panic: incorrect npmc count

Fabien Thomas fabien.thomas at
Thu May 10 14:28:50 UTC 2012

Le 9 mai 2012 à 16:30, Ryan Stone a écrit :

> On Wed, May 9, 2012 at 1:16 AM, Peter Jeremy <peter at> wrote:
>> [This may be a duplicate because I forgot to update my subscription
>>  after changing address but I've also corrected a typo]
>> (I've copied fabient@ because r233628 appears to have been the last
>> commit in this area).
>> I've just updated a P4 test box from r232545 to r235127 and it now
>> panics during boot:
>>  panic: [intel,202] incorrect npmc count 35
>> Looking at sys/dev/hwpmc/hmpmc_intel.c line 202, the expected
>> npmc count is 19.
>> When I look at the actual code in pmc_intel_initialize():
>> pmc_mdep_alloc() initialises pmd_npmc to zero and then increments
>>  it by SOFT_NPMCS (16) in pmc_soft_initialize().
>> pmc_tsc_initialize() then increments it by TSC_NPMCS (1)
>> pmc_p4_initialize() then increments it by P4_NPMCS (18)
>> This totals 35 (as per the panic message).
>> Can someone explain the KASSERT() that expects 19 - it boils down to
>> KASSERT(0+16+1+18 == 1+18, ...)
>> I gather not many people are running -current on a P4.
>> --
>> Peter Jeremy
> That KASSERT is just out of date.  The soft PMC support is quite new.
> I would just drop the KASSERT entirely; it really isn't adding any
> value.

Back from vacation.
 Yes, as Ryan stated the KASSERT is out of date and i've missed
the update / removal with soft PMC.

Fixed with r235229.


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