Re: [PATCH] Fix: PowerNV crash with 4.4.0-rc8 at sched_init_numa
From: Jan Stancek <jstancek@redhat.com>
Date: 2016-01-18 11:07:22
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linux-mm, lkml
----- Original Message -----
From: "Raghavendra K T" <redacted>
To: mingo@redhat.com, peterz@infradead.org, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au,
anton@samba.org, akpm@linux-foundation.org
Cc: jstancek@redhat.com, gkurz@linux.vnet.ibm.com, "grant likely" <redacted>,
nikunj@linux.vnet.ibm.com, vdavydov@parallels.com, "raghavendra kt" [off-list ref],
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
Sent: Friday, 15 January, 2016 8:01:23 PM
Subject: [PATCH] Fix: PowerNV crash with 4.4.0-rc8 at sched_init_numa
Commit c118baf80256 ("arch/powerpc/mm/numa.c: do not allocate bootmem
memory for non existing nodes") avoided bootmem memory allocation for
non existent nodes.
When DEBUG_PER_CPU_MAPS enabled, powerNV system failed to boot because
in sched_init_numa, cpumask_or operation was done on unallocated nodes.
Fix that by making cpumask_or operation only on existing nodes.
[ Tested with and w/o DEBUG_PER_CPU_MAPS on x86 and powerpc ]
Reported-by: Jan Stancek <jstancek@redhat.com>Tested-by: Jan Stancek <jstancek@redhat.com> I also verified with my setup, that this made the crash go away. Report mail thread for reference: https://lists.ozlabs.org/pipermail/linuxppc-dev/2016-January/137691.html Regards, Jan
quoted hunk ↗ jump to hunk
Signed-off-by: Raghavendra K T <redacted> --- kernel/sched/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 44253ad..474658b 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c@@ -6840,7 +6840,7 @@ static void sched_init_numa(void) sched_domains_numa_masks[i][j] = mask; - for (k = 0; k < nr_node_ids; k++) { + for_each_node(k) { if (node_distance(j, k) > sched_domains_numa_distance[i]) continue; --1.7.11.7