Vaibhav Nagarnaik
> <[email protected]> wrote:
> > On Sun, May 26, 2013 at 1:52 AM, Wang YanQing <[email protected]> wrote:
> >> Commit 4f271a2a60c748599b30bb4dafff30d770439b96
> >> (tracing: Add a proc file to stop tracing and free buffer)
> >> implement a method to free up ring buffer in kernel memory
> >> in the release code path of free_buffer's fd.
> >>
> >> Then we don't need read/write support for free_buffer,
> >> indeed we just have a dummy write fop, and don't implement read fop.
> >>
> >> So the 0200 is more reasonable file mode for free_buffer than
> >> the current file mode 0644.
> >>
> >> Signed-off-by: Wang YanQing <[email protected]>
> >
> > Acked-by: Vaibhav Nagarnaik <[email protected]>
>
> Acked-by: David Sharp <[email protected]>
>
> >

Thanks guys,

As this isn't that big of a deal, I'm going to just queue this for 3.11.

-- Steve