On (07/02/17 20:28), Seth Jennings wrote: > On Sun, Jul 2, 2017 at 9:19 AM, Srividya Desireddy > > Zswap is a cache which compresses the pages that are being swapped out > > and stores them into a dynamically allocated RAM-based memory pool. > > Experiments have shown that around 10-20% of pages stored in zswap > > are zero-filled pages (i.e. contents of the page are all zeros), but > > these pages are handled as normal pages by compressing and allocating > > memory in the pool. > > I am somewhat surprised that this many anon pages are zero filled. > > If this is true, then maybe we should consider solving this at the > swap level in general, as we can de-dup zero pages in all swap > devices, not just zswap. > > That being said, this is a fair small change and I don't see anything > objectionable. However, I do think the better solution would be to do > this at a higher level. zero-filled pages are just 1 case. in general, it's better to handle pages that are memset-ed with the same value (e.g. memset(page, 0x01, page_size)). which includes, but not limited to, 0x00. zram does it. -ss -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
