diff options
Diffstat (limited to 'mm/gup.c')
| -rw-r--r-- | mm/gup.c | 20 |
1 files changed, 9 insertions, 11 deletions
@@ -99,12 +99,11 @@ retry: * * FOLL_GET: page's refcount will be incremented by @refs. * - * FOLL_PIN on compound pages that are > two pages long: page's refcount will - * be incremented by @refs, and page[2].hpage_pinned_refcount will be - * incremented by @refs * GUP_PIN_COUNTING_BIAS. + * FOLL_PIN on compound pages: page's refcount will be incremented by + * @refs, and page[1].compound_pincount will be incremented by @refs. * - * FOLL_PIN on normal pages, or compound pages that are two pages long: - * page's refcount will be incremented by @refs * GUP_PIN_COUNTING_BIAS. + * FOLL_PIN on normal pages: page's refcount will be incremented by + * @refs * GUP_PIN_COUNTING_BIAS. * * Return: head page (with refcount appropriately incremented) for success, or * NULL upon failure. If neither FOLL_GET nor FOLL_PIN was set, that's @@ -135,16 +134,15 @@ __maybe_unused struct page *try_grab_compound_head(struct page *page, return NULL; /* - * When pinning a compound page of order > 1 (which is - * what hpage_pincount_available() checks for), use an - * exact count to track it. + * When pinning a compound page, use an exact count to + * track it. * * However, be sure to *also* increment the normal page * refcount field at least once, so that the page really * is pinned. That's why the refcount from the earlier * try_get_compound_head() is left intact. */ - if (hpage_pincount_available(page)) + if (PageHead(page)) atomic_add(refs, compound_pincount_ptr(page)); else page_ref_add(page, refs * (GUP_PIN_COUNTING_BIAS - 1)); @@ -166,7 +164,7 @@ static void put_compound_head(struct page *page, int refs, unsigned int flags) if (flags & FOLL_PIN) { mod_node_page_state(page_pgdat(page), NR_FOLL_PIN_RELEASED, refs); - if (hpage_pincount_available(page)) + if (PageHead(page)) atomic_sub(refs, compound_pincount_ptr(page)); else refs *= GUP_PIN_COUNTING_BIAS; @@ -211,7 +209,7 @@ bool __must_check try_grab_page(struct page *page, unsigned int flags) * increment the normal page refcount field at least once, * so that the page really is pinned. */ - if (hpage_pincount_available(page)) { + if (PageHead(page)) { page_ref_add(page, 1); atomic_add(1, compound_pincount_ptr(page)); } else { |