Re: [PATCH v4 04/14] mm/memremap: add ZONE_DEVICE support for compound pages
flat view
From: Christoph Hellwig <hch@lst.de>
Date: 2021-08-27 15:33:14
Also in:
linux-mm, nvdimm
On Fri, Aug 27, 2021 at 03:58:09PM +0100, Joao Martins wrote:
quoted hunk ↗ jump to hunk
+ * @geometry: structural definition of how the vmemmap metadata is populated. + * A zero or 1 defaults to using base pages as the memmap metadata + * representation. A bigger value will set up compound struct pages + * representative of the requested geometry size. * @ops: method table * @owner: an opaque pointer identifying the entity that manages this * instance. Used by various helpers to make sure that no@@ -114,6 +118,7 @@ struct dev_pagemap { struct completion done; enum memory_type type; unsigned int flags; + unsigned long geometry;
So why not make this a shift as I suggested somewhere deep in the last thread? Also geometry sounds a bit strange, even if I can't really offer anything better offhand.
quoted hunk ↗ jump to hunk
+static inline unsigned long pgmap_geometry(struct dev_pagemap *pgmap) +{ + if (pgmap && pgmap->geometry) + return pgmap->geometry;
Why does this need to support a NULL pgmap?
+static void __ref memmap_init_compound(struct page *head, unsigned long head_pfn,
Overly long line.