A PIXEL_PIPE_STAT_DUMP event (EVENT_WRITE 0x39, Recorder::DumpSamples)
ended the render pass the previous draw left open: the dump ended the
batch-long occlusion query, copied its result with
vkCmdCopyQueryPoolResults and ran the fold kernel, none of which Vulkan
allows inside a render pass. VulkanDevice::DumpSamplesOnGpu also flushed
the queued store run over the dumped bytes first, which ended the pass
and recorded the run's barriers as well. A title that clears each query
slot with WRITE_DATA and brackets every bounding draw with a begin and an
end dump gets a render pass, two copy barriers and a label run per draw.
Samples are now counted in segments. A segment is one slot of a
per-batch occlusion query pool (128 slots, reset outside any pass when the
batch's first pass needs one). It begins at the first draw recorded after
a pass begins or after a dump, inside that pass's subpass, and ends at the
next dump or right before vkCmdEndRenderPass, so each query begins and
ends in one subpass. A pass whose pool has no free slot left is not
continued, so a new pool can be reset. The draw path that records a whole
pass of its own prepares a slot before its pass and ends its segment
before ending it.
A dump ends the open segment and is queued in the batch's store run with
the number of segments before it; it no longer ends the pass and no
longer flushes the queued stores. The run is recorded where queued stores
already are: at Submit, or earlier when a later command reads or writes
the queued bytes. Its recording copies the results of the segments the
dumps need (one vkCmdCopyQueryPoolResults per contiguous slot range) and
the dump list, then records the queue in groups: a group's stores, then
one dispatch of the SampleDumps kernel, which adds each dump's segments to
the running total and stores the 16 counters in queue order. A store over
bytes a dump of the current group writes starts a new group, so every
byte ends with the value of its last write in program order
(Recorder::QueuedWriteGroups). At Submit, segments no dump consumed are
folded the same way once 64 are pending.
No reader sees a dump later than before: a CPU reader of the dumped bytes
syncs the batch (the dump still notes them as a pending write), and Submit
records the run before the batch ends; a later label or store is queued
after the dump in the same run; GPU work that reads or writes the queued
bytes flushes the run first, as for queued label stores. No reader sees it
earlier either: the dump is recorded after every draw whose samples it
counts, and its segments end at the dump. Without the GPU sample counter
(no buffer device addresses) the batch-long query is kept as before.
Tests (agc_driver_recorder_tests, GPU, run by hand): QueuedWriteGroups
keeps the program order's bytes for 20,000 random store and dump
sequences; a queued dump does not land before its run is recorded, a
reader of other bytes leaves it queued and a reader of its bytes records
it; clear, dump and store orders over shared bytes; two dumps inside one
render pass keep it open (the next draw continues it) and split its three
draws' samples exactly with precise queries; a reader flushing a dump
inside a pass ends the pass; 160 dumps in one pass past a pool's 128
slots; 70 passes without a dump folded at Submit.
Treat equal BASE_ARRAY and DEPTH as a six-face cube. Measured with image_load, image_sample and image_get_resinfo on RX 6600 gfx1032 using base slices 0, 5 and 6. Partial cube ranges still throw because filtered sampling differs from load bounds.
Graphics tests and GPU snapshot/storage sampling tests pass for all six faces at each tested base.
Assisted-by: OpenAI Codex
T# word1 MIN_LOD (unsigned 4.8, in levels of the whole surface) was
rejected. Sampled views now chain VkImageViewMinLodCreateInfoEXT
(VK_EXT_image_view_min_lod, enabled when the device offers the minLod
feature). Its minLod counts levels of the whole image exactly as MIN_LOD
counts levels of the whole surface, because the image holds every mip and
the view starts at BASE_LEVEL.
- A clamp at or below BASE_LEVEL cannot change which level a sample reads
and is left off; one past the view's last level is bounded by it (the
view selects that level anyway, and Vulkan requires the bound).
- A clamp that binds on a device without the feature throws.
- The texture cache already keys by the eight descriptor words, so views
with different clamps are not shared.
- Storage views address one level: a clamp at or below that level is
accepted, one above it still throws.
jweidenh
Dean Galvin
TibixDev
boykopovar