linux-kernel - [PATCH] vfio/type1: Add conditional rescheduling after iommu map failed

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Date:   Mon, 22 Jun 2020 15:02:17 +0800
From:   Xiang Zheng <zhengxiang9@...wei.com>
To:     <kvm@...r.kernel.org>, <linux-kernel@...r.kernel.org>
CC:     <alex.williamson@...hat.com>, <cohuck@...hat.com>,
        <wanghaibin.wang@...wei.com>
Subject: [PATCH] vfio/type1: Add conditional rescheduling after iommu map failed

c5e6688752c25 ("vfio/type1: Add conditional rescheduling") missed
a "cond_resched()" in vfio_iommu_map if iommu map failed.

This is a very tiny optimization and the case can hardly happen.

Signed-off-by: Xiang Zheng <zhengxiang9@...wei.com>
---
 drivers/vfio/vfio_iommu_type1.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 5e556ac9102a..48fb9cc4a40a 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -1225,8 +1225,10 @@ static int vfio_iommu_map(struct vfio_iommu *iommu, dma_addr_t iova,
 	return 0;
 
 unwind:
-	list_for_each_entry_continue_reverse(d, &iommu->domain_list, next)
+	list_for_each_entry_continue_reverse(d, &iommu->domain_list, next) {
 		iommu_unmap(d->domain, iova, npage << PAGE_SHIFT);
+		cond_resched();
+	}
 
 	return ret;
 }
-- 
2.19.1