Re: [PATCH v6] Unified trace buffer

From: Martin Bligh
Date: Fri Sep 26 2008 - 15:46:52 EST


On Fri, Sep 26, 2008 at 11:59 AM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> On Fri, 2008-09-26 at 14:05 -0400, Steven Rostedt wrote:
>
>> +struct buffer_page {
>> + u64 time_stamp;
>> + unsigned char body[];
>> +};
>> +
>> +#define BUF_PAGE_SIZE (PAGE_SIZE - sizeof(u64))
>
> Since you're already using the page frame, you can stick this per page
> timestamp in there as well, and get the full page for data.
>
> You can either use a struct page overlay like slob does, or add a u64 in
> the union that contains struct {private, mapping}.

What did you guys think of Mathieu's idea of sticking the buffer length
in the header here, rather than using padding events? Seemed cleaner
to me.
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