> >From a quick peek it seems that the patch makes negligible difference for a > kernel compilation when prefaulting 1-2 pages and slows the workload down > quite a lot when prefaulting up to 16 pages.
well the last time I saw prefaulting experiments (Ingo was involved iirc) the problem was that the hitrate for the prefaults was such that the costs for tearing down the extra redundant rmap chains was more expensive than taking the "extra" faults. It seems linux has pretty cheap faulting logic invalidating some of traditional OS assumptions... (fwiw one of the worst tests I remember was doing a lot of very short shell script executions; the case where bash lives briefly so that you get maximum cost for the extra teardowns while not a lot of bash gets run so prefaulting doesn't make a lot of difference) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
