Re: lockdep: BUG: MAX_LOCKDEP_ENTRIES too low!

From: Dave Jones
Date: Thu Dec 19 2013 - 10:59:59 EST


On Thu, Dec 19, 2013 at 04:51:21PM +0100, Peter Zijlstra wrote:
> On Thu, Dec 19, 2013 at 10:39:57AM -0500, Sasha Levin wrote:
> > That discusses lockdep classes, which is actually fine in my case. I ran out of
> > MAX_LOCKDEP_ENTRIES, which isn't mentioned anywhere in Documentation/ .
>
> Yeah, it suffers from the same problem though. Lockdep has static
> resource allocation and never frees them.
>
> The lock classes are the smallest pool and usually run out first, but
> the same could happen for the entries, after all, the more classes we
> have the more class connections can happen.
>
> Anyway, barring a leak and silly class mistakes like mentioned in the
> document there's nothing we can do except raise the number.

I tried this. When you bump it to 32k, it fares better but then you
start seeing "BUG: MAX_LOCKDEP_CHAINS too low!" instead.
I've not tried bumping that yet, as I've stopped seeing these lately
due to hitting more serious bugs first.

Dave

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/