| Subject | Re: [PATCH 06/13] writeback: bdi write bandwidth estimation | From | Peter Zijlstra <> | Date | Thu, 18 Nov 2010 00:24:59 +0100 |
| |
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@intel.com> 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.
|