* sycl: fix use-after-return of the SDPA scale in the oneDNN flash-attention path
The scale was uploaded with an async memcpy sourced from a stack local. On the
in-order queue that copy is ordered behind the K/V staging kernels; once n_kv is
large enough (>= ~26k observed on Arc Pro B70) the staging outlives the host
stack frame and the copy reads recycled memory, feeding the SDPA a garbage scale.
Output then collapses to a single repeated token and the KV cache is poisoned
for the rest of the session.
Short contexts win the race by accident, and test-backend-ops caps
FLASH_ATTN_EXT at kv=1024, which is why CI never caught it. The previous
device_count > 1 wait_and_throw() gate (and reverting it, PR #25741) fixes the
symptom only by keeping the frame alive across the copy at the cost of a host
sync on every FA call.
Fix: cache one device scalar per (device, value) -- the scale is constant per
model -- and upload it synchronously once. The single-device fast path (no
per-call host sync) is then safe: every device-side hazard already serializes
on the in-order queue. The multi-GPU conservative wait is kept unchanged.
Also:
- GGML_SYCL_FA_ONEDNN_MAX_KV env (0 = unlimited): optional n_kv ceiling that
routes very long sequences to the native FA kernel.
- test-backend-ops: FLASH_ATTN_EXT F16 cases up to kv=65536 (Qwen3.6-27B
geometry hsk=hsv=256 GQA 6, and hsk=128 GQA 4), closing the kv=1024 blind
spot. Note the race itself needs a live multi-op pipeline to reproduce;
single-op runs pass even on broken builds.
Verified on Arc Pro B70 (bmg_g31), Qwen3.6-27B Q4_K, -c 131072: output
byte-identical at temp 0 to the native FA path through 32k-deep prefill, with
prefill depth-flat at 820-840 t/s (vs 340-350 native at 32k depth).
Assisted-by: Claude Fable 5
* sycl: handle GGML_SYCL_FA_ONEDNN_MAX_KV like the other runtime env vars and document it
Review feedback on #25880:
- read the variable once at backend init into g_ggml_sycl_fa_onednn_max_kv via
ggml_sycl_get_env, and print it in the startup env listing (-lv 4 shows it)
- document GGML_SYCL_FA_ONEDNN and GGML_SYCL_FA_ONEDNN_MAX_KV in the SYCL.md
runtime table
Also trim the added FLASH_ATTN_EXT cases to kv={4096,16384}: the 32768/65536
shapes exceed the legacy NMSE threshold on both the oneDNN and native kernels
(long-sequence fp16 accumulation drift, present before this PR) and would fail
CI for an unrelated reason.
Assisted-by: Claude Fable 5
* sycl: clarify GGML_SYCL_FA_ONEDNN_MAX_KV default is disabled
Assisted-by: Claude Fable 5
* sycl: state default behavior of GGML_SYCL_FA_ONEDNN_MAX_KV explicitly
Assisted-by: Claude Fable 5
* Update ggml/src/ggml-sycl/fattn-onednn.cpp
Co-authored-by: Neo Zhang <zhang.jianyu@outlook.com>
* sycl: write the SDPA scale from a kernel instead of caching it
The per-(device, value) scale cache was a function-local static
unordered_map with no synchronization, so concurrent backend instances
could access and rehash it at the same time.
Write the scalar with a single_task instead. The value is captured into
the command, so no host memory has to outlive the call -- which is what
the use-after-return fix needed in the first place. That removes the
shared container, the leaked device allocation and the string key, and
it also closes the remaining async-memcpy-from-a-stack-local on the
first flash-attention call.
Ordering does not rely on timing: the queue is created with
sycl::property::queue::in_order and the dnnl stream wraps that same
queue, so the write completes before the SDPA reads the scalar. The
multi-GPU wait_and_throw() branch is unchanged.
Also drop the <cstdlib> include, which is unused.
Assisted-by: Claude Opus 5
---------
Co-authored-by: Neo Zhang <zhang.jianyu@outlook.com>
* [SYCL] F16 (default) Flash Attention with XMX engine via oneDNN graph API; Qwen3.6-27b-Q8_0 prefill speed up x1.21 at p=512 and x4.26 at p=80k
* [SYCL] Address review on FA oneDNN path. Result: llama-bench---pp512; 32% increase with fa1; llama-perplexity---0.11% difference; tested model: mradermacher/Meta-Llama-3.1-8B-Instruct-Q8_0.gguf
* PR-25222 revision v2: addressed audits
* [SYCL] flash-attn oneDNN SDPA KV F16 rev 3.0: add BMG gate + multi-device sync. Narrow the scrope of this PR to Battlemage only (bmg; Xe2). Other archs (e.g., alchemist) fall back to existing FA kernel. When device_count >1, apply stream -> wait_and_throw(), validated working path for multi-gpu sync fix by @maxious.
Co-authored-by: maxious <81432+maxious@users.noreply.github.com>
* updated comment on bmg gate, noted the issue
---------
Co-authored-by: scientist3 <scientist.3@users.noreply.github.com>
Co-authored-by: hmscider <hmscider@users.noreply.github.com>
Co-authored-by: maxious <81432+maxious@users.noreply.github.com>
* rename GGML_SYCL_SUPPORT_LEVEL_ZERO to GGML_SYCL_SUPPORT_LEVEL_ZERO_API, and GGML_SYCL_ENABLE_LEVEL_ZERO to GGML_SYCL_USE_LEVEL_ZERO_API
* fix code format
* fix error when rebase
* add dev2dev memcpy by SYCL API
* mv GGML_SYCL_DEV2DEV_MEMCPY to runntime table
* update the detect method for p2p comm
* fix the erro created during fix confilct
---------
Co-authored-by: Neo Zhang <NA>
* SYCL: fix a bug with async memcpy
* make mmid_row_mapping_host persistent
* comment on stream->wait
* Apply suggestion from @sanmai
* Apply suggestion from @sanmai
* Apply suggestion from @sanmai
This introduces an optional feature to allocate large GPU buffers (≥ 1GB)
using USM system allocations if supported by the device. It allows using
buffers from the system allocator then letting the system manage memory
migrations between host and device as necessary.
This feature is disabled by default and requires the GGML_SYCL_USM_SYSTEM
environment variable to enable. If USM system allocations are not supported
by the device or the system, we fallback to regular allocations.
This feature can allow VRAM overcommit. For example, the test below fails
on B580 due to lack of memory for allocation, but it passes when enabling
USM system allocations:
./examples/sycl/test.sh -m Qwen3.5-27B-Q3_K_M.gguf -lv 4
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
* [SYCL] Centralize Level Zero detection in ggml_sycl_init
* use the same wording
* get back the warning
* [SYCL] Remove per-allocation getenv() for GGML_SYCL_ENABLE_LEVEL_ZERO
* bring back the comment
* move it up to make sure devices call the shots
* move the env detection early
* replace g_ggml_sycl_enable_level_zero with a direct call to .ext_oneapi_level_zero
* update the comment
* switch back to g_ggml_sycl_enable_level_zero with a sentinel
* remove the check
* Reduce the diff
* reword, move lower
* move things aroudn
* remove forward declaration if favor of a full replace
* pre-cache results of zeDeviceGetProperties
* put ggml_sycl_get_env back
* replace get_sycl_env with ggml_sycl_get_env
* add whitespace back
* Apply suggestion from @sanmai
* 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>
* SYCL: reduce allocation overhead during flash attention
* tidy up whitespace
* add a note about the flag
* move ggml_sycl_fattn_* into fattn-buffers.hpp
* refactor implementation into fattn-buffers.cpp
* move new_fattn_kv_buffers back into ggml-sycl.cpp
* opt arc770 for Q4_0
* add for Q4_0
* update the script
* add help script for windows
* update guide
* fix format issue
* convert from dos to unix for format issue
* fix missed -sm parameter
* sycl: size mul_mat_id staging buffers by routed rows
Previously src1_contiguous/dst_contiguous in ggml_sycl_mul_mat_id were
sized to ggml_nelements(src1/dst), which over-allocates when ne12 > 1
and can fail with UR_RESULT_ERROR_OUT_OF_HOST_MEMORY on Level Zero for
MoE models (notably with --cpu-moe). Size them by the actual number of
routed rows (ids->ne[1] * n_ids) instead.
* sycl: add bf16 mul_mat fast path via DNNL
When src0 is BF16 (commonly the case for lm_head / output.weight), the
existing f16 path is skipped because bf16 isn't covered, and the f32
fallback dequantizes the entire src0 slab to f32 in a single pool alloc
(row_diff*ne00 floats). For large-vocab models this can reach several
GB and fail with UR_RESULT_ERROR_OUT_OF_HOST_MEMORY on Level Zero.
Add a bf16xbf16 -> f32 DNNL matmul fast path that uses the bf16 storage
in place and only materializes a small src1 bf16 conversion buffer. bf16
matmul accumulates in f32, so it's correct even when the op requests
GGML_PREC_F32 (as lm_head does).
- gemm.hpp: map bfloat16 to dnnl::memory::data_type::bf16.
- convert.{hpp,cpp}: expose ggml_get_to_bf16_sycl for f32/f16/bf16 -> bf16.
- ggml-sycl.cpp: take the bf16 path early in ggml_sycl_op_mul_mat_sycl
when DNNL and GGML_SYCL_HAS_BF16 are both available.
* fix/refactor OP argsort, pad
* fix count-equal op
* update SYCL OP list
* fix format issue
---------
Co-authored-by: Zhang Jianyu <zhang.jianyu@outlook.com>
* refactor to support soft_max_ext
* fix error and support soft_max_back
* rm unused functions
* fix format issue
---------
Co-authored-by: Zhang Jianyu <zhang.jianyu@outlook.com>
* SYCL: Add non contiguous input support to norm kernel
* refactor and add RMS_NORM non contiguous input support
ggml-ci
* restore subgroup reduction for multi-subgroup thread blocks in norm kernels
* Swap grid dims of nsamples and nrows
ggml-ci
* Revert "Swap grid dims of nsamples and nrows"
This reverts commit 43be2d657fec7f7fba54e2cd154106bc0fc45adf.
* restore not required changes
ggml-ci
* address review comments: change it to more like SYCL
* Use a common function to calculate offset
* remove wrap around logic for handling broadcasts
* remove static from calculate_offset fn and use ceil_div
* sycl : Implemented reorder Q4_0 mmvq
Signed-off-by: Alberto Cabrera <alberto.cabrera@codeplay.com>
* sycl : Fixed mmvq being called when reorder is disabled
* sycl : Improved comments in the quants header
Signed-off-by: Alberto Cabrera <alberto.cabrera@codeplay.com>
* Use static_assert
* safe_div -> ceil_div
* Clarify qi comment
* change the reorder tensor from init to execute OP
* dbg
* Undo changes to test-backend-ops
* Refactor changes on top of q4_0 reorder fix
* Missing Reverts
* Refactored opt_for_reorder logic to simplify code path
* Explicit inlining and unroll
* Renamed mul_mat_algo enum for consistency
---------
Signed-off-by: Alberto Cabrera <alberto.cabrera@codeplay.com>
Co-authored-by: romain.biessy <romain.biessy@codeplay.com>
* ggml : remove MSVC warnings pragmas
This commit removes the MSVC-specific pragmas as these are now handled
in ggml/CMakeLists.txt.
* whisper : remove MSVC warning pragmas
This commit removes the MSVC-specific pragmas. These are now handled in
the ggml/CMakeLists.txt file.
* SYCL: Add all missing unary kernels
ggml-ci
* decouple kernel launch range from data size using strided loop
* use ciel_div helper for num_blocks
ggml-ci
* clean auto imported header files
* opt performance by reorder for Intel GPU
* detect hw type and save opt feature, and print opt feature
* correct name
* support optimize graph once when compute graph, record the opt status in tensor->extra, make CI passed
* add env variable GGML_SYCL_DISABLE_OPT for debug
* use syclex::architecture replace the custom hw define, update the guide for GGML_SYCL_DISABLE_OPT
* add performance data
* mv getrows functions to separeted files
* fix global variables
---------
Co-authored-by: arthw <14088817+arthw@users.noreply.github.com>
* Implement host pool for matrix_info
Creating a new memory pool on the host to store memory location for
matrix_info needed to launch gemm_batch from oneMKL/oneMath.
Removing complex support in gemm_batch since it is not used in llama.cpp
* Remove unnecessary headers and cast
* Reorder member variable to avoid warning on initialization
* Formatting
* Remove unused variable
* Address PR review feedback - remove warning
---------
Signed-off-by: nscipione <nicolo.scipione@codeplay.com>
* SYCL: refactor ggml_sycl_compute_forward
* SYCL: add back GGML_USED(dst) to ggml_sycl_cpy
* SYCL: add function name to noop debug
* SYCL: Some device info print refactoring and add details of XMX availability
* Migrate to tensor->buffer for checking backend buffer type: 1
* SYCL: common.cpp try to migrate away from tensor->backend
* SYCL: fix assertions and add proper comments
* SYCL: remove extra space
* SYCL: Add back static to ggml_backend_buffer_is_sycl_split function
* SYCL: Add pragma directive to suppress warning spam
* SYCL: Integrate debug logs with GGML_LOG and other fixes
* Revert "SYCL: Integrate debug logs with GGML_LOG and other fixes"
This reverts commit 2607b7de0f0d2f4f1f690226f86fa861aa39cb97.
Let's keep the current SYCL specific logging mechanism for now
* SYCL: Use GGML_SYCL_DEBUG after reverting
* SYCL: reg_get_proc_address func, update to the current func signature
* SYCL: Refactor SYCL buffer checks in ggml_sycl_cpy_tensor_2d
* Try to reduce some unused and typecast warnings
* Reduce compiler warnings step 2
* add a newline at the end of the file
* Initialize nreduce as size_t
* [SYCL] Remove pragma directives from mmq.cpp
* SYCL: mmq add condition to prevent blocks_per_tile_x_row variable from becoming 0
* SYCL softmax: Initialize nreduce as size_t
* ggml-sycl.cpp: fix some trailing whitespaces
* SYCL: remove the unused variables instead of commenting it out
* SYCL poo2d kernel: set NAN for invalid pooling op
* SYCL gemm.hpp: remove pragma directives
* SYCL gemm.hpp: use const cast to properly support dnnl::memory
* SYCL: wkv6 remove a comment
* SYCL: clean comments step 2
* SYCL: clean comments and variables step 3
* SYCL: Use GGML_UNUSED for unused variables
* SYCL: remove extra empty lines and a comment
* Remove TODO
* cleanup spaces
* add a stdout for unsupported op
* use sycl printf over fprintf
* remove prints for CI
* SYCL ggml-sycl: pool2D use sycl::nan and remove if-else block
---------
Co-authored-by: Abhilash Majumder <30946547+abhilash1910@users.noreply.github.com>
* rwkv6: rename to wkv6
* rwkv6: support avx2 avx512 armv8 armv9
* rwkv6: update cuda file name
* rwkv6: rename params
* wkv on sycl
* sycl: add some ops
* sycl: Enhance OP support judgment
* wkv6: drop armv9 and tranfer to GGML style
ggml-ci
* sync : ggml
* update the function to use appropriate types
* fix define error
* Update ggml/src/ggml-cpu.c
* add appropriate asserts
* move element-wise functions outside
* put the declaration outside the loop
* rewrite to be more inline with the common pattern for distributing threads
* use recommended way GGML_TENSOR_LOCALS
---------
Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>
Co-authored-by: Diego Devesa <slarengh@gmail.com>
Co-authored-by: Plamen Minev <pacominev@gmail.com>
Co-authored-by: Yuri Khrustalev <ykhrustalev@users.noreply.github.com>
Co-authored-by: Meng, Hengyu <airdldl@163.com>
KyleHagy