[RFC][PATCH 06/10] Task watchers v2 Register NUMA mempolicy task watcher

Matt Helsley
2006-09-29T02:02:38Z

[-- Attachment #1: task-watchers-register-numa-mempolicy --]
[-- Type: text/plain, Size: 4126 bytes --]

Register a NUMA mempolicy task watcher instead of hooking into
copy_process() and do_exit() directly.

Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
---
kernel/exit.c | 4 ----
kernel/fork.c | 15 +--------------
mm/mempolicy.c | 24 ++++++++++++++++++++++++
3 files changed, 25 insertions(+), 18 deletions(-)

Index: linux-2.6.18-mm1/mm/mempolicy.c
===================================================================
--- linux-2.6.18-mm1.orig/mm/mempolicy.c
+++ linux-2.6.18-mm1/mm/mempolicy.c
@@ -87,10 +87,11 @@
#include <linux/seq_file.h>
#include <linux/proc_fs.h>
#include <linux/migrate.h>
#include <linux/rmap.h>
#include <linux/security.h>
+#include <linux/task_watchers.h>

#include <asm/tlbflush.h>
#include <asm/uaccess.h>

/* Internal flags */
@@ -1331,10 +1332,33 @@ struct mempolicy *__mpol_copy(struct mem
}
}
return new;
}

+static int init_task_mempolicy(unsigned long clone_flags,
+ struct task_struct *tsk)
+{
+ tsk->mempolicy = mpol_copy(tsk->mempolicy);
+ if (IS_ERR(tsk->mempolicy)) {
+ int retval;
+
+ retval = PTR_ERR(tsk->mempolicy);
+ tsk->mempolicy = NULL;
+ return retval;
+ }
+ mpol_fix_fork_child_flag(tsk);
+ return 0;
+}
+task_watcher_func(init, init_task_mempolicy);
+
+static int free_task_mempolicy(unsigned int ignored, struct task_struct *tsk)
+{
+ mpol_free(tsk);
+ tsk->mempolicy = NULL;
+}
+task_watcher_func(free, free_task_mempolicy);
+
/* Slow path of a mempolicy comparison */
int __mpol_equal(struct mempolicy *a, struct mempolicy *b)
{
if (!a || !b)
return 0;
Index: linux-2.6.18-mm1/kernel/fork.c
===================================================================
--- linux-2.6.18-mm1.orig/kernel/fork.c
+++ linux-2.6.18-mm1/kernel/fork.c
@@ -1058,19 +1058,10 @@ 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;
-#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_delays_binfmt;
- }
- mpol_fix_fork_child_flag(p);
-#endif
#ifdef CONFIG_TRACE_IRQFLAGS
p->irq_events = 0;
#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
p->hardirqs_enabled = 1;
#else
@@ -1099,11 +1090,11 @@ static struct task_struct *copy_process(
#ifdef CONFIG_DEBUG_MUTEXES
p->blocked_on = NULL; /* not blocked yet */
#endif

if ((retval = security_task_alloc(p)))
- goto bad_fork_cleanup_policy;
+ goto bad_fork_cleanup_delays_binfmt;
/* copy all the process information */
if ((retval = copy_files(clone_flags, p)))
goto bad_fork_cleanup_security;
if ((retval = copy_fs(clone_flags, p)))
goto bad_fork_cleanup_files;
@@ -1275,14 +1266,10 @@ bad_fork_cleanup_fs:
exit_fs(p); /* blocking */
bad_fork_cleanup_files:
exit_files(p); /* blocking */
bad_fork_cleanup_security:
security_task_free(p);
-bad_fork_cleanup_policy:
-#ifdef CONFIG_NUMA
- mpol_free(p->mempolicy);
-#endif
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-2.6.18-mm1/kernel/exit.c
===================================================================
--- linux-2.6.18-mm1.orig/kernel/exit.c
+++ linux-2.6.18-mm1/kernel/exit.c
@@ -930,14 +930,10 @@ fastcall NORET_TYPE void do_exit(long co

tsk->exit_code = code;
proc_exit_connector(tsk);
exit_notify(tsk);
exit_task_namespaces(tsk);
-#ifdef CONFIG_NUMA
- mpol_free(tsk->mempolicy);
- tsk->mempolicy = NULL;
-#endif
/*
* This must happen late, after the PID is not
* hashed anymore:
*/
if (unlikely(!list_empty(&tsk->pi_state_list)))