2014-12-03 01:35:55

by Joonsoo Kim

Subject: [PATCH] Documentation: describe trace_buf_size parameter more accurately

I'm stuck into panic that too litte free memory is left when I boot with
trace_buf_size parameter. After digging into the problem, I found that
trace_buf_size is the size of trace buffer on each cpu rather than total
size of trace buffer. To prevent victim like me, change description of
trace_buf_size parameter more accurately.

Signed-off-by: Joonsoo Kim <[email protected]>
---
Documentation/kernel-parameters.txt | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 70cfce5..fc77457 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -3546,7 +3546,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
are saved.

trace_buf_size=nn[KMG]
- [FTRACE] will set tracing buffer size.
+ [FTRACE] will set tracing buffer size on each cpu.

trace_event=[event-list]
[FTRACE] Set and start specified trace events in order
--
1.7.9.5

2014-12-03 09:06:36

by Steven Rostedt

Subject: Re: [PATCH] Documentation: describe trace_buf_size parameter more accurately

On Wed, 3 Dec 2014 10:39:20 +0900
Joonsoo Kim <[email protected]> wrote:

> I'm stuck into panic that too litte free memory is left when I boot with
> trace_buf_size parameter. After digging into the problem, I found that
> trace_buf_size is the size of trace buffer on each cpu rather than total
> size of trace buffer. To prevent victim like me, change description of
> trace_buf_size parameter more accurately.

Heh, Thanks, I'll apply this.

-- Steve

>
> Signed-off-by: Joonsoo Kim <[email protected]>
> ---
> Documentation/kernel-parameters.txt | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> index 70cfce5..fc77457 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -3546,7 +3546,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
> are saved.
>
> trace_buf_size=nn[KMG]
> - [FTRACE] will set tracing buffer size.
> + [FTRACE] will set tracing buffer size on each cpu.
>
> trace_event=[event-list]
> [FTRACE] Set and start specified trace events in order