Commit-ID: c1ad41f1f7270c1956da13fa8fd59d8d5929d56e
Gitweb: http://git.kernel.org/tip/c1ad41f1f7270c1956da13fa8fd59d8d5929d56e
Author: Ingo Molnar <mingo@xxxxxxxxxx>
AuthorDate: Tue, 11 Dec 2012 10:23:45 +0100
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 11 Dec 2012 10:23:45 +0100
Revert "sched/autogroup: Fix crash on reboot when autogroup is disabled"
This reverts commit 5258f386ea4e8454bc801fb443e8a4217da1947c,
because the underlying autogroups bug got fixed upstream in
a better way, via:
fd8ef11730f1 Revert "sched, autogroup: Stop going ahead if autogroup is disabled"
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Yong Zhang <yong.zhang0@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
fs/proc/base.c | 78 +++++++++++++++++++++++++++++++++++++++++++++++
kernel/sched/auto_group.c | 68 ++++++++++++++++++++++++++++++++++-------
kernel/sched/auto_group.h | 9 +++++-
kernel/sysctl.c | 6 ++--
4 files changed, 147 insertions(+), 14 deletions(-)
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 587631e..9e28356 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1272,6 +1272,81 @@ static const struct file_operations proc_pid_sched_operations = {
#endif
+#ifdef CONFIG_SCHED_AUTOGROUP
+/*
+ * Print out autogroup related information:
+ */
+static int sched_autogroup_show(struct seq_file *m, void *v)
+{
+ struct inode *inode = m->private;
+ struct task_struct *p;
+
+ p = get_proc_task(inode);
+ if (!p)
+ return -ESRCH;
+ proc_sched_autogroup_show_task(p, m);
+
+ put_task_struct(p);
+
+ return 0;
+}
+
+static ssize_t
+sched_autogroup_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *offset)
+{
+ struct inode *inode = file->f_path.dentry->d_inode;
+ struct task_struct *p;
+ char buffer[PROC_NUMBUF];
+ int nice;
+ int err;
+
+ memset(buffer, 0, sizeof(buffer));
+ if (count > sizeof(buffer) - 1)
+ count = sizeof(buffer) - 1;
+ if (copy_from_user(buffer, buf, count))
+ return -EFAULT;
+
+ err = kstrtoint(strstrip(buffer), 0, &nice);
+ if (err < 0)
+ return err;
+
+ p = get_proc_task(inode);
+ if (!p)
+ return -ESRCH;
+
+ err = proc_sched_autogroup_set_nice(p, nice);
+ if (err)
+ count = err;
+
+ put_task_struct(p);
+
+ return count;
+}
+
+static int sched_autogroup_open(struct inode *inode, struct file *filp)
+{
+ int ret;
+
+ ret = single_open(filp, sched_autogroup_show, NULL);
+ if (!ret) {
+ struct seq_file *m = filp->private_data;
+
+ m->private = inode;
+ }
+ return ret;
+}
+
+static const struct file_operations proc_pid_sched_autogroup_operations = {
+ .open = sched_autogroup_open,
+ .read = seq_read,
+ .write = sched_autogroup_write,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+#endif /* CONFIG_SCHED_AUTOGROUP */
+
static ssize_t comm_write(struct file *file, const char __user *buf,
size_t count, loff_t *offset)
{
@@ -2583,6 +2658,9 @@ static const struct pid_entry tgid_base_stuff[] = {
#ifdef CONFIG_SCHED_DEBUG
REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
#endif
+#ifdef CONFIG_SCHED_AUTOGROUP
+ REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
+#endif
REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
INF("syscall", S_IRUGO, proc_pid_syscall),
diff --git a/kernel/sched/auto_group.c b/kernel/sched/auto_group.c
index 0f1bacb..0984a21 100644
--- a/kernel/sched/auto_group.c
+++ b/kernel/sched/auto_group.c
@@ -110,9 +110,6 @@ out_fail:
bool task_wants_autogroup(struct task_struct *p, struct task_group *tg)
{
- if (!sysctl_sched_autogroup_enabled)
- return false;
-
if (tg != &root_task_group)
return false;
@@ -146,11 +143,15 @@ autogroup_move_group(struct task_struct *p, struct autogroup *ag)
p->signal->autogroup = autogroup_kref_get(ag);
+ if (!ACCESS_ONCE(sysctl_sched_autogroup_enabled))
+ goto out;
+
t = p;
do {
sched_move_task(t);
} while_each_thread(p, t);
+out:
unlock_task_sighand(p, &flags);
autogroup_kref_put(prev);
}
@@ -158,11 +159,8 @@ autogroup_move_group(struct task_struct *p, struct autogroup *ag)
/* Allocates GFP_KERNEL, cannot be called under any spinlock */
void sched_autogroup_create_attach(struct task_struct *p)
{
- struct autogroup *ag;
+ struct autogroup *ag = autogroup_create();
- if (!sysctl_sched_autogroup_enabled)
- return;
- ag = autogroup_create();
autogroup_move_group(p, ag);
/* drop extra reference added by autogroup_create() */
autogroup_kref_put(ag);
@@ -178,15 +176,11 @@ EXPORT_SYMBOL(sched_autogroup_detach);
void sched_autogroup_fork(struct signal_struct *sig)
{
- if (!sysctl_sched_autogroup_enabled)
- return;
sig->autogroup = autogroup_task_get(current);
}
void sched_autogroup_exit(struct signal_struct *sig)
{
- if (!sysctl_sched_autogroup_enabled)
- return;
autogroup_kref_put(sig->autogroup);
}
@@ -199,6 +193,58 @@ static int __init setup_autogroup(char *str)
__setup("noautogroup", setup_autogroup);
+#ifdef CONFIG_PROC_FS
+
+int proc_sched_autogroup_set_nice(struct task_struct *p, int nice)
+{
+ static unsigned long next = INITIAL_JIFFIES;
+ struct autogroup *ag;
+ int err;
+
+ if (nice < -20 || nice > 19)
+ return -EINVAL;
+
+ err = security_task_setnice(current, nice);
+ if (err)
+ return err;
+
+ if (nice < 0 && !can_nice(current, nice))
+ return -EPERM;
+
+ /* this is a heavy operation taking global locks.. */
+ if (!capable(CAP_SYS_ADMIN) && time_before(jiffies, next))
+ return -EAGAIN;
+
+ next = HZ / 10 + jiffies;
+ ag = autogroup_task_get(p);
+
+ down_write(&ag->lock);
+ err = sched_group_set_shares(ag->tg, prio_to_weight[nice + 20]);
+ if (!err)
+ ag->nice = nice;
+ up_write(&ag->lock);
+
+ autogroup_kref_put(ag);
+
+ return err;
+}
+
+void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m)
+{
+ struct autogroup *ag = autogroup_task_get(p);
+
+ if (!task_group_is_autogroup(ag->tg))
+ goto out;
+
+ down_read(&ag->lock);
+ seq_printf(m, "/autogroup-%ld nice %d\n", ag->id, ag->nice);
+ up_read(&ag->lock);
+
+out:
+ autogroup_kref_put(ag);
+}
+#endif /* CONFIG_PROC_FS */
+
#ifdef CONFIG_SCHED_DEBUG
int autogroup_path(struct task_group *tg, char *buf, int buflen)
{
diff --git a/kernel/sched/auto_group.h b/kernel/sched/auto_group.h
index 4552c6b..8bd0471 100644
--- a/kernel/sched/auto_group.h
+++ b/kernel/sched/auto_group.h
@@ -4,6 +4,11 @@
#include <linux/rwsem.h>
struct autogroup {
+ /*
+ * reference doesn't mean how many thread attach to this
+ * autogroup now. It just stands for the number of task
+ * could use this autogroup.
+ */
struct kref kref;
struct task_group *tg;
struct rw_semaphore lock;
@@ -24,7 +29,9 @@ extern bool task_wants_autogroup(struct task_struct *p, struct task_group *tg);
static inline struct task_group *
autogroup_task_group(struct task_struct *p, struct task_group *tg)
{
- if (task_wants_autogroup(p, tg))
+ int enabled = ACCESS_ONCE(sysctl_sched_autogroup_enabled);
+
+ if (enabled && task_wants_autogroup(p, tg))
return p->signal->autogroup->tg;
return tg;
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index b0fa5ad..26f65ea 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -367,8 +367,10 @@ static struct ctl_table kern_table[] = {
.procname = "sched_autogroup_enabled",
.data = &sysctl_sched_autogroup_enabled,
.maxlen = sizeof(unsigned int),
- .mode = 0444,
- .proc_handler = proc_dointvec,
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &one,
},
#endif
#ifdef CONFIG_CFS_BANDWIDTH
--
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