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Differential D4134

perf: call _generatechangelog() instead of group()
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Authored by indygreg on Aug 6 2018, 3:51 PM.

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rHGa1f694779b2f: perf: call _generatechangelog() instead of group()
Summary

Now that we have a separate function for generating just the changelog
bits, the perf command should call it so it gets more accurate
behavior.

This changes the results of this command on my hg repo significantly:

! wall 1.390502 comb 1.390000 user 1.370000 sys 0.020000 (best of 8)
! wall 1.768750 comb 1.760000 user 1.760000 sys 0.000000 (best of 6)

Profiling seems to reveal that ~20% of execution time is spent in
progress bar accounting and printing! If we run with
progress.disable=true:

! wall 1.639134 comb 1.650000 user 1.630000 sys 0.020000 (best of 7)

A nice speedup. But profiling still shows a good chunk of time being
spent in progress bar accounting code. The reason is that the
progress bar is conditionally enabled via an argument to
cgpacker.group(). The previous code in perf.py calling into group()
did not enable the progress bar but _generatechangelog() always does.

I think it is important for the perf* commands to capture real-world
use cases. And this code always runs with an active progress bar. So
the regression is acceptable.

That being said, terminal printing performance can vary substantially.
I don't think perf* commands should test terminal printing unless
explicitly desired. So I've disabled progress bar printing in this
command.

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Event Timeline

indygreg created this revision.Aug 6 2018, 3:51 PM
Closed by commit rHGa1f694779b2f: perf: call _generatechangelog() instead of group() (authored by indygreg). · Explain WhyAug 9 2018, 2:15 PM
This revision was automatically updated to reflect the committed changes.

Revision Contents
Changeset List

PathPackages
Mcontrib/perf.py (17 lines)

Diff 10005

contrib/perf.py

This measures the time spent processing the changelog during a This measures the time spent processing the changelog during a
bundle operation. This occurs during `hg bundle` and on a server bundle operation. This occurs during `hg bundle` and on a server
processing a `getbundle` wire protocol request (handles clones processing a `getbundle` wire protocol request (handles clones
and pull requests). and pull requests).
By default, all revisions are added to the changegroup. By default, all revisions are added to the changegroup.
""" """
cl = repo.changelog cl = repo.changelog
revs = [cl.lookup(r) for r in repo.revs(rev or 'all()')] nodes = [cl.lookup(r) for r in repo.revs(rev or 'all()')]
bundler = changegroup.getbundler(version, repo) bundler = changegroup.getbundler(version, repo)
def lookup(node):
# The real bundler reads the revision in order to access the
# manifest node and files list. Do that here.
cl.read(node)
return node
def d(): def d():
for chunk in bundler.group(revs, cl, lookup): state, chunks = bundler._generatechangelog(cl, nodes)
for chunk in chunks:
pass pass
timer, fm = gettimer(ui, opts) timer, fm = gettimer(ui, opts)
# Terminal printing can interfere with timing. So disable it.
with ui.configoverride({('progress', 'disable'): True}):
timer(d) timer(d)
fm.end() fm.end()
@command('perfdirs', formatteropts) @command('perfdirs', formatteropts)
def perfdirs(ui, repo, **opts): def perfdirs(ui, repo, **opts):
timer, fm = gettimer(ui, opts) timer, fm = gettimer(ui, opts)
dirstate = repo.dirstate dirstate = repo.dirstate
'a' in dirstate 'a' in dirstate
def d(): def d():