Messages in this thread Patch in this message | | | Date | Tue, 22 Mar 2022 08:02:45 -0000 | From | "tip-bot2 for Huang, Ying" <> | Subject | [tip: sched/core] sched/numa: Fix boot crash on arm64 systems |
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The following commit has been merged into the sched/core branch of tip:
Commit-ID: ab31c7fd2d37bc3580d9d712d5f2dfb69901fca9 Gitweb: https://git.kernel.org/tip/ab31c7fd2d37bc3580d9d712d5f2dfb69901fca9 Author: Huang, Ying <ying.huang@intel.com> AuthorDate: Tue, 22 Mar 2022 08:39:22 +01:00 Committer: Ingo Molnar <mingo@kernel.org> CommitterDate: Tue, 22 Mar 2022 08:49:22 +01:00
sched/numa: Fix boot crash on arm64 systems
Qian Cai reported a boot crash on arm64 systems, caused by:
0fb3978b0aac ("sched/numa: Fix NUMA topology for systems with CPU-less nodes")
The bug is that node_state() must be supplied a valid node_states[] array index, but in task_numa_placement() the max_nid search can fail with NUMA_NO_NODE, which is not a valid index.
Fix it by checking that max_nid is a valid index.
[ mingo: Added changelog. ]
Fixes: 0fb3978b0aac ("sched/numa: Fix NUMA topology for systems with CPU-less nodes") Reported-by: Qian Cai <quic_qiancai@quicinc.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> --- kernel/sched/fair.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 89d21fd..ee0664c 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2437,7 +2437,7 @@ static void task_numa_placement(struct task_struct *p) } /* Cannot migrate task to CPU-less node */ - if (!node_state(max_nid, N_CPU)) { + if (max_nid != NUMA_NO_NODE && !node_state(max_nid, N_CPU)) { int near_nid = max_nid; int distance, near_distance = INT_MAX;
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