"bzr log" by revision-id is slow

[Martin Pool]

On 13 October 2011 09:18, Eli Zaretskii <eliz at gnu.org> wrote:
> It looks like "bzr log -r REVID" is O(1), but with a very large
> constant.  The time is roughly the same as it takes "bzr
> revision-info" to return the revno by revision-id.
>
> Here are a few examples from the Emacs repository, which show that the
> time taken by "bzr log -r REVNO" grows for older revisions, but the
> same command by REVID takes constant time, which happens to be the
> same as for "bzr log -r 1".
>
> Is this expected?

It ought to be possible to get a single revision in reasonable O(1)
time, so I think something is wrong here.

In general if you hit something that looks unreasonably slow, please
file a bug tagged 'performance affects-emacs', trying to make sure
it's not already a dupe, with reproduction instructions and if
possible the --lsprof-file output attached.

m