On 19.05.2017 12:09, Peter Zijlstra wrote:
On Fri, May 19, 2017 at 10:06:01AM +0300, Konstantin Khlebnikov wrote:
Currently this counter shown in /proc/lockdep if CONFIG_DEBUG_LOCKDEP=y
This patch disables it completely if this option is disabled.
This counter might be useful for debugging lockdep itself, but for normal
debugging it seems useless. Lockstat provides more detailed statistics.
This atomic_inc is a hot spot inside __lock_acquire() for debug kernel.
With patch "netperf -H localhost" shows some boost: 2500 -> 2600
Nothing against these patches, but I do wonder why you're performance
optimizing debug kernels ;-)
Performance of debug features matters too
Obviously this saves time and money for massive testing