mirror of
https://github.com/ggml-org/llama.cpp.git
synced 2026-08-04 09:00:48 -05:00
9d9a6d29f6
* SYCL: add oneMKL GEMM flash attention for XMX-accelerated prompt processing * fattn-mkl: fix interleaved dst layout in normalize kernel - Fix mkl_fa_normalize_head: use interleaved dst layout ((query * n_q_heads + head) * DV) matching TILE's flash_attn_combine_results. Previously used dense head-major layout which wrote head outputs to wrong addresses, corrupting attention for all models except Qwen3.6-27B (where GQA=6 heads were sparse enough to avoid visible overlap). - Remove 7 redundant stream->wait() calls — SYCL in-order queue already serializes pure SYCL kernel dependencies. Retain only the 4 MKL GEMM ↔ SYCL handshake barriers (oneMKL GEMM uses its own internal queue that does not respect SYCL in-order). - Remove unused dst_row_stride, diagnostic clutter, and dead K/V hex dump (fa_diag block in fattn-mkl.cpp). - Add MKL_FA_DISABLE=1 env var for A/B testing. - Add FA-DISP watchdog (MKL_FA_DEBUG=1) and FA-DIAG output fingerprint (MKL_FA_DIAG=1) in fattn.cpp. Tested: Gemma-4-26B, Gemma-4-31B, Qwen3.6-27B, Qwen3.6-35B-A3B Perf (B70/Battlemage, 32K, q8_0 KV): Gemma-4-26B: 1473 t/s MKL vs 746 TILE (1.97x) Qwen3.6-27B: 609 t/s MKL vs 330 TILE (1.85x) Co-Authored-By: Claude Code on DeepSeek-v4-Pro * Thank you for the review feedback: rename env vars, use GGML_LOG_INFO, document in SYCL.md Completed the following: - Rename MKL_FA_DISABLE → GGML_SYCL_ENABLE_MKL_FA (inverted: 0 to disable) - Rename MKL_FA_DEBUG → GGML_SYCL_MKL_FA_DEBUG - Rename MKL_FA_DIAG → GGML_SYCL_MKL_FA_DIAG - Replace fprintf(stderr, ...) / fflush(stderr) with GGML_LOG_INFO() macro - Document all three env vars in docs/backend/SYCL.md under Runtime - Add comment explaining MKL FA activation trigger (flash-attn + quantized KV cache + batch-size >= 1024 + n_kv >= 1024) Resolves review feedback from arthw. Again, thank you!!! Co-Authored-By: Claude Code on DeepSeek-v4-Pro * Thank you for the review feedback round 2: use ggml_sycl_get_env, remove dup waits, gate perf macros - Replace raw getenv() with ggml_sycl_get_env() in all 4 env-var checks (fattn.cpp: GGML_SYCL_ENABLE_MKL_FA, GGML_SYCL_MKL_FA_DEBUG, GGML_SYCL_MKL_FA_DIAG; fattn-mkl.cpp: GGML_SYCL_MKL_FA_DEBUG) - Remove duplicated stream->wait() before ev.wait_and_throw() in GEMM KQ and GEMM VKQ — ev.wait_and_throw() already waits for completion - Gate MKL_ACCUM macro behind do_print so timing accumulators are no-ops in normal operation - Remove redundant MIT/Intel copyright header from fattn-mkl.cpp - Remove unused #include <cfloat> - Expand SYCL.md MKL FA docs with step-by-step activation trigger and example llama-cli command Again, thank you!!! Co-Authored-By: Claude Code on DeepSeek-v4-Pro * fattn-mkl: enable MKL FA for all KV cache types Remove the quantized-only restriction on MKL activation — the MKL kernel converts any non-F16 K/V to F16 via to_fp16_sycl before GEMM, so F16 (default), BF16, and F32 caches all benefit from XMX hardware acceleration. The type restriction was an unnecessary gate. Before (F16/BF16 default cache + FA on at 32K prefill): ~356 t/s (TILE path) After: ~670 t/s (MKL path, matching quantized-cache baseline) Minimal change: two conditions removed, one comment updated in fattn.cpp. No kernel or conversion code changes — the dequant pipeline already covers all types. * fattn-mkl: rename mkl_disable -> mkl_enable for clarity * fattn-mkl: refine MKL FA dispatch gates Three changes: 1. Remove quantized-only restriction - MKL FA activates for all KV cache types (F16 default, BF16, F32, quantized). The MKL kernel converts non-F16 K/V via to_fp16_sycl before GEMM. 2. Rename mkl_disable -> mkl_enable to match env var (GGML_SYCL_ENABLE_MKL_FA). 3. Replace batch-size threshold with Q->ne[1] >= 32 gate. Keeps TG (Q=1) and MTP drafts (Q=3-8) on VEC path where fused kernel beats MKL launch overhead. Routes all multi-token prefill through XMX-accelerated GEMM. Production data confirms Q patterns: 1-8 TG, 32-127 cache reuse, 128+ full reprocess. At 32K F16/BF16 FA-on: 356 -> 670 t/s. * ggml-sycl: fix F16 cache + MKL FA multi-turn corruption; add gate guards Two changes: 1. Always copy F16 K/V to dense row-major buffers before MKL GEMM. Previously F16 was read in-place with raw tensor strides. During multi-turn conversations, the accumulated KV cache had different stride properties than a fresh prefill, producing corrupted outputs. Now dense F16 gets a fast memcpy; interleaved (Gemma) gets a strided copy kernel. This matches what the quantized paths already did through to_fp16_sycl. 2. Gate MKL FA on unsupported op params (max_bias, logit_softcap, batch dim mismatch) and pathological F16 strides (nb[1] not a multiple of ne[0]*2). These conditions would previously crash inside the MKL kernel. Pathological strides (test-only) and ALiBi/softcap fall through to TILE/VEC which handle them correctly. The stride check uses modulo rather than equality, so both dense (nb1 == ne0*2) and interleaved (nb1 == H * ne0*2) pass — all real models use these layouts. Only test cases with overlapping rows (nb1=32 or nb1=75 for ne0=40) are blocked. Thanks to hmscider for the oneDNN FA PR (#25222) which surfaced the same insight: always normalize inputs to contiguous F16 before GEMM. Co-Authored-By: Claude Code using DeepSeek-V4-Pro <noreply@anthropic.com> * fattn-mkl: fix quant+GQA KV strides, tighten MKL gate, add K>=1024 tests Adding K>=1024 flash-attn test cases surfaced several MKL bugs: - Quant K/V with a padded seq-view (real KV cache) used the wrong strides in the dequant path... only the true Gemma interleave layout should reconstruct strides. nb[2] vs ne[1]*nb[1] - Gate was firing on shapes the kernel doesn't handle: head_dim < 64 or not a multiple of 64, MHA, attention sinks, and bf16 decode... fell through to vec which no bf16 case. Gate MKL to the validated envelope: gqa>=2, head_dim 64 through 512 (has to be a multiple of 64) with matching K/V head size, mask, no sinks/alibi/softcap... everything else falls back to tile. Covers Qwen Dense/MoE and Gemma4 Dense/MoE Ran test-backend-ops -o FLASH_ATTN_EXT: 3641/3641 pass. Perplexity unchanged... 6.7267 MKL vs 6.7290 stock using Qwen 27b q5_k_xl * Update ggml/src/ggml-sycl/fattn.cpp Co-authored-by: Neo Zhang <zhang.jianyu@outlook.com> * Update ggml/src/ggml-sycl/fattn.cpp Co-authored-by: Neo Zhang <zhang.jianyu@outlook.com> * Update ggml/src/ggml-sycl/fattn.cpp Co-authored-by: Neo Zhang <zhang.jianyu@outlook.com> * fattn-mkl: bound attention scratch so it doesn't grow with batch or context... also dropped the bf16 comment in fattn.cpp per arthw review. * Update ggml/src/ggml-sycl/fattn-mkl.cpp Co-authored-by: Neo Zhang <zhang.jianyu@outlook.com> * Update ggml/src/ggml-sycl/fattn-mkl.cpp Co-authored-by: Neo Zhang <zhang.jianyu@outlook.com> * apply arthw suggestions: enum for dequant modes, macro for wg_size, env-var one-liners --------- Co-authored-by: Claude Code using DeepSeek-V4-Pro <noreply@anthropic.com> Co-authored-by: Neo Zhang <zhang.jianyu@outlook.com>
llama.cpp
LLM inference in C/C++
manifesto / ggml / ops / maintainer PRs / dev branches / compile times / lib llama API / llama-server REST API
Quick start
A few options to get llama.cpp installed on your machine:
- Visit https://llama.app and follow the instructions
- Run with Docker - see our Docker documentation
- Download pre-built binaries from the releases page
- Build from source by cloning this repository - check out our build guide
Once installed:
# Download and run a model directly from Hugging Face
llama cli -hf ggml-org/Qwen3.5-0.8B-GGUF
# Launch OpenAI-compatible API server
llama serve -hf ggml-org/Qwen3.5-0.8B-GGUF
|
|
|
Description
The main goal of llama.cpp is to enable LLM (and VLM) inference with minimal setup and state-of-the-art performance on
a wide range of hardware - locally and in the cloud.
- Plain C/C++ implementation without any dependencies
- Apple silicon is a first-class citizen - optimized via ARM NEON, Accelerate and Metal frameworks
- AVX, AVX2, AVX512 and AMX support for x86 architectures
- RVV, ZVFH, ZFH, ZICBOP and ZIHINTPAUSE support for RISC-V architectures
- 1.5-bit, 2-bit, 3-bit, 4-bit, 5-bit, 6-bit, and 8-bit integer quantization for faster inference and reduced memory use
- Custom CUDA kernels for running LLMs on NVIDIA GPUs (support for AMD GPUs via HIP and Moore Threads GPUs via MUSA)
- Vulkan and SYCL backend support
- CPU+GPU hybrid inference to partially accelerate models larger than the total VRAM capacity
The llama.cpp project is build on top of the ggml library.
Supported backends
| Backend | Target devices |
|---|---|
| BLAS | All |
| BLIS | All |
| CANN | Ascend NPU |
| CUDA | Nvidia GPU |
| HIP | AMD GPU |
| Hexagon [In Progress] | Snapdragon |
| IBM zDNN | IBM Z & LinuxONE |
| MUSA | Moore Threads GPU |
| Metal | Apple Silicon |
| OpenCL | Adreno GPU |
| OpenVINO [In Progress] | Intel CPUs, GPUs, and NPUs |
| RPC | All |
| SYCL | Intel GPU |
| VirtGPU | VirtGPU APIR |
| Vulkan | GPU |
| WebGPU | All |
| ZenDNN | AMD CPU |
Documentation
Tools
Development
- How to build
- Running on Docker
- Build on Android
- Multi-GPU usage
- Performance troubleshooting
- GGML tips & tricks
- XCFramework
- Completions
- Models
Contributing
- Contributors can open PRs
- Collaborators will be invited based on contributions
- Maintainers can push to branches in the
llama.cpprepo and merge PRs into themasterbranch - Any help with managing issues, PRs and projects is very appreciated!
- Read the CONTRIBUTING.md for more information
Acknowledgements
- yhirose/cpp-httplib - Single-header HTTP server, used by
llama-server- MIT license - stb-image - Single-header image format decoder, used by multimodal subsystem - Public domain
- nlohmann/json - Single-header JSON library, used by various tools/examples - MIT License
- miniaudio.h - Single-header audio format decoder, used by multimodal subsystem - Public domain
- subprocess.h - Single-header process launching solution for C and C++ - Public domain