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drm/nv50: Fix large 3D performance regression caused by the interchannel sync patches.

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Reported-by: Christoph Bumiller <e0425955@student.tuwien.ac.at>
Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Tested-by: Maarten Maathuis <madman2003@gmail.com>
Tested-by: Xavier Chantry <chantry.xavier@gmail.com>
Tested-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
This commit is contained in:
Francisco Jerez 2010-10-02 17:04:46 +02:00 committed by Ben Skeggs
parent 6479881752
commit 8af29ccd79
2 changed files with 40 additions and 7 deletions
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1
drivers/gpu/drm/nouveau/nouveau_drv.h
View File

@ -1473,6 +1473,7 @@ nv_match_device(struct drm_device *dev, unsigned device,
#define NV_SW_SEMAPHORE_OFFSET 0x00000064
#define NV_SW_SEMAPHORE_ACQUIRE 0x00000068
#define NV_SW_SEMAPHORE_RELEASE 0x0000006c
#define NV_SW_YIELD 0x00000080
#define NV_SW_DMA_VBLSEM 0x0000018c
#define NV_SW_VBLSEM_OFFSET 0x00000400
#define NV_SW_VBLSEM_RELEASE_VALUE 0x00000404

46
drivers/gpu/drm/nouveau/nouveau_fence.c
View File

@ -308,21 +308,54 @@ emit_semaphore(struct nouveau_channel *chan, int method,
{
struct drm_nouveau_private *dev_priv = sema->dev->dev_private;
struct nouveau_fence *fence;
bool smart = (dev_priv->card_type >= NV_50);
int ret;
ret = RING_SPACE(chan, dev_priv->card_type >= NV_50 ? 6 : 4);
ret = RING_SPACE(chan, smart ? 8 : 4);
if (ret)
return ret;
if (dev_priv->card_type >= NV_50) {
if (smart) {
BEGIN_RING(chan, NvSubSw, NV_SW_DMA_SEMAPHORE, 1);
OUT_RING(chan, NvSema);
}
BEGIN_RING(chan, NvSubSw, NV_SW_SEMAPHORE_OFFSET, 1);
OUT_RING(chan, sema->mem->start);
if (smart && method == NV_SW_SEMAPHORE_ACQUIRE) {
/*
* NV50 tries to be too smart and context-switch
* between semaphores instead of doing a "first come,
* first served" strategy like previous cards
* do.
*
* That's bad because the ACQUIRE latency can get as
* large as the PFIFO context time slice in the
* typical DRI2 case where you have several
* outstanding semaphores at the same moment.
*
* If we're going to ACQUIRE, force the card to
* context switch before, just in case the matching
* RELEASE is already scheduled to be executed in
* another channel.
*/
BEGIN_RING(chan, NvSubSw, NV_SW_YIELD, 1);
OUT_RING(chan, 0);
}
BEGIN_RING(chan, NvSubSw, method, 1);
OUT_RING(chan, 1);
if (smart && method == NV_SW_SEMAPHORE_RELEASE) {
/*
* Force the card to context switch, there may be
* another channel waiting for the semaphore we just
* released.
*/
BEGIN_RING(chan, NvSubSw, NV_SW_YIELD, 1);
OUT_RING(chan, 0);
}
/* Delay semaphore destruction until its work is done */
ret = nouveau_fence_new(chan, &fence, true);
if (ret)
@ -355,14 +388,13 @@ nouveau_fence_sync(struct nouveau_fence *fence,
return nouveau_fence_wait(fence, NULL, false, false);
}
/* Signal the semaphore from chan */
ret = emit_semaphore(chan, NV_SW_SEMAPHORE_RELEASE, sema);
/* Make wchan wait until it gets signalled */
ret = emit_semaphore(wchan, NV_SW_SEMAPHORE_ACQUIRE, sema);
if (ret)
goto out;
/* Make wchan wait until it gets signalled */
ret = emit_semaphore(wchan, NV_SW_SEMAPHORE_ACQUIRE, sema);
/* Signal the semaphore from chan */
ret = emit_semaphore(chan, NV_SW_SEMAPHORE_RELEASE, sema);
out:
kref_put(&sema->ref, free_semaphore);
return ret;