vm.txt: document min_free_pages as critical for correctness
min_free_pages is critical for correctness, document it as such.
Signed-off-by: Pavel Machek <pavel@suse.cz>
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 17346da..b89570c 100644
--- a/Documentation/sysctl/vm.txt
+++ b/Documentation/sysctl/vm.txt
@@ -112,6 +112,12 @@
value for each lowmem zone in the system. Each lowmem zone gets
a number of reserved free pages based proportionally on its size.
+Some minimal ammount of memory is needed to satisfy PF_MEMALLOC
+allocations; if you set this to lower than 1024KB, your system will
+become subtly broken, and prone to deadlock under high loads.
+
+Setting this too high will OOM your machine instantly.
+
==============================================================
percpu_pagelist_fraction