On 8/8/21 6:39 PM, Matthew Wilcox wrote:
On Sun, Aug 08, 2021 at 04:50:16PM -0700, John Hubbard wrote:@@ -103,8 +103,14 @@ static inline struct page *try_get_compound_head(struct page *page, int refs) * same time. (That's true throughout the get_user_pages*() and * pin_user_pages*() APIs.) Cases: * - * FOLL_GET: page's refcount will be incremented by 1. - * FOLL_PIN: page's refcount will be incremented by GUP_PIN_COUNTING_BIAS. + * FOLL_GET: page's refcount will be incremented by refs.I think this would read more clearly if it said @refs (throughout).
OK, will change that for v2.
+ * + * 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 normal pages, or compound pages that are two pages long: + * 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'sDid you run 'make htmldocs' and see how it renders? I haven't looked, but this might work better as an rst list?
Hadn't occurred to me, due to my own incorrect mental separation between
comment kernel docs, and rst formatting ("rst == Documentation/"). I'll give it a try.
thanks,
--
John Hubbard
NVIDIA
