Re: [LKP] More information please. Re: [fs] 54cc07a761: BUG: kernel test crashed

[Dave Jones <davej@codemonkey.org.uk>]

On Tue, Jul 26, 2016 at 02:50:58PM -0500, Eric W. Biederman wrote:

 > > Yes that's the right directions to follow. We'll make the reports more
 > > understandable and the test/bisects more reliable.
 > 
 > Thanks.  Does trinity have a random seed it can export/import to rerun
 > the same tests?  I ask because there was a failure these tests caught
 > that if the right kernel options was enabled was 100% reliable and it
 > blamed a commit 10 patches down from the indicated commit.

It does log the random seed on startup, and can replay it with the -s option

There is some variance if you were to do two runs with the same seed back
to back, because on startup, it walks /proc & /sys, and they'd see different things
so for eg "read() from fd 100" might mean something entirely different.

But as the testbot runs a pretty minimal userspace, only runs trinity once,
and really early in boot, this point might not matter.

	Dave