Hi, > > > > The symbol rw_vm is recurring and seems to be consuming lots of time. > > As I don't know what rw_vm does, and I can't find this symbol in the > > sources, I can't understand what's happening in the system. > > > > Could someone explain me what rw_vm is ? And maybe tell me to what part > > of the kernel code it's related ? > > > > My system runs a 2.6.9 kernel with smp enabled. > > rw_vm is a fedora specific routine that basically is the workhorse for > copy_from_user and copy_to_user and friends... I suggest you try compiling your kernel in UNI mode and then look at the percentage of time spent in rw_vm. Compare the percentage of time spent in rw_vm in both SMP and UNI kernels. If there is big difference, it is quite possible that cache line bouncing is taking place between processors causing a large overhead for the copy routines. Do share your experience, I would be interested in the result. Shourya -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
