podman/docs/source/markdown/options/shm-size.md

--shm-size=number[unit]

Size of /dev/shm. A unit can be b (bytes), k (kibibytes), m (mebibytes), or g (gibibytes). If you omit the unit, the system uses bytes. If you omit the size entirely, the default is 64m. When size is 0, there is no limit on the amount of memory used for IPC by the <<container|pod>>. This option conflicts with --ipc=host.