From 43240bbd871e2c8f89584d369278a3d18680d9ea Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Thu, 15 Jun 2017 02:18:43 +0300 Subject: [PATCH] gpu: host1x: At first try a non-blocking allocation for the gather copy The blocking gather copy allocation is a major performance downside of the Host1x firewall, it may take hundreds milliseconds which is unacceptable for the real-time graphics operations. Let's try a non-blocking allocation first as a least invasive solution, it makes opentegra (Xorg driver) performance indistinguishable with/without the firewall. Signed-off-by: Dmitry Osipenko Reviewed-by: Erik Faye-Lund Signed-off-by: Thierry Reding --- drivers/gpu/host1x/job.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/host1x/job.c b/drivers/gpu/host1x/job.c index f32ae69a68c7..bee504406cfc 100644 --- a/drivers/gpu/host1x/job.c +++ b/drivers/gpu/host1x/job.c @@ -574,12 +574,20 @@ static inline int copy_gathers(struct host1x_job *job, struct device *dev) size += g->words * sizeof(u32); } + /* + * Try a non-blocking allocation from a higher priority pools first, + * as awaiting for the allocation here is a major performance hit. + */ job->gather_copy_mapped = dma_alloc_wc(dev, size, &job->gather_copy, - GFP_KERNEL); - if (!job->gather_copy_mapped) { - job->gather_copy_mapped = NULL; + GFP_NOWAIT); + + /* the higher priority allocation failed, try the generic-blocking */ + if (!job->gather_copy_mapped) + job->gather_copy_mapped = dma_alloc_wc(dev, size, + &job->gather_copy, + GFP_KERNEL); + if (!job->gather_copy_mapped) return -ENOMEM; - } job->gather_copy_size = size; -- 2.20.1