Alexey Starikovskiy wrote:
> Sitsofe Wheeler wrote:
>> Hi Alexey,
>>
>> Alexey Starikovskiy wrote:
>>> I think the least troubling place to add cond_resched() is then 
>>> ACPICA is exiting interpreter.
>>> Please check if the attached patch helps with latencies.
>>
>> There was no real change (latency was still bad). If you look at the 
>> trace (before your patch) on 
>> http://sucs.org/~sits/test/eeepc-debug/20080923/latency_trace.gz 
>> (700kbyte compressed, 15Mbytes uncompressed) you can see that 
>> acpi_ex_exit_interpreter is only called once near the end of the trace:
>>
>>      cat-5901    0.N.. 270496us : acpi_ex_exit_interpreter 
>> (acpi_ev_address_space_dispatch)
>>
>> By then the time had already been racked up...
>>
> Ok, let's add it to the end of acpi_ps_complete_op() then... They 
> appear every 100usec or so...
>
acpi_ps_parse_aml() is called not so often (~10000usec), so maybe it is 
a "sweet spot"