[PATCH] Represent laptop_mode as jiffies internally
Make that the internal value for /proc/sys/vm/laptop_mode is stored as
jiffies instead of seconds. Let the sysctl interface do the conversions,
instead of doing on-the-fly conversions every time the value is used.
Add a description of the fact that laptop_mode doubles as a flag and a
timeout to the comment above the laptop_mode variable.
Signed-off-by: Bart Samwel <bart@samwel.tk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 817ba25..d134266 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -848,9 +848,8 @@
.data = &laptop_mode,
.maxlen = sizeof(laptop_mode),
.mode = 0644,
- .proc_handler = &proc_dointvec,
- .strategy = &sysctl_intvec,
- .extra1 = &zero,
+ .proc_handler = &proc_dointvec_jiffies,
+ .strategy = &sysctl_jiffies,
},
{
.ctl_name = VM_BLOCK_DUMP,
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index e7910799..c1052ee 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -88,7 +88,8 @@
int block_dump;
/*
- * Flag that puts the machine in "laptop mode".
+ * Flag that puts the machine in "laptop mode". Doubles as a timeout in jiffies:
+ * a full sync is triggered after this time elapses without any disk activity.
*/
int laptop_mode;
@@ -468,7 +469,7 @@
*/
void laptop_io_completion(void)
{
- mod_timer(&laptop_mode_wb_timer, jiffies + laptop_mode * HZ);
+ mod_timer(&laptop_mode_wb_timer, jiffies + laptop_mode);
}
/*