From: Suresh Siddha Date: Mon, 25 Jun 2012 20:38:29 +0000 (-0700) Subject: x86/apic/x2apic: Use multiple cluster members for the irq destination only with the... X-Git-Tag: v3.6-rc1~162^2~1 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d872818dbbeed1bccf58c7f8c7db432154c802f9;p=pandora-kernel.git x86/apic/x2apic: Use multiple cluster members for the irq destination only with the explicit affinity During boot or driver load etc, interrupt destination is setup using default target cpu's. Later the user (irqbalance etc) or the driver (irq_set_affinity/ irq_set_affinity_hint) can request the interrupt to be migrated to some specific set of cpu's. In the x2apic cluster routing, for the default scenario use single cpu as the interrupt destination and when there is an explicit interrupt affinity request, route the interrupt to multiple members of a x2apic cluster specified in the cpumask of the migration request. This will minmize the vector pressure when there are lot of interrupt sources and relatively few x2apic clusters (for example a single socket server). This will allow the performance critical interrupts to be routed to multiple cpu's in the x2apic cluster (irqbalance for example uses the cache siblings etc while specifying the interrupt destination) and allow non-critical interrupts to be serviced by a single logical cpu. Signed-off-by: Suresh Siddha Acked-by: Yinghai Lu Acked-by: Alexander Gordeev Acked-by: Cyrill Gorcunov Link: http://lkml.kernel.org/r/1340656709-11423-4-git-send-email-suresh.b.siddha@intel.com Signed-off-by: Ingo Molnar --- Reading git-diff-tree failed