[PATCH V2] perf: add threading capability to perfbdiff

[Augie Fackler]

On Wed, Jan 10, 2018 at 03:23:13PM +0100, Paul Morelle wrote:
> # HG changeset patch
> # User Boris Feld <boris.feld at octobus.net>
> # Date 1513481487 -3600
> #      Sun Dec 17 04:31:27 2017 +0100
> # Node ID a04df08f0f218da10bb57c9f7080770a7f3e56c0
> # Parent  b55a142f00c5a92a19ff94fbe9b5d09e28716860
> # EXP-Topic threaded-diff
> # Available At https://bitbucket.org/octobus/mercurial-devel/
> #              hg pull https://bitbucket.org/octobus/mercurial-devel/ -r a04df08f0f21
> perf: add threading capability to perfbdiff

queued, thanks

Some more history on bdiff and the GIL: code.google.com used a
thread-per-connection webserver, and some pathological case or other
was causing our server to die because it failed too many health checks
in a row. We modified bdiff to release the GIL and immediately stopped
having the "bdiff of death" problem, but also suddenly were able to
use a LOT more CPU on our servers in a single process.