Each change of pipeline state in prepare_draw re-recorded the whole dynamic state through vk_pipeline_set_dynamic:
about twenty commands, the vertex input packet rebuilt, and the blend enable, equation and write mask of every
attachment, however few fields differed. Every replay pipeline declares the same dynamic states, which a pipeline bind
leaves as they were, so vk_pipeline_set_dynamic_delta compares the values with what the command buffer already holds
and records only the commands that differ; the vertex input is rebuilt only when the vertex shader, attributes or
streams change. The record is per command buffer (B.dyn_valid, cleared with the rest of B on a new one or a split).
TOTK_DYN_DELTA=0 records the full set as before; ab alternates; TOTK_TRACE=perf counts calls, commands and calls that
changed nothing.
1.4.3, RTX 4070 Ti, 2560x1440 DLAA, standing still on Great Sky Island, TOTK_AB=10 (tools/ab_summary.py): 13.75 ms
a frame with the full sets, 12.59 ms with the deltas (-8.5%, 72.7 to 79.4 fps); replay 7.77 to 6.67 ms. An A/A run
with the same method moved the frame by 0.08 ms.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BspNcezsiV8zT8wcnXrrME
After vk_exec_ub_flush the full barrier barrier_to records makes the copied bytes visible, so later bindings can read
the real buffer. The overlays stayed until the submission's end instead: every later binding inside their span
scanned them, and a block an overlay covered in part got a merged scratch copy that the descriptor build skip then
left alone. With the updates between passes overlaid too (Great Sky Island: 274 of 594 per submission) that was 290
merged copies and 1.1 ms more replay a frame, more than the barriers saved on the GPU (0.3 ms).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BspNcezsiV8zT8wcnXrrME
An update between passes was copied at once behind a full barrier of its own, and the copy it recorded made the next
update or pass begin need another: a run of k updates before a pass cost k + 1 full barriers, about 250 updates a
frame on Great Sky Island. They now become overlays like the updates inside a pass; every GPU reader of the real
buffer after them comes behind barrier_to, which records the copies first. TOTK_UB_OVERLAY_OUT: 1, 0, ab; the perf
line counts the overlays made between passes.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BspNcezsiV8zT8wcnXrrME
vk_exec_ub_flush recorded the copies of a pass's overlaid uniform updates back to back behind one barrier. Copies
with no barrier between them may run in any order, and ov_add only drops an older pending copy of exactly the same
range, so two updates that overlap in part could leave the older bytes in the buffer where they overlap. A copy that
overlaps one recorded since the last barrier now waits for it behind a transfer-to-transfer barrier; the perf line
counts those barriers.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BspNcezsiV8zT8wcnXrrME
nvnCommandBufferUpdateUniformBuffer between draws was replayed as a buffer copy at that point, which needs a barrier
against the draws that read the old bytes, and a barrier ends the open pass. The terrain and the sky islands' meshes
update before most of their draws: about 200 updates inside passes in a field submission, each a pass end, a full
barrier and a pass begin.
An update inside a pass now goes to the scratch buffer only. Later bindings of a range it covers bind the scratch
bytes (ub_bind, from ubo_info and bind_range); a binding it covers only in part, or at an offset the alignment
refuses, gets a merged copy of the snapshot or guest memory with the submission's updates on top. The copies into the
real buffers are recorded behind one barrier of their own at the next full barrier (vk_exec_ub_flush from
barrier_to). A new update of a range replaces the older overlay and pending copy of it, so the lists stay as short as
the blocks. Copies, fills and storage writes of the same bytes retire the overlays they touch, and a storage binding
over a pending copy brings the copies forward with a pass restart. bind_sig hashes the overlay each of the draw's
uniform and storage bindings reads, so a draw of an updated block binds the newest bytes and the others still skip
their descriptor build. TOTK_UB_OVERLAY=0 copies at once as before; ab alternates; TOTK_TRACE=perf prints the
counts.
1.4.3, RTX 4070 Ti, 2560x1440 DLAA, standing still on Great Sky Island, TOTK_AB=10 (tools/ab_summary.py):
17.03 ms a frame with the copies at once, 14.39 ms with the overlays (-15.5%, 58.7 to 69.5 fps); replay time on the
CPU 8.81 to 8.30 ms.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BspNcezsiV8zT8wcnXrrME
Claude