On Wed, Feb 23, 2011 at 04:18:18PM -0800, Andrew Morton wrote: > On Tue, 22 Feb 2011 10:02:36 +0000 > Mel Gorman <mel@xxxxxxxxx> wrote: > > > On Mon, Feb 21, 2011 at 04:47:49PM +0100, Petr Holasek wrote: > > > When user insert negative value into /proc/sys/vm/nr_hugepages it will result > > > in the setting a random number of HugePages in system (can be easily showed > > > at /proc/meminfo output). > > > > I bet you a shiny penny that the value of HugePages becomes the maximum > > number that could be allocated by the system at the time rather than a > > random value. > > That seems to be the case from my reading. In which case the patch > removes probably-undocumented and possibly-useful existing behavior. > It's not proof that no one does this but I'm not aware of any documentation related to hugetlbfs that recommends writing negative values to take advantage of this side-effect. It's more likely they simply wrote a very large number to nr_hugepages if they wanted "as many hugepages as possible" as it makes more intuitive sense than asking for a negative amount of pages. hugeadm at least is not depending on this behaviour AFAIK. -- Mel Gorman SUSE Labs -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>