rpms/kernel/devel kernel.spec, 1.1584, 1.1585 sched-introduce-SCHED_RESET_ON_FORK-scheduling-policy-flag.patch, 1.1, 1.2

Kyle McMartin kyle at fedoraproject.org
Mon Jun 22 16:15:43 UTC 2009 

Author: kyle

Update of /cvs/pkgs/rpms/kernel/devel
In directory cvs1.fedora.phx.redhat.com:/tmp/cvs-serv24479

Modified Files:
	kernel.spec 
	sched-introduce-SCHED_RESET_ON_FORK-scheduling-policy-flag.patch 
Log Message:
* Mon Jun 22 2009 Kyle McMartin <kyle at redhat.com>
- sched-introduce-SCHED_RESET_ON_FORK-scheduling-policy-flag.patch: pull in
  two fixes from Mike Galbraith from tip.git



Index: kernel.spec
===================================================================
RCS file: /cvs/pkgs/rpms/kernel/devel/kernel.spec,v
retrieving revision 1.1584
retrieving revision 1.1585
diff -u -p -r1.1584 -r1.1585
--- kernel.spec	22 Jun 2009 03:30:42 -0000	1.1584
+++ kernel.spec	22 Jun 2009 16:15:12 -0000	1.1585
@@ -1826,6 +1826,10 @@ fi
 # and build.
 
 %changelog
+* Mon Jun 22 2009 Kyle McMartin <kyle at redhat.com>
+- sched-introduce-SCHED_RESET_ON_FORK-scheduling-policy-flag.patch: pull in
+  two fixes from Mike Galbraith from tip.git
+
 * Sun Jun 21 2009 Dave Jones <davej at redhat.com> 2.6.31-0.21.rc0.git18
 - Add patch to possibly fix the pktlen problem on via-velocity.
 

sched-introduce-SCHED_RESET_ON_FORK-scheduling-policy-flag.patch:

Index: sched-introduce-SCHED_RESET_ON_FORK-scheduling-policy-flag.patch
===================================================================
RCS file: /cvs/pkgs/rpms/kernel/devel/sched-introduce-SCHED_RESET_ON_FORK-scheduling-policy-flag.patch,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -p -r1.1 -r1.2
--- sched-introduce-SCHED_RESET_ON_FORK-scheduling-policy-flag.patch	20 Jun 2009 19:36:14 -0000	1.1
+++ sched-introduce-SCHED_RESET_ON_FORK-scheduling-policy-flag.patch	22 Jun 2009 16:15:12 -0000	1.2
@@ -1,56 +1,5 @@
-From: Lennart Poettering <lennart at poettering.net>
-Date: Mon, 15 Jun 2009 15:17:47 +0000 (+0200)
-Subject: sched: Introduce SCHED_RESET_ON_FORK scheduling policy flag
-X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Fx86%2Flinux-2.6-tip.git;a=commitdiff_plain;h=ca94c442535a44d508c99a77e54f21a59f4fc462
-
-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, &param);
-
-by this:
-
-  sched_setscheduler(pid, SCHED_FIFO|SCHED_RESET_ON_FORK, &param);
-
-Signed-off-by: Lennart Poettering <lennart at poettering.net>
-Acked-by: Peter Zijlstra <a.p.zijlstra at chello.nl>
-LKML-Reference: <20090615152714.GA29092 at tango.0pointer.de>
-Signed-off-by: Ingo Molnar <mingo at elte.hu>
----
-
 diff --git a/include/linux/sched.h b/include/linux/sched.h
-index 4896fdf..d4a2c66 100644
+index 4d07542..5ba2c37 100644
 --- a/include/linux/sched.h
 +++ b/include/linux/sched.h
 @@ -38,6 +38,8 @@
@@ -62,7 +11,7 @@ index 4896fdf..d4a2c66 100644
  
  #ifdef __KERNEL__
  
-@@ -1209,6 +1211,10 @@ struct task_struct {
+@@ -1208,6 +1210,10 @@ struct task_struct {
  	unsigned did_exec:1;
  	unsigned in_execve:1;	/* Tell the LSMs that the process is doing an
  				 * execve */
@@ -74,41 +23,44 @@ index 4896fdf..d4a2c66 100644
  	pid_t tgid;
  
 diff --git a/kernel/sched.c b/kernel/sched.c
-index 8ec9d13..32e6ede 100644
+index 7c9098d..168b268 100644
 --- a/kernel/sched.c
 +++ b/kernel/sched.c
-@@ -2613,12 +2613,28 @@ void sched_fork(struct task_struct *p, int clone_flags)
+@@ -2614,9 +2614,32 @@ 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.
++	 * 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;
+ 	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:
++	 * Revert to default priority/policy on fork if requested.
 +	 */
-+	p->sched_reset_on_fork = 0;
++	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 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,
+ 	if (!rt_prio(p->prio))
+ 		p->sched_class = &fair_sched_class;
+ 
+@@ -6100,17 +6123,25 @@ 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;
@@ -139,7 +91,7 @@ index 8ec9d13..32e6ede 100644
  	/*
  	 * 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:
+@@ -6154,6 +6185,10 @@ recheck:
  		/* can't change other user's priorities */
  		if (!check_same_owner(p))
  			return -EPERM;
@@ -150,7 +102,7 @@ index 8ec9d13..32e6ede 100644
  	}
  
  	if (user) {
-@@ -6191,6 +6219,8 @@ recheck:
+@@ -6197,6 +6232,8 @@ recheck:
  	if (running)
  		p->sched_class->put_prev_task(rq, p);
  
@@ -159,7 +111,7 @@ index 8ec9d13..32e6ede 100644
  	oldprio = p->prio;
  	__setscheduler(rq, p, policy, param->sched_priority);
  
-@@ -6307,14 +6337,15 @@ SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
+@@ -6313,14 +6350,15 @@ SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
  	if (p) {
  		retval = security_task_getscheduler(p);
  		if (!retval)

More information about the fedora-extras-commits mailing list