sched: Update normalized values on user updates via proc
The normalized values are also recalculated in case the scaling factor
changes.
This patch updates the internally used scheduler tuning values that are
normalized to one cpu in case a user sets new values via sysfs.
Together with patch 2 of this series this allows to let user configured
values scale (or not) to cpu add/remove events taking place later.
Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1259579808-11357-4-git-send-email-ehrhardt@linux.vnet.ibm.com>
[ v2: fix warning ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched.c b/kernel/sched.c
index 116efed..0a60e8e 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1816,6 +1816,7 @@
static void calc_load_account_active(struct rq *this_rq);
static void update_sysctl(void);
+static int get_update_sysctl_factor(void);
static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
{
@@ -7030,9 +7031,9 @@
*
* This idea comes from the SD scheduler of Con Kolivas:
*/
-static void update_sysctl(void)
+static int get_update_sysctl_factor(void)
{
- unsigned int cpus = min(num_online_cpus(), 8U);
+ unsigned int cpus = min(num_online_cpus(), 8);
unsigned int factor;
switch (sysctl_sched_tunable_scaling) {
@@ -7048,6 +7049,13 @@
break;
}
+ return factor;
+}
+
+static void update_sysctl(void)
+{
+ unsigned int factor = get_update_sysctl_factor();
+
#define SET_SYSCTL(name) \
(sysctl_##name = (factor) * normalized_sysctl_##name)
SET_SYSCTL(sched_min_granularity);
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 455106d..804a411 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -399,11 +399,12 @@
*/
#ifdef CONFIG_SCHED_DEBUG
-int sched_nr_latency_handler(struct ctl_table *table, int write,
+int sched_proc_update_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp,
loff_t *ppos)
{
int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+ int factor = get_update_sysctl_factor();
if (ret || !write)
return ret;
@@ -411,6 +412,14 @@
sched_nr_latency = DIV_ROUND_UP(sysctl_sched_latency,
sysctl_sched_min_granularity);
+#define WRT_SYSCTL(name) \
+ (normalized_sysctl_##name = sysctl_##name / (factor))
+ WRT_SYSCTL(sched_min_granularity);
+ WRT_SYSCTL(sched_latency);
+ WRT_SYSCTL(sched_wakeup_granularity);
+ WRT_SYSCTL(sched_shares_ratelimit);
+#undef WRT_SYSCTL
+
return 0;
}
#endif
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index d10406e..b9e5a45 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -253,6 +253,8 @@
static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
+static int min_sched_shares_ratelimit = 100000; /* 100 usec */
+static int max_sched_shares_ratelimit = NSEC_PER_SEC; /* 1 second */
#endif
static struct ctl_table kern_table[] = {
@@ -271,7 +273,7 @@
.data = &sysctl_sched_min_granularity,
.maxlen = sizeof(unsigned int),
.mode = 0644,
- .proc_handler = &sched_nr_latency_handler,
+ .proc_handler = &sched_proc_update_handler,
.strategy = &sysctl_intvec,
.extra1 = &min_sched_granularity_ns,
.extra2 = &max_sched_granularity_ns,
@@ -282,7 +284,7 @@
.data = &sysctl_sched_latency,
.maxlen = sizeof(unsigned int),
.mode = 0644,
- .proc_handler = &sched_nr_latency_handler,
+ .proc_handler = &sched_proc_update_handler,
.strategy = &sysctl_intvec,
.extra1 = &min_sched_granularity_ns,
.extra2 = &max_sched_granularity_ns,
@@ -293,7 +295,7 @@
.data = &sysctl_sched_wakeup_granularity,
.maxlen = sizeof(unsigned int),
.mode = 0644,
- .proc_handler = &proc_dointvec_minmax,
+ .proc_handler = &sched_proc_update_handler,
.strategy = &sysctl_intvec,
.extra1 = &min_wakeup_granularity_ns,
.extra2 = &max_wakeup_granularity_ns,
@@ -304,7 +306,9 @@
.data = &sysctl_sched_shares_ratelimit,
.maxlen = sizeof(unsigned int),
.mode = 0644,
- .proc_handler = &proc_dointvec,
+ .proc_handler = &sched_proc_update_handler,
+ .extra1 = &min_sched_shares_ratelimit,
+ .extra2 = &max_sched_shares_ratelimit,
},
{
.ctl_name = CTL_UNNUMBERED,
@@ -312,7 +316,7 @@
.data = &sysctl_sched_tunable_scaling,
.maxlen = sizeof(enum sched_tunable_scaling),
.mode = 0644,
- .proc_handler = &proc_dointvec_minmax,
+ .proc_handler = &sched_proc_update_handler,
.strategy = &sysctl_intvec,
.extra1 = &min_sched_tunable_scaling,
.extra2 = &max_sched_tunable_scaling,