From 21f86651a66abefcfce33f4611c2de7863a8642b Mon Sep 17 00:00:00 2001 From: Liam Mark Date: Thu, 7 Feb 2013 14:31:36 -0800 Subject: android/lowmemorykiller: Ignore tasks with freed mm A killed task can stay in the task list long after its memory has been returned to the system, therefore ignore any tasks whose mm struct has been freed. Change-Id: I76394b203b4ab2312437c839976f0ecb7b6dde4e CRs-fixed: 450383 Signed-off-by: Liam Mark --- kernel/exit.c | 6 +++++- kernel/fork.c | 5 ++++- 2 files changed, 9 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/exit.c b/kernel/exit.c index 77d54139672b..a32e83d567b9 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -388,6 +388,7 @@ static void exit_mm(struct task_struct *tsk) { struct mm_struct *mm = tsk->mm; struct core_state *core_state; + int mm_released; mm_release(tsk, mm); if (!mm) @@ -434,9 +435,12 @@ static void exit_mm(struct task_struct *tsk) enter_lazy_tlb(mm, current); task_unlock(tsk); mm_update_next_owner(mm); - mmput(mm); + + mm_released = mmput(mm); if (test_thread_flag(TIF_MEMDIE)) exit_oom_victim(); + if (mm_released) + set_tsk_thread_flag(tsk, TIF_MM_RELEASED); } static struct task_struct *find_alive_thread(struct task_struct *p) diff --git a/kernel/fork.c b/kernel/fork.c index 859b949d106f..c9eb86b646ab 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -694,8 +694,9 @@ EXPORT_SYMBOL_GPL(__mmdrop); /* * Decrement the use count and release all resources for an mm. */ -void mmput(struct mm_struct *mm) +int mmput(struct mm_struct *mm) { + int mm_freed = 0; might_sleep(); if (atomic_dec_and_test(&mm->mm_users)) { @@ -713,7 +714,9 @@ void mmput(struct mm_struct *mm) if (mm->binfmt) module_put(mm->binfmt->module); mmdrop(mm); + mm_freed = 1; } + return mm_freed; } EXPORT_SYMBOL_GPL(mmput); -- cgit v1.2.3