{"shas":[["22515497e59a5f5c17583951d6573888efc68b07","c172b4de1f75622c8447dbeaf5bcbdb70e9e8b5c@hotmail.com","vmscan: prevent background aging of anon page in no swap system\nYing Han reported that backing aging of anon pages in no swap system causes unnecessary TLB flush. When I sent a patch(69c8548175), I wanted this patch but Rik pointed out and allowed aging of anon pages to give a chance to promote from inactive to active LRU. It has a two problem. 1) non-swap system Never make sense to age anon pages. 2) swap configured but still doesn't swapon It doesn't make sense to age anon pages until swap-on time. But it's arguable. If we have aged anon pages by swapon, VM have moved anon pages from active to inactive. And in the time swapon by admin, the VM can't reclaim hot pages so we can protect hot pages swapout. But let's think about it. When does swap-on happen? It depends on admin. we can't expect it. Nonetheless, we have done aging of anon pages to protect hot pages swapout. It means we lost run time overhead when below high watermark but gain hot page swap-[in/out] overhead when VM decide swapout. Is it true? Let's think more detail. We don't promote anon pages in case of non-swap system. So even though VM does aging of anon pages, the pages would be in inactive LRU for a long time. It means many of pages in there would mark access bit again. So access bit hot/code separation would be pointless. This patch prevents unnecessary anon pages demotion in not-yet-swapon and non-configured swap system. Even, in non-configuared swap system inactive_anon_is_low can be compiled out. It could make side effect that hot anon pages could swap out when admin does swap on. But I think sooner or later it would be steady state. So it's not a big problem. We could lose someting but gain more thing(TLB flush and unnecessary function call to demote anon pages). Signed-off-by: Ying Han <yinghan@google.com> Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Brandon Berhent <bbedward@gmail.com>","cattleprod"],["35be6ac32ff0858b8942c231946f3afd31e97600","c172b4de1f75622c8447dbeaf5bcbdb70e9e8b5c@hotmail.com","change path name for new initramfs","cattleprod"],["40d0b77b49c6a154b71bcc10b92d12482aba1a67","c172b4de1f75622c8447dbeaf5bcbdb70e9e8b5c@hotmail.com","remove cflag, slim the code","cattleprod"]],"ref":"refs/heads/master","size":3,"head":"40d0b77b49c6a154b71bcc10b92d12482aba1a67","push_id":40551532}