Messages in this thread | | | Date | Wed, 15 Aug 2012 15:56:05 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] SGI XPC fails to load when cpu 0 is out of IRQ resources. |
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On Fri, 3 Aug 2012 14:46:29 -0500 Robin Holt <holt@sgi.com> wrote:
> On many of our larger systems, CPU 0 has had all of its IRQ resources > consumed before XPC loads. Worse cases on machines with multiple > 10 GigE cards and multiple IB cards have depleted the entire first > socket of IRQs. That patch makes selecting the node upon which > IRQs are allocated (as well as all the other GRU Message Queue > structures) specifiable as a module load param and has a default > behavior of searching all nodes/cpus for an available resource. >
Is this problem serious enough to warrant a -stable backport? If you want it to appear in vendor kernels then I guess "yes".
> +static int > +xpc_init_mq_node(int nid) > +{ > + int cpu; > + > + for_each_cpu(cpu, cpumask_of_node(nid)) { > + xpc_activate_mq_uv = xpc_create_gru_mq_uv(XPC_ACTIVATE_MQ_SIZE_UV, nid, > + XPC_ACTIVATE_IRQ_NAME, > + xpc_handle_activate_IRQ_uv); > + if (!IS_ERR(xpc_activate_mq_uv)) > + break; > + } > + if (IS_ERR(xpc_activate_mq_uv)) > + return PTR_ERR(xpc_activate_mq_uv); > + > + for_each_cpu(cpu, cpumask_of_node(nid)) { > + xpc_notify_mq_uv = xpc_create_gru_mq_uv(XPC_NOTIFY_MQ_SIZE_UV, nid, > + XPC_NOTIFY_IRQ_NAME, > + xpc_handle_notify_IRQ_uv); > + if (!IS_ERR(xpc_notify_mq_uv)) > + break; > + } > + if (IS_ERR(xpc_notify_mq_uv)) { > + xpc_destroy_gru_mq_uv(xpc_activate_mq_uv); > + return PTR_ERR(xpc_notify_mq_uv); > + } > + > + return 0; > +}
This seems to take the optimistic approach to CPU hotplug ;) get_online_cpus(), perhaps?
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