On Thu, Dec 20, 2007 at 05:53:41PM +0100, Peter Zijlstra wrote: > > On Thu, 2007-12-20 at 15:26 +0000, Hugh Dickins wrote: > > > The asynch code: perhaps not worth doing for MADV_WILLNEED alone, > > but might prove useful for more general use when swapping in. > > Not really the same as Con's swap prefetch, but worth looking > > at that for reference. But I guess this becomes a much bigger > > issue than you were intending to get into here. > > heh, yeah, got somewhat more complex that I'd hoped for. > > last patch for today (not even compile tested), will do a proper patch > and test it tomorrow. > > --- > A best effort MADV_WILLNEED implementation for anonymous memory. > > It adds a batch method to the page table walk routines so we can > copy a few ptes while holding the kmap, which makes it possible to > allocate the backing pages using GFP_KERNEL.
Yuck. We actually need to just fix the atomic kmap issue in the existing pagemap code rather than add a new method, I think. If performance of map/unmap is too slow at a granularity of 1, we can add some internal batching in the CONFIG_HIGHPTE case. -- Mathematics is the supreme nostalgia of our time. -- 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/
