The patch titled
Subject: mm,sparse: fix deactivate_section for early sections
has been added to the -mm tree. Its filename is
mm-sparsemem-support-sub-section-hotplug-fix.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-sparsemem-support-sub-section-hotplug-fix.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-sparsemem-support-sub-section-hotplug-fix.patch
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------------------------------------------------------
From: Oscar Salvador <osalvador@xxxxxxx>
Subject: mm,sparse: fix deactivate_section for early sections
deactivate_section checks whether a section is early or not in order to
either call free_map_bootmem() or depopulate_section_memmap(). Being the
former for sections added at boot time, and the latter for sections
hotplugged.
The problem is that we zero section_mem_map, so the last early_section()
will always report false and the section will not be removed.
Fix this checking whether a section is early or not at function
entry.
Link: http://lkml.kernel.org/r/20190715081549.32577-2-osalvador@xxxxxxx
Fixes: mmotm ("mm/sparsemem: Support sub-section hotplug")
Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/sparse.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/mm/sparse.c~mm-sparsemem-support-sub-section-hotplug-fix
+++ a/mm/sparse.c
@@ -738,6 +738,7 @@ static void section_deactivate(unsigned
DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
DECLARE_BITMAP(tmp, SUBSECTIONS_PER_SECTION) = { 0 };
struct mem_section *ms = __pfn_to_section(pfn);
+ bool section_is_early = early_section(ms);
struct page *memmap = NULL;
unsigned long *subsection_map = ms->usage
? &ms->usage->subsection_map[0] : NULL;
@@ -772,7 +773,7 @@ static void section_deactivate(unsigned
if (bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION)) {
unsigned long section_nr = pfn_to_section_nr(pfn);
- if (!early_section(ms)) {
+ if (!section_is_early) {
kfree(ms->usage);
ms->usage = NULL;
}
@@ -780,7 +781,7 @@ static void section_deactivate(unsigned
ms->section_mem_map = sparse_encode_mem_map(NULL, section_nr);
}
- if (early_section(ms) && memmap)
+ if (section_is_early && memmap)
free_map_bootmem(memmap);
else
depopulate_section_memmap(pfn, nr_pages, altmap);
_
Patches currently in -mm which might be from osalvador@xxxxxxx are
mm-sparsemem-support-sub-section-hotplug-fix.patch
