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Re: CVS commit: src/sys
> On Wed, Nov 18, 2009 at 03:51:02AM +0000, YAMAMOTO Takashi wrote:
>> > Log Message:
>> > Add a kernel configuration flag, SPLDEBUG, that activates a per-CPU log
>> > of transitions to IPL_HIGH from lower IPLs. SPLDEBUG is only available
>> > on i386 and Xen kernels, today.
>> > 'options SPLDEBUG' adds instrumentation to spllower() and splraise() as
>> > well as routines to start/stop debugging and to record IPL transitions:
>> > spldebug_start(), spldebug_stop(), spldebug_raise(), spldebug_lower().
>> this seems too ad-hoc to me.
> If you have suggestions for providing a comparable function that is less
> ad-hoc, let me know.
>> - please don't put MD code like this in kern/. IPL_ values can't be
>> compared with >= in MI code. return_address.9 is in man.i386.
> Thanks for pointing this out. I am not going to move it from sys/kern/,
> since it is fairly easy to make it MI. I will compare IPL values with
> == and !=, and write an MI stub for return_address(9) that returns NULL
> on non-i386.
>> - there are other places where the spl value is modified.
>> eg. interrupt stubs, lock stubs, etc.
> Code references, please?
"grep ILEVEL *.S"
eg. mutex_spin_enter, intr_lapic_ltimer, etc
>> - can you explain "cpu_index(ci) > MAXCPUS" and "cpu_index(ci) >= MAXCPUS" ?
why are these checks necessary in the first place?
> David Young OJC Technologies
> dyoung%ojctech.com@localhost Urbana, IL * (217) 278-3933
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