On Tue, May 18, 2021 at 6:09 PM Mike Rapoport [off-list ref] wrote:

On Mon, May 17, 2021 at 07:20:41PM +0800, Dong Aisheng wrote:

quoted

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@linux-foundation.org>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
---
 mm/sparse.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/sparse.c b/mm/sparse.c
index 7ac481353b6b..98bfacc763da 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c

@@ -549,12 +549,14 @@ static void __init sparse_init_nid(int nid, unsigned long pnum_begin,
                             __func__, nid);
                      pnum_begin = pnum;
                      sparse_buffer_fini();
+                     memblock_free_early(__pa(usage), map_count * mem_section_usage_size());

I'd move both sparse_buffer_fini() and freeing of 'usage' memory after the
failed label.

Doing that needs to introduce another 'failed' label.
Do you think if it's necessary?

e.g.

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;

Regards
Aisheng

quoted

                      goto failed;
              }
              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;
--
2.25.1

--
Sincerely yours,
Mike.