Re: [PATCH 1/5] prune-packed: don't call display_progress() for every file
- From
Shawn O. Pearce <spearce@spearce.org>
- Date
- Nov 1, 2007, 02:58 UTC
- Message-ID
- <20071101025830.GX14735@spearce.org>
- In-Reply-To
- <1193770655-20492-2-git-send-email-nico@cam.org>
Nicolas Pitre <nico@cam.org> wrote:
> The progress count is per fanout directory, so it is useless to call > it for every file as the count doesn't change that often.
If you go back into the history and look at the commit message for when I introduced this per-object display_progress() call we find the following:
commit b5d72f0a4cd3cce945ca0d37e4fa0ebbfcdcdb52 Author: Shawn O. Pearce <spearce@spearce.org> Date: Fri Oct 19 00:08:37 2007 -0400
[...snip...]
We perform the display_progress() call from within the very innermost
loop in case we spend more than 1 second within any single object
directory. This ensures that a progress_update event from the
timer will still trigger in a timely fashion and allow the user to
see the progress meter.During my testing with a 40,000 loose object case (yea, I fully unpacked a git.git clone I had laying around) my system stalled hard in the first object directory. A *lot* longer than 1 second. So I got no progress meter for a long time, and then a progress meter appeared on the second directory.
The display_progress() call already does a reasonably cheap comparsion to see if the timer has tripped or if the percent complete has changed. So I figured it was more useful to get feedback to the user that we were working, but were going to take a while, than it was to optimize a few machine instructions out of that inner-most per-object loop.
So I'm a little against this patch. But I think I understand why you think its worth doing. I just consider the progress feedback more important than the few machine cycles avoiding it saves.
-- Shawn.