On Mon, 20.12.10 13:07, Fernando Lopez-Lezcano (nando(a)ccrma.Stanford.EDU) wrote:
Jack (the Jack Audio Connection Kit,
jackaudio.org) has been using
the
file api (apologies if my wording is not absolutely correct in unix
terms) on the tmpfs filesystem that is mounted on /dev/shm for a very
long time (10 years?). "/tmp" is not useful to Jack because Jack's
internal communication pipes can't be stored in any disk based journaled
filesystem as the latencies involved in accessing them cause glitches in
the audio streams handled by Jack.
to be frank I don't really buy this. A FIFO or socket in /tmp should be
fine as long as it is opened with O_NOATIME. The data in the fifo buffers
or the socket buffers never ever touches the disk and hence it is
irrelevant whether it is tmpfs or a real disk.
I raise this issue because "The API for /dev/shm is
shm_open()"
statement above means to me that in the future there will be no file api
access to a ram mounted filesystem in Fedora (I understand that this is
my own conclusion, but I can't see any other given the wording of the
statement above). Before someone implements that idea, please consider
the needs of a filesystem in ram for such uses as those mentioned in
this thread (and that is supported by the Fedora distribution by
default). Just in case...
This too appears to be a good usecase for XDG_RUNTIME_DIR btw.
Lennart
--
Lennart Poettering - Red Hat, Inc.