vm_page_t related KBI [Was: Re: panic at vm_page_wire with FreeBSD 9.0 Beta 3]

[Attilio Rao]

2011/11/18 Kostik Belousov <kostikbel at gmail.com>:
> On Fri, Nov 18, 2011 at 11:40:28AM +0100, Attilio Rao wrote:
>> 2011/11/16 Kostik Belousov <kostikbel at gmail.com>:
>> > On Tue, Nov 15, 2011 at 07:15:01PM +0100, Attilio Rao wrote:
>> >> 2011/11/7 Kostik Belousov <kostikbel at gmail.com>:
>> >> > On Mon, Nov 07, 2011 at 11:45:38AM -0600, Alan Cox wrote:
>> >> >> Ok.  I'll offer one final suggestion.  Please consider an alternative
>> >> >> suffix to "func".  Perhaps, "kbi" or "KBI".  In other words, something
>> >> >> that hints at the function's reason for existing.
>> >> >
>> >> > Sure. Below is the extraction of only vm_page_lock() bits, together
>> >> > with the suggested rename. When Attilio provides the promised simplification
>> >> > of the mutex KPI, this can be reduced.
>> >>
>> >> My tentative patch is here:
>> >> http://www.freebsd.org/~attilio/mutexfileline.patch
>> >>
>> >> I need to make more compile testing later, but it already compiles
>> >> GENERIC + modules fine on HEAD.
>> >>
>> >> The patch provides a common entrypoint, option independent, for both
>> >> fast case and debug/compat case.
>> >> Additively, it almost entirely fixes the standard violation of the
>> >> reserved namespace, as you described (the notable exception being the
>> >> macro used in the fast path, that I want to fix as well, but in a
>> >> separate commit).
>> >>
>> >> Now the file/line couplet can be passed to the "_" suffix variant of
>> >> the flag functions.
>> > Yes, this is exactly KPI that I would use when available for the
>> > vm_page_lock() patch.
>> >
>> >>
>> >> eadler@ reviewed the mutex.h comment.
>> >>
>> >> Please let me know what you think about it, as long as we agree on the
>> >> patch I'll commit it.
>> > But I also agree with John that imposing large churn due to the elimination
>> > of the '__' prefix is too late now. At least it will make the change
>> > non-MFCable. Besides, we already lived with the names for 10+ years.
>> >
>> > I will be happy to have the part of the patch that exports the mtx_XXX_(mtx,
>> > file, line) defines which can be used without taking care of LOCK_DEBUG
>> > or MUTEX_NOINLINE in the consumer code.
>>
>> Ok, this patch should just add the compat stub:
>> http://www.freebsd.org/~attilio/mutexfileline2.patch
> Am I right that I would use mtx_lock_(mtx, file, line) etc ?
> If yes, I am fine with it.

Yes that is correct.

However, I'm a bit confused on one aspect: would you mind using
_mtx_lock_flags() instead?
If you don't mind the "underscore namespace violation" I think I can
make a much smaller patch against HEAD for it.

Otherwise, the one now posted should be ok.

Attilio


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