Messages in this thread | | | Date | Wed, 23 Apr 2008 03:36:17 +0200 | From | Nick Piggin <> | Subject | Re: [PATCH 2/11] x86: convert to generic helpers for IPI function calls |
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On Tue, Apr 22, 2008 at 06:22:17PM -0700, Linus Torvalds wrote: > > > On Wed, 23 Apr 2008, Nick Piggin wrote: > > > > The "too expensive to check the shared queue" is one aspect of it. The > > shared queue need not have events *for us* (at least, unless Jens has > > changed the implementation a bit) but it can still have events that we > > would need to check through. > > > > I don't think deadlock is a problem (any more than with multiple vectors). > > I'm happy with it either way, but as pointed out by Ralf, for the MIPS > version of the patch there aren't even other vectors available.
Yep.
> So sharing the vector is going to be a requirement on other architectures, > maybe we should look at whether we can make it generic and peform well > regardless?
I don't think it will perform terribly _poorly_ by sharing the vector. If you have a look at how serialised the old code is...
If there is a noticable slowdown anywhere, we could I suppose create a 2nd variant for small numbers of CPUs, or shared vector case, but I'd say the existing code should be fine I think.
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