postgres.git / summary / log / commit / refs

commit    599336c64fc9ef75727ec3ba4684644dc23f8ddb
Author:   Tomas Vondra <tomas.vondra@postgresql.org>
Date:     Thu Nov 20 11:51:58 2025 +0000
First released in: 18.2

    Handle EPERM in pg_numa_init
    
    When running in Docker, the container may not have privileges needed by
    get_mempolicy(). This is called by numa_available() in libnuma, but
    versions prior to 2.0.19 did not expect that. The numa_available() call
    seemingly succeeds, but then we get unexpected failures when trying to
    query status of pages:
    
      postgres =# select * from pg_shmem_allocations_numa;
      ERROR:  XX000: failed NUMA pages inquiry status: Operation not
              permitted
      LOCATION:  pg_get_shmem_allocations_numa, shmem.c:691
    
    The best solution is to call get_mempolicy() first, and proceed to
    numa_available() only when it does not fail with EPERM. Otherwise we'd
    need to treat older libnuma versions as insufficient, which seems a bit
    too harsh, as this only affects containerized systems.
    
    Fix by me, based on suggestions by Christoph. Backpatch to 18, where the
    NUMA functions were introduced.
    
    Reported-by: Christoph Berg <myon@debian.org>
    Reviewed-by: Christoph Berg <myon@debian.org>
    Discussion: https://postgr.es/m/aPDZOxjrmEo_1JRG@msg.df7cb.de
    Backpatch-through: 18


 src/port/pg_numa.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/port/pg_numa.c b/src/port/pg_numa.c
index 3368a43a338..540ada3f8ef 100644
--- a/src/port/pg_numa.c
+++ b/src/port/pg_numa.c
@@ -47,7 +47,17 @@
 int
 pg_numa_init(void)
 {
-	int			r = numa_available();
+	int			r;
+
+	/*
+	 * XXX libnuma versions before 2.0.19 don't handle EPERM by disabling
+	 * NUMA, which then leads to unexpected failures later. This affects
+	 * containers that disable get_mempolicy by a seccomp profile.
+	 */
+	if (get_mempolicy(NULL, NULL, 0, 0, 0) < 0 && (errno == EPERM))
+		r = -1;
+	else
+		r = numa_available();
 
 	return r;
 }


[parent: b5623cc5e419]