Re: noexec on /dev/shm

On Mon, 20.12.10 19:16, Fernando Lopez-Lezcano (nando@ccrma.Stanford.EDU) wrote:

this isn't exactly correct.

in /dev/shm on linux we have:

(a) unix-domain sockets for non-RT communication with the server
(b) FIFOs for RT wakeups (this could use semaphores now)

If this uses O_NOATIME it shouldnt matter whether the backing fs is tmpfs or real disk.

(c) shared memory created via either the sysv or posix shm API

As mentioned by other people too: sysv shm is not placed in /dev/shm. It lives in an independent non-fs namespace.

we don't care about the unix domain sockets' performance characteristics, but its convenient to have them in a known location that happens to be close to where (b) is located.

we do care about the performance of (b)

If O_NOATIME is not the answer to your questions, then you could even pass the fifo fd via the unix socket and have it completely independent of any real fs.

Lennart