From 32120c10e33baae8061e9961e6c3f1248302a331 Mon Sep 17 00:00:00 2001 From: Winston Ma Date: Tue, 16 Jun 2026 15:36:52 +0800 Subject: [PATCH] vulkan: prefer host-visible memory buffers on UMA devices (#22930) * implement UMA host-visible memory * update based on 0cc4m's suggestion --- ggml/src/ggml-vulkan/ggml-vulkan.cpp | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/ggml/src/ggml-vulkan/ggml-vulkan.cpp b/ggml/src/ggml-vulkan/ggml-vulkan.cpp index 59582e4f0..243ab76ee 100644 --- a/ggml/src/ggml-vulkan/ggml-vulkan.cpp +++ b/ggml/src/ggml-vulkan/ggml-vulkan.cpp @@ -3080,8 +3080,10 @@ static vk_buffer ggml_vk_create_buffer_device(vk_device& device, size_t size) { buf = ggml_vk_create_buffer(device, size, {vk::MemoryPropertyFlagBits::eHostVisible | vk::MemoryPropertyFlagBits::eHostCoherent, vk::MemoryPropertyFlagBits::eDeviceLocal}); } else if (device->uma) { - // Fall back to host memory type - buf = ggml_vk_create_buffer(device, size, {vk::MemoryPropertyFlagBits::eDeviceLocal, + // On UMA, prefer host-visible memory so direct tensor borrowing works. + // If unavailable, fall back to device-local memory. + buf = ggml_vk_create_buffer(device, size, {vk::MemoryPropertyFlagBits::eDeviceLocal | vk::MemoryPropertyFlagBits::eHostVisible | vk::MemoryPropertyFlagBits::eHostCoherent, + vk::MemoryPropertyFlagBits::eDeviceLocal, vk::MemoryPropertyFlagBits::eHostVisible | vk::MemoryPropertyFlagBits::eHostCoherent}); } else if (device->disable_host_visible_vidmem) { if (device->allow_sysmem_fallback) {