From: Anton Blanchard Date: Sun, 3 Jun 2012 19:43:02 +0000 (+0000) Subject: powerpc/iommu: Reduce spinlock coverage in iommu_alloc and iommu_free X-Git-Tag: v3.6-rc1~132^2~55 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0e4bc95d87394364f408627067238453830bdbf3;p=pandora-kernel.git powerpc/iommu: Reduce spinlock coverage in iommu_alloc and iommu_free We currently hold the IOMMU spinlock around tce_build and tce_flush. This causes our spinlock hold times to be much higher than required and can impact multiqueue adapters. This patch moves tce_build and tce_flush outside of the lock in iommu_alloc, and tce_flush outside of the lock in iommu_free. Some performance numbers were obtained with a Chelsio T3 adapter on two POWER7 boxes, running a 100 session TCP round robin test. Performance improved 32% with this patch applied. Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt --- Reading git-diff-tree failed