Re: [PATCH] ring_buffer: map to cpu not page

[Ingo Molnar <mingo@elte.hu>]

* Steven Rostedt <rostedt@goodmis.org> wrote:

> My original patch had a compile bug when NUMA was configured. I 
> referenced cpu when it should have been cpu_buffer->cpu.
> 
> Ingo quickly fixed this bug by replacing cpu with 'i' because that was 
> the loop counter. Unfortunately, the 'i' was the counter of pages, not 
> CPUs. This caused a crash when the number of pages allocated for the 
> buffers exceeded the number of pages, which would usually be the case.
> 
> Signed-off-by: Steven Rostedt <srostedt@redhat.com>

>  	for (i = 0; i < nr_pages; i++) {
>  		page = kzalloc_node(ALIGN(sizeof(*page), cache_line_size()),
> -				    GFP_KERNEL, cpu_to_node(i));
> +				    GFP_KERNEL, cpu_to_node(cpu_buffer->cpu));

oh, stupid typo of the year :-)

applied to tip/tracing/ring-buffer, thanks for tracking it down! I've 
reactivated the topic branch for tip/master and i'm running a few tests 
before pushing it out for wider testing.

	Ingo