[perfmon2] ctx->lock not using pfm_spin_lock_irqsave/pfm_spin_unlock_irqrestore

[Corey A. <cja...@us...>]

Hi,

We are working on a utility that uses perfmon2 for sampling PMU 
counters, and at a very high overflow (sample) rate (~16k samples/sec), 
we are seeing frequent kernel deadlocks which appear to be due to some 
of the perfmon kernel code calling spin_lock/spin_unlock instead of 
pfm_spin_lock_irqsave/pfm_spin_unlock_irqrestore on ctx->lock.  In 
particular, the calls in question are perfmon_ctxsw.c and in perfmon_intr.c.

We have modified the code to call the pfm irq versions and will report 
back if it fixes the problem.

- Corey

-- 
Corey Ashford
Software Engineer
IBM Linux Technology Center, Linux Toolchain
Beaverton, OR
503-578-3507
cja...@us...