On Tue, 13 Mar 2007, Andrew Morton wrote: > > 1. We need to support other states of pages other than zeroed. > > What does this mean?
pgd are not completely zeroed. They contain mappings that are always present. Thus the state is not a zeroed state. > > 2. Prezeroing does not make much sense if a large portion of the > > page is being used. Performance is better if the whole page > > is zeroed directly before use.Prezeroing only makes sense for sparse > > allocations like the page table pages. > > This is not related to the above discussion. Really? I definitely see the word prezeroing in the discussion. > > I already tried that 3 years ago and there was *no* benefit for usual > > users of the a page allocator. The advantage exists only if a small > > portion of the page is used. F.e. For one cacheline there was a 4x > > improvement. See lkml archives for prezeroing. > > Unsurprised. Were non-temporal stores tried? Yes with no material change. The work lead to making ia64 use non temporal stores for spin unlock but it was not useful for prezeroing. - 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/
