[PATCH] delay accounting: temporarily enable by default

Enable delay accounting by default so that feature gets coverage testing
without requiring special measures.

Earlier, it was off by default and had to be enabled via a boot time param.
 This patch reverses the default behaviour to improve coverage testing.  It
can be removed late in the kernel development cycle if its believed users
shouldn't have to incur any cost if they don't want delay accounting.  Or
it can be retained forever if the utility of the stats is deemed common
enough to warrant keeping the feature on.

Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Shailabh Nagar 2006-07-30 03:03:11 -07:00 committed by Linus Torvalds
parent d94a041519
commit 163ecdff06
4 changed files with 14 additions and 12 deletions

View file

@ -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

View file

@ -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]

View file

@ -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);
}

View file

@ -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)
{