view CONTRIBUTORS @ 51592:24844407fa0d

perf: clear vfs audit_cache before each run

When generating a stream clone, we spend a large amount of time auditing path.
Before this changes, the first run was warming the vfs cache for the other
runs, leading to a large runtime difference and a "faulty" reported timing for
the operation.

We now clear this important cache between run to get a more realistic timing.

Below are some example of median time change when clearing these cases. The
maximum time for a run did not changed significantly.

### data-env-vars.name             = mozilla-central-2018-08-01-zstd-sparse-revlog
  # benchmark.name                = hg.perf.exchange.stream.generate
  # bin-env-vars.hg.flavor         = default
  # bin-env-vars.hg.py-re2-module  = default
  # benchmark.variants.version    = latest
no-clearing:    17.289905
cache-clearing: 21.587965  (+24.86%, +4.30)
 ## data-env-vars.name             = mozilla-central-2024-03-22-zstd-sparse-revlog
no-clearing:    32.670748
cache-clearing: 40.467095  (+23.86%, +7.80)
 ## data-env-vars.name             = mozilla-try-2019-02-18-zstd-sparse-revlog
no-clearing:    37.838858
cache-clearing: 46.072749  (+21.76%, +8.23)
 ## data-env-vars.name             = mozilla-unified-2024-03-22-zstd-sparse-revlog
no-clearing:    32.969395
cache-clearing: 39.646209  (+20.25%, +6.68)

In addition, this significantly reduce the timing difference between the
performance command, from the perf extensions and a `real `hg bundle` call
producing a stream bundle. Some significant differences remain especially on
the "mozilla-try" repositories, but they are now smaller.

Note that some of that difference will actually not be
attributable to the stream generation (like maybe phases or branch map
computation).

Below are some benchmarks done on a currently draft changeset fixing some
unrelated slowness in `hg bundle` (34a78972af409d1ff37c29e60f6ca811ad1a457d)

### data-env-vars.name             = mozilla-central-2018-08-01-zstd-sparse-revlog
  # bin-env-vars.hg.flavor         = default
  # bin-env-vars.hg.py-re2-module  = default
hg.perf.exchange.stream.generate:  21.587965
hg.command.bundle:                 24.301799  (+12.57%, +2.71)
 ## data-env-vars.name             = mozilla-central-2024-03-22-zstd-sparse-revlog
hg.perf.exchange.stream.generate:  40.467095
hg.command.bundle:                 44.831317  (+10.78%, +4.36)
 ## data-env-vars.name             = mozilla-unified-2024-03-22-zstd-sparse-revlog
hg.perf.exchange.stream.generate:  39.646209
hg.command.bundle:                 45.395258  (+14.50%, +5.75)
 ## data-env-vars.name             = mozilla-try-2019-02-18-zstd-sparse-revlog
hg.perf.exchange.stream.generate:  46.072749
hg.command.bundle:                 55.882608  (+21.29%, +9.81)
 ## data-env-vars.name             = mozilla-try-2023-03-22-zlib-general-delta
hg.perf.exchange.stream.generate: 334.716708
hg.command.bundle:                377.856767  (+12.89%, +43.14)
 ## data-env-vars.name             = mozilla-try-2023-03-22-zstd-sparse-revlog
hg.perf.exchange.stream.generate: 302.972301
hg.command.bundle:                326.098755  (+7.63%, +23.13)

[This file is here for historical purposes, all recent contributors
should appear in the changelog directly]

Andrea Arcangeli <andrea at suse.de>
Thomas Arendsen Hein <thomas at intevation.de>
Goffredo Baroncelli <kreijack at libero.it>
Muli Ben-Yehuda <mulix at mulix.org>
Mikael Berthe <mikael at lilotux.net>
Benoit Boissinot <bboissin at gmail.com>
Brendan Cully <brendan at kublai.com>
Vincent Danjean <vdanjean.ml at free.fr>
Jake Edge <jake at edge2.net>
Michael Fetterman <michael.fetterman at intel.com>
Edouard Gomez <ed.gomez at free.fr>
Eric Hopper <hopper at omnifarious.org>
Alecs King <alecsk at gmail.com>
Volker Kleinfeld <Volker.Kleinfeld at gmx.de>
Vadim Lebedev <vadim at mbdsys.com>
Christopher Li <hg at chrisli.org>
Chris Mason <mason at suse.com>
Colin McMillen <mcmillen at cs.cmu.edu>
Wojciech Milkowski <wmilkowski at interia.pl>
Chad Netzer <chad.netzer at gmail.com>
Bryan O'Sullivan <bos at serpentine.com>
Vicent Seguí Pascual <vseguip at gmail.com>
Sean Perry <shaleh at speakeasy.net>
Nguyen Anh Quynh <aquynh at gmail.com>
Ollivier Robert <roberto at keltia.freenix.fr>
Alexander Schremmer <alex at alexanderweb.de>
Arun Sharma <arun at sharma-home.net>
Josef "Jeff" Sipek <jeffpc at optonline.net>
Kevin Smith <yarcs at qualitycode.com>
TK Soh <teekaysoh at yahoo.com>
Radoslaw Szkodzinski <astralstorm at gorzow.mm.pl>
Samuel Tardieu <sam at rfc1149.net>
K Thananchayan <thananck at yahoo.com>
Andrew Thompson <andrewkt at aktzero.com>
Michael S. Tsirkin <mst at mellanox.co.il>
Rafael Villar Burke <pachi at mmn-arquitectos.com>
Tristan Wibberley <tristan at wibberley.org>
Mark Williamson <mark.williamson at cl.cam.ac.uk>