Re: [Linaro-mm-sig] [Intel-gfx] [PATCH 14/26] drm/i915: use the new iterator in i915_sw_fence_await_reservation v3

On 17/09/2021 13:35, Christian König wrote:

Simplifying the code a bit.

v2: use dma_resv_for_each_fence instead, according to Tvrtko the lock is held here anyway. v3: back to using dma_resv_for_each_fence_unlocked.

It did not work out - what happened?

Regards,

Tvrtko

Signed-off-by: Christian König christian.koenig@amd.com

drivers/gpu/drm/i915/i915_sw_fence.c | 57 ++++++++-------------------- 1 file changed, 15 insertions(+), 42 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_sw_fence.c b/drivers/gpu/drm/i915/i915_sw_fence.c index c589a681da77..7635b0478ea5 100644 --- a/drivers/gpu/drm/i915/i915_sw_fence.c +++ b/drivers/gpu/drm/i915/i915_sw_fence.c @@ -572,56 +572,29 @@ int i915_sw_fence_await_reservation(struct i915_sw_fence *fence, unsigned long timeout, gfp_t gfp) {

• struct dma_fence *excl;

• struct dma_resv_iter cursor;
• struct dma_fence *f; int ret = 0, pending;

debug_fence_assert(fence); might_sleep_if(gfpflags_allow_blocking(gfp));

• if (write) {

• struct dma_fence **shared;
  

• unsigned int count, i;
  

• ret = dma_resv_get_fences(resv, &excl, &count, &shared);
  

• if (ret)
  

• 	return ret;
  

• for (i = 0; i < count; i++) {
  

• 	if (shared[i]->ops == exclude)
  

• 		continue;
  

• 	pending = i915_sw_fence_await_dma_fence(fence,
  

• 						shared[i],
  

• 						timeout,
  

• 						gfp);
  

• 	if (pending < 0) {
  

• 		ret = pending;
  

• 		break;
  

• 	}
  

• 	ret |= pending;
  

• }
  

• for (i = 0; i < count; i++)
  

• 	dma_fence_put(shared[i]);
  

• kfree(shared);
  

• } else {

• excl = dma_resv_get_excl_unlocked(resv);
  

• }
• if (ret >= 0 && excl && excl->ops != exclude) {

• pending = i915_sw_fence_await_dma_fence(fence,
  

• 					excl,
  

• 					timeout,
  

• rcu_read_lock();
• dma_resv_iter_begin(&cursor, resv, write);
• dma_resv_for_each_fence_unlocked(&cursor, f) {

• rcu_read_unlock();
  

• pending = i915_sw_fence_await_dma_fence(fence, f, timeout,
  				gfp);
  

• if (pending < 0)
  

• rcu_read_lock();
  

• if (pending < 0) {
  ret = pending;
  

• else
  

• 	ret |= pending;
  

• }
• dma_fence_put(excl);

• 	break;
  

• }
  

• ret |= pending;
  

• }
• dma_resv_iter_end(&cursor);
• rcu_read_unlock(); return ret; }