Re: [PATCH 1/1] merge-ort: begin performance work; instrument with trace2_region_* calls

On Fri, Jan 08, 2021 at 12:51:11PM -0800, Elijah Newren wrote:

Overall timings, using hyperfine (1 warmup run, 3 runs for mega-renames,
10 runs for the other two cases):

Ah, I love hyperfine. In case you don't already have this in your
arsenal, the following `--prepare` step is useful for measuring
cold-cache performance:

    --prepare='sync; echo 3 | sudo tee /proc/sys/vm/drop_caches'

=== Goals ===

This patch is obviously just the beginning.  Here are some of my goals
that this measurement will help us achieve:

* Drive the cost of rename detection down considerably for merges
* After the above has been achieved, see if there are other slowness
  factors (which would have previously been overshadowed by rename
  detection costs) which we can then focus on and also optimize.
* Ensure our rebase testcase that requires little rename detection
  is noticeably faster with merge-ort than with apply-based rebase.

These are great, and I am looking forward to your work.

Signed-off-by: Elijah Newren <redacted>

Thanks, this patch looks good to me.

Thanks,
Taylor