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

2011/11/18 Attilio Rao <attilio_at_freebsd.org>:
> 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_at_ 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.

After thinking more about it, I think that is basically the shorter
version I can came up with.

Please consider:
http://www.freebsd.org/~attilio/mutexfileline2.patch

as a possible commit candidate for me.

Attilio


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