diff options
| author | Dhaval Giani <dhaval@linux.vnet.ibm.com> | 2007-10-15 17:00:14 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2007-10-15 17:00:14 +0200 |
| commit | 5cb350baf580017da38199625b7365b1763d7180 (patch) | |
| tree | 3830339798b1c6f19f1580700ea6ba240fb56ef2 /kernel/sched.c | |
| parent | 8ca0e14ffb12c257de591571a9e96102acdb1c64 (diff) | |
sched: group scheduling, sysfs tunables
Add tunables in sysfs to modify a user's cpu share.
A directory is created in sysfs for each new user in the system.
/sys/kernel/uids/<uid>/cpu_share
Reading this file returns the cpu shares granted for the user.
Writing into this file modifies the cpu share for the user. Only an
administrator is allowed to modify a user's cpu share.
Ex:
# cd /sys/kernel/uids/
# cat 512/cpu_share
1024
# echo 2048 > 512/cpu_share
# cat 512/cpu_share
2048
#
Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched.c')
| -rw-r--r-- | kernel/sched.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index a3c3ec825f42..9ac99896db8f 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -162,6 +162,8 @@ struct task_group { /* runqueue "owned" by this group on each cpu */ struct cfs_rq **cfs_rq; unsigned long shares; + /* spinlock to serialize modification to shares */ + spinlock_t lock; }; /* Default task group's sched entity on each cpu */ @@ -6533,6 +6535,7 @@ void __init sched_init(void) se->parent = NULL; } init_task_group.shares = init_task_group_load; + spin_lock_init(&init_task_group.lock); #endif for (j = 0; j < CPU_LOAD_IDX_MAX; j++) @@ -6777,6 +6780,7 @@ struct task_group *sched_create_group(void) } tg->shares = NICE_0_LOAD; + spin_lock_init(&tg->lock); return tg; @@ -6897,8 +6901,9 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares) { int i; + spin_lock(&tg->lock); if (tg->shares == shares) - return 0; + goto done; /* return -EINVAL if the new value is not sane */ @@ -6906,7 +6911,14 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares) for_each_possible_cpu(i) set_se_shares(tg->se[i], shares); +done: + spin_unlock(&tg->lock); return 0; } +unsigned long sched_group_shares(struct task_group *tg) +{ + return tg->shares; +} + #endif /* CONFIG_FAIR_GROUP_SCHED */ |