(this is the fourth version of the patch, only change is that I added
the missing Signed-off-by line, as Ingo requested)
This patch introduces a new flag SCHED_RESET_ON_FORK which can be passed
to the kernel via sched_setscheduler(), ORed in the policy parameter. If
set this will make sure that when the process forks a) the scheduling
priority is reset to DEFAULT_PRIO if it was higher and b) the scheduling
policy is reset to SCHED_NORMAL if it was either SCHED_FIFO or SCHED_RR.
Why have this?
Currently, if a process is real-time scheduled this will 'leak' to all
its child processes. For security reasons it is often (always?) a good
idea to make sure that if a process acquires RT scheduling this is
confined to this process and only this process. More specifically this
makes the per-process resource limit RLIMIT_RTTIME useful for security
purposes, because it makes it impossible to use a fork bomb to
circumvent the per-process RLIMIT_RTTIME accounting.
This feature is also useful for tools like 'renice' which can then
change the nice level of a process without having this spill to all its
child processes.
Why expose this via sched_setscheduler() and not other syscalls such as
prctl() or sched_setparam()?
prctl() does not take a pid parameter. Due to that it would be
impossible to modify this flag for other processes than the current one.
The struct passed to sched_setparam() can unfortunately not be extended
without breaking compatibility, since sched_setparam() lacks a size
parameter.
How to use this from userspace? In your RT program simply replace this:
sched_setscheduler(pid, SCHED_FIFO, ¶m);
by this:
sched_setscheduler(pid, SCHED_FIFO|SCHED_RESET_ON_FORK, ¶m);
Lennart
Signed-off-by: Lennart Poettering <[email protected]>
---
include/linux/sched.h | 6 ++++++
kernel/sched.c | 47 ++++++++++++++++++++++++++++++++++++++---------
2 files changed, 44 insertions(+), 9 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 83f3564..bd503ce 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -38,6 +38,8 @@
#define SCHED_BATCH 3
/* SCHED_ISO: reserved but not implemented yet */
#define SCHED_IDLE 5
+/* Can be ORed in to make sure the process is reverted back to SCHED_NORMAL on fork */
+#define SCHED_RESET_ON_FORK 0x40000000
#ifdef __KERNEL__
@@ -1209,6 +1211,10 @@ struct task_struct {
unsigned did_exec:1;
unsigned in_execve:1; /* Tell the LSMs that the process is doing an
* execve */
+
+ /* Revert to default priority/policy when forking */
+ unsigned sched_reset_on_fork:1;
+
pid_t pid;
pid_t tgid;
diff --git a/kernel/sched.c b/kernel/sched.c
index 8ec9d13..1db3e4a 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2613,12 +2613,26 @@ void sched_fork(struct task_struct *p, int clone_flags)
set_task_cpu(p, cpu);
/*
- * Make sure we do not leak PI boosting priority to the child:
+ * Revert to default priority/policy on fork if requested. Make sure we
+ * do not leak PI boosting priority to the child.
*/
- p->prio = current->normal_prio;
+ if (current->sched_reset_on_fork &&
+ (p->policy == SCHED_FIFO || p->policy == SCHED_RR))
+ p->policy = SCHED_NORMAL;
+
+ if (current->sched_reset_on_fork &&
+ (current->normal_prio < DEFAULT_PRIO))
+ p->prio = DEFAULT_PRIO;
+ else
+ p->prio = current->normal_prio;
+
if (!rt_prio(p->prio))
p->sched_class = &fair_sched_class;
+ /* We don't need the reset flag anymore after the fork. It has
+ * fulfilled its duty. */
+ p->sched_reset_on_fork = 0;
+
#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
if (likely(sched_info_on()))
memset(&p->sched_info, 0, sizeof(p->sched_info));
@@ -6094,17 +6108,25 @@ static int __sched_setscheduler(struct task_struct *p, int policy,
unsigned long flags;
const struct sched_class *prev_class = p->sched_class;
struct rq *rq;
+ int reset_on_fork;
/* may grab non-irq protected spin_locks */
BUG_ON(in_interrupt());
recheck:
/* double check policy once rq lock held */
- if (policy < 0)
+ if (policy < 0) {
+ reset_on_fork = p->sched_reset_on_fork;
policy = oldpolicy = p->policy;
- else if (policy != SCHED_FIFO && policy != SCHED_RR &&
- policy != SCHED_NORMAL && policy != SCHED_BATCH &&
- policy != SCHED_IDLE)
- return -EINVAL;
+ } else {
+ reset_on_fork = !!(policy & SCHED_RESET_ON_FORK);
+ policy &= ~SCHED_RESET_ON_FORK;
+
+ if (policy != SCHED_FIFO && policy != SCHED_RR &&
+ policy != SCHED_NORMAL && policy != SCHED_BATCH &&
+ policy != SCHED_IDLE)
+ return -EINVAL;
+ }
+
/*
* Valid priorities for SCHED_FIFO and SCHED_RR are
* 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL,
@@ -6148,6 +6170,10 @@ recheck:
/* can't change other user's priorities */
if (!check_same_owner(p))
return -EPERM;
+
+ /* normal users shall not reset the sched_reset_on_fork flag */
+ if (p->sched_reset_on_fork && !reset_on_fork)
+ return -EPERM;
}
if (user) {
@@ -6191,6 +6217,8 @@ recheck:
if (running)
p->sched_class->put_prev_task(rq, p);
+ p->sched_reset_on_fork = reset_on_fork;
+
oldprio = p->prio;
__setscheduler(rq, p, policy, param->sched_priority);
@@ -6307,14 +6335,15 @@ SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
if (p) {
retval = security_task_getscheduler(p);
if (!retval)
- retval = p->policy;
+ retval = p->policy
+ | (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0);
}
read_unlock(&tasklist_lock);
return retval;
}
/**
- * sys_sched_getscheduler - get the RT priority of a thread
+ * sys_sched_getparam - get the RT priority of a thread
* @pid: the pid in question.
* @param: structure containing the RT priority.
*/
--
1.6.2.2
Lennart
--
Lennart Poettering Red Hat, Inc.
lennart [at] poettering [dot] net
http://0pointer.net/lennart/ GnuPG 0x1A015CC4
Commit-ID: ca94c442535a44d508c99a77e54f21a59f4fc462
Gitweb: http://git.kernel.org/tip/ca94c442535a44d508c99a77e54f21a59f4fc462
Author: Lennart Poettering <[email protected]>
AuthorDate: Mon, 15 Jun 2009 17:17:47 +0200
Committer: Ingo Molnar <[email protected]>
CommitDate: Mon, 15 Jun 2009 17:31:59 +0200
sched: Introduce SCHED_RESET_ON_FORK scheduling policy flag
This patch introduces a new flag SCHED_RESET_ON_FORK which can be passed
to the kernel via sched_setscheduler(), ORed in the policy parameter. If
set this will make sure that when the process forks a) the scheduling
priority is reset to DEFAULT_PRIO if it was higher and b) the scheduling
policy is reset to SCHED_NORMAL if it was either SCHED_FIFO or SCHED_RR.
Why have this?
Currently, if a process is real-time scheduled this will 'leak' to all
its child processes. For security reasons it is often (always?) a good
idea to make sure that if a process acquires RT scheduling this is
confined to this process and only this process. More specifically this
makes the per-process resource limit RLIMIT_RTTIME useful for security
purposes, because it makes it impossible to use a fork bomb to
circumvent the per-process RLIMIT_RTTIME accounting.
This feature is also useful for tools like 'renice' which can then
change the nice level of a process without having this spill to all its
child processes.
Why expose this via sched_setscheduler() and not other syscalls such as
prctl() or sched_setparam()?
prctl() does not take a pid parameter. Due to that it would be
impossible to modify this flag for other processes than the current one.
The struct passed to sched_setparam() can unfortunately not be extended
without breaking compatibility, since sched_setparam() lacks a size
parameter.
How to use this from userspace? In your RT program simply replace this:
sched_setscheduler(pid, SCHED_FIFO, ¶m);
by this:
sched_setscheduler(pid, SCHED_FIFO|SCHED_RESET_ON_FORK, ¶m);
Signed-off-by: Lennart Poettering <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
---
include/linux/sched.h | 6 ++++++
kernel/sched.c | 49 ++++++++++++++++++++++++++++++++++++++++---------
2 files changed, 46 insertions(+), 9 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 4896fdf..d4a2c66 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -38,6 +38,8 @@
#define SCHED_BATCH 3
/* SCHED_ISO: reserved but not implemented yet */
#define SCHED_IDLE 5
+/* Can be ORed in to make sure the process is reverted back to SCHED_NORMAL on fork */
+#define SCHED_RESET_ON_FORK 0x40000000
#ifdef __KERNEL__
@@ -1209,6 +1211,10 @@ struct task_struct {
unsigned did_exec:1;
unsigned in_execve:1; /* Tell the LSMs that the process is doing an
* execve */
+
+ /* Revert to default priority/policy when forking */
+ unsigned sched_reset_on_fork:1;
+
pid_t pid;
pid_t tgid;
diff --git a/kernel/sched.c b/kernel/sched.c
index 8ec9d13..32e6ede 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2613,12 +2613,28 @@ void sched_fork(struct task_struct *p, int clone_flags)
set_task_cpu(p, cpu);
/*
- * Make sure we do not leak PI boosting priority to the child:
+ * Revert to default priority/policy on fork if requested. Make sure we
+ * do not leak PI boosting priority to the child.
*/
- p->prio = current->normal_prio;
+ if (current->sched_reset_on_fork &&
+ (p->policy == SCHED_FIFO || p->policy == SCHED_RR))
+ p->policy = SCHED_NORMAL;
+
+ if (current->sched_reset_on_fork &&
+ (current->normal_prio < DEFAULT_PRIO))
+ p->prio = DEFAULT_PRIO;
+ else
+ p->prio = current->normal_prio;
+
if (!rt_prio(p->prio))
p->sched_class = &fair_sched_class;
+ /*
+ * We don't need the reset flag anymore after the fork. It has
+ * fulfilled its duty:
+ */
+ p->sched_reset_on_fork = 0;
+
#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
if (likely(sched_info_on()))
memset(&p->sched_info, 0, sizeof(p->sched_info));
@@ -6094,17 +6110,25 @@ static int __sched_setscheduler(struct task_struct *p, int policy,
unsigned long flags;
const struct sched_class *prev_class = p->sched_class;
struct rq *rq;
+ int reset_on_fork;
/* may grab non-irq protected spin_locks */
BUG_ON(in_interrupt());
recheck:
/* double check policy once rq lock held */
- if (policy < 0)
+ if (policy < 0) {
+ reset_on_fork = p->sched_reset_on_fork;
policy = oldpolicy = p->policy;
- else if (policy != SCHED_FIFO && policy != SCHED_RR &&
- policy != SCHED_NORMAL && policy != SCHED_BATCH &&
- policy != SCHED_IDLE)
- return -EINVAL;
+ } else {
+ reset_on_fork = !!(policy & SCHED_RESET_ON_FORK);
+ policy &= ~SCHED_RESET_ON_FORK;
+
+ if (policy != SCHED_FIFO && policy != SCHED_RR &&
+ policy != SCHED_NORMAL && policy != SCHED_BATCH &&
+ policy != SCHED_IDLE)
+ return -EINVAL;
+ }
+
/*
* Valid priorities for SCHED_FIFO and SCHED_RR are
* 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL,
@@ -6148,6 +6172,10 @@ recheck:
/* can't change other user's priorities */
if (!check_same_owner(p))
return -EPERM;
+
+ /* Normal users shall not reset the sched_reset_on_fork flag */
+ if (p->sched_reset_on_fork && !reset_on_fork)
+ return -EPERM;
}
if (user) {
@@ -6191,6 +6219,8 @@ recheck:
if (running)
p->sched_class->put_prev_task(rq, p);
+ p->sched_reset_on_fork = reset_on_fork;
+
oldprio = p->prio;
__setscheduler(rq, p, policy, param->sched_priority);
@@ -6307,14 +6337,15 @@ SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
if (p) {
retval = security_task_getscheduler(p);
if (!retval)
- retval = p->policy;
+ retval = p->policy
+ | (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0);
}
read_unlock(&tasklist_lock);
return retval;
}
/**
- * sys_sched_getscheduler - get the RT priority of a thread
+ * sys_sched_getparam - get the RT priority of a thread
* @pid: the pid in question.
* @param: structure containing the RT priority.
*/
On Mon, 2009-06-15 at 17:27 +0200, Lennart Poettering wrote:
> (this is the fourth version of the patch, only change is that I added
> the missing Signed-off-by line, as Ingo requested)
>
> This patch introduces a new flag SCHED_RESET_ON_FORK which can be passed
> to the kernel via sched_setscheduler(), ORed in the policy parameter. If
> set this will make sure that when the process forks a) the scheduling
> priority is reset to DEFAULT_PRIO if it was higher and b) the scheduling
> policy is reset to SCHED_NORMAL if it was either SCHED_FIFO or SCHED_RR.
>
> Why have this?
>
> Currently, if a process is real-time scheduled this will 'leak' to all
> its child processes. For security reasons it is often (always?) a good
> idea to make sure that if a process acquires RT scheduling this is
> confined to this process and only this process. More specifically this
> makes the per-process resource limit RLIMIT_RTTIME useful for security
> purposes, because it makes it impossible to use a fork bomb to
> circumvent the per-process RLIMIT_RTTIME accounting.
>
> This feature is also useful for tools like 'renice' which can then
> change the nice level of a process without having this spill to all its
> child processes.
That didn't work for me, reniced tasks with the flag set retained their
-nice status. See patchlet and comments below.
> diff --git a/kernel/sched.c b/kernel/sched.c
> index 8ec9d13..1db3e4a 100644
> --- a/kernel/sched.c
> +++ b/kernel/sched.c
> @@ -2613,12 +2613,26 @@ void sched_fork(struct task_struct *p, int clone_flags)
> set_task_cpu(p, cpu);
>
> /*
> - * Make sure we do not leak PI boosting priority to the child:
> + * Revert to default priority/policy on fork if requested. Make sure we
> + * do not leak PI boosting priority to the child.
> */
> - p->prio = current->normal_prio;
Nit: that comment/assignment was placed there to make sure that readers
knew that this specific line was critical to PI. Now, it's mixed in
with something unrelated.
> + if (current->sched_reset_on_fork &&
> + (p->policy == SCHED_FIFO || p->policy == SCHED_RR))
> + p->policy = SCHED_NORMAL;
> +
> + if (current->sched_reset_on_fork &&
> + (current->normal_prio < DEFAULT_PRIO))
> + p->prio = DEFAULT_PRIO;
> + else
> + p->prio = current->normal_prio;
> +
I think it's cleaner to keep reset_on_fork functionality separate.
Thoughts on the below?
Make SCHED_RESET_ON_FORK to DTRT for reniced tasks, and make the sched_fork()
SCHED_RESET_ON_FORK bits a self-contained unlikely code block.
Signed-off-by: Mike Galbraith <[email protected]>
kernel/sched.c | 39 +++++++++++++++++++++++----------------
1 files changed, 23 insertions(+), 16 deletions(-)
diff --git a/kernel/sched.c b/kernel/sched.c
index 80636ed..cb6bbc6 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2613,28 +2613,35 @@ void sched_fork(struct task_struct *p, int clone_flags)
set_task_cpu(p, cpu);
/*
- * Revert to default priority/policy on fork if requested. Make sure we
- * do not leak PI boosting priority to the child.
+ * Make sure we do not leak PI boosting priority to the child.
*/
- if (current->sched_reset_on_fork &&
- (p->policy == SCHED_FIFO || p->policy == SCHED_RR))
- p->policy = SCHED_NORMAL;
+ p->prio = current->normal_prio;
- if (current->sched_reset_on_fork &&
- (current->normal_prio < DEFAULT_PRIO))
- p->prio = DEFAULT_PRIO;
- else
- p->prio = current->normal_prio;
+ /*
+ * Revert to default priority/policy on fork if requested.
+ */
+ if (unlikely(p->sched_reset_on_fork)) {
+ if (p->policy == SCHED_FIFO || p->policy == SCHED_RR)
+ p->policy = SCHED_NORMAL;
+
+ if (p->normal_prio < DEFAULT_PRIO)
+ p->prio = DEFAULT_PRIO;
+
+ if (PRIO_TO_NICE(p->static_prio) < 0) {
+ p->static_prio = NICE_TO_PRIO(0);
+ set_load_weight(p);
+ }
+
+ /*
+ * We don't need the reset flag anymore after the fork. It has
+ * fulfilled its duty:
+ */
+ p->sched_reset_on_fork = 0;
+ }
if (!rt_prio(p->prio))
p->sched_class = &fair_sched_class;
- /*
- * We don't need the reset flag anymore after the fork. It has
- * fulfilled its duty:
- */
- p->sched_reset_on_fork = 0;
-
#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
if (likely(sched_info_on()))
memset(&p->sched_info, 0, sizeof(p->sched_info));
On Tue, 16.06.09 11:05, Mike Galbraith ([email protected]) wrote:
> I think it's cleaner to keep reset_on_fork functionality separate.
> Thoughts on the below?
Looks good to me!
Lennart
> Make SCHED_RESET_ON_FORK to DTRT for reniced tasks, and make the sched_fork()
> SCHED_RESET_ON_FORK bits a self-contained unlikely code block.
>
> Signed-off-by: Mike Galbraith <[email protected]>
>
> kernel/sched.c | 39 +++++++++++++++++++++++----------------
> 1 files changed, 23 insertions(+), 16 deletions(-)
>
> diff --git a/kernel/sched.c b/kernel/sched.c
> index 80636ed..cb6bbc6 100644
> --- a/kernel/sched.c
> +++ b/kernel/sched.c
> @@ -2613,28 +2613,35 @@ void sched_fork(struct task_struct *p, int clone_flags)
> set_task_cpu(p, cpu);
>
> /*
> - * Revert to default priority/policy on fork if requested. Make sure we
> - * do not leak PI boosting priority to the child.
> + * Make sure we do not leak PI boosting priority to the child.
> */
> - if (current->sched_reset_on_fork &&
> - (p->policy == SCHED_FIFO || p->policy == SCHED_RR))
> - p->policy = SCHED_NORMAL;
> + p->prio = current->normal_prio;
>
> - if (current->sched_reset_on_fork &&
> - (current->normal_prio < DEFAULT_PRIO))
> - p->prio = DEFAULT_PRIO;
> - else
> - p->prio = current->normal_prio;
> + /*
> + * Revert to default priority/policy on fork if requested.
> + */
> + if (unlikely(p->sched_reset_on_fork)) {
> + if (p->policy == SCHED_FIFO || p->policy == SCHED_RR)
> + p->policy = SCHED_NORMAL;
> +
> + if (p->normal_prio < DEFAULT_PRIO)
> + p->prio = DEFAULT_PRIO;
> +
> + if (PRIO_TO_NICE(p->static_prio) < 0) {
> + p->static_prio = NICE_TO_PRIO(0);
> + set_load_weight(p);
> + }
> +
> + /*
> + * We don't need the reset flag anymore after the fork. It has
> + * fulfilled its duty:
> + */
> + p->sched_reset_on_fork = 0;
> + }
>
> if (!rt_prio(p->prio))
> p->sched_class = &fair_sched_class;
>
> - /*
> - * We don't need the reset flag anymore after the fork. It has
> - * fulfilled its duty:
> - */
> - p->sched_reset_on_fork = 0;
> -
> #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
> if (likely(sched_info_on()))
> memset(&p->sched_info, 0, sizeof(p->sched_info));
>
Lennart
--
Lennart Poettering Red Hat, Inc.
lennart [at] poettering [dot] net
http://0pointer.net/lennart/ GnuPG 0x1A015CC4
On Tue, 2009-06-16 at 18:47 +0200, Lennart Poettering wrote:
> On Tue, 16.06.09 11:05, Mike Galbraith ([email protected]) wrote:
>
> > I think it's cleaner to keep reset_on_fork functionality separate.
> > Thoughts on the below?
>
> Looks good to me!
OK, I'll submit then, splitting cleanup from functionality addition.
commit 58e1710a8a525e0fb1f4c608d5f73377fb56c893
Author: Mike Galbraith <[email protected]>
Date: Wed Jun 17 10:16:26 2009 +0200
sched: SCHED_RESET_ON_FORK cleanup.
Make SCHED_RESET_ON_FORK sched_fork() bits a self-contained unlikely code path.
Signed-off-by: Mike Galbraith <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Lennart Poettering <[email protected]>
LKML-Reference: <new-submission>
---
kernel/sched.c | 34 ++++++++++++++++++----------------
1 files changed, 18 insertions(+), 16 deletions(-)
diff --git a/kernel/sched.c b/kernel/sched.c
index 095892c..3c27e44 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2613,28 +2613,30 @@ void sched_fork(struct task_struct *p, int clone_flags)
set_task_cpu(p, cpu);
/*
- * Revert to default priority/policy on fork if requested. Make sure we
- * do not leak PI boosting priority to the child.
+ * Make sure we do not leak PI boosting priority to the child.
*/
- if (current->sched_reset_on_fork &&
- (p->policy == SCHED_FIFO || p->policy == SCHED_RR))
- p->policy = SCHED_NORMAL;
+ p->prio = current->normal_prio;
- if (current->sched_reset_on_fork &&
- (current->normal_prio < DEFAULT_PRIO))
- p->prio = DEFAULT_PRIO;
- else
- p->prio = current->normal_prio;
+ /*
+ * Revert to default priority/policy on fork if requested.
+ */
+ if (unlikely(p->sched_reset_on_fork)) {
+ if (p->policy == SCHED_FIFO || p->policy == SCHED_RR)
+ p->policy = SCHED_NORMAL;
+
+ if (p->normal_prio < DEFAULT_PRIO)
+ p->prio = DEFAULT_PRIO;
+
+ /*
+ * We don't need the reset flag anymore after the fork. It has
+ * fulfilled its duty:
+ */
+ p->sched_reset_on_fork = 0;
+ }
if (!rt_prio(p->prio))
p->sched_class = &fair_sched_class;
- /*
- * We don't need the reset flag anymore after the fork. It has
- * fulfilled its duty:
- */
- p->sched_reset_on_fork = 0;
-
#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
if (likely(sched_info_on()))
memset(&p->sched_info, 0, sizeof(p->sched_info));
commit 50f3ff67c7fbcd37f0a135113ecd56f724d9b081
Author: Mike Galbraith <[email protected]>
Date: Wed Jun 17 10:30:19 2009 +0200
sched: Add SCHED_RESET_ON_FORK functionality for nice < 0 tasks.
Signed-off-by: Mike Galbraith <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Lennart Poettering <[email protected]>
LKML-Reference: <new-submission>
---
kernel/sched.c | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/kernel/sched.c b/kernel/sched.c
index 3c27e44..fe31c2d 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2627,6 +2627,11 @@ void sched_fork(struct task_struct *p, int clone_flags)
if (p->normal_prio < DEFAULT_PRIO)
p->prio = DEFAULT_PRIO;
+ if (PRIO_TO_NICE(p->static_prio) < 0) {
+ p->static_prio = NICE_TO_PRIO(0);
+ set_load_weight(p);
+ }
+
/*
* We don't need the reset flag anymore after the fork. It has
* fulfilled its duty:
Commit-ID: e53438963eacc5624b61293f64e9f93c71f71198
Gitweb: http://git.kernel.org/tip/e53438963eacc5624b61293f64e9f93c71f71198
Author: Mike Galbraith <[email protected]>
AuthorDate: Tue, 16 Jun 2009 11:05:08 +0200
Committer: Ingo Molnar <[email protected]>
CommitDate: Wed, 17 Jun 2009 09:01:51 +0200
sched: Introduce SCHED_RESET_ON_FORK scheduling policy flag, fix
Make SCHED_RESET_ON_FORK to DTRT for reniced tasks, and make the
sched_fork() SCHED_RESET_ON_FORK bits a self-contained unlikely
code block.
Signed-off-by: Mike Galbraith <[email protected]>
Acked-by: Lennart Poettering <[email protected]>
Cc: Peter Zijlstra <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
kernel/sched.c | 41 ++++++++++++++++++++++++-----------------
1 file changed, 24 insertions(+), 17 deletions(-)
---
kernel/sched.c | 39 +++++++++++++++++++++++----------------
1 files changed, 23 insertions(+), 16 deletions(-)
diff --git a/kernel/sched.c b/kernel/sched.c
index 32e6ede..34f9424 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2613,28 +2613,35 @@ void sched_fork(struct task_struct *p, int clone_flags)
set_task_cpu(p, cpu);
/*
- * Revert to default priority/policy on fork if requested. Make sure we
- * do not leak PI boosting priority to the child.
+ * Make sure we do not leak PI boosting priority to the child.
*/
- if (current->sched_reset_on_fork &&
- (p->policy == SCHED_FIFO || p->policy == SCHED_RR))
- p->policy = SCHED_NORMAL;
+ p->prio = current->normal_prio;
- if (current->sched_reset_on_fork &&
- (current->normal_prio < DEFAULT_PRIO))
- p->prio = DEFAULT_PRIO;
- else
- p->prio = current->normal_prio;
+ /*
+ * Revert to default priority/policy on fork if requested.
+ */
+ if (unlikely(p->sched_reset_on_fork)) {
+ if (p->policy == SCHED_FIFO || p->policy == SCHED_RR)
+ p->policy = SCHED_NORMAL;
+
+ if (p->normal_prio < DEFAULT_PRIO)
+ p->prio = DEFAULT_PRIO;
+
+ if (PRIO_TO_NICE(p->static_prio) < 0) {
+ p->static_prio = NICE_TO_PRIO(0);
+ set_load_weight(p);
+ }
+
+ /*
+ * We don't need the reset flag anymore after the fork. It has
+ * fulfilled its duty:
+ */
+ p->sched_reset_on_fork = 0;
+ }
if (!rt_prio(p->prio))
p->sched_class = &fair_sched_class;
- /*
- * We don't need the reset flag anymore after the fork. It has
- * fulfilled its duty:
- */
- p->sched_reset_on_fork = 0;
-
#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
if (likely(sched_info_on()))
memset(&p->sched_info, 0, sizeof(p->sched_info));
Commit-ID: 6c697bdf08a09ce461e305a22362973036e95db3
Gitweb: http://git.kernel.org/tip/6c697bdf08a09ce461e305a22362973036e95db3
Author: Mike Galbraith <[email protected]>
AuthorDate: Wed, 17 Jun 2009 10:48:02 +0200
Committer: Ingo Molnar <[email protected]>
CommitDate: Wed, 17 Jun 2009 18:34:18 +0200
sched: Add SCHED_RESET_ON_FORK functionality for nice < 0 tasks
Signed-off-by: Mike Galbraith <[email protected]>
Acked-by: Lennart Poettering <[email protected]>
Cc: Peter Zijlstra <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
---
kernel/sched.c | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/kernel/sched.c b/kernel/sched.c
index 50e4e3d..34f9424 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2627,6 +2627,11 @@ void sched_fork(struct task_struct *p, int clone_flags)
if (p->normal_prio < DEFAULT_PRIO)
p->prio = DEFAULT_PRIO;
+ if (PRIO_TO_NICE(p->static_prio) < 0) {
+ p->static_prio = NICE_TO_PRIO(0);
+ set_load_weight(p);
+ }
+
/*
* We don't need the reset flag anymore after the fork. It has
* fulfilled its duty:
Commit-ID: b9dc29e72fd3dc2a739ce8eafd958220d0745734
Gitweb: http://git.kernel.org/tip/b9dc29e72fd3dc2a739ce8eafd958220d0745734
Author: Mike Galbraith <[email protected]>
AuthorDate: Wed, 17 Jun 2009 10:46:01 +0200
Committer: Ingo Molnar <[email protected]>
CommitDate: Wed, 17 Jun 2009 18:34:17 +0200
sched: Clean up SCHED_RESET_ON_FORK
Make SCHED_RESET_ON_FORK sched_fork() bits a self-contained unlikely code path.
Signed-off-by: Mike Galbraith <[email protected]>
Acked-by: Lennart Poettering <[email protected]>
Cc: Peter Zijlstra <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
---
kernel/sched.c | 34 ++++++++++++++++++----------------
1 files changed, 18 insertions(+), 16 deletions(-)
diff --git a/kernel/sched.c b/kernel/sched.c
index 32e6ede..50e4e3d 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2613,28 +2613,30 @@ void sched_fork(struct task_struct *p, int clone_flags)
set_task_cpu(p, cpu);
/*
- * Revert to default priority/policy on fork if requested. Make sure we
- * do not leak PI boosting priority to the child.
+ * Make sure we do not leak PI boosting priority to the child.
*/
- if (current->sched_reset_on_fork &&
- (p->policy == SCHED_FIFO || p->policy == SCHED_RR))
- p->policy = SCHED_NORMAL;
+ p->prio = current->normal_prio;
- if (current->sched_reset_on_fork &&
- (current->normal_prio < DEFAULT_PRIO))
- p->prio = DEFAULT_PRIO;
- else
- p->prio = current->normal_prio;
+ /*
+ * Revert to default priority/policy on fork if requested.
+ */
+ if (unlikely(p->sched_reset_on_fork)) {
+ if (p->policy == SCHED_FIFO || p->policy == SCHED_RR)
+ p->policy = SCHED_NORMAL;
+
+ if (p->normal_prio < DEFAULT_PRIO)
+ p->prio = DEFAULT_PRIO;
+
+ /*
+ * We don't need the reset flag anymore after the fork. It has
+ * fulfilled its duty:
+ */
+ p->sched_reset_on_fork = 0;
+ }
if (!rt_prio(p->prio))
p->sched_class = &fair_sched_class;
- /*
- * We don't need the reset flag anymore after the fork. It has
- * fulfilled its duty:
- */
- p->sched_reset_on_fork = 0;
-
#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
if (likely(sched_info_on()))
memset(&p->sched_info, 0, sizeof(p->sched_info));