Re: [PATCH 3/3] git-p4: improve submit performance on new P4 servers

From: Nicolas Pitre <nico@fluxnic.net>
Date: Jan 22, 2010, 03:59 UTC
Message-ID: <alpine.LFD.2.00.1001212242550.1726@xanadu.home>
In-Reply-To: <4B591455.7050409@naughtydog.com>

On Thu, 21 Jan 2010, Pal-Kristian Engstad wrote:

Show 14 quoted lines

> Nicolas Pitre wrote:
> > On Thu, 21 Jan 2010, Pal-Kristian Engstad wrote:
> > 
> >> Improve git-p4 submit performance on newer (from 2009.2) Perforce
> >> servers by changing "p4 diff -du" to "p4 diff -dub". This change is
> >> harmless since the output is only used for display purposes.
> >>
> >> Signed-off-by: Pal-Kristian Engstad <pal_engstad@naughtydog.com>
> > 
> > Why is the b flag impacting performance?
> 
> That's a very good question. The release notes say that they've been 
> changing how 'p4 diff -du' works, but the net effect of it all is that
> it stats all files in the whole working set.

And so does git.

> For large projects, this
> takes forever. We say pauses of 3 minutes per submit...

This is abominable.

> > And even if for display purposes, why might you wish not to see 
> > differences in whitespace changes?
> 
> That's a good point, but what alternative is there?

Have the option of not seeing the diff in the submit template maybe?

I agree that P4 is slow. Painfully slow. I even needed to make git-p4 even slower by adding a time.sleep(1) in p4_build_cmd() otherwise the server would randomly drop the connection with the client when being contacted back to back.

I'm so glad Simon wrote this git-p4 nevertheless. Makes working with P4 almost enjoyable.

Nicolas