Messages in this thread | | | Date | Thu, 11 Sep 2008 13:04:35 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [RFC 0/4] dynamically allocate arch specific system vectors |
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Dean Nelson wrote: > > We (SGI) need somewhere around eight vectors. > > There are two kernel modules, sgi-gru and sgi-xp (in drivers/misc), that > each need two vectors. And there's the broadcast assist unit (BAU) that is > involved in tlb shootdown on uv, which currently uses statically reserved > vector 0xf8 (UV_BAU_MESSAGE -- see uv_bau_init()). I know of a debugger that > also uses 0xf8 because it was previously available until UV_BAU_MESSAGE came > along. The BAU would be happy with a dynamically allocated system vector. > We have a couple of other things in the works that also need vectors. > > All of these eight or so vectors are only meaningful on SGI uv systems. >
Are these kernel-internal vectors, or exposed to userspace (i.e. the INT instruction works in userspace)? From what I'm gathering, I think this is the former.
There are the occational user who wants fixed user-space addressible vectors, effectively as secondary system call entry vectors (lguest is the only in-kernel user that I know of); those need to be static and non-conflicting, which is kind of difficult. It seems to me that anything else probably should be possible to be dynamic.
-hpa
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