Re: return value of ptep_get_and_clear

Kumar Gala wrote:

ptep_get_and_clear has a signature that looks something like:

static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,

                                       pte_t *ptep)

It appears that its suppose to return the pte_t pointed to by ptep before its modified. Why do we bother doing this? The caller seems perfectly able to dereference ptep and hold on to it. Am I missing something here?

You need to be able to *atomically* clear the pte and retrieve the
old value.

Nick

--
SUSE Labs, Novell Inc.

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