From: Xiang Chen Date: Thu, 25 Mar 2021 03:38:24 +0000 (+0800) Subject: iommu: Fix a boundary issue to avoid performance drop X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=3431c3f660a39f6ced954548a59dba6541ce3eb1;p=linux.git iommu: Fix a boundary issue to avoid performance drop 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 Acked-by: Will Deacon Link: https://lore.kernel.org/r/1616643504-120688-1-git-send-email-chenxiang66@hisilicon.com Signed-off-by: Joerg Roedel --- diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 5e7fe519430af..9ca6e6b8084dc 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -547,7 +547,7 @@ 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;