mpc880 linux-2.6.32 slow running processes

[Joakim Tjernlund]

>>> +  /* On 8xx, cache control instructions (particularly
>>> +   * "dcbst" from flush_dcache_icache) fault as write
>>> +   * operation if there is an unpopulated TLB entry
>>> +   * for the address in question. To workaround that,
>>> +   * we invalidate the TLB here, thus avoiding dcbst
>>> +   * misbehaviour.
>>> +   */
>>> +  /* 8xx doesn't care about PID, size or ind args */
>>> +  _tlbil_va(addr, 0, 0, 0);
>>>   #endif /* CONFIG_8xx */
>>> +
>>> +  if (!pg)
>>> +   return pte;
>>> +
>>> +  if (!PageReserved(pg)&&  !test_bit(PG_arch_1,&pg->flags)) {
>>>      flush_dcache_icache_page(pg);
>>>      set_bit(PG_arch_1,&pg->flags);
>>>     }
>> Rex, do you recall under what specific circumstances the _tlbil_va is
>> needed?  Is it possible that it will be caused by a dcbst in other
>> contexts that are not dependent on the state of PG_arch_1?

The 8xx tlbil_va should not be needed in recent 2.6 after I fixed the 8xx TLB code
to workaround the dcbst bug there instead. See 
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=0a2ab51ffb8dfdf51402dcfb446629648c96bc78;hp=60e071fee994ff98c37d03a4a7c5a3f8b1e3b8e5

Not sure what release it went into though.

 Jocke