Name and Version

Vulkan\Llama-server.exe on Windows b7064+
Last good version: b7063

Operating systems

Windows

Which llama.cpp modules do you know to be affected?

llama-server

Command line

--flash-attn on

Problem description & steps to reproduce

b7063 with "--flash-attn on" processes prompts and shows results in WebUI.
b7064+ with "--flash-attn on" hangs while processing, needing ctrl+c multiple times to kill program.
b7064+ with "--flash-attn off" proceeds normally.

Vulkan on Intel Iris Xe GPU.

First Bad Commit

Working fine on b7063, versions b7064-b7079 same freezing.

Relevant log output