4 files changed, 14 insertions, 12 deletions

diff --git a/Documentation/accounting/delay-accounting.txt b/Documentation/accounting/delay-accounting.txt
index be215e58423b..1443cd71d263 100644
--- a/Documentation/accounting/delay-accounting.txt
+++ b/Documentation/accounting/delay-accounting.txt
@@ -64,11 +64,13 @@ Compile the kernel with
         CONFIG_TASK_DELAY_ACCT=y
         CONFIG_TASKSTATS=y
 
-Enable the accounting at boot time by adding
-the following to the kernel boot options
-        delayacct
+Delay accounting is enabled by default at boot up.
+To disable, add
+   nodelayacct
+to the kernel boot options. The rest of the instructions
+below assume this has not been done.
 
-and after the system has booted up, use a utility
+After the system has booted up, use a utility
 similar to  getdelays.c to access the delays
 seen by a given task or a task group (tgid).
 The utility also allows a given command to be
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index e11f7728ec6f..b50595a0550f 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -448,8 +448,6 @@ running once the system is up.
                         Format: <area>[,<node>]
                         See also Documentation/networking/decnet.txt.
 
-        delayacct       [KNL] Enable per-task delay accounting
-
         dhash_entries=  [KNL]
                         Set number of hash buckets for dentry cache.
 
@@ -1031,6 +1029,8 @@ running once the system is up.
 
         nocache         [ARM]
 
+        nodelayacct     [KNL] Disable per-task delay accounting
+
         nodisconnect    [HW,SCSI,M68K] Disables SCSI disconnects.
 
         noexec          [IA-64]
diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h
index 8a284cc6fd5f..11487b6e7127 100644
--- a/include/linux/delayacct.h
+++ b/include/linux/delayacct.h
@@ -55,7 +55,7 @@ static inline void delayacct_tsk_init(struct task_struct *tsk)
 {
         /* reinitialize in case parent's non-null pointer was dup'ed*/
         tsk->delays = NULL;
-        if (unlikely(delayacct_on))
+        if (delayacct_on)
                 __delayacct_tsk_init(tsk);
 }
 
@@ -80,7 +80,7 @@ static inline void delayacct_blkio_end(void)
 static inline int delayacct_add_tsk(struct taskstats *d,
                                         struct task_struct *tsk)
 {
-        if (likely(!delayacct_on) || !tsk->delays)
+        if (!delayacct_on || !tsk->delays)
                 return 0;
         return __delayacct_add_tsk(d, tsk);
 }
diff --git a/kernel/delayacct.c b/kernel/delayacct.c
index f05392d64267..57ca3730205d 100644
--- a/kernel/delayacct.c
+++ b/kernel/delayacct.c
@@ -19,15 +19,15 @@
 #include <linux/sysctl.h>
 #include <linux/delayacct.h>
 
-int delayacct_on __read_mostly; /* Delay accounting turned on/off */
+int delayacct_on __read_mostly = 1;     /* Delay accounting turned on/off */
 kmem_cache_t *delayacct_cache;
 
-static int __init delayacct_setup_enable(char *str)
+static int __init delayacct_setup_disable(char *str)
 {
-        delayacct_on = 1;
+        delayacct_on = 0;
         return 1;
 }
-__setup("delayacct", delayacct_setup_enable);
+__setup("nodelayacct", delayacct_setup_disable);
 
 void delayacct_init(void)
 {