Messages in this thread | | | Date | Mon, 1 Feb 2010 07:55:54 -0500 | Subject | Re: [PATCH 0/7] Increase maximum Infiniband HCAs per-system | From | Hal Rosenstock <> |
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On Fri, Jan 29, 2010 at 6:41 PM, Alex Chiang <achiang@hp.com> wrote: > * Roland Dreier <rdreier@cisco.com>: >> >> Have you considered drivers/infiniband/core/user_mad.c and ucm.c? > > Ah, darn. I had not considered those drivers. You're gonna make > me learn a lot more about IB than I'd originally intended. ;) > >> I think user_mad.c is somewhat more important, as that is what >> allows an adapter to be used for running the SM. So I think >> we're still left with some potential issues around lots of >> adapters in one system. (I think use of ucm by real apps is >> minimal to nonexistent, but someday we should deal with that >> too) > > Ok, a quick glance through those drivers shows: > > enum { > IB_UMAD_MAX_PORTS = 64, > IB_UMAD_MAX_AGENTS = 32, > > IB_UMAD_MAJOR = 231, > IB_UMAD_MINOR_BASE = 0 > }; > > and > > enum { > IB_UCM_MAJOR = 231, > IB_UCM_BASE_MINOR = 224, > IB_UCM_MAX_DEVICES = 32 > }; > > They're all sharing the same major number, so they'll all have to > get the same treatment as the uverbs driver wrt overflow (to > prevent minor number overlap). > > What I'm a little unsure of is, does IB_UMAD_MAX_AGENTS need to > double too? We don't export the agent id in the filesystem > anywhere, but we do give it to the user via an ioctl. That's just > used for book keeping purposes but... > > Currently, there are 2x as many ports as there are agents. Do we > want to keep that ratio, or would it be ok to have 4x as many > ports as there are agents?
I think it's 2x as many ports as devices (based on the common HCAs being 2 ports max). This should be maintained as that is still the case.
-- Hal
> > Thanks (and sorry for the n00b questions). > > /ac > -- > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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