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anv: chain batch buffers within a given VkSubmitInfo

Lionel Landwerlin requested to merge llandwerlin/mesa:review/anv-primary-cmd-buffer-chaining into master

VkSubmitInfo contains an array of VkCommandBuffer to execute. When those are not created with VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT, they can be modified in vkQueueSubmit to chain them all together so that we only do a single execbuffer ioctl for all the batches.

This has 2 advantages :

  • Reduce the size of the generated aub files

  • Speed up vkQueueSubmit() (by decreasing the number of ioctl required)

Using a crucible micro benchmark on KBL GT2:

   Before:
      bench.queue-submit.q0:                  Called vkQueueSubmit with 256 buffers 4096 times,         took 1702689us (415us each)
      bench.queue-submit-many-cmd-buffers.q0: Called vkQueueSubmit with 256 command buffers 4096 times, took 12679754us (3095us each)
   After:
      bench.queue-submit.q0:                  Called vkQueueSubmit with 256 buffers 4096 times,         took 1741659us (425us each)
      bench.queue-submit-many-cmd-buffers.q0: Called vkQueueSubmit with 256 command buffers 4096 times, took 2259032us (551us each)

Aztech Ruins:

   On KBL GT2 +0.1fps
   On SKL GT4 +0.6fps

Signed-off-by: Lionel Landwerlin lionel.g.landwerlin@intel.com

Edited by Lionel Landwerlin

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