Re: [PATCH 4/4] lockdep: make MAX_LOCK_DEPTH configurable from Kconfig

From: Govindarajulu Varadarajan
Date: Thu Sep 28 2017 - 19:52:47 EST


On Thu, 28 Sep 2017, Peter Zijlstra wrote:

On Wed, Sep 27, 2017 at 02:42:20PM -0700, Govindarajulu Varadarajan wrote:
Make MAX_LOCK_DEPTH configurable. It is set to 48 right now. Number of
VFs under a PCI pf bus can exceed 48 and this disables lockdep.

lockdep currently allows max of 63 held_locks.

But why a config knob? Why not just raise the number to 64
unconditionally? And is that sufficient; you only state 48 is
insufficient, you don't actually state the VF limit.


I did not want to change the default configuration for everyone.

I will change it 63 unconditionally in v2 and resubmit the series.