Public bug reported: When a timeout of zero is specified, the caller is only interested in the fence status.
In the current implementation, dma_fence_default_wait will always call schedule_timeout() at least once for an unsignaled fence. This adds a significant overhead to a fence status query. Avoid this overhead by returning early if a zero timeout is specified. https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=03c0c5f6641533f5fc14bf4e76d2304197402552 ** Affects: linux (Ubuntu) Importance: Medium Status: Triaged ** Affects: linux (Ubuntu Zesty) Importance: Medium Assignee: Alberto Milone (albertomilone) Status: In Progress ** Changed in: linux (Ubuntu) Status: New => In Progress ** Changed in: linux (Ubuntu) Importance: Undecided => Medium ** Also affects: linux (Ubuntu Zesty) Importance: Undecided Status: New ** Changed in: linux (Ubuntu Zesty) Status: New => In Progress ** Changed in: linux (Ubuntu Zesty) Importance: Undecided => Medium ** Changed in: linux (Ubuntu Zesty) Assignee: (unassigned) => Alberto Milone (albertomilone) ** Changed in: linux (Ubuntu) Status: In Progress => Triaged -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1711096 Title: dma-buf: performance issue when looking up the fence status Status in linux package in Ubuntu: Triaged Status in linux source package in Zesty: In Progress Bug description: When a timeout of zero is specified, the caller is only interested in the fence status. In the current implementation, dma_fence_default_wait will always call schedule_timeout() at least once for an unsignaled fence. This adds a significant overhead to a fence status query. Avoid this overhead by returning early if a zero timeout is specified. https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=03c0c5f6641533f5fc14bf4e76d2304197402552 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1711096/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
