On Friday 12 December 2008 13:47, Andrew Morton wrote: > On Fri, 12 Dec 2008 12:31:33 +1000 Nick Piggin <nickpig...@yahoo.com.au> wrote: > > On Friday 12 December 2008 07:43, Andrew Morton wrote: > > > On Thu, 11 Dec 2008 20:28:00 +0000 > > > > > > > Do they actually cross the page boundaries? > > > > > > Some flavours of slab have at times done an order-1 allocation for > > > objects which would fit into an order-0 page (etc) if it looks like > > > that will be beneficial from a packing POV. I'm unsure whether that > > > still happens - I tried to get it stamped out for reliability reasons. > > > > Hmph, SLUB uses order-3 allocations for 832 byte sized objects > > by default here (mm struct). > > That sucks, but at least it's <= PAGE_ALLOC_COSTLY_ORDER.
Which is somewhat arbitrary a value. order-1 is costly compared to order-0... After running my system here for a while and doing various things with it, I have the ability to allocate 898 order-0 pages (3592K), or 36 order-3 pages (1152K). Not as bad as I expected, but the system's only been up for an hour, and not exactly doing anything unusual (and it has nearly 30MB free, out of 4GB). > It's fortunate that everyone has more than 128GB of memory. And that SLAB still works quite well :) _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
