Hi mm,
I was looking to use
find_get_pages (struct address_space *mapping, pgoff_t start, unsigned int nr_pages, struct page **pages)
and the comment in the code says -- "There may be holes in the
indices due to not-present pages." I perceived this to be filling
pages which are in the cache and skipping the ones which are not
present -- after the function returns, pages[i] to be not set (NULL
when pages is from a kzalloc) if corresponding page at index i +
offset is not in cache ie. a hole.
But from what I have seen, what it does is set pages[0..nr_in_cache]
to pages found and rest pages[nr_in_cache + 1 .. nr_pages] to be
unset/NULL. By looking at the code, it is calling
radix_tree_gang_lookup_slot, which again returns entries in a
similar way and loops nr_found times (and not nr_pages times). I
looked at the difference between find_get_pages and
find_get_pages_contig, and the only difference I could spot is it
increments index which is used only when a condition is true.
So, does holes in indices mean something else or is there a
different function which can be used for this ?
--------------------------
Raghavendra Prabhu
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