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 116efed962c6e4bb747b17a955915758f636040c..0a60e8e9b094cf8b0a195d43d0ab22030ff72628 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1816,6 +1816,7 @@ static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares)
 
 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 @@ cpumask_var_t nohz_cpu_mask;
  *
  * 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 @@ static void update_sysctl(void)
                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 455106d318a8ae5c87e7a56c19c8e8c05ced83cd..804a411838f12e68690ff9db41796aa4f2a3eefe 100644 (file)
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -399,11 +399,12 @@ static struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
  */
 
 #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 @@ int sched_nr_latency_handler(struct ctl_table *table, int write,
        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 d10406e5fdfe988ba6f5ea34bc13d2ab85f43950..b9e5a45f1e28e50936db393fc13703af86361479 100644 (file)
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -253,6 +253,8 @@ static int min_wakeup_granularity_ns;                       /* 0 usecs */
 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 @@ static struct ctl_table kern_table[] = {
                .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 @@ static struct ctl_table kern_table[] = {
                .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 @@ static struct ctl_table kern_table[] = {
                .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 @@ static struct ctl_table kern_table[] = {
                .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 @@ static struct ctl_table kern_table[] = {
                .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,