10:23 p.m.
Register a NUMA mempolicy task watcher instead of hooking into
copy_process() and do_exit() directly.
Signed-off-by: Matt Helsley <matthltc(a)us.ibm.com>
---
kernel/exit.c | 4 ----
kernel/fork.c | 15 +--------------
mm/mempolicy.c | 24 ++++++++++++++++++++++++
3 files changed, 25 insertions(+), 18 deletions(-)
Benchmark results:
System: 4 1.7GHz ppc64 (Power 4+) processors, 30968600MB RAM, 2.6.19-rc2-mm2 kernel
Clone Number of Children Cloned
5000 7500 10000 12500 15000 17500
---------------------------------------------------------------------------------------
Mean 17836.3 18085.2 18220.4 18225 18319 18339
Dev 302.801 314.617 303.079 293.46 287.267 294.819
Err (%) 1.69767 1.73963 1.6634 1.6102 1.56814 1.60761
Fork Number of Children Forked
5000 7500 10000 12500 15000 17500
---------------------------------------------------------------------------------------
Mean 17896.2 17990 18100.6 18242.3 18244 18346.9
Dev 301.64 285.698 295.646 304.361 299.472 287.153
Err (%) 1.6855 1.58809 1.63335 1.66844 1.64148 1.56513
Kernbench:
Elapsed: 124.532s User: 439.732s System: 46.497s CPU: 389.9%
439.71user 46.48system 2:04.24elapsed 391%CPU (0avgtext+0avgdata 0maxresident)k
439.79user 46.42system 2:05.10elapsed 388%CPU (0avgtext+0avgdata 0maxresident)k
439.74user 46.44system 2:04.60elapsed 390%CPU (0avgtext+0avgdata 0maxresident)k
439.75user 46.64system 2:04.74elapsed 389%CPU (0avgtext+0avgdata 0maxresident)k
439.61user 46.45system 2:05.36elapsed 387%CPU (0avgtext+0avgdata 0maxresident)k
439.60user 46.43system 2:04.33elapsed 390%CPU (0avgtext+0avgdata 0maxresident)k
439.77user 46.47system 2:04.34elapsed 391%CPU (0avgtext+0avgdata 0maxresident)k
439.87user 46.45system 2:04.10elapsed 391%CPU (0avgtext+0avgdata 0maxresident)k
439.76user 46.71system 2:04.58elapsed 390%CPU (0avgtext+0avgdata 0maxresident)k
439.72user 46.48system 2:03.93elapsed 392%CPU (0avgtext+0avgdata 0maxresident)k
Index: linux-2.6.19-rc2-mm2/mm/mempolicy.c
===================================================================
--- linux-2.6.19-rc2-mm2.orig/mm/mempolicy.c
+++ linux-2.6.19-rc2-mm2/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 */
@@ -1333,10 +1334,33 @@ 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-2.6.19-rc2-mm2/kernel/fork.c
===================================================================
--- linux-2.6.19-rc2-mm2.orig/kernel/fork.c
+++ linux-2.6.19-rc2-mm2/kernel/fork.c
@@ -1052,19 +1052,10 @@ 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
@@ -1091,11 +1082,11 @@ 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;
@@ -1267,14 +1258,10 @@ 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-2.6.19-rc2-mm2/kernel/exit.c
===================================================================
--- linux-2.6.19-rc2-mm2.orig/kernel/exit.c
+++ linux-2.6.19-rc2-mm2/kernel/exit.c
@@ -932,14 +932,10 @@ 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)))
--