forked from luck/tmp_suning_uos_patched
[PATCH] swapoff: use atomic_inc_not_zero() on mm_users
Now that we have atomic_inc_not_zero, it's more elegant for try_to_unuse to use that on mm_users: doesn't actually matter at present, but safer to be sure that once mm_users has gone to 0, nothing raises it for an instant. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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@ -772,10 +772,8 @@ static int try_to_unuse(unsigned int type)
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while (*swap_map > 1 && !retval &&
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(p = p->next) != &start_mm->mmlist) {
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mm = list_entry(p, struct mm_struct, mmlist);
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if (atomic_inc_return(&mm->mm_users) == 1) {
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atomic_dec(&mm->mm_users);
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if (!atomic_inc_not_zero(&mm->mm_users))
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continue;
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}
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spin_unlock(&mmlist_lock);
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mmput(prev_mm);
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prev_mm = mm;
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