H. Peter Anvin asked to evaluate other implementation: virtual huge zero page. The idea to have pmd table where all entires point to normal zero page. This way should be more effective from cache usage point of view, but it will increase pressure on TLB. I'm going to implement it and compare with current implementation.
Posted Oct 12, 2012 11:51 UTC (Fri) by etienne (subscriber, #25256)
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Sorry, late comment.
Shortening a huge zero page is good from the cache point of view, but maybe bad from DMA point of view, a:
dd if=/dev/zero of=/dev/sda18
may be forced to use 4 Kbytes pages because the huge zero page is not contiguous in physical memory...
Just my £0.02