6 Commits
Author SHA1 Message Date
KatostrofikandGitHub e3bb1add8c SYCL: use native subgroup size for K-quant DMMV (#21700) 2026-06-15 10:10:53 +03:00
8cc67efcd4 SYCL: add BF16 to DMMV kernel path (~4x tg speedup on Intel Arc) (#21580)
* SYCL: add BF16 to DMMV kernel path for ~4x token generation speedup

BF16 models had no dedicated token generation kernel — they fell through
to the generic full-GEMM path, resulting in ~14% memory bandwidth
utilization on Intel Arc GPUs. This adds BF16 support to the DMMV
(dequantize mul-mat-vec) path, matching the existing F16 implementation.

Fixes #20478

* SYCL: fix BF16 DMMV out-of-bounds when ncols % 64 != 0

The qk=1 kernel (used for F16 and BF16) iterates with stride
2*GGML_SYCL_DMMV_X (= 64 on Intel targets where WARP_SIZE=16). When
ncols is a multiple of DMMV_X (32) but not of 2*DMMV_X (64), the last
warp iteration accesses elements at col >= ncols, producing NaN for the
final row and wrong values for interior rows.

Fix: tighten can_use_dequantize_mul_mat_vec to require ne[0] %
(2*DMMV_X) == 0 for F16/BF16 types, and update the ASSERT in the BF16
launcher to match. Quantized types use block-structured kernels with
different access patterns and keep the existing DMMV_X check.

Verified: test-backend-ops MUL_MAT passes 913/913 on Intel Arc Pro B70.
Previously failing: m=128/129 n=1 k=1056 cases (NaN and ERR > 0.0005).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-22 15:48:24 +03:00
9ed6e19b9d SYCL: fix multi-GPU system RAM exhaustion by using Level Zero allocations (#21597)
* SYCL: fix multi-GPU system RAM exhaustion by using Level Zero allocations

Replace sycl::malloc_device with zeMemAllocDevice for GPU memory allocation
in the SYCL backend. sycl::malloc_device triggers the xe kernel driver's
DMA-buf/TTM path which mirrors every VRAM allocation 1:1 in system RAM.
zeMemAllocDevice uses the SVM/P2P path with no host staging.

On a dual Intel Arc Pro B70 system (64GB VRAM, 64GB RAM), a 15.6 GiB model
consumed 60 GiB of system RAM via sycl::malloc_device, causing OOM crashes.
With zeMemAllocDevice, the same workload uses ~6.7 GiB of system RAM with
no performance regression.

All Level Zero calls include automatic fallback to the original SYCL
allocation path if Level Zero interop is unavailable.

* SYCL: address review feedback - remove try/catch, check device types, deduplicate

- Remove try/catch from malloc/free/memcpy helpers, check backend and
  device type upfront instead (ggml_sycl_is_level_zero, ggml_sycl_is_dgpu)
- Move shared helpers (is_level_zero, is_dgpu, free_device) to common.cpp
  and declare in common.hpp to eliminate code duplication
- Use SYCL_CHECK(CHECK_TRY_ERROR()) for fallback sycl::free calls
- Guard dev2dev_memcpy L0 path to dGPU-to-dGPU only, preserving the
  host-staged path for iGPU-to-dGPU transfers
- Add Windows Level Zero SDK path detection (LEVEL_ZERO_V1_SDK_PATH)
  in CMakeLists.txt (co-authored with @arthw)

* SYCL: add build/runtime flags for Level Zero, address review feedback

Implements the architecture suggested by @arthw: compile-time and runtime
flags to cleanly separate Level Zero and SYCL memory API paths.

- Add GGML_SYCL_SUPPORT_LEVEL_ZERO cmake option (default ON). All Level
  Zero code is wrapped in #ifdef so the build works on systems without
  the Level Zero SDK installed (e.g. CPU-only CI servers). Both the
  loader library and headers are checked before enabling.

- Add GGML_SYCL_ENABLE_LEVEL_ZERO runtime env var (default 1). Controls
  whether Level Zero or SYCL memory APIs are used. Only one API style is
  used per session, no mixing. If Level Zero is enabled but the devices
  don't support the Level Zero backend, it auto-disables with a warning.

- Remove Level Zero code from dpct_malloc. It was unused (dpct::device_memory
  is not called anywhere in the backend) and used try/catch for flow control.

- Update SYCL.md with documentation for both new parameters.

Tested on Intel Arc Pro B70 (32GB), single-GPU and dual-GPU, with both
GGML_SYCL_SUPPORT_LEVEL_ZERO=ON and OFF builds. AI-assisted development
(Claude). Code reviewed and tested on my hardware.

* SYCL: unify Level Zero malloc/free call sites, address review feedback

Move ggml_sycl_malloc_device to common.cpp alongside ggml_sycl_free_device.
Both functions are now unconditionally available — Level Zero code is
#ifdef'd inside the functions, not at call sites. All call sites use
uniform SYCL_CHECK(CHECK_TRY_ERROR()) wrapping with no #ifdef blocks.

Addresses arthw's review: wrap all malloc/free in SYCL_CHECK for stack
traces on failure, eliminate duplicated #ifdef/else patterns at 6 call
sites (-29 lines net).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* SYCL: add Level Zero SDK to CI, fix device check and missed alloc paths

Add Level Zero SDK installation to Ubuntu and Windows SYCL CI jobs
so the Level Zero code path is compiled and tested in CI.

Fix two bugs found during extended dual-GPU testing (no
ONEAPI_DEVICE_SELECTOR set):

- The Level Zero backend check was iterating all SYCL devices
  including CPU. The OpenCL CPU device caused Level Zero to be
  disabled for the GPUs, defeating the fix on multi-GPU systems.
  Added is_gpu() filter so only GPU devices are checked.

- sycl_ext_malloc_device/sycl_ext_free (tensor reorder temp buffers)
  were still calling sycl::malloc/sycl::free directly, bypassing the
  Level Zero path. Routed through ggml_sycl_malloc_device/free_device
  for consistency with the other device memory call sites.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* SYCL: address arthw review feedback on Level Zero memory API structure

- Move ggml_sycl_malloc_device to static function in ggml-sycl.cpp;
  only ggml_sycl_free_device (used by common.cpp) stays in common.cpp
- Switch both helpers to use g_ggml_sycl_enable_level_zero global
  instead of per-call queue backend checks
- Remove #ifdef wrapper from global definition; always declare at 0,
  add #else branch in init block so it stays 0 when L0 not compiled in
- Update init loop comment to explain GPU-only device check
- CMakeLists: message(STATUS) before the if block; align option wording

AI-assisted implementation. Reviewed and tested on dual Intel Arc Pro
B70 (32 GB each): test-backend-ops OK on both GPUs, single/dual-GPU
Q4_K_M and Q8_0 bench correct, zeMemAllocDevice GTT delta confirmed
<5 MiB per 4 GiB allocation (vs ~4 GiB shadow with sycl::malloc_device).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* SYCL: remove unused cstdio/cstdlib includes from common.cpp

Leftover from the deleted ggml_sycl_queue_supports_level_zero helper.

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

* Apply suggestions from code review

Co-authored-by: Neo Zhang <zhang.jianyu@outlook.com>

* SYCL: preserve Level Zero allocation path during early malloc

* ci: fix Level Zero package conflict in Intel Docker build

* ci: find Level Zero loader in oneAPI package step

* ci: allow Windows SYCL package without Level Zero DLL

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Co-authored-by: Neo Zhang <zhang.jianyu@outlook.com>
2026-05-14 13:39:14 +08:00
KatostrofikandGitHub 788fcbc5dd [SYCL] Fix reorder MMVQ assert on unaligned vocab sizes (#22035)
* [SYCL] Fix reorder MMVQ assert on unaligned vocab sizes

The reorder mul_mat_vec_q dispatchers for Q4_0, Q8_0, Q4_K, and Q6_K
asserted that block_num_y was a multiple of 16 subgroups. Models with
a vocab size not divisible by 16 (for example HY-MT at 120818) aborted
on model load when the output projection tripped the assert.

I replaced the assert with padding: block_num_y now rounds up to a
whole number of subgroup-sized workgroups. The kernel already has the
row bounds check (`if (row >= nrows) return;`) so the extra padded
threads early-exit cleanly. Row values are uniform across a subgroup
so the collective reduce stays safe.

For aligned vocab sizes the padded block_num_y equals the old value,
so the kernel launch is identical and there is no regression.

Thanks to @arthw for flagging the relationship to #21527.

Fixes #22020.

AI assisted coding, tested on Intel B70 hardware.

* sycl: use WARP_SIZE for num_subgroups in reorder MMVQ launches

Replaces the hardcoded 16 with WARP_SIZE in the four reorder_mul_mat_vec
launch helpers (Q4_0, Q8_0, Q4_K, Q6_K). Compile-time no-op on the Intel
target where WARP_SIZE is 16, but makes the relationship to subgroup
size explicit. Per review by @NeoZhangJianyu on #22035.

Assisted by Claude.
2026-04-20 08:39:45 +03:00
b1be68e8ca [SYCL] Fix Q8_0 reorder: garbage on 2nd prompt + crash on full VRAM (#21638)
* [SYCL] Fix Q8_0 reorder: add missing dequantize path for GEMM

The Q8_0 reorder optimization (#21527) was missing a reorder-aware
dequantizer for the GEMM code path used during prompt processing.
After token generation reordered Q8_0 weights (via DMMV/MMVQ), the
next prompt processing pass would read them with the standard
dequantizer, producing garbage output.

Add dequantize_block_q8_0_reorder() and wire it into both
ggml_get_to_fp16_sycl() and ggml_get_to_fp32_sycl(), matching the
pattern already used by Q4_0, Q4_K, and Q6_K.

Fixes #21589

AI (Claude) was used to assist with root cause investigation and
writing the kernel code. All code was human-reviewed and tested
on real hardware.

* SYCL: fix reorder crash when device memory is full

The reorder optimization allocates a temporary buffer the full size of
the weight tensor on the device. When VRAM is nearly full (large models
on a single GPU), this allocation fails and the subsequent memcpy crashes
on a NULL pointer.

Fix: try device allocation first, fall back to host memory if device
memory is full. The reorder kernel still works correctly reading from
host memory over PCIe. This is slower for the one-time reorder (~21 t/s
vs ~38 t/s on Intel Arc Pro B70), but the optimization is preserved for
all subsequent inference. If both device and host allocation fail, skip
the reorder and fall back to the unoptimized kernel path.

Also fixes a bug where opt_for_reorder() marked tensors as reordered
even when the reorder was skipped due to allocation failure. This caused
DMMV/MMVQ kernels to read the original AoS data as if it were SoA,
producing garbage output or NaN results.

Tested on Intel Arc Pro B70 (32GB) with Q8_0, Q4_K_M models. Coding was
AI-assisted (Claude), reviewed and tested on hardware by a human.

Fixes #20478

* SYCL: add RAII temp buffer class + macro guard for host fallback

Replace sycl_ext_malloc_with_fallback/sycl_ext_free_fallback free
functions with sycl_reorder_temp_buffer RAII class. The host_fallback
bool is now a private member, and cleanup happens automatically at
scope exit.

Add GGML_SYCL_HOST_MEM_FALLBACK cmake option (default ON) to guard
the host memory fallback code path. Device access to host memory
requires Linux kernel 6.8+ (Ubuntu 26.04+); users on older kernels
can set -DGGML_SYCL_HOST_MEM_FALLBACK=OFF to disable it.

Addresses arthw's review on PR #21638.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* SYCL: document GGML_SYCL_HOST_MEM_FALLBACK build option in SYCL.md

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* SYCL: add reorder-aware DMMV dequantizers for Q4_K and Q6_K

Q4_K and Q6_K had reorder support for MMVQ and GEMM paths but not
DMMV. When the DMMV path encountered reordered data it would abort.

Add DMMV kernels that read from the SOA reorder layout for both
types. Same math as the non-reorder versions, different memory
access pattern.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-16 08:34:05 +03:00
PMZFXandGitHub 0988accf82 [SYCL] Add Q8_0 reorder optimization (~3x tg speedup on Intel Arc) (#21527)
Extend the existing reorder optimization to Q8_0. The reorder
separates scale factors from weight data for coalesced memory
access -- was implemented for Q4_0/Q4_K/Q6_K but Q8_0 was missing.

On Arc Pro B70 (Xe2), Q8_0 tg goes from 4.88 to 15.24 t/s (3.1x)
on Qwen3.5-27B. BW utilization: 21% -> 66%.

The key fix beyond the kernels: Q8_0 was missing from the type
check in ggml_backend_sycl_buffer_init_tensor() that allocates
the extra struct carrying the reorder flag -- so the optimization
was silently skipped.

AI (Claude) was used to assist with root cause investigation and
writing the kernel code. All code was human-reviewed and tested
on real hardware.

Fixes: #21517
2026-04-07 16:12:49 +08:00