From: Cyrill Gorcunov Date: Thu, 19 May 2011 23:45:49 +0000 (-0700) Subject: x86, x2apic: Minimize IPI register writes using cluster groups X-Git-Tag: v3.0-rc1~334^2~6 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9d0fa6c5f43f2d9c6966dcab7af96a717682fdec;p=pandora-kernel.git x86, x2apic: Minimize IPI register writes using cluster groups In the case of x2apic cluster mode we can group IPI register writes based on the cluster group instead of individual per-cpu destination messages. This reduces the apic register writes and reduces the amount of IPI messages (in the best case we can reduce it by a factor of 16). With this change, the cost of flush_tlb_others(), with the flush tlb IPI being sent from a cpu in the socket-1 to all the logical cpus in socket-2 (on a Westmere-EX system that has 20 logical cpus in a socket) is 3x times better now (compared to the former 'send one-by-one' algorithm). Signed-off-by: Cyrill Gorcunov Signed-off-by: Suresh Siddha Cc: steiner@sgi.com Cc: yinghai@kernel.org Link: http://lkml.kernel.org/r/20110519234637.512271057@sbsiddha-MOBL3.sc.intel.com Signed-off-by: Ingo Molnar --- Reading git-diff-tree failed