jbonf wrote: > Hi, I'm adding a queuing disc. inside kernel. I am > confused that it seems few other qdiscs allocate > memory dynamically. Is it invalid to use memory calls > like molloc No, you can kmalloc(...,GPF_ATOMIC) in enqueue and dequeue functions. > or just a suggest that do not use it often? As a general rule, enqueue and dequeue are performance-critical, so if you can move processing elsewhere, that's better. (E.g. if you just need to allocate some scratch space, you might as well do this at qdisc init time - calls to enqueue, dequeue, and requeue are serialized through dev->queue_lock.) Of course, kmalloc and kfree are reasonably fast, so if you really need to use them, that's no tragedy. I'd be more worried about the times it takes to do whatever you're going to do with that kmalloc'ed space ... For more details on locking in traffic control and such, you may want to read tc.ps in ftp://icaftp.epfl.ch/pub/people/almesber/junk/tc-04FEB2001-0.tar.gz it's a bit old and also unfinished, but it should give you an idea of how things are organized. - Werner -- _________________________________________________________________________ / Werner Almesberger, Buenos Aires, Argentina wa@almesberger.net / /_http://www.almesberger.net/____________________________________________/ _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
