On Saturday 08 April 2006 10:55, Nick Piggin wrote:
Con Kolivas wrote:
On Friday 07 April 2006 22:40, Nick Piggin wrote:
How would zone_watermark_ok always fail though?
Withdrew this patch a while back; ignore
Well, whether or not that particular patch isa good idea, it
is definitely a bug if zone_watermark_ok could ever always
fail due to lowmem reserve and we should fix it.
Ok. I think I presented enough information for why I thought zone_watermark_ok would fail (for ZONE_DMA). With 16MB ZONE_DMA and a vmsplit of 3GB we have a lowmem_reserve of 12MB. It's pretty hard to keep that much ZONE_DMA free, I don't think I've ever seen that much free on my ZONE_DMA on an ordinary desktop without any particular ZONE_DMA users. Changing the tunable can make the lowmem_reserve larger than ZONE_DMA is on any vmsplit too as far as I understand the ratio.