From befb3a35627432473f143c90994557d78ff5bc67 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Johannes=20G=C3=A4=C3=9Fler?= Date: Sat, 1 Jul 2023 21:47:26 +0200 Subject: Test-based VRAM scratch size + context adjustment (#2056) --- llama.cpp | 38 +++++++++++++++++++++++++++++++++++--- 1 file changed, 35 insertions(+), 3 deletions(-) (limited to 'llama.cpp') diff --git a/llama.cpp b/llama.cpp index 561accf..a869bba 100644 --- a/llama.cpp +++ b/llama.cpp @@ -66,6 +66,7 @@ enum e_model { MODEL_65B, }; +static const size_t kB = 1024; static const size_t MB = 1024*1024; // computed for n_ctx == 2048 @@ -129,6 +130,34 @@ static const std::map & MEM_REQ_EVAL() return k_sizes; } +// amount of VRAM needed per batch size to hold temporary results +// the values for 3b and 65b are not derived from testing but instead chosen conservatively +static const std::map & VRAM_REQ_SCRATCH_BASE() +{ + static std::map k_sizes = { + { MODEL_3B, 512ull * kB }, + { MODEL_7B, 512ull * kB }, + { MODEL_13B, 640ull * kB }, + { MODEL_30B, 768ull * kB }, + { MODEL_65B, 1536ull * kB }, + }; + return k_sizes; +} + +// amount of VRAM needed per batch size and context to hold temporary results +// the values for 3b and 65b are not derived from testing but instead chosen conservatively +static const std::map & VRAM_REQ_SCRATCH_PER_CONTEXT() +{ + static std::map k_sizes = { + { MODEL_3B, 128ull }, + { MODEL_7B, 128ull }, + { MODEL_13B, 160ull }, + { MODEL_30B, 208ull }, + { MODEL_65B, 416ull }, + }; + return k_sizes; +} + // default hparams (LLaMA 7B) struct llama_hparams { uint32_t n_vocab = 32000; @@ -1118,11 +1147,14 @@ static void llama_model_load_internal( fprintf(stderr, "%s: not allocating a VRAM scratch buffer due to low VRAM option\n", __func__); ggml_cuda_set_scratch_size(0); // disable scratch } else { - vram_scratch = n_batch * MB; + const size_t vram_scratch_base = VRAM_REQ_SCRATCH_BASE().at(model.type); + const size_t vram_scratch_per_context = VRAM_REQ_SCRATCH_PER_CONTEXT().at(model.type); + vram_scratch = n_batch * (vram_scratch_base + n_ctx * vram_scratch_per_context); ggml_cuda_set_scratch_size(vram_scratch); if (n_gpu_layers > 0) { - fprintf(stderr, "%s: allocating batch_size x 1 MB = %zd MB VRAM for the scratch buffer\n", - __func__, vram_scratch / MB); + fprintf(stderr, "%s: allocating batch_size x (%zd kB + n_ctx x %zd B) = %zd MB VRAM for the scratch buffer\n", + __func__, vram_scratch_base / kB, vram_scratch_per_context, + (vram_scratch + MB - 1) / MB); // round up } } #endif // GGML_USE_CUBLAS -- cgit v1.2.3