On 29/11/19 10:27, Daniel P. Berrangé wrote: >> Yes, with a fallback path currently using a temporary file under /tmp >> (we may want to use shm_open() instead, or a different location such >> as XDG_RUNTIME_DIR? - and use O_TMPFILE) > We can't assume either /tmp or XDG_RUNTIME_DIR is on tmpfs as that is no > where near standard across all OS distros, and even if on tmpfs these > dirs can be size limited to a significant subset of available RAM. IOW > we can't safely use them unless explicitly told to.
Agreed, mkstemp+shm_open seems better. Perhaps this could be done in hostmem-memfd.c though, basically as a fallback option? In principle one could even use getmntent to search for a hugetlbfs mount. Paolo
