From 9363b9f23c9cc36cc8ef6c05fdf879ee4a96ae92 Mon Sep 17 00:00:00 2001 From: Balbir Singh Date: Wed, 15 Oct 2008 22:01:05 -0700 Subject: memrlimit: cgroup mm owner callback changes to add task info This patch adds an additional field to the mm_owner callbacks. This field is required to get to the mm that changed. Hold mmap_sem in write mode before calling the mm_owner_changed callback [hugh@veritas.com: fix mmap_sem deadlock] Signed-off-by: Balbir Singh Cc: Sudhir Kumar Cc: YAMAMOTO Takashi Cc: Paul Menage Cc: Li Zefan Cc: Pavel Emelianov Cc: Balbir Singh Cc: KAMEZAWA Hiroyuki Cc: David Rientjes Cc: Vivek Goyal Signed-off-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exit.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'kernel/exit.c') diff --git a/kernel/exit.c b/kernel/exit.c index 85a83c83185..0ef4673e351 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -640,24 +640,23 @@ retry: assign_new_owner: BUG_ON(c == p); get_task_struct(c); + read_unlock(&tasklist_lock); + down_write(&mm->mmap_sem); /* * The task_lock protects c->mm from changing. * We always want mm->owner->mm == mm */ task_lock(c); - /* - * Delay read_unlock() till we have the task_lock() - * to ensure that c does not slip away underneath us - */ - read_unlock(&tasklist_lock); if (c->mm != mm) { task_unlock(c); + up_write(&mm->mmap_sem); put_task_struct(c); goto retry; } cgroup_mm_owner_callbacks(mm->owner, c); mm->owner = c; task_unlock(c); + up_write(&mm->mmap_sem); put_task_struct(c); } #endif /* CONFIG_MM_OWNER */ -- cgit v1.2.3-18-g5258