On Fri, Feb 11, 2011 at 11:49:06AM +0100, Andrea Arcangeli wrote: > On Thu, Feb 10, 2011 at 11:02:50PM -0800, Hugh Dickins wrote: > > There is a separate little issue here, Andrea. > > > > Although we went to some trouble for bad_page() to take the page out > > of circulation yet let the system continue, your VM_BUG_ON(!PageBuddy) > > inside __ClearPageBuddy(page), from two callsites in bad_page(), is > > turning it into a fatal error when CONFIG_DEBUG_VM. > > I see what you mean. Of course it is only a problem after bad_page > already triggered.... but then it trigger an BUG_ON instead of only a > bad_page. > > > You could that only MM developers switch CONFIG_DEBUG_VM=y, and they > > would like bad_page() to be fatal; maybe, but if so we should do that > > as an intentional patch, rather than as an unexpected side-effect ;) > > Fedora kernels are built with CONFIG_DEBUG_VM, all my kernels runs > with CONFIG_DEBUG_VM too, so we want it to be as "production" as > possible, and we don't want DEBUG_VM to decrease any reliability (only > to increase it of course). Are you sure? $ grep DEBUG_VM /boot/config-* /boot/config-2.6.35.10-74.fc14.x86_64:# CONFIG_DEBUG_VM is not set /boot/config-2.6.35.6-45.fc14.x86_64:# CONFIG_DEBUG_VM is not set Only the one from the kernel-debug package has it set on this F14. Hannes -- 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>