Messages in this thread | | | Date | Thu, 12 May 2011 20:26:58 +0800 | From | Yong Zhang <> | Subject | Re: lock_stat &rq->lock/1 class name meaning |
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On Thu, May 12, 2011 at 02:11:02PM +0200, Juri Lelli wrote: > Thanks! > > On 05/12/2011 12:57 PM, Yong Zhang wrote: > >On Wed, May 11, 2011 at 06:26:10PM +0200, Juri Lelli wrote: > >>Hi, > >>I'm trying to collect contention statistics through /proc/lock_stat > >>about scheduler data structures. > >> > >>What I obtain if a do "cat /proc/lock_stat" is something like: > >>... > >>&rq->lock: 13128 13128 0.43 > >>[...] > >> > >>I guess the first one is about the per-rq (per-CPU) spinlock, but > >>what about the second? What the "/1" stands for? > > > >It is also rq but it's subclass is 1. > > > >Take a look at raw_spin_lock_nested(&this_rq->lock, SINGLE_DEPTH_NESTING); > >in _double_lock_balance() > > Ok, I've put more light on this also looking at lockdep.h comments > and lockdep-design documentation. > > Since I'm probably not the only one having troubles undestanding > lock_stat output, maybe could be useful to add something on this > inside lockstat documentation (I can try to do this). What you > think?
Any improvement will be good :)
Cc'ing PeterZ and Ingo.
Thanks, Yong
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