Re: [mm PATCH v5 6/7] mm: Add reserved flag setting to set_page_links

This patch modifies the set_page_links function to include the setting of the reserved flag via a simple AND and OR operation. The motivation for this is the fact that the existing __set_bit call still seems to have effects on performance as replacing the call with the AND and OR can reduce initialization time. Looking over the assembly code before and after the change the main difference between the two is that the reserved bit is stored in a value that is generated outside of the main initialization loop and is then written with the other flags field values in one write to the page->flags value. Previously the generated value was written and then then a btsq instruction was issued. On my x86_64 test system with 3TB of persistent memory per node I saw the persistent memory initialization time on average drop from 23.49s to 19.12s per node. Signed-off-by: Alexander Duyck <alexander.h.duyck(a)linux.intel.com&gt;