From 78d9d6ced31ad2f242e44bd24b774fd99c2d663d Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Fri, 7 Jan 2022 14:15:11 -0500 Subject: [PATCH] mm/gup: Remove hpage_pincount_add() It's clearer to call atomic_add() in the callers; the assertions clearly can't fire there because they're part of the condition for calling atomic_add(). Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: John Hubbard Reviewed-by: Christoph Hellwig --- mm/gup.c | 31 +++++++++++-------------------- 1 file changed, 11 insertions(+), 20 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index d3e8266d8e70..299b78736a4a 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -29,14 +29,6 @@ struct follow_page_context { unsigned int page_mask; }; -static void hpage_pincount_add(struct page *page, int refs) -{ - VM_BUG_ON_PAGE(!hpage_pincount_available(page), page); - VM_BUG_ON_PAGE(page != compound_head(page), page); - - atomic_add(refs, compound_pincount_ptr(page)); -} - static void hpage_pincount_sub(struct page *page, int refs) { VM_BUG_ON_PAGE(!hpage_pincount_available(page), page); @@ -151,17 +143,17 @@ __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, via hpage_pincount_add/_sub(). + * When pinning a compound page of order > 1 (which is + * what hpage_pincount_available() checks for), 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 + * 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)) - hpage_pincount_add(page, refs); + atomic_add(refs, compound_pincount_ptr(page)); else page_ref_add(page, refs * (GUP_PIN_COUNTING_BIAS - 1)); @@ -222,14 +214,13 @@ bool __must_check try_grab_page(struct page *page, unsigned int flags) return false; /* - * Similar to try_grab_compound_head(): even if using the - * hpage_pincount_add/_sub() routines, be sure to - * *also* increment the normal page refcount field at least - * once, so that the page really is pinned. + * Similar to try_grab_compound_head(): be sure to *also* + * increment the normal page refcount field at least once, + * so that the page really is pinned. */ if (hpage_pincount_available(page)) { page_ref_add(page, 1); - hpage_pincount_add(page, 1); + atomic_add(1, compound_pincount_ptr(page)); } else { page_ref_add(page, GUP_PIN_COUNTING_BIAS); }