Qian Cai <quic_qiancai@xxxxxxxxxxx> writes: > On Thu, Feb 17, 2022 at 06:56:52PM -0000, tip-bot2 for Huang Ying wrote: >> The following commit has been merged into the sched/core branch of tip: >> >> Commit-ID: 5c7b1aaf139dab5072311853bacc40fc3457d1f9 >> Gitweb: https://git.kernel.org/tip/5c7b1aaf139dab5072311853bacc40fc3457d1f9 >> Author: Huang Ying <ying.huang@xxxxxxxxx> >> AuthorDate: Mon, 14 Feb 2022 20:15:53 +08:00 >> Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx> >> CommitterDate: Wed, 16 Feb 2022 15:57:53 +01:00 >> >> sched/numa: Avoid migrating task to CPU-less node >> >> In a typical memory tiering system, there's no CPU in slow (PMEM) NUMA >> nodes. But if the number of the hint page faults on a PMEM node is >> the max for a task, The current NUMA balancing policy may try to place >> the task on the PMEM node instead of DRAM node. This is unreasonable, >> because there's no CPU in PMEM NUMA nodes. To fix this, CPU-less >> nodes are ignored when searching the migration target node for a task >> in this patch. >> >> To test the patch, we run a workload that accesses more memory in PMEM >> node than memory in DRAM node. Without the patch, the PMEM node will >> be chosen as preferred node in task_numa_placement(). While the DRAM >> node will be chosen instead with the patch. >> >> Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx> >> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> >> Link: https://lkml.kernel.org/r/20220214121553.582248-2-ying.huang@xxxxxxxxx > > Reverting this commit on the top of today's linux-next fixed a boot crash > on arm64 NUMA systems. > > Unable to handle kernel paging request at virtual address ffff7a6601694aec > KASAN: maybe wild-memory-access in range [0xffffd3300b4a5760-0xffffd3300b4a5767] > Mem abort info: > ESR = 0x96000005 > EC = 0x25: DABT (current EL), IL = 32 bits > mlx5_core 0007:02:00.0: enabling device (0100 -> 0102) > SET = 0, FnV = 0 > EA = 0, S1PTW = 0 > FSC = 0x05: level 1 translation fault > Data abort info: > ISV = 0, ISS = 0x00000005 > CM = 0, WnR = 0 > swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000400b3d6c6000 > [ffff7a6601694aec] pgd=0000403fc007f003, p4d=0000403fc007f003, pud=0000000000000000 > Internal error: Oops: 96000005 [#1] PREEMPT SMP > Modules linked in: nouveau(+) drm_ttm_helper ttm nvme(+) drm_dp_helper drm_kms_helper mlx5_core(+) mpt3sas(+) xhci_pci(+) nvme_core raid_class xhci_pci_renesas drm > CPU: 85 PID: 1308 Comm: udevadm Not tainted 5.17.0-rc6-next-20220301 #1 > pstate: 40400009 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : task_numa_placement > lr : task_numa_placement > sp : ffff800031047760 > x29: ffff800031047760 x28: ffff3fffab916c00 x27: 0000000000000020 > x26: 0000000000000001 x25: 0000000000000000 x24: 0000000000000000 > > x23: ffff07ffe5289a80 x22: ffffd3300b4a5760 x21: 000000000000003f > x20: ffffd32feb4a5768 x19: 0000000000000000 x18: ffff07ffe528ad88 > x17: ffffd32fe5693a1c x16: 0000000000000000 x15: ffff8000310478e0 > > x14: ffff07ffe528ad90 x13: 0000000000000002 x12: dfff80000000000d > x11: 0000000000000001 x10: 000000000000b6be x9 : 0000000000000000 > x8 : 00000000ffffffff x7 : ffffd32feb4a5780 x6 : 0000000000000000 > x5 : 0000000000000000 x4 : 0000000000000000 x3 : 1ffffa6601694aec > x2 : 0000000000000000 x1 : dfff800000000000 x0 : 000000001ffffff8 > Call trace: > task_numa_placement > arch_test_bit at include/asm-generic/bitops/non-atomic.h:118 > (inlined by) node_state at include/linux/nodemask.h:416 > (inlined by) task_numa_placement at kernel/sched/fair.c:2439 > task_numa_fault > do_numa_page > handle_pte_fault > __handle_mm_fault > handle_mm_fault > do_page_fault > do_translation_fault > do_mem_abort > el0_da > el0t_64_sync_handler > el0t_64_sync > Code: 8b000296 d2d00001 f2fbffe1 d343fec3 (38e16861) > ---[ end trace 0000000000000000 ]--- > Kernel panic - not syncing: Oops: Fatal exception > SMP: stopping secondary CPUs > Kernel Offset: 0x532fdcf70000 from 0xffff800008000000 > PHYS_OFFSET: 0x80000000 > CPU features: 0x00,00042c0c,19801c82 > Memory Limit: none > ---[ end Kernel panic - not syncing: Oops: Fatal exception ]--- Thanks for reporting! Can you try whether the following debug patch can fix the issue? Best Regards, Huang, Ying ----------------------------8<-------------------------------------------
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