On 28/05/2021 17:15, Leo Yan wrote:

The callback cs_etm_find_snapshot() is invoked for snapshot mode, its
main purpose is to find the correct AUX trace data and returns "head"
and "old" (we can call "old" as "old head") to the caller, the caller
__auxtrace_mmap__read() uses these two pointers to decide the AUX trace
data size.

quoted

cs_etm_find_snapshot() should be removed with below reasons:

- The first thing in cs_etm_find_snapshot() is to check if the head has
  wrapped around, if it is not, directly bails out.  The checking is
  pointless, this is because the "head" and "old" pointers both are
  monotonical increasing so they never wrap around.

For patch 3:

Reviewed-by: James Clark <redacted>
Tested-by: James Clark <redacted>

I think it's a good simplification and it also fixes the duplicate buffers
issue. And I agree with the reasoning about the pointer increasing monotonically.


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