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authorJason Gunthorpe <jgg@nvidia.com>2023-06-27 14:06:29 -0300
committerJason Gunthorpe <jgg@nvidia.com>2023-06-27 14:06:29 -0300
commit5f004bcaee4cb552cf1b46a505f18f08777db7e5 (patch)
treec81bdd8e01ba8de9862c8bdb1b210559d4bcf154 /include/linux/page-flags.h
parent4251f631fdfba0b38e4634510c5950ee157cc069 (diff)
parent6995e2de6891c724bfeb2db33d7b87775f913ad1 (diff)
Merge tag 'v6.4' into rdma.git for-next
Linux 6.4 Resolve conflicts between rdma rc and next in rxe_cq matching linux-next: drivers/infiniband/sw/rxe/rxe_cq.c: https://lore.kernel.org/r/20230622115246.365d30ad@canb.auug.org.au Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Diffstat (limited to 'include/linux/page-flags.h')
-rw-r--r--include/linux/page-flags.h6
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 1c68d67b832f..92a2063a0a23 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -617,6 +617,12 @@ PAGEFLAG_FALSE(VmemmapSelfHosted, vmemmap_self_hosted)
* Please note that, confusingly, "page_mapping" refers to the inode
* address_space which maps the page from disk; whereas "page_mapped"
* refers to user virtual address space into which the page is mapped.
+ *
+ * For slab pages, since slab reuses the bits in struct page to store its
+ * internal states, the page->mapping does not exist as such, nor do these
+ * flags below. So in order to avoid testing non-existent bits, please
+ * make sure that PageSlab(page) actually evaluates to false before calling
+ * the following functions (e.g., PageAnon). See mm/slab.h.
*/
#define PAGE_MAPPING_ANON 0x1
#define PAGE_MAPPING_MOVABLE 0x2