Re: [PATCH 2/6: v4] lockdep: Make MAX_STACK_TRACE_ENTRIES configurable.

[John Kacur <jkacur@redhat.com>]

On Wed, 16 Jun 2010, Peter Zijlstra wrote:

> On Tue, 2010-06-15 at 00:21 +0200, John Kacur wrote:
> > Certain debug configurations that have LOCKDEP turned on, run into the limit
> > where the MAX_STACK_TRACE_ENTRIES are too small. Rather than simply turning
> > off the locking correctness validator, let the user configure this value
> > to something reasonable for their system.
> > 
> > This patch was generated against 2.6.33.5-rt23 but is also intended to be
> > picked-up for mainline.
> 
> NACK
> 
> patches like 4726f2a617ebd868a4fdeb5679613b897e5f1676 are the way to go.

I've been testing 4726f2a617ebd868a4fdeb5679613b897e5f1676 in rt
(Thomas has it in tip/rt/2.6.33 now) and so far it is doing the trick for 
me, at least on my laptop. I still need to test it on larger machines.
However, this problem seems to continuably come up, and I'm not the only 
one who has expessed the wish / need to have this tunable.
See Message-Id	 <4BCEAD7B0200005A0006513E@soto.provo.novell.com>

and here in the same thread is even an argument that some configs
might tune it down. (I needed to increase it for rt-debug configs)
See Message-Id	 <1271861581.29617.13.camel@sven.thebigcorporation.com>

fwiw regarding a nacked patch, v4 is the least intrusive version
(smallest number of changes), based on a bit of trout wacking induced 
hints.  

Thanks