Re: [GIT] Networking

Ingo Molnar
2011-08-01T15:14:05Z

* David Miller <davem@davemloft.net> wrote:

> forcedeth: do vlan cleanup

Trying to bring latest -git into latest -tip today i managed to
bisect back to a pretty bad networking breakage on one of my
testboxes back to this commit - where i have discovered that it has
been fixed freshly.

This bug cost me multiple days of debugging so here's a bit of a post
mortem.

The bit that IMO wasnt very optimal was the timing of the merge path:

- AuthorDate: Wed Jul 20 04:54:38 2011 +0000
- CommitDate: Thu Jul 21 13:47:57 2011 -0700
- tree Linus merge CommitDate: Fri Jul 22 14:43:13 2011 -0700
- first lkml bugreport: Sun Jul 24 16:10:59 2011 -0700
- fix CommitDate: Wed Jul 27 22:39:30 2011 -0700
- fix Linus merge CommitDate: Thu Jul 28 05:58:19 2011 -0700

So you can see that the commit was committed to net-next within 24
hours of it being submitted, the (bad) breakage was not discovered
until 4 days down the road.

I submit that *no one* with real forcedeth hardware actually tested
this commit before it hit upstream. It has not touched linux-next
before going to Linus and it took 8 days for the fix to get upstream.

If the latency of common driver bugfixes is on the order of 1 week
then the golden rule is that commits must be tested for at least 1
week as well. One day of testing was *way* too short.

Furthermore, the changelog of the fix:

0891b0e08937: forcedeth: fix vlans

Doesn't contain any reference to the bisection work done by
walt <w41ter@gmail.com> nor by any of the other bugreporters.

So this really sucked all around - could we please improve on it?

Thanks,

Ingo