From: Xiang Chen chenxiang66@hisilicon.com
[ Upstream commit 3431c3f660a39f6ced954548a59dba6541ce3eb1 ]
After the change of patch ("iommu: Switch gather->end to the inclusive end"), the performace drops from 1600+K IOPS to 1200K in our kunpeng ARM64 platform. We find that the range [start1, end1) actually is joint from the range [end1, end2), but it is considered as disjoint after the change, so it needs more times of TLB sync, and spends more time on it. So fix the boundary issue to avoid performance drop.
Fixes: 862c3715de8f ("iommu: Switch gather->end to the inclusive end") Signed-off-by: Xiang Chen chenxiang66@hisilicon.com Acked-by: Will Deacon will@kernel.org Link: https://lore.kernel.org/r/1616643504-120688-1-git-send-email-chenxiang66@his... Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/iommu.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h index d63d3e9cc7b6..3e82f0dce3cc 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -546,7 +546,7 @@ static inline void iommu_iotlb_gather_add_page(struct iommu_domain *domain, * structure can be rewritten. */ if (gather->pgsize != size || - end < gather->start || start > gather->end) { + end + 1 < gather->start || start > gather->end + 1) { if (gather->pgsize) iommu_iotlb_sync(domain, gather); gather->pgsize = size;