Re: [PATCH] perf_events: improve DS/BTS/PEBS buffer allocation

Stephane Eranian
2010-09-13T15:31:39Z

On Mon, Sep 13, 2010 at 5:24 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> On Mon, 2010-09-13 at 17:20 +0200, Stephane Eranian wrote:
>
>> That is the case we the sizes you have chosen today. For DS, we
>> could round up to one page for now.
>
> Markus chose the BTS size, for PEBS a single page was plenty since we do
> single event things (although we could do multiple for attr.precise_ip <
> 2).
>
> For DS there's:
>  kmalloc_node(sizeof(struct ds), GFP_KERNEL | __GFP_ZERO, cpu_node(cpu));
>
Ok, let try again with alloc_pages_node() + kmalloc_node().
I think we can stick with kmalloc() for DS because we are far from
consuming a page.

>
>