fix(rocm): stop building the ggml CPU variant matrix for hipblas llama.cpp (#11346)

No -gpu-rocm-hipblas-llama-cpp image has been published since 2026-08-01.
Every build since has been killed by GitHub at exactly its 6h job limit:

    job 91830652349  cancelled  6h00m   (2026-08-04)
    job 91763226161  cancelled  6h00m   (2026-08-03)
    job 91466626154  cancelled  6h00m   (2026-08-02 full matrix)

The registry shows the damage: master-gpu-rocm-hipblas-llama-cpp last
built 2026-08-01 05:53, latest-gpu-rocm-hipblas-llama-cpp 2026-07-15,
against master-cpu-llama-cpp which is current.

Same cause as #11321, different mechanism. Since #11255 every x86 GPU
image also builds ggml's CPU_ALL_VARIANTS matrix. SYCL died because icpx
stalls on one translation unit; ROCm dies on volume. hipcc compiles the
HIP kernels once per entry in AMDGPU_TARGETS, and that list is eleven
architectures (gfx908, gfx90a, gfx942, gfx950, gfx1030, gfx1100, gfx1101,
gfx1102, gfx1151, gfx1200, gfx1201). The CPU matrix lands on top of that.

The numbers are unambiguous. The same job took 2h27m in the 2026-07-26
full matrix, before #11255. #11255 merged 2026-08-01 07:26, an hour and a
half after the last image was published, and it has been 6h00m ever since.
The tail of the last run shows it 61% through ggml-hip at the 83 minute
mark, still building HIP template instances.

Route hipblas to the portable fallback, exactly as #11321 did for SYCL and
for the same practical reason: it is what these images shipped before
#11255, and run.sh already prefers *-cpu-all when present and falls back
otherwise. Expected to restore the 2h27m build with room to spare.

Not fixed here: the CPU variant matrix is genuinely wanted on ROCm for
partial offload. Getting it needs the build to fit in 6h, which means
trimming AMDGPU_TARGETS or splitting the job per architecture. Both are
larger changes than unbreaking the image, and neither should ride along
with a build that is currently not shipping at all.

Verified: make test-build-scripts passes, including the extended
llama-cpp-build-target_test.sh. bonsai is unaffected (own compile script,
ROCm builds in 1h52m) and turboquant has no hipblas variant.


Assisted-by: Claude Code:claude-opus-5 [Read] [Edit] [Bash]

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Co-authored-by: Ettore Di Giacinto <mudler@localai.io>

.docker/llama-cpp-build-target.sh

@@ -8,8 +8,15 @@ build_type=${2-}
 # ggml-cpu/arch/x86/repack.cpp at -march=sapphirerapids: the job sits on that one
 # translation unit until GitHub kills it at 6h. gcc builds the same file in
 # seconds, so only the SYCL images have to give up the CPU variant matrix.
+#
+# ROCm runs out of the same 6h budget for a different reason: volume, not a
+# stall. hipcc compiles ggml's HIP kernels once per entry in AMDGPU_TARGETS,
+# which is eleven architectures (gfx908 through gfx1201), and the CPU variant
+# matrix lands on top of that. The job built in 2h27m before it was added and
+# has been killed at exactly 6h00m on every run since, so no ROCm llama-cpp
+# image has been published since 2026-08-01.
 case "$build_type" in
-  sycl*)
+  sycl*|hipblas*)
     echo llama-cpp-fallback
     exit 0
     ;;

scripts/build/llama-cpp-build-target_test.sh

@@ -29,4 +29,11 @@ assert_target arm64 "" llama-cpp-cpu-all
 assert_target amd64 sycl_f16 llama-cpp-fallback
 assert_target amd64 sycl_f32 llama-cpp-fallback
 
+# ROCm exhausts the same 6h budget through volume rather than a stall: hipcc
+# compiles ggml's HIP kernels once per AMDGPU target, eleven of them, and the
+# CPU variant matrix goes on top. 2h27m before it was added, killed at exactly
+# 6h00m on every run since.
+assert_target amd64 hipblas llama-cpp-fallback
+assert_target arm64 hipblas llama-cpp-fallback
+
 echo "PASS: llama.cpp build target preserves CPU variants where supported"