Messages in this thread | | | Date | Thu, 31 Jan 2008 02:19:49 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH] mm: MADV_WILLNEED implementation for anonymous memory |
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On Thu, 31 Jan 2008 11:15:08 +0100 Andi Kleen <andi@firstfloor.org> wrote:
> Peter Zijlstra <a.p.zijlstra@chello.nl> writes: > > > > Ah, that is Lennarts Pulse Audio thing, he has samples in memory which > > might not have been used for a while, and he wants to be able to > > pre-fetch those when he suspects they might need to be played. So that > > once the audio thread comes along and stuffs them down /dev/dsp its all > > nice in memory. > > The real problem that seems to make swapping so slow is that the data > tends to be badly fragmented on the swap partition. I suspect if that > problem was attached the need for such prefetching would be far less > because swap in would be much faster. >
Yeah, the 2.5 switch to physical scanning killed us there.
I still don't know why my allocate-swapspace-according-to-virtual-address change didn't help. Much. Marcelo played with that a bit too.
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