Messages in this thread Patch in this message | | | From | Xie Yongji <> | Subject | [PATCH v3 1/5] vduse: Remove unnecessary spin lock protection | Date | Wed, 20 Jul 2022 12:41:40 +0800 |
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Now we use domain->iotlb_lock to protect two different variables: domain->bounce_maps->bounce_page and domain->iotlb. But for domain->bounce_maps->bounce_page, we actually don't need any synchronization between vduse_domain_get_bounce_page() and vduse_domain_free_bounce_pages() since vduse_domain_get_bounce_page() will only be called in page fault handler and vduse_domain_free_bounce_pages() will be called during file release.
So let's remove the unnecessary spin lock protection in vduse_domain_get_bounce_page(). Then the usage of domain->iotlb_lock could be more clear: the lock will be only used to protect the domain->iotlb.
Signed-off-by: Xie Yongji <xieyongji@bytedance.com> --- drivers/vdpa/vdpa_user/iova_domain.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/drivers/vdpa/vdpa_user/iova_domain.c b/drivers/vdpa/vdpa_user/iova_domain.c index 6daa3978d290..bca1f0b8850c 100644 --- a/drivers/vdpa/vdpa_user/iova_domain.c +++ b/drivers/vdpa/vdpa_user/iova_domain.c @@ -211,17 +211,14 @@ static struct page * vduse_domain_get_bounce_page(struct vduse_iova_domain *domain, u64 iova) { struct vduse_bounce_map *map; - struct page *page = NULL; + struct page *page; - spin_lock(&domain->iotlb_lock); map = &domain->bounce_maps[iova >> PAGE_SHIFT]; if (!map->bounce_page) - goto out; + return NULL; page = map->bounce_page; get_page(page); -out: - spin_unlock(&domain->iotlb_lock); return page; } -- 2.20.1
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