Commit 7ea8574e authored Aug 29, 2014 by Michal Hocko Committed by Linus Torvalds Aug 29, 2014

hugetlb_cgroup: use lockdep_assert_held rather than spin_is_locked



spin_lock may be an empty struct for !SMP configurations and so
arch_spin_is_locked may return unconditional 0 and trigger the VM_BUG_ON
even when the lock is held.

Replace spin_is_locked by lockdep_assert_held.  We will not BUG anymore
but it is questionable whether crashing makes a lot of sense in the
uncharge path.  Uncharge happens after the last page reference was
released so nobody should touch the page and the function doesn't update
any shared state except for res counter which uses synchronization of
its own.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 137f8cff

mm/hugetlb_cgroup.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -217,7 +217,7 @@ void hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages,

		if (hugetlb_cgroup_disabled())
		return;
		VM_BUG_ON(!spin_is_locked(&hugetlb_lock));
		lockdep_assert_held(&hugetlb_lock);
		h_cg = hugetlb_cgroup_from_page(page);
		if (unlikely(!h_cg))
		return;

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