Re: [RT] lockdep munching nr_list_entries like popcorn

From: Mike Galbraith
Date: Thu Feb 16 2017 - 13:07:11 EST


On Thu, 2017-02-16 at 15:53 +0100, Sebastian Andrzej Siewior wrote:
> On 2017-02-16 15:42:59 [+0100], Mike Galbraith wrote:
> >
> > Weeell, I'm trying to cobble something kinda like that together using
> > __RT_SPIN_INITIALIZER() instead, but seems mean ole Mr. Compiler NAKs
> > the PER_CPU_DEP_MAP_INIT() thingy.
> >
> > CC mm/swap.o
> > mm/swap.c:54:689: error: braced-group within expression allowed only
> > inside a function
>
> so this is what I have now. I need to get the `static' symbol working
> again and PER_CPU_DEP_MAP_INIT but aside from that it seems to do its
> job.

...

Yeah, works, I should be able to do an ltp run with stock lockdep
settings without it taking it's toys and going home in a snit.

berio:/sys/kernel/debug/tracing/:[0]# !while
while sleep 60; do tail -1 trace; done
<...>-10315 [064] d...1.. 226.953935: add_lock_to_list.isra.24.constprop.42: nr_list_entries: 14223
w-13148 [120] d...111 287.414978: add_lock_to_list.isra.24.constprop.42: nr_list_entries: 14465
w-16492 [089] d...111 347.128742: add_lock_to_list.isra.24.constprop.42: nr_list_entries: 14653
(starts kbuild loop)
btrfs-transacti-1964 [016] d...1.. 411.101549: add_lock_to_list.isra.24.constprop.42: nr_list_entries: 17011
<...>-100268 [127] d...112 472.271769: add_lock_to_list.isra.24.constprop.42: nr_list_entries: 18153
w-18864 [011] d...1.. 534.386443: add_lock_to_list.isra.24.constprop.42: nr_list_entries: 18543
<...>-50390 [035] dN..2.. 597.794164: add_lock_to_list.isra.24.constprop.42: nr_list_entries: 18765
<...>-80098 [127] d...111 659.912145: add_lock_to_list.isra.24.constprop.42: nr_list_entries: 18977
checkproc-11123 [017] d...1.. 721.483463: add_lock_to_list.isra.24.constprop.42: nr_list_entries: 19247
<idle>-0 [055] d..h5.. 782.685953: add_lock_to_list.isra.24.constprop.42: nr_list_entries: 19383
<...>-93632 [055] d...111 835.527817: add_lock_to_list.isra.24.constprop.42: nr_list_entries: 19441