Re: [PATCH V2 2/6] mm/sparse: free section usage memory in case populate_section_memmap failed

From: David Hildenbrand
Date: Tue Jun 01 2021 - 04:19:43 EST


On 31.05.21 11:19, Dong Aisheng wrote:
Free section usage memory in case populate_section_memmap failed.
We use map_count to track the remain unused memory to be freed.

Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxx>
Signed-off-by: Dong Aisheng <aisheng.dong@xxxxxxx>
---
ChangeLog:
v1->v2:
* using goto + lable according to Mike's suggestion
---
mm/sparse.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/mm/sparse.c b/mm/sparse.c
index 7ac481353b6b..408b737e168e 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -533,7 +533,7 @@ static void __init sparse_init_nid(int nid, unsigned long pnum_begin,
mem_section_usage_size() * map_count);
if (!usage) {
pr_err("%s: node[%d] usemap allocation failed", __func__, nid);
- goto failed;
+ goto failed1;
}
sparse_buffer_init(map_count * section_map_size(), nid);
for_each_present_section_nr(pnum_begin, pnum) {
@@ -548,17 +548,20 @@ static void __init sparse_init_nid(int nid, unsigned long pnum_begin,
pr_err("%s: node[%d] memory map backing failed. Some memory will not be available.",
__func__, nid);
pnum_begin = pnum;
- sparse_buffer_fini();
- goto failed;
+ goto failed2;
}
check_usemap_section_nr(nid, usage);
sparse_init_one_section(__nr_to_section(pnum), pnum, map, usage,
SECTION_IS_EARLY);
usage = (void *) usage + mem_section_usage_size();
+ map_count--;
}
sparse_buffer_fini();
return;
-failed:
+failed2:
+ sparse_buffer_fini();
+ memblock_free_early(__pa(usage), map_count * mem_section_usage_size());
+failed1:
/* We failed to allocate, mark all the following pnums as not present */
for_each_present_section_nr(pnum_begin, pnum) {
struct mem_section *ms;


I still don't think we need this. Did you even manage to trigger this to test your patch?

--
Thanks,

David / dhildenb