Re: [PATCH 1/3] perf events: fix WARN_ON_ONCE for 64-bit raw data, SW events

Em Fri, Feb 18, 2011 at 07:33:28AM -0700, David Ahern escreveu:

On 02/18/11 04:00, Peter Zijlstra wrote:

quoted

On Thu, 2011-02-17 at 22:53 -0700, David Ahern wrote:

quoted

This check does not work out for 64-bit counter:

    sizeof(u32) + sizeof(u64) = 4 + 8 = 12

which does not pass the WARN_ON_ONCE test. I'm guessing (hoping
really) that the intent is that the size of the raw data is a
multiple of 4 bytes, not 8.

No the data must come in 8bytes strides.

Then the sizeof the size field needs to be moved to u64; right now it is
u32:

struct perf_raw_record {
    u32             size;
    void                *data;
};

So size should be changed to u64 rather than modifying the WARN_ON_ONCE?

Yeah, I guess so, 32-bit has to die it seems, gets in the way of testing
:-)

- Arnaldo