On 10.09.2024 18:06, Peter Xu wrote:
On Tue, Aug 27, 2024 at 07:54:31PM +0200, Maciej S. Szmigiero wrote:+bool multifd_queue_device_state(char *idstr, uint32_t instance_id, + char *data, size_t len) +{ + /* Device state submissions can come from multiple threads */ + QEMU_LOCK_GUARD(&queue_job_mutex);Ah, just notice there's the mutex. So please consider the reply in the other thread, IIUC we can make it for multifd_send() to be a generic mutex to simplify the other patch too, then drop here. I assume the ram code should be fine taking one more mutex even without vfio, if it only takes once for each ~128 pages to enqueue, and only take in the main thread, then each update should be also in the hot path (e.g. no cache bouncing).
Will check whether it is possible to use a common mutex here for both RAM and device state submission without drop in performance. Thanks, Maciej
