Messages in this thread | | | Date | Sat, 2 May 1998 04:13:23 +0200 (MET DST) | From | Rik van Riel <> | Subject | Re: page coloring |
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On 2 May 1998, Andi Kleen wrote:
> Implementing page colouring into the underlying buddy page allocator > was tried, but given up because it actually slowed down some things and > leads to bad fragmentation [it is probably required to replace the simply > and fast buddy allocator with a more sophisticated zone allocator to > prevent fragmentation].
Now that we speak of it, does anybody have some pointers to documents about zone allocators, or does someone have some nice & simple algoritms in mind?
Some of the things that come to mind: - use 128K (or 512K) zones - allocate non-swappable and swappable stuff in separate zones - allocate 4-page and bigger stuff in a separate zone from 1-page allocs - use page coloring on >16M machines, we allocate 8 zones for user-stuff at a time and switch zones after every allocation - inside zones, we could use a buddy-like scheme, but that probably isn't needed - we fill up each zone as much as possible before allocating a new (batch of) zone(s) - there's a large penalty involved when kswapd encounters a zone with just a single swappable page inside it (when there aren't enough empty zones available) - ??? what else ???
Rik. +-------------------------------------------+--------------------------+ | Linux: - LinuxHQ MM-patches page | Scouting webmaster | | - kswapd ask-him & complain-to guy | Vries cubscout leader | | http://www.phys.uu.nl/~riel/ | <H.H.vanRiel@phys.uu.nl> | +-------------------------------------------+--------------------------+
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