Re: [PATCH 6/6] powerpc: Enable sparse irq_descs on powerpc

On Wed, Oct 14, 2009 at 5:51 PM, Michael Ellerman
[off-list ref] wrote:

On Wed, 2009-10-14 at 12:44 -0600, Grant Likely wrote:

quoted

Why not make sparse IRQs manditory for all platforms? =A0Is there a
performance concern with doing so? =A0From a maintenance perspective,
I'd rather see IRQ descs manged in one way only to keep the code
simple.

I agree on the maintenance angle. My thinking was we'd run with it
optional but default y for a release or two, and if no one complains we
can make it mandatory.

It does make some code paths bigger, and looking up an irq_desc is going
to take slightly more cycles. I don't think it's a big issue, but I
thought we should try it for a while before making it mandatory. The
code has only been tested on x86 and sh as far as I know.

No guts, no glory.  I say throw it into linux-next to give it some
time before the next merge window.  I don't think you'll get any
better results by having it optional for a few releases (in fact, I
suspect that people who do have problems will just end up turning it
off and waiting for someone else to report/fix the problems).  If this
is the direction IRQ handling is going, then just make the change and
force any bugs to be dealt with before the next release.

ps. thanks for the review

You're welcome.

g.

--=20
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.