hg branches performance regression

Matt Mackall mpm at selenic.com
Fri Apr 27 13:07:58 CDT 2012


On Wed, 2012-04-25 at 22:10 +0800, Steven Brown wrote:
> This changeset makes "hg branches" slower on a branchy repo:
> 
> changeset:   16439:e5750c6716eb
> user:        Matt Mackall <mpm at selenic.com>
> date:        Fri Apr 13 21:35:48 2012 -0500
> summary:     revlog: increase readahead size
> 
> Before:
> $ time ./hg branches -R ../10k > /dev/null
> real	0m4.225s
> user	0m3.132s
> sys	0m0.960s
> 
> After:
> $ time ./hg branches -R ../10k > /dev/null
> real	0m19.068s
> user	0m3.768s
> sys	0m15.265s
> 
> where ../10k is a local clone of https://bitbucket.org/mg/10k with an
> existing .hg/cache/branchheads file.
> 
> Caching the closed state of the branch heads fixes this, but I don't
> yet have a finished patch ready, and it doesn't seem appropriate for
> the stable branch anyway.
> 
> Is it OK to back out this change for the 2.2 release and revisit it afterwards?

Yep, done.

-- 
Mathematics is the supreme nostalgia of our time.




More information about the Mercurial-devel mailing list