Messages in this thread | | | Date | Tue, 26 Oct 2004 22:33:35 -0700 | From | Andrew Morton <> | Subject | Re: lowmem_reserve (replaces protection) |
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Andrea Arcangeli <andrea@novell.com> wrote: > > So after allocating the highmem pages we invoke kswapd > again
Nope. We don't wake kswapd until the lower zones are below pages_low as well. Then we rebalance all the zones which are below pages_high.
As I say: run a workload mix and monitor /proc/vmstat:
pgscan_kswapd_high pgscan_kswapd_normal pgscan_kswapd_dma
These should be increasing at rates which are proportional to their size, if most allocations have __GFP_HIGHMEM.
The lower-zone protection thing means that the scanning rate really should be proportional to (zone size - (protection from __GFP_HIGHMEM allocations)), but it's not too far off at present.
The balancing of the zone scanning rates is subtle and easy to break. As is the balancing of that against slab scanning. - 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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