From 3783689a1aa82ef27a6418b043dd7a077b8330c5 Mon Sep 17 00:00:00 2001 From: Minchan Kim Date: Tue, 26 Jul 2016 15:23:23 -0700 Subject: zsmalloc: introduce zspage structure We have squeezed meta data of zspage into first page's descriptor. So, to get meta data from subpage, we should get first page first of all. But it makes trouble to implment page migration feature of zsmalloc because any place where to get first page from subpage can be raced with first page migration. IOW, first page it got could be stale. For preventing it, I have tried several approahces but it made code complicated so finally, I concluded to separate metadata from first page. Of course, it consumes more memory. IOW, 16bytes per zspage on 32bit at the moment. It means we lost 1% at *worst case*(40B/4096B) which is not bad I think at the cost of maintenance. Link: http://lkml.kernel.org/r/1464736881-24886-9-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim Cc: Sergey Senozhatsky Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/compaction.c | 1 - 1 file changed, 1 deletion(-) (limited to 'mm/compaction.c') diff --git a/mm/compaction.c b/mm/compaction.c index d85520647d1d..6095055bd70f 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -15,7 +15,6 @@ #include #include #include -#include #include #include #include -- cgit v1.2.3