[PATCH] memsw: handle swapaccount kernel parameter correctly

[Michal Hocko <mhocko@suse.cz>]

Hi Andrew,
I am sorry but the patch which added swapaccount parameter is not
correct (we have discussed it https://lkml.org/lkml/2010/11/16/103).
I didn't get the way how __setup parameters are handled correctly.
The patch bellow fixes that.

I am CCing stable as well because the patch got into .37 kernel.

---
>From 144c2e8aed27d82d48217896ee1f58dbaa7f1f84 Mon Sep 17 00:00:00 2001
From: Michal Hocko <mhocko@suse.cz>
Date: Wed, 26 Jan 2011 14:12:41 +0100
Subject: [PATCH] memsw: handle swapaccount kernel parameter correctly

__setup based kernel command line parameters handled in
obsolete_checksetup provides the parameter value including = (more
precisely everything right after the parameter name) so we have to check
for =0 resp. =1 here. If no value is given then we get an empty string
rather then NULL.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
---
 mm/memcontrol.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index db76ef7..cea2be48 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5013,9 +5013,9 @@ struct cgroup_subsys mem_cgroup_subsys = {
 static int __init enable_swap_account(char *s)
 {
 	/* consider enabled if no parameter or 1 is given */
-	if (!s || !strcmp(s, "1"))
+	if (!(*s) || !strcmp(s, "=1"))
 		really_do_swap_account = 1;
-	else if (!strcmp(s, "0"))
+	else if (!strcmp(s, "=0"))
 		really_do_swap_account = 0;
 	return 1;
 }
@@ -5023,7 +5023,7 @@ __setup("swapaccount", enable_swap_account);
 
 static int __init disable_swap_account(char *s)
 {
-	enable_swap_account("0");
+	enable_swap_account("=0");
 	return 1;
 }
 __setup("noswapaccount", disable_swap_account);
-- 
1.7.2.3

-- 
Michal Hocko
SUSE Labs
SUSE LINUX s.r.o.
Lihovarska 1060/12
190 00 Praha 9    
Czech Republic