Re: lockdep: BUG: MAX_LOCKDEP_ENTRIES too low!

From: Sasha Levin
Date: Thu Dec 19 2013 - 11:52:09 EST


On 12/19/2013 10:59 AM, Dave Jones wrote:
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.

Yeah, I see what you're saying. After upping that to 32k I've hit MAX_STACK_TRACE_ENTRIES.

Going to try upping that and see how that goes.


Thanks,
Sasha
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