On Wed, 2010-11-17 at 15:38 -0800, Andrew Morton wrote: > On Thu, 18 Nov 2010 00:24:59 +0100 > Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote: > > > On Wed, 2010-11-17 at 15:08 -0800, Andrew Morton wrote: > > > On Wed, 17 Nov 2010 12:27:26 +0800 > > > Wu Fengguang <fengguang.wu@xxxxxxxxx> wrote: > > > > > > > + w = min(elapsed / (HZ/100), 128UL); > > > > > > I did try setting HZ=10 many years ago, and the kernel blew up. > > > > > > I do recall hearing of people who set HZ very low, perhaps because > > > their huge machines were seeing performance prolems when the timer tick > > > went off. Probably there's no need to do that any more. > > > > > > But still, we shouldn't hard-wire the (HZ >= 100) assumption if we > > > don't absolutely need to, and I don't think it is absolutely needed > > > here. > > > > People who do cpu bring-up on very slow FPGAs also lower HZ as far as > > possible. > > grep -r "[^a-zA-Z0-9_]HZ[ ]*/[ ]*100[^0-9]" . Maybe they've got a patch-kit somewhere,. I'll ask around. It would be nice to have that sorted. -- 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 policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>