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Con Kolivas wrote: > On Thursday 18 May 2006 17:11, Nick Piggin wrote: > >>If we're under memory pressure, kswapd will try to free up any candidate >>zone, yes. >> >> >>>On my test case this indeed happens and my ZONE_DMA never goes below 3000 >>>pages free. If I lower the reserve even further my pages free gets stuck >>>at 3208 and can't free any more, and doesn't ever drop below that either. >>> >>>Here is the patch I was proposing >> >>What problem does that fix though? > > > It's a generic concern and I honestly don't know how significant it is which > is why I'm asking if it needs attention. That concern being that any time > we're under any sort of memory pressure, ZONE_DMA will undergo intense > reclaim even though there may not really be anything specifically going on in > ZONE_DMA. It just seems a waste of cycles doing that. > If it doesn't have any/much pagecache or slab cache in it, there won't be intense reclaim; if it does then it can be reclaimed and the memory used. reclaim / allocation could be slightly smarter about scaling watermarks, however I don't think it is much of an issue at the moment. -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com - 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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