[ponhei9502]

What

Every prepared shader artifact keeps its SPIR-V words resident in the process-wide source registry, although they are read again only to build a specialised module or to be copied into a result. The same words are already in the shader disk cache entry. Measured by the author on one Demon's Souls level load: the disk cache holds 8,766 entries, 11.5 GB, 99.4% of it SPIR-V words, and all of those words stayed resident.

SharedSpirv can now hold a backing instead of the words:

• After the disk cache writer has written an entry and checked that the file holds the artifact's words byte for byte, it evicts them in favour of a file backing (entry path, key size, word count, file size). A cache hit evicts right after decoding.
• Pin() returns the words for as long as the returned pointer lives, reading them back from the entry when evicted, without keeping them. The readers of a prepared artifact (SpecializeVertexInputTypes, PrepareVertexInputSpecialization, EncodeEntry) use it.
• Words() makes them resident again and marks the holder so a later eviction is refused, because callers keep the reference.
• A copy reads the words back and is never evicted, so a RecompileResult the driver holds stays resident as before.
• The reload applies the checks Load applies (magic, format, source version, key size, payload size and hash) plus the stored word count. A missing or altered entry throws.

The entry format is unchanged. Nothing is evicted when the disk cache is off or when APS5_NO_PERF_SPIRV_EVICTION is set. CompiledShaderArtifact and RecompileResult grow by 24 bytes; the size assertions follow.

Review notes, stated plainly:

• All SharedSpirv state is behind one process-wide mutex (not held during file reads). Copying a SharedSpirv now takes it. I did not measure contention.
• Using an evicted artifact costs a read and hash of its whole cache entry each time (copying it into a result, or building a specialised module from it). I did not measure this cost in isolation.
• Deleting or changing cache files while a title runs now makes the next use of that shader throw instead of going unnoticed.
• size(), empty(), data() and iteration go through Words() and therefore keep the words resident for that holder; this is safe but forfeits the saving for it.

Tested

• CachyOS Linux, kernel 7.3-rc, x86-64, GCC, NVIDIA RTX 3080 10 GB (driver 615.78), 31 GB RAM. Based on main 961b25f.
• New unit test verifySpirvEviction in agc_shader_disk_cache: stored words reload identically, a copy stays resident after the entry file is removed, the evicted holder throws while its entry is missing and reloads once it is restored, and a holder with a live Words() reference is not evicted. It fails with APS5_NO_PERF_SPIRV_EVICTION=1, as expected.
• Built libs and ran, on this branch: agc_shader_disk_cache, agc_shader_memory, agc_shader_bindless, agc_shader_frontend_pair, agc_shader_frontend_pair_off, agc_masked_select, agc_shader_control_flow, agc_shader_mode_register: 8 of 8 passed. python3 tools/check_conventions.py --base origin/main passes.
• Measured by the author offline, on the local tree the change was written on (not re-run on this branch): 439 captured Demon's Souls shader requests prepared in one process and retained like the driver does: retained artifact SPIR-V 638 MiB -> 0, peak RSS 1166 -> 660 MiB, prepared SPIR-V and binding plan output identical for all 439.
• Measured by the author in the game (Demon's Souls): swap in use at minute 3-4 fell from 11.8 GB to 3.3 GB. In-game numbers come from a local tree that also carries other changes (upstream main plus several open pull requests plus local fixes), not from this branch alone.
• Not tested: Windows (including whether an entry file can be re-read while the writer replaces it), AMD and Intel GPUs, any other title, the GPU execution tests (agc_driver_*), the full ctest run. This branch as submitted was not run in a title; it differs from the measured one by the removal of code comments and local accounting, the renamed switch and the size assertions for main.

Checklist

• Based on current main; no other open PR implements the same functions
• One topic per PR; follow-ups go in a new PR
• No comments in code except technical debt
• Unimplemented paths throw (NotImplemented_nid_no_patch); silent stubs are listed in TechnicalDebt
• No notes, investigation .md files or images added to the repository (attach them to this PR)
• New third-party code is a submodule built from source (none added)
• Generic behaviour, not specific to one title
• Depends on: none
• AI-assisted: yes

🤖 Generated with Claude Code

[github-actions]

Thank you for your interest in the project! We are sorry, but we cannot accept more PRs while we work through the existing backlog. This PR has been automatically closed and labeled "intake paused". This is not a judgment of the quality of your changes.

[github-actions]

Some comparisons could not be completed because a pull request conflicts with the base branch. Review these shared files manually before concluding that there is no overlap.

Pull request	Shared files not compared
PR 4072	core/shader/recompiler/Recompiler.cpp
PR 5021	core/shader/recompiler/Recompiler.cpp
PR 5315	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp
PR 5500	core/shader/recompiler/Recompiler.cpp core/shader/recompiler/Recompiler.hpp core/shader/recompiler/ShaderDiskCache.cpp
PR 5609	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/Recompiler.cpp core/shader/recompiler/Recompiler.hpp core/shader/recompiler/ShaderDiskCache.cpp
PR 5656	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/Recompiler.cpp core/shader/recompiler/Recompiler.hpp core/shader/recompiler/ShaderDiskCache.cpp
PR 5925	core/shader/recompiler/Recompiler.hpp core/shader/recompiler/ShaderDiskCache.cpp
PR 6177	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/Recompiler.cpp core/shader/recompiler/Recompiler.hpp
PR 6188	core/shader/recompiler/Recompiler.hpp
PR 6235	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/Recompiler.hpp
PR 6280	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/ShaderDiskCache.cpp
PR 6412	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/Recompiler.cpp core/shader/recompiler/Recompiler.hpp core/shader/recompiler/ShaderDiskCache.cpp
PR 6488	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/Recompiler.cpp core/shader/recompiler/ShaderDiskCache.cpp
PR 6539	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/Recompiler.cpp core/shader/recompiler/Recompiler.hpp core/shader/recompiler/ShaderDiskCache.cpp
PR 6611	core/shader/recompiler/Recompiler.cpp
PR 6612	core/shader/recompiler/Recompiler.cpp core/shader/recompiler/Recompiler.hpp
PR 6639	core/shader/recompiler/Recompiler.hpp
PR 6679	core/shader/recompiler/Recompiler.cpp core/shader/recompiler/Recompiler.hpp
PR 6683	core/shader/recompiler/Recompiler.hpp
PR 6801	core/shader/recompiler/Recompiler.hpp
PR 6858	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/Recompiler.cpp core/shader/recompiler/ShaderDiskCache.cpp
PR 6879	core/shader/recompiler/Recompiler.cpp core/shader/recompiler/Recompiler.hpp core/shader/recompiler/ShaderDiskCache.cpp
PR 6924	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/Recompiler.cpp core/shader/recompiler/ShaderDiskCache.cpp
PR 6941	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/Recompiler.cpp core/shader/recompiler/Recompiler.hpp core/shader/recompiler/ShaderDiskCache.cpp
PR 6946	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/Recompiler.cpp core/shader/recompiler/Recompiler.hpp core/shader/recompiler/ShaderDiskCache.cpp
PR 6947	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/Recompiler.cpp core/shader/recompiler/Recompiler.hpp core/shader/recompiler/ShaderDiskCache.cpp
PR 6959	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/Recompiler.cpp core/shader/recompiler/Recompiler.hpp core/shader/recompiler/ShaderDiskCache.cpp
PR 6970	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/Recompiler.hpp core/shader/recompiler/ShaderDiskCache.cpp
PR 6977	core/shader/recompiler/Recompiler.cpp core/shader/recompiler/ShaderDiskCache.cpp
PR 7085	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/ShaderDiskCache.cpp
PR 7201	core/shader/recompiler/Recompiler.cpp core/shader/recompiler/Recompiler.hpp
PR 7223	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/Recompiler.cpp core/shader/recompiler/ShaderDiskCache.cpp
PR 7332	core/shader/recompiler/Recompiler.cpp core/shader/recompiler/Recompiler.hpp
PR 7381	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/ShaderDiskCache.cpp
PR 7395	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/Recompiler.cpp core/shader/recompiler/ShaderDiskCache.cpp
PR 7410	core/shader/recompiler/Recompiler.cpp core/shader/recompiler/Recompiler.hpp
PR 7426	core/shader/recompiler/Recompiler.hpp
PR 7484	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/Recompiler.cpp core/shader/recompiler/Recompiler.hpp
PR 7520	core/shader/recompiler/ShaderDiskCache.cpp
PR 7522	core/shader/recompiler/Recompiler.cpp
PR 7550	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/ShaderDiskCache.cpp
PR 7560	core/shader/recompiler/Recompiler.cpp
PR 7622	core/shader/recompiler/ShaderDiskCache.cpp
PR 7642	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/Recompiler.cpp core/shader/recompiler/Recompiler.hpp core/shader/recompiler/ShaderDiskCache.cpp
PR 7684	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/ShaderDiskCache.cpp
PR 7689	core/shader/recompiler/Recompiler.hpp core/shader/recompiler/ShaderDiskCache.cpp
PR 7731	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/ShaderDiskCache.cpp
PR 7816	core/shader/recompiler/Recompiler.cpp
PR 7817	core/shader/recompiler/Recompiler.cpp
PR 7831	core/shader/recompiler/Recompiler.cpp core/shader/recompiler/Recompiler.hpp core/shader/recompiler/ShaderDiskCache.cpp
PR 7888	core/shader/recompiler/Recompiler.cpp core/shader/recompiler/Recompiler.hpp core/shader/recompiler/ShaderDiskCache.cpp
PR 7945	core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp core/shader/recompiler/ShaderDiskCache.cpp
PR 8004	core/shader/recompiler/Recompiler.cpp core/shader/recompiler/Recompiler.hpp

[oneandonlydean]

Thanks for reopening this. It no longer merges cleanly into current main: Recompiler.hpp has moved since this was written. Could you rebase onto current main? Evicting prepared SPIR-V is still wanted (main keeps it resident). We'll review and run full CI on the new head.

[oneandonlydean]

Closing this as superseded by #4806 (merged 14 Oct, 43349d4, "map retained SPIR-V from shader cache entries"). On main, SharedSpirv now keeps a read-only mapping of the disk-cache entry instead of resident words, which is what this PR set out to do. The conflicts here (Recompiler.hpp, ShaderDiskCache.cpp, the tests) are exactly that code.

A correction to our 17 Oct comment: we said main keeps prepared SPIR-V resident. That was wrong; #4806 had already changed it.

Thanks @ponhei9502 for the work on this. If you see a case #4806 doesn't cover, please open a new PR against current main.