Re: [PATCH v6 02/13] mm: remove extra ZONE_DEVICE struct page refcount
From: Christoph Hellwig <hch@lst.de>
Date: 2021-08-15 15:37:19
Also in:
amd-gfx, linux-ext4, linux-xfs
quoted hunk ↗ jump to hunk
diff --git a/include/linux/mm.h b/include/linux/mm.h index 8ae31622deef..d48a1f0889d1 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h@@ -1218,7 +1218,7 @@ __maybe_unused struct page *try_grab_compound_head(struct page *page, int refs, static inline __must_check bool try_get_page(struct page *page) { page = compound_head(page); - if (WARN_ON_ONCE(page_ref_count(page) <= 0)) + if (WARN_ON_ONCE(page_ref_count(page) < (int)!is_zone_device_page(page)))
Please avoid the overly long line. In fact I'd be tempted to just not bother here and keep the old, more lose check. Especially given that John has a patch ready that removes try_get_page entirely.