On Wed, Jun 22, 2011 at 07:07:25PM +0800, Cong Wang wrote: > Actually, if we move this out of kernel, to user-space, everything > you worried will be solved by just changing the user-space code. > Just add the following pseudo code into your init script, > > if [ $total_memory -lt 512 ] > then > echo never > /sys/kernel/mm/transparent_hugepage/enabled > fi By the time this script runs some app may have allocated hugepages already potentially wasting mbytes of ram and undoing the min_free_kbytes isn't possible from userland using the kernel algorithm (it is possible actually but it's not nearly as simple as the above). There's no reason to complicate things and involve userland here when a simple kernel check can get the default right without userland dependency. Plus if this user really wants THP on 512m of ram he can still enable it and run hugeadm to enable antifrag too, without the need of =force. And forcing when PSE is enabled sounds impossible to be useful (maybe with the except of nopentium being passed to the kernel ;). There is no bug here, just send that printk cleanup and if you really want to save 8k the patch to change the number of hash heads structs at boot, like for dcache/icache. No other change required. After you do the above, you can go ahead picking one kernel crashing bug and fix it, that is more useful than making this 512m thing a .config variable or anything like that, .config is a nightmare already so it's probably better not to add anything there. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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>