Re: [PATCH v2 3/5] trace: Add per_cpu ring buffer control files

[Vaibhav Nagarnaik]

On Mon, Aug 22, 2011 at 1:29 PM, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> On Tue, 2011-08-16 at 14:46 -0700, Vaibhav Nagarnaik wrote:
>> Add a debugfs entry under per_cpu/ folder for each cpu called
>> buffer_size_kb to control the ring buffer size for each CPU
>> independently.
>>
>> If the global file buffer_size_kb is used to set size, the individual
>> ring buffers will be adjusted to the given size. The buffer_size_kb will
>> report the common size to maintain backward compatibility.
>>
>> If the buffer_size_kb file under the per_cpu/ directory is used to
>> change buffer size for a specific CPU, only the size of the respective
>> ring buffer is updated. When tracing/buffer_size_kb is read, it reports
>> 'X' to indicate that sizes of per_cpu ring buffers are not equivalent.
>>
>> Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@xxxxxxxxxx>
>
> This patch wasn't tested against any of the latency tracers being
> enabled or hot plug:
>
>
> /home/rostedt/work/autotest/nobackup/linux-test.git/kernel/trace/ring_buffer.c: In function 'ring_buffer_swap_cpu':
> /home/rostedt/work/autotest/nobackup/linux-test.git/kernel/trace/ring_buffer.c:3761:14: error: 'struct ring_buffer' has no member named 'pages'
> /home/rostedt/work/autotest/nobackup/linux-test.git/kernel/trace/ring_buffer.c:3761:33: error: 'struct ring_buffer' has no member named 'pages'
>  CC      kernel/trace/trace_syscalls.o
> /home/rostedt/work/autotest/nobackup/linux-test.git/kernel/trace/ring_buffer.c: In function 'rb_cpu_notify':
> /home/rostedt/work/autotest/nobackup/linux-test.git/kernel/trace/ring_buffer.c:4136:4: error: too few arguments to function 'rb_allocate_cpu_buffer'
> /home/rostedt/work/autotest/nobackup/linux-test.git/kernel/trace/ring_buffer.c:1066:1: note: declared here
>
>
> -- Steve

Oops, sorry about that. I will send a respin of the patch.


Vaibhav Nagarnaik
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