| Message ID | 1502884784-24775-1-git-send-email-alberto.milone@canonical.com |
|---|---|
| State | New |
| Headers | show |
On 08/16/17 13:59, Alberto Milone wrote: > From: Andres Rodriguez <andresx7@gmail.com> > > 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. > > v2: move early return after enable_signaling > > Signed-off-by: Andres Rodriguez <andresx7@gmail.com> > Reviewed-by: Christian König <christian.koenig@amd.com> > Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com> > Link: http://patchwork.freedesktop.org/patch/msgid/20170426144620.3560-1-andresx7@gmail.com > > BugLink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1711096 > > (cherry-picked from commit 03c0c5f6641533f5fc14bf4e76d2304197402552) > Signed-off-by: Alberto Milone <alberto.milone@canonical.com> > --- Clean cherry pick, seems to be a reasonable performance fix. My only comment is about the BugLink, which needs to be in the format "http://bugs.launchpad.net/bugs/<bug-id>", and not in the expanded format. But this can be fixed when applying the patch. Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com> > drivers/dma-buf/dma-fence.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c > index 0212af7..96b3221 100644 > --- a/drivers/dma-buf/dma-fence.c > +++ b/drivers/dma-buf/dma-fence.c > @@ -373,6 +373,11 @@ dma_fence_default_wait(struct dma_fence *fence, bool intr, signed long timeout) > } > } > > + if (!timeout) { > + ret = 0; > + goto out; > + } > + > cb.base.func = dma_fence_default_wait_cb; > cb.task = current; > list_add(&cb.base.node, &fence->cb_list); >
On 16.08.2017 13:59, Alberto Milone wrote: > From: Andres Rodriguez <andresx7@gmail.com> > > 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. > > v2: move early return after enable_signaling > > Signed-off-by: Andres Rodriguez <andresx7@gmail.com> > Reviewed-by: Christian König <christian.koenig@amd.com> > Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com> > Link: http://patchwork.freedesktop.org/patch/msgid/20170426144620.3560-1-andresx7@gmail.com > > BugLink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1711096 > > (cherry-picked from commit 03c0c5f6641533f5fc14bf4e76d2304197402552) > Signed-off-by: Alberto Milone <alberto.milone@canonical.com> Acked-by: Stefan Bader <stefan.bader@canonical.com> > --- Same BugLink update as in other submission. > drivers/dma-buf/dma-fence.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c > index 0212af7..96b3221 100644 > --- a/drivers/dma-buf/dma-fence.c > +++ b/drivers/dma-buf/dma-fence.c > @@ -373,6 +373,11 @@ dma_fence_default_wait(struct dma_fence *fence, bool intr, signed long timeout) > } > } > > + if (!timeout) { > + ret = 0; > + goto out; > + } > + > cb.base.func = dma_fence_default_wait_cb; > cb.task = current; > list_add(&cb.base.node, &fence->cb_list); >
On Wed, Aug 16, 2017 at 01:59:44PM +0200, Alberto Milone wrote: > From: Andres Rodriguez <andresx7@gmail.com> > > 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. > > v2: move early return after enable_signaling > > Signed-off-by: Andres Rodriguez <andresx7@gmail.com> > Reviewed-by: Christian König <christian.koenig@amd.com> > Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com> > Link: http://patchwork.freedesktop.org/patch/msgid/20170426144620.3560-1-andresx7@gmail.com > > BugLink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1711096 > > (cherry-picked from commit 03c0c5f6641533f5fc14bf4e76d2304197402552) > Signed-off-by: Alberto Milone <alberto.milone@canonical.com> Applied to artful/master-next, thanks.
Applied to zesty/master-next branch. Thanks.
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 0212af7..96b3221 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -373,6 +373,11 @@ dma_fence_default_wait(struct dma_fence *fence, bool intr, signed long timeout) } } + if (!timeout) { + ret = 0; + goto out; + } + cb.base.func = dma_fence_default_wait_cb; cb.task = current; list_add(&cb.base.node, &fence->cb_list);