Re: [PATCH 04/17] mm: pass the vmem_altmap to arch_add_memory and __add_pages
From: Dan Williams <hidden>
Date: 2017-12-23 01:49:03
Also in:
linuxppc-dev, lkml, nvdimm
Subsystem:
the rest · Maintainer:
Linus Torvalds
On Fri, Dec 15, 2017 at 6:09 AM, Christoph Hellwig [off-list ref] wrote:
We can just pass this on instead of having to do a radix tree lookup without proper locking 2 levels into the callchain. Signed-off-by: Christoph Hellwig <hch@lst.de>
[..]
quoted hunk ↗ jump to hunk
diff --git a/kernel/memremap.c b/kernel/memremap.c index 403ab9cdb949..16456117a1b1 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c@@ -427,7 +427,7 @@ void *devm_memremap_pages(struct device *dev, struct resource *res, goto err_pfn_remap; mem_hotplug_begin(); - error = arch_add_memory(nid, align_start, align_size, false); + error = arch_add_memory(nid, align_start, align_size, altmap, false); if (!error) move_pfn_range_to_zone(&NODE_DATA(nid)->node_zones[ZONE_DEVICE], align_start >> PAGE_SHIFT,
Subtle bug here. This altmap is the one that was passed in that we copy into its permanent location in the pgmap, so it looks like this patch needs to fold the following fix:
diff --git a/kernel/memremap.c b/kernel/memremap.c
index f277bf5b8c57..157a3756e1d5 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c@@ -382,6 +382,7 @@ void *devm_memremap_pages(struct device *dev,struct resource *res,
if (altmap) {
memcpy(&page_map->altmap, altmap, sizeof(*altmap));
pgmap->altmap = &page_map->altmap;
+ altmap = pgmap->altmap;
}
pgmap->ref = ref;
pgmap->res = &page_map->res;
--
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