* KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> [2010-08-02 19:20:06]: > From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> > > This patch replaces bit_spinlock with spinlock. In general, > spinlock has good functinality than bit_spin_lock and we should use > it if we have a room for it. In 64bit arch, we have extra 4bytes. > Let's use it. > expected effects: > - use better codes. > - ticket lock on x86-64 > - para-vitualization aware lock > etc.. > > Chagelog: 20090729 > - fixed page_cgroup_is_locked(). > > Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> > -- The additional space usage is a big concern, I think saving space would be of highest priority. I understand the expected benefits, but a spinlock_t per page_cgroup is quite expensive at the moment. If anything I think it should be a config option under CONFIG_DEBUG or something else to play with and see the side effects. -- Three Cheers, Balbir -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>