The patch titled
oom-kill: mm locking fix
has been added to the -mm tree. Its filename is
oom-kill-mm-locking-fix.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
From: Andrew Morton <akpm@xxxxxxxx>
Dave Peterson <dsp@xxxxxxxx> points out that badness() is playing with
mm_structs without taking a reference on them.
mmput() can sleep, so taking a reference here (inside tasklist_lock) is hard.
Fix it up via task_lock() instead.
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
mm/oom_kill.c | 26 ++++++++++++++++++--------
1 files changed, 18 insertions(+), 8 deletions(-)
diff -puN mm/oom_kill.c~oom-kill-mm-locking-fix mm/oom_kill.c
--- 25/mm/oom_kill.c~oom-kill-mm-locking-fix Fri Apr 14 14:31:29 2006
+++ 25-akpm/mm/oom_kill.c Fri Apr 14 14:31:29 2006
@@ -47,15 +47,25 @@ int sysctl_panic_on_oom;
unsigned long badness(struct task_struct *p, unsigned long uptime)
{
unsigned long points, cpu_time, run_time, s;
- struct list_head *tsk;
+ struct mm_struct *mm;
+ struct task_struct *child;
- if (!p->mm)
+ task_lock(p);
+ mm = p->mm;
+ if (!mm) {
+ task_unlock(p);
return 0;
+ }
/*
* The memory size of the process is the basis for the badness.
*/
- points = p->mm->total_vm;
+ points = mm->total_vm;
+
+ /*
+ * After this unlock we can no longer dereference local variable `mm'
+ */
+ task_unlock(p);
/*
* Processes which fork a lot of child processes are likely
@@ -65,11 +75,11 @@ unsigned long badness(struct task_struct
* child is eating the vast majority of memory, adding only half
* to the parents will make the child our kill candidate of choice.
*/
- list_for_each(tsk, &p->children) {
- struct task_struct *chld;
- chld = list_entry(tsk, struct task_struct, sibling);
- if (chld->mm != p->mm && chld->mm)
- points += chld->mm->total_vm/2 + 1;
+ list_for_each_entry(child, &p->children, sibling) {
+ task_lock(child);
+ if (child->mm != mm && child->mm)
+ points += child->mm->total_vm/2 + 1;
+ task_unlock(child);
}
/*
_
Patches currently in -mm which might be from akpm@xxxxxxxx are
origin.patch
config_net=n-build-fix.patch
git-acpi.patch
acpi-update-asus_acpi-driver-registration-fix.patch
acpi-memory-hotplug-cannot-manage-_crs-with-plural-resoureces.patch
catch-notification-of-memory-add-event-of-acpi-via-container-driver-register-start-func-for-memory-device.patch
catch-notification-of-memory-add-event-of-acpi-via-container-driveravoid-redundant-call-add_memory.patch
sony_apci-resume.patch
git-audit-master-fixup.patch
powernow-k8-crash-workaround.patch
git-drm.patch
git-dvb.patch
git-dvb-compat-build-fix.patch
bt866-build-fix.patch
connector-exports.patch
pci-error-recovery-e1000-network-device-driver.patch
git-pcmcia.patch
git-scsi-misc.patch
megaraid-unused-variable.patch
git-sas-jg.patch
git-sas-jg-build-hack.patch
git-splice-fixup.patch
git-watchdog.patch
arm-add_memory-build-fix.patch
pg_uncached-is-ia64-only.patch
migration-remove-unnecessary-pageswapcache-checks-fix.patch
wait_table-and-zonelist-initializing-for-memory-hotadd-wait_table-initialization-fixes.patch
oom-kill-mm-locking-fix.patch
page_allocc-buddy-handling-cleanup.patch
acx1xx-wireless-driver.patch
prune_one_dentry-tweaks.patch
fix-cdrom-being-confused-on-using-kdump-tweaks.patch
mmput-might-sleep.patch
tpm-use-clear_bit-fix.patch
tpm-use-clear_bit-fix-fix.patch
tpm-use-clear_bit-fix-fix-fix-fix.patch
hangcheck-remove-monotomic_clock-on-x86.patch
pi-futex-futex-code-cleanups-fix.patch
reiser4.patch
kgdb-core-lite-add-reboot-command.patch
kgdb-8250-fix.patch
nr_blockdev_pages-in_interrupt-warning.patch
device-suspend-debug.patch
revert-tty-buffering-comment-out-debug-code.patch
slab-leaks3-default-y.patch
x86-kmap_atomic-debugging.patch
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