Messages in this thread | | | Subject | Re: [PATCH 01/10] IB/ehca: Support for multiple event queues | From | Hoang-Nam Nguyen <> | Date | Mon, 16 Jul 2007 22:37:44 +0200 |
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Roland Dreier <rdreier@cisco.com> wrote on 16.07.2007 18:04:26: > Do you have any data on how well this round-robin assignment works? > It seems not quite right to me for the driver to advertise nr_eqs > completion vectors, but then if round-robin is turned on to ignore the > consumer's decision about which vector to use. No, I've no figures to provide here. The background of this dist_eqs option is actually to allow us testing across all event queues without to change the testcases resp consumers to use certain event queue number. Thus, I should comment it as EXPERIMENTAL? > Maybe if round-robin is turned on you should report 0 as the number of > completion vectors? Or maybe we should allow well-known values for > the completion vector passed to ib_create_cq to allow consumers to > specify a policy (like round robin) instead of a particular vector? > Maybe the whole interface is broken and we should only be exposing > policies to consumers instead of the specific vector? Agree in that device driver should not overwrite consumer's policy of event queue assigment. Since dist_eqs is disabled as default, there's no issue, isn't it? Regarding ib_verbs: perhaps we should provide create/destroy_eq() and let upper level protocols or consumers dictate the assignment to cq by passing an event queue pointer to create_cq()... > I think I would rather hold off on multiple EQs for this merge window > and plan on having something really solid and thought-out for 2.6.24. Fair enough. However why don't let us gather experience with this feature now? Should we remove dist_eqs option for more consistency? Thanks Nam
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