Re: [PATCH] mm/hmm: remove redundant check non_swap_entry()

[Matthew Wilcox]

On Fri, Jun 12, 2020 at 12:26:18PM -0700, Ralph Campbell wrote:
> In zap_pte_range(), the check for non_swap_entry() and
> is_device_private_entry() is redundant since the latter is a subset of the
> former. Remove the redundant check to simplify the code and for clarity.

That is highly configuration dependent.

#else /* CONFIG_DEVICE_PRIVATE */
...
static inline bool is_device_private_entry(swp_entry_t entry)
{
        return false;
}

...
#if defined(CONFIG_MEMORY_FAILURE) || defined(CONFIG_MIGRATION) || \
    defined(CONFIG_DEVICE_PRIVATE)
static inline int non_swap_entry(swp_entry_t entry)
{
        return swp_type(entry) >= MAX_SWAPFILES;
}
#else
static inline int non_swap_entry(swp_entry_t entry)
{
        return 0;
}
#endif