[Speed] Analysis of a Python performance issue

[serge guelton]

On Mon, Nov 21, 2016 at 03:26:19PM -0800, Kevin Modzelewski wrote:
> Oh sorry I was unclear, yes this is for the pyston binary itself, and yes
> PGO does a better job and I definitely think it should be used.

That raised a second question: do you collect branch / hotness info
during lower tier jitted code run, so as to improve performance of
higher tiers ?

> Separately, we often use non-pgo builds for quick checks, so we also have
> the system I described that makes our non-pgo build more reliable by using
> the function ordering from the pgo build.

ok. Are you just « putting hot stuff in the hot section » or did you try
to specify an ordering to further improve locality? (I don't know if it's possible, it's mentionned in one of the paper)

Thanks,

Serge