On 01/19/2016 07:08 PM, tip-bot for Raghavendra K T wrote:
Commit-ID: 9c03ee147193645be4c186d3688232fa438c57c7 Gitweb: http://git.kernel.org/tip/9c03ee147193645be4c186d3688232fa438c57c7 Author: Raghavendra K T <raghavendra.kt@xxxxxxxxxxxxxxxxxx> AuthorDate: Sat, 16 Jan 2016 00:31:23 +0530 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Tue, 19 Jan 2016 08:42:20 +0100 sched: Fix crash in sched_init_numa() The following PowerPC commit: c118baf80256 ("arch/powerpc/mm/numa.c: do not allocate bootmem memory for non existing nodes") avoids allocating bootmem memory for non existent nodes. But when DEBUG_PER_CPU_MAPS=y is enabled, my 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=y on x86 and PowerPC. ] Reported-by: Jan Stancek <jstancek@xxxxxxxxxx> Tested-by: Jan Stancek <jstancek@xxxxxxxxxx> Signed-off-by: Raghavendra K T <raghavendra.kt@xxxxxxxxxxxxxxxxxx> Cc: <gkurz@xxxxxxxxxxxxxxxxxx> Cc: <grant.likely@xxxxxxxxxx> Cc: <nikunj@xxxxxxxxxxxxxxxxxx> Cc: <vdavydov@xxxxxxxxxxxxx> Cc: <linuxppc-dev@xxxxxxxxxxxxxxxx> Cc: <linux-mm@xxxxxxxxx> Cc: <peterz@xxxxxxxxxxxxx> Cc: <benh@xxxxxxxxxxxxxxxxxxx> Cc: <paulus@xxxxxxxxx> Cc: <mpe@xxxxxxxxxxxxxx> Cc: <anton@xxxxxxxxx> Link: http://lkml.kernel.org/r/1452884483-11676-1-git-send-email-raghavendra.kt@xxxxxxxxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- 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;
Hello Greg, Above commit fixes the debug kernel crash in 4.4 kernel [ when DEBUG_PER_CPU_MAPS=y to be precise]. This is a regression in 4.4 from 4.3 and should be ideally present in 4.4-stable. Could you please pull in this change.? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>