shmat/shmdt penalty

shmat/shmdt penalty

[Janez Pers]

Hi all,

Is there significant penalty for doing shmat/shmdt to a preexisting/
pre-created shared memory segment 60-200 times a second in multiple
processes using a modern (2.6) linux kernel on i386 architecture?

Specifically, do I risk:

* significant slowdown due to context switching (e.g. more than 10%)?
* memory fragmentation (?)
* any other resource exhaustion if such code runs for hours?
* scorn and laughter by people who read my code?

Sorry if this is faq or documented anywhere (I could not find it) - then
the pointer/url to the relevant literature will be enough.

Regards,

Janez.