On Thu, 29 Jul 2010 09:32:26 +0900 KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote: > On Wed, 28 Jul 2010 12:45:13 -0700 > Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > My gut reaction to this sort of thing is "run away in terror". It > > encourages kernel developers to operate like lackadaisical userspace > > developers and to assume that underlying code can perform heroic and > > immortal feats. But it can't. This is the kernel and the kernel is a > > tough and hostile place and callers should be careful and defensive and > > take great efforts to minimise the strain they put upon other systems. > > > > IOW, can we avoid doing this? > > > I'll use pre-allocated pointer array in the next version. It's simple even if a bit slow. == struct mem_cgroup *mem_cgroups[CONFIG_MAX_MEM_CGROUPS] __read_mostly; #define id_to_memcg(id) mem_cgroups[id]; == But this can use hugepage-mapping-for-kernel...so, can be quick. Thanks, -Kame -- 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>