mm/page_alloc.c: fix a misleading comment
The comment says that the per-cpu batchsize and zone watermarks are
determined by present_pages which is definitely wrong, they are both
calculated from managed_pages. Fix it.
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt
index 9c3f2f8..a4482fc 100644
--- a/Documentation/sysctl/vm.txt
+++ b/Documentation/sysctl/vm.txt
@@ -349,7 +349,7 @@
(i < j):
zone[i]->protection[j]
- = (total sums of present_pages from zone[i+1] to zone[j] on the node)
+ = (total sums of managed_pages from zone[i+1] to zone[j] on the node)
/ lowmem_reserve_ratio[i];
(i = j):
(should not be protected. = 0;
@@ -360,7 +360,7 @@
256 (if zone[i] means DMA or DMA32 zone)
32 (others).
As above expression, they are reciprocal number of ratio.
-256 means 1/256. # of protection pages becomes about "0.39%" of total present
+256 means 1/256. # of protection pages becomes about "0.39%" of total managed
pages of higher zones on the node.
If you would like to protect more pages, smaller values are effective.