Register cpuset task watcher

From: Matt Helsley
Date: Thu Dec 14 2006 - 19:27:47 EST


Register a task watcher for cpusets instead of hooking into
copy_process() and do_exit() directly.

Signed-off-by: Matt Helsley <matthltc@xxxxxxxxxx>
Cc: Paul Jackson <pj@xxxxxxx>
---
include/linux/cpuset.h | 4 ----
kernel/cpuset.c | 11 +++++++++--
kernel/exit.c | 2 --
kernel/fork.c | 6 +-----
4 files changed, 10 insertions(+), 13 deletions(-)

Index: linux-2.6.19/kernel/fork.c
===================================================================
--- linux-2.6.19.orig/kernel/fork.c
+++ linux-2.6.19/kernel/fork.c
@@ -28,11 +28,10 @@
#include <linux/mman.h>
#include <linux/fs.h>
#include <linux/nsproxy.h>
#include <linux/capability.h>
#include <linux/cpu.h>
-#include <linux/cpuset.h>
#include <linux/security.h>
#include <linux/swap.h>
#include <linux/syscalls.h>
#include <linux/jiffies.h>
#include <linux/futex.h>
@@ -1060,17 +1059,16 @@ static struct task_struct *copy_process(
p->tgid = current->tgid;

retval = notify_task_watchers(WATCH_TASK_INIT, clone_flags, p);
if (retval < 0)
goto bad_fork_cleanup_delays_binfmt;
- cpuset_fork(p);
#ifdef CONFIG_NUMA
p->mempolicy = mpol_copy(p->mempolicy);
if (IS_ERR(p->mempolicy)) {
retval = PTR_ERR(p->mempolicy);
p->mempolicy = NULL;
- goto bad_fork_cleanup_cpuset;
+ goto bad_fork_cleanup_delays_binfmt;
}
mpol_fix_fork_child_flag(p);
#endif
#ifdef CONFIG_TRACE_IRQFLAGS
p->irq_events = 0;
@@ -1279,13 +1277,11 @@ bad_fork_cleanup_files:
bad_fork_cleanup_security:
security_task_free(p);
bad_fork_cleanup_policy:
#ifdef CONFIG_NUMA
mpol_free(p->mempolicy);
-bad_fork_cleanup_cpuset:
#endif
- cpuset_exit(p);
bad_fork_cleanup_delays_binfmt:
delayacct_tsk_free(p);
notify_task_watchers(WATCH_TASK_FREE, 0, p);
if (p->binfmt)
module_put(p->binfmt->module);
Index: linux-2.6.19/kernel/cpuset.c
===================================================================
--- linux-2.6.19.orig/kernel/cpuset.c
+++ linux-2.6.19/kernel/cpuset.c
@@ -47,10 +47,11 @@
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/time.h>
#include <linux/backing-dev.h>
#include <linux/sort.h>
+#include <linux/init.h>

#include <asm/uaccess.h>
#include <asm/atomic.h>
#include <linux/mutex.h>

@@ -2173,17 +2174,20 @@ void __init cpuset_init_smp(void)
*
* At the point that cpuset_fork() is called, 'current' is the parent
* task, and the passed argument 'child' points to the child task.
**/

-void cpuset_fork(struct task_struct *child)
+static int __task_init cpuset_fork(unsigned long clone_flags,
+ struct task_struct *child)
{
task_lock(current);
child->cpuset = current->cpuset;
atomic_inc(&child->cpuset->count);
task_unlock(current);
+ return 0;
}
+DEFINE_TASK_INITCALL(cpuset_fork);

/**
* cpuset_exit - detach cpuset from exiting task
* @tsk: pointer to task_struct of exiting process
*
@@ -2240,11 +2244,12 @@ void cpuset_fork(struct task_struct *chi
* to NULL here, and check in cpuset_update_task_memory_state()
* for a NULL pointer. This hack avoids that NULL check, for no
* cost (other than this way too long comment ;).
**/

-void cpuset_exit(struct task_struct *tsk)
+static int __task_free cpuset_exit(unsigned long exit_code,
+ struct task_struct *tsk)
{
struct cpuset *cs;

cs = tsk->cpuset;
tsk->cpuset = &top_cpuset; /* the_top_cpuset_hack - see above */
@@ -2258,11 +2263,13 @@ void cpuset_exit(struct task_struct *tsk
mutex_unlock(&manage_mutex);
cpuset_release_agent(pathbuf);
} else {
atomic_dec(&cs->count);
}
+ return 0;
}
+DEFINE_TASK_FREECALL(cpuset_exit);

/**
* cpuset_cpus_allowed - return cpus_allowed mask from a tasks cpuset.
* @tsk: pointer to task_struct from which to obtain cpuset->cpus_allowed.
*
Index: linux-2.6.19/kernel/exit.c
===================================================================
--- linux-2.6.19.orig/kernel/exit.c
+++ linux-2.6.19/kernel/exit.c
@@ -28,11 +28,10 @@
#include <linux/mount.h>
#include <linux/proc_fs.h>
#include <linux/mempolicy.h>
#include <linux/taskstats_kern.h>
#include <linux/delayacct.h>
-#include <linux/cpuset.h>
#include <linux/syscalls.h>
#include <linux/signal.h>
#include <linux/posix-timers.h>
#include <linux/cn_proc.h>
#include <linux/mutex.h>
@@ -918,11 +917,10 @@ fastcall NORET_TYPE void do_exit(long co
if (group_dead)
acct_process();
__exit_files(tsk);
__exit_fs(tsk);
exit_thread();
- cpuset_exit(tsk);
exit_keys(tsk);

if (group_dead && tsk->signal->leader)
disassociate_ctty(1);

Index: linux-2.6.19/include/linux/cpuset.h
===================================================================
--- linux-2.6.19.orig/include/linux/cpuset.h
+++ linux-2.6.19/include/linux/cpuset.h
@@ -17,12 +17,10 @@
extern int number_of_cpusets; /* How many cpusets are defined in system? */

extern int cpuset_init_early(void);
extern int cpuset_init(void);
extern void cpuset_init_smp(void);
-extern void cpuset_fork(struct task_struct *p);
-extern void cpuset_exit(struct task_struct *p);
extern cpumask_t cpuset_cpus_allowed(struct task_struct *p);
extern nodemask_t cpuset_mems_allowed(struct task_struct *p);
void cpuset_init_current_mems_allowed(void);
void cpuset_update_task_memory_state(void);
#define cpuset_nodes_subset_current_mems_allowed(nodes) \
@@ -68,12 +66,10 @@ extern void cpuset_track_online_nodes(vo
#else /* !CONFIG_CPUSETS */

static inline int cpuset_init_early(void) { return 0; }
static inline int cpuset_init(void) { return 0; }
static inline void cpuset_init_smp(void) {}
-static inline void cpuset_fork(struct task_struct *p) {}
-static inline void cpuset_exit(struct task_struct *p) {}

static inline cpumask_t cpuset_cpus_allowed(struct task_struct *p)
{
return cpu_possible_map;
}

--
-
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