Messages in this thread | | | Date | Sun, 05 Sep 2004 16:16:41 +1000 | From | Nick Piggin <> | Subject | Re: [RFC][PATCH 0/3] beat kswapd with the proverbial clue-bat |
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David S. Miller wrote: > On Sun, 05 Sep 2004 15:44:18 +1000 > Nick Piggin <nickpiggin@yahoo.com.au> wrote: > > >>So my solution? Just teach kswapd and the watermark code about higher >>order allocations in a fairly simple way. If pages_low is (say), 1024KB, >>we now also require 512KB of order-1 and above pages, 256K of order-2 >>and up, 128K of order 3, etc. (perhaps we should stop at about order-3?) > > > Whether to stop at order 3 is indeed an interesting question. > > The reality is that the high-order allocations come mostly from folks > using jumbo 9K MTUs on gigabit and faster technologies. On x86, an > order 2 would cover those packet allocations, but on sparc64 for example > order 1 would be enough, whereas on a 2K PAGE_SIZE system order 3 would > be necessary. >
Yeah I see.
> People using e1000 cards are hitting this case, and some of the e1000 > developers are going to play around with using page array based SKBs > (via the existing SKB page frags mechanism). So instead of allocating > a huge linear chunk for RX packets, they'll allocate a header area of > 256 bytes then an array of pages to cover the rest. >
Yes, I guess that would be ideal from the memory manager's POV.
> Right now, my current suggestion would not be to stop at a certain order. >
OK I'll keep it as is and we'll see how that goes. Thanks. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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