On Wed, Oct 11, 2023 at 6:53 PM Sourabh Jain <sourabhjain@xxxxxxxxxxxxx> wrote:
>
> Hello Pingfan,
> >>> With this patch series applied, the kdump kernel fails to boot on
> >>> powerpc with nr_cpus=1.
> >>>
> >>> Console logs:
> >>> -------------------
> >>> [root]# echo c > /proc/sysrq-trigger
> >>> [ 74.783235] sysrq: Trigger a crash
> >>> [ 74.783244] Kernel panic - not syncing: sysrq triggered crash
> >>> [ 74.783252] CPU: 58 PID: 3838 Comm: bash Kdump: loaded Not tainted
> >>> 6.6.0-rc5pf-nr-cpus+ #3
> >>> [ 74.783259] Hardware name: POWER10 (raw) phyp pSeries
> >>> [ 74.783275] Call Trace:
> >>> [ 74.783280] [c00000020f4ebac0] [c000000000ed9f38]
> >>> dump_stack_lvl+0x6c/0x9c (unreliable)
> >>> [ 74.783291] [c00000020f4ebaf0] [c000000000150300] panic+0x178/0x438
> >>> [ 74.783298] [c00000020f4ebb90] [c000000000936d48]
> >>> sysrq_handle_crash+0x28/0x30
> >>> [ 74.783304] [c00000020f4ebbf0] [c00000000093773c]
> >>> __handle_sysrq+0x10c/0x250
> >>> [ 74.783309] [c00000020f4ebc90] [c000000000937fa8]
> >>> write_sysrq_trigger+0xc8/0x168
> >>> [ 74.783314] [c00000020f4ebcd0] [c000000000665d8c]
> >>> proc_reg_write+0x10c/0x1b0
> >>> [ 74.783321] [c00000020f4ebd00] [c00000000058da54]
> >>> vfs_write+0x104/0x4b0
> >>> [ 74.783326] [c00000020f4ebdc0] [c00000000058dfdc]
> >>> ksys_write+0x7c/0x140
> >>> [ 74.783331] [c00000020f4ebe10] [c000000000033a64]
> >>> system_call_exception+0x144/0x3a0
> >>> [ 74.783337] [c00000020f4ebe50] [c00000000000c554]
> >>> system_call_common+0xf4/0x258
> >>> [ 74.783343] --- interrupt: c00 at 0x7fffa0721594
> >>> [ 74.783352] NIP: 00007fffa0721594 LR: 00007fffa0697bf4 CTR:
> >>> 0000000000000000
> >>> [ 74.783364] REGS: c00000020f4ebe80 TRAP: 0c00 Not tainted
> >>> (6.6.0-rc5pf-nr-cpus+)
> >>> [ 74.783376] MSR: 800000000280f033
> >>> <SF,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE> CR: 28222202 XER: 00000000
> >>> [ 74.783394] IRQMASK: 0
> >>> [ 74.783394] GPR00: 0000000000000004 00007ffffc4b6800 00007fffa0807300
> >>> 0000000000000001
> >>> [ 74.783394] GPR04: 000000013549ea60 0000000000000002 0000000000000010
> >>> 0000000000000000
> >>> [ 74.783394] GPR08: 0000000000000000 0000000000000000 0000000000000000
> >>> 0000000000000000
> >>> [ 74.783394] GPR12: 0000000000000000 00007fffa0abaf70 0000000040000000
> >>> 000000011a0f9798
> >>> [ 74.783394] GPR16: 000000011a0f9724 000000011a097688 000000011a02ff70
> >>> 000000011a0fd568
> >>> [ 74.783394] GPR20: 0000000135554bf0 0000000000000001 000000011a0aa478
> >>> 00007ffffc4b6a24
> >>> [ 74.783394] GPR24: 00007ffffc4b6a20 000000011a0faf94 0000000000000002
> >>> 000000013549ea60
> >>> [ 74.783394] GPR28: 0000000000000002 00007fffa08017a0 000000013549ea60
> >>> 0000000000000002
> >>> [ 74.783440] NIP [00007fffa0721594] 0x7fffa0721594
> >>> [ 74.783443] LR [00007fffa0697bf4] 0x7fffa0697bf4
> >>> [ 74.783447] --- interrupt: c00
> >>> I'm in purgatory
> >>> [ 0.000000] radix-mmu: Page sizes from device-tree:
> >>> [ 0.000000] radix-mmu: Page size shift = 12 AP=0x0
> >>> [ 0.000000] radix-mmu: Page size shift = 16 AP=0x5
> >>> [ 0.000000] radix-mmu: Page size shift = 21 AP=0x1
> >>> [ 0.000000] radix-mmu: Page size shift = 30 AP=0x2
> >>> [ 0.000000] Activating Kernel Userspace Access Prevention
> >>> [ 0.000000] Activating Kernel Userspace Execution Prevention
> >>> [ 0.000000] radix-mmu: Mapped 0x0000000000000000-0x0000000000010000
> >>> with 64.0 KiB pages (exec)
> >>> [ 0.000000] radix-mmu: Mapped 0x0000000000010000-0x0000000000200000
> >>> with 64.0 KiB pages
> >>> [ 0.000000] radix-mmu: Mapped 0x0000000000200000-0x0000000020000000
> >>> with 2.00 MiB pages
> >>> [ 0.000000] radix-mmu: Mapped 0x0000000020000000-0x0000000022600000
> >>> with 2.00 MiB pages (exec)
> >>> [ 0.000000] radix-mmu: Mapped 0x0000000022600000-0x0000000040000000
> >>> with 2.00 MiB pages
> >>> [ 0.000000] radix-mmu: Mapped 0x0000000040000000-0x0000000180000000
> >>> with 1.00 GiB pages
> >>> [ 0.000000] radix-mmu: Mapped 0x0000000180000000-0x00000001a0000000
> >>> with 2.00 MiB pages
> >>> [ 0.000000] lpar: Using radix MMU under hypervisor
> >>> [ 0.000000] Linux version 6.6.0-rc5pf-nr-cpus+
> >>> (root@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx) (gcc (GCC) 8.5.0 20210514 (Red
> >>> Hat 8.5.0-20), GNU ld version 2.30-123.el8) #3 SMP Mon Oct 9 11:07:
> >>> 41 CDT 2023
> >>> [ 0.000000] Found initrd at 0xc000000022e60000:0xc0000000248f08d8
> >>> [ 0.000000] Hardware name: IBM,9043-MRX POWER10 (raw) 0x800200
> >>> 0xf000006 of:IBM,FW1060.00 (NM1060_016) hv:phyp pSeries
> >>> [ 0.000000] printk: bootconsole [udbg0] enabled
> >>> [ 0.000000] the round shift between dt seq and the cpu logic number:
> >>> 56
> >>> [ 0.000000] BUG: Unable to handle kernel data access on write at
> >>> 0xc0000001a0000000
> >>> [ 0.000000] Faulting instruction address: 0xc000000022009c64
> >>> [ 0.000000] Oops: Kernel access of bad area, sig: 11 [#1]
> >>> [ 0.000000] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
> >>> [ 0.000000] Modules linked in:
> >>> [ 0.000000] CPU: 2 PID: 0 Comm: swapper Not tainted
> >>> 6.6.0-rc5pf-nr-cpus+ #3
> >>> [ 0.000000] Hardware name: POWER10 (raw) hv:phyp pSeries
> >>> [ 0.000000] NIP: c000000022009c64 LR: c000000022009c54 CTR:
> >>> c0000000201ff348
> >>> [ 0.000000] REGS: c000000022aebb00 TRAP: 0300 Not tainted
> >>> (6.6.0-rc5pf-nr-cpus+)
> >>> [ 0.000000] MSR: 8000000000001033 <SF,ME,IR,DR,RI,LE> CR: 28222824
> >>> XER: 00000001
> >>> [ 0.000000] CFAR: c000000020031574 DAR: c0000001a0000000 DSISR:
> >>> 42000000 IRQMASK: 1
> >>> [ 0.000000] GPR00: c000000022009ba0 c000000022aebda0 c0000000213d1300
> >>> 0000000000000004
> >>> [ 0.000000] GPR04: 0000000000000001 c000000022aebbc0 c000000022aebbb8
> >>> 0000000000000000
> >>> [ 0.000000] GPR08: 0000000000000001 c00000019ffffff8 000000000000003a
> >>> c0000000229c8a78
> >>> [ 0.000000] GPR12: 0000000000002000 c000000022e4a800 c0000000211d34b8
> >>> c0000000211d3aa8
> >>> [ 0.000000] GPR16: c0000000211d75a0 c0000000211d75b0 c0000000225f3b98
> >>> 0000000000000000
> >>> [ 0.000000] GPR20: 0000000000000001 0000000000000001 0000000000000001
> >>> 0000000000000001
> >>> [ 0.000000] GPR24: 0000000000000008 0000000000000000 0000000000000001
> >>> c00000019ffffdc0
> >>> [ 0.000000] GPR28: 0000000000000002 c000000022b368e0 c000000022aebe08
> >>> 0000000000000008
> >>> [ 0.000000] NIP [c000000022009c64] smp_setup_cpu_maps+0x420/0x724
> >>> [ 0.000000] LR [c000000022009c54] smp_setup_cpu_maps+0x410/0x724
> >>> [ 0.000000] Call Trace:
> >>> [ 0.000000] [c000000022aebda0] [c000000022009ba0]
> >>> smp_setup_cpu_maps+0x35c/0x724 (unreliable)
> >>> [ 0.000000] [c000000022aebeb0] [c00000002200a19c]
> >>> setup_arch+0x1b8/0x54c
> >>> [ 0.000000] [c000000022aebf30] [c000000022003f88]
> >>> start_kernel+0xb0/0x768
> >>> [ 0.000000] [c000000022aebfe0] [c00000002000d888]
> >>> start_here_common+0x1c/0x20
> >>> [ 0.000000] Code: 3929ffff 7f89e040 409c002c 7ec4b378 7f83e378
> >>> 4a027939 7f83e378 4a0278e5 e95b0018 3d22017d e929f028 7d4ac42c
> >>> <7d49c12e> eb7b0000 7e99a378 4bffff3c
> >> The faulting instruction address, 0xc000000022009c6, corresponds to the code
> >> below:
> >>
> >> File:
> >> arch/powerpc/kernel/setup-common.c
> >>
> >> Function
> >> void __init smp_setup_cpu_maps(void)
> >> {
> >> ...
> >> cpu_to_phys_id[bt_thread] =
> >> be32_to_cpu(intserv_node->intserv[bt_thread]);
> >> ...
> >> }
> >>
> >> Hope it helps.
> >>
> > Appreciate your help.
> >
> > This issue should be linked with the capability of cpu_to_phys_id[].
> >
> > Could you please to try the fix suggested at the end of the email?
> > It should be a fix for
> > [PATCHv8 3/5] powerpc/setup: Handle the case when boot_cpuid greater than nr_cpus
> >
> >
> > Thanks,
> >
> > Pingfan
> >
> > ---
> >
> > diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
> > index bd7853a4bc91..849adc7a4b47 100644
> > --- a/arch/powerpc/kernel/setup-common.c
> > +++ b/arch/powerpc/kernel/setup-common.c
> > @@ -464,12 +464,6 @@ void __init smp_setup_cpu_maps(void)
> > DBG("smp_setup_cpu_maps()\n");
> >
> > INIT_LIST_HEAD(&head);
> > - cpu_to_phys_id = memblock_alloc(nr_cpu_ids * sizeof(u32),
> > - __alignof__(u32));
> > - if (!cpu_to_phys_id)
> > - panic("%s: Failed to allocate %zu bytes align=0x%zx\n",
> > - __func__, nr_cpu_ids * sizeof(u32), __alignof__(u32));
> > -
> > for_each_node_by_type(dn, "cpu") {
> > const __be32 *intserv;
> > __be32 cpu_be;
> > @@ -533,6 +527,16 @@ void __init smp_setup_cpu_maps(void)
> > }
> >
> > }
> > +
> > + /* There may be hole between cpu0 and boot cpu */
> > + j = (bt_thread + 1) > nr_cpu_ids ? (bt_thread + 1) : nr_cpu_ids;
> > + cpu_to_phys_id = memblock_alloc(j * sizeof(u32),
> > + __alignof__(u32));
> > + if (!cpu_to_phys_id)
> > + panic("%s: Failed to allocate %zu bytes align=0x%zx\n",
> > + __func__, nr_cpu_ids * sizeof(u32), __alignof__(u32));
> > +
> > +
> > cpu = 0;
> > list_del_init(&head);
> > /* Select the primary thread, the boot cpu's slibing, as the logic 0 */
>
> With the above changes applied, kdump kernel boots fine with a WARNING:
>
> [root]# echo c > /proc/sysrq-trigger
> [ 310.748248] sysrq: Trigger a crash
> [ 310.748256] Kernel panic - not syncing: sysrq triggered crash
> [ 310.748266] CPU: 26 PID: 2610 Comm: bash Kdump: loaded Not tainted
> 6.6.0-rc5-fix-setup-common+ #3
> [ 310.748273] Hardware name: IBM,9043-MRX POWER10 hv:phyp pSeries
> [ 310.748280] Call Trace:
> [ 310.748284] [c000000184717ac0] [c000000000ecf8d8]
> dump_stack_lvl+0x6c/0x9c (unreliable)
> [ 310.748298] [c000000184717af0] [c000000000150310] panic+0x178/0x438
> [ 310.748307] [c000000184717b90] [c00000000092c8b8]
> sysrq_handle_crash+0x28/0x30
> [ 310.748316] [c000000184717bf0] [c00000000092d2ac]
> __handle_sysrq+0x10c/0x250
> [ 310.748330] [c000000184717c90] [c00000000092db18]
> write_sysrq_trigger+0xc8/0x168
> [ 310.748339] [c000000184717cd0] [c00000000065c21c]
> proc_reg_write+0x10c/0x1b0
> [ 310.748349] [c000000184717d00] [c000000000583f94] vfs_write+0x104/0x4b0
> [ 310.748356] [c000000184717dc0] [c00000000058451c] ksys_write+0x7c/0x140
> [ 310.748365] [c000000184717e10] [c000000000033a54]
> system_call_exception+0x144/0x3a0
> [ 310.748377] [c000000184717e50] [c00000000000c554]
> system_call_common+0xf4/0x258
> [ 310.748389] --- interrupt: c00 at 0x7fff97720c34
> [ 310.748395] NIP: 00007fff97720c34 LR: 00007fff97697c74 CTR:
> 0000000000000000
> [ 310.748404] REGS: c000000184717e80 TRAP: 0c00 Not tainted
> (6.6.0-rc5-fix-setup-common+)
> [ 310.748413] MSR: 800000000280f033
> <SF,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE> CR: 28222202 XER: 00000000
> [ 310.748430] IRQMASK: 0
> [ 310.748430] GPR00: 0000000000000004 00007fffffabc510 00007fff97807300
> 0000000000000001
> [ 310.748430] GPR04: 00000001624f7910 0000000000000002 0000000000000010
> 00007fff97669724
> [ 310.748430] GPR08: 0000000000000000 0000000000000000 0000000000000000
> 0000000000000000
> [ 310.748430] GPR12: 0000000000000000 00007fff97a5aee0 0000000040000000
> 0000000125c39798
> [ 310.748430] GPR16: 0000000125c39724 0000000125bd8128 0000000125b70370
> 0000000125c3d568
> [ 310.748430] GPR20: 0000000162551030 0000000000000001 0000000125beaf18
> 00007fffffabc734
> [ 310.748430] GPR24: 00007fffffabc730 0000000125c3af94 0000000000000002
> 00000001624f7910
> [ 310.748430] GPR28: 0000000000000002 00007fff97801798 00000001624f7910
> 0000000000000002
> [ 310.748475] NIP [00007fff97720c34] 0x7fff97720c34
> [ 310.748478] LR [00007fff97697c74] 0x7fff97697c74
> [ 310.748482] --- interrupt: c00
> I'm in purgatory
> [ 0.000000] radix-mmu: Page sizes from device-tree:
> [ 0.000000] radix-mmu: Page size shift = 12 AP=0x0
> [ 0.000000] radix-mmu: Page size shift = 16 AP=0x5
> [ 0.000000] radix-mmu: Page size shift = 21 AP=0x1
> [ 0.000000] radix-mmu: Page size shift = 30 AP=0x2
> [ 0.000000] Activating Kernel Userspace Access Prevention
> [ 0.000000] Activating Kernel Userspace Execution Prevention
> [ 0.000000] radix-mmu: Mapped 0x0000000000000000-0x0000000000010000
> with 64.0 KiB pages (exec)
> [ 0.000000] radix-mmu: Mapped 0x0000000000010000-0x0000000000200000
> with 64.0 KiB pages
> [ 0.000000] radix-mmu: Mapped 0x0000000000200000-0x0000000020000000
> with 2.00 MiB pages
> [ 0.000000] radix-mmu: Mapped 0x0000000020000000-0x0000000022600000
> with 2.00 MiB pages (exec)
> [ 0.000000] radix-mmu: Mapped 0x0000000022600000-0x0000000040000000
> with 2.00 MiB pages
>
> Trimmed logs ....
>
> [ 0.001738] Mount-cache hash table entries: 16384 (order: 1, 131072
> bytes, linear)
> [ 0.001751] Mountpoint-cache hash table entries: 16384 (order: 1,
> 131072 bytes, linear)
> [ 0.007339] ------------[ cut here ]------------
> [ 0.007356] WARNING: CPU: 2 PID: 1 at arch/powerpc/kernel/smp.c:941
> update_mask_from_threadgroup+0x128/0x1a0
> [ 0.007371] Modules linked in:
> [ 0.007377] CPU: 2 PID: 1 Comm: swapper/2 Not tainted
> 6.6.0-rc5-fix-setup-common+ #3
> [ 0.007385] Hardware name: IBM,9043-MRX POWER10 hv:phyp pSeries
> [ 0.007393] NIP: c000000022011ed8 LR: c000000022011e10 CTR:
> 0000000000000000
> [ 0.007411] REGS: c0000000256338f0 TRAP: 0700 Not tainted
> (6.6.0-rc5-fix-setup-common+)
> [ 0.007425] MSR: 8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE> CR:
> 44000842 XER: 0000000c
> [ 0.007444] CFAR: c000000022011e78 IRQMASK: 0
> [ 0.007444] GPR00: c000000022011e10 c000000025633b90 c0000000213c1300
> 0000000000000002
> [ 0.007444] GPR04: 0000000000000000 0000000000000005 0000000000000001
> 0000000000000002
> [ 0.007444] GPR08: 0000000000000008 0000000000000001 0000000000000002
> 0000000000000004
> [ 0.007444] GPR12: 0000000000000000 c000000022e3ac00 c000000020010138
> 0000000000000000
> [ 0.007444] GPR16: 0000000000000000 0000000000000000 0000000000000000
> 0000000000000000
> [ 0.007444] GPR20: 0000000000000018 c000000022150968 c000000022093580
> c0000000253df000
> [ 0.007444] GPR24: 0000000000000002 0000000000000000 c000000022b32058
> 0000000000000000
> [ 0.007444] GPR28: c00000015fca0a68 c000000022ba0330 c00000002209352c
> 0000000000000000
> [ 0.007520] NIP [c000000022011ed8]
> update_mask_from_threadgroup+0x128/0x1a0
> [ 0.007528] LR [c000000022011e10] update_mask_from_threadgroup+0x60/0x1a0
> [ 0.007536] Call Trace:
> [ 0.007539] [c000000025633b90] [c000000022011e10]
> update_mask_from_threadgroup+0x60/0x1a0 (unreliable)
> [ 0.007550] [c000000025633be0] [c000000022012210]
> init_thread_group_cache_map+0x2c0/0x338
> [ 0.007559] [c000000025633c50] [c0000000220125a0]
> smp_prepare_cpus+0x318/0x510
> [ 0.007568] [c000000025633d10] [c000000022004874]
> kernel_init_freeable+0x198/0x3cc
> [ 0.007578] [c000000025633de0] [c000000020010164] kernel_init+0x34/0x1b0
> [ 0.007586] [c000000025633e50] [c00000002000cd94]
> ret_from_kernel_user_thread+0x14/0x1c
> [ 0.007596] --- interrupt: 0 at 0x0
> [ 0.007601] NIP: 0000000000000000 LR: 0000000000000000 CTR:
> 0000000000000000
> [ 0.007608] REGS: c000000025633e80 TRAP: 0000 Not tainted
> (6.6.0-rc5-fix-setup-common+)
> [ 0.007632] MSR: 0000000000000000 <> CR: 00000000 XER: 00000000
> [ 0.007651] CFAR: 0000000000000000 IRQMASK: 0
> [ 0.007651] GPR00: 0000000000000000 0000000000000000 0000000000000000
> 0000000000000000
> [ 0.007651] GPR04: 0000000000000000 0000000000000000 0000000000000000
> 0000000000000000
> [ 0.007651] GPR08: 0000000000000000 0000000000000000 0000000000000000
> 0000000000000000
> [ 0.007651] GPR12: 0000000000000000 0000000000000000 0000000000000000
> 0000000000000000
> [ 0.007651] GPR16: 0000000000000000 0000000000000000 0000000000000000
> 0000000000000000
> [ 0.007651] GPR20: 0000000000000000 0000000000000000 0000000000000000
> 0000000000000000
> [ 0.007651] GPR24: 0000000000000000 0000000000000000 0000000000000000
> 0000000000000000
> [ 0.007651] GPR28: 0000000000000000 0000000000000000 0000000000000000
> 0000000000000000
> [ 0.007742] NIP [0000000000000000] 0x0
> [ 0.007756] LR [0000000000000000] 0x0
> [ 0.007769] --- interrupt: 0
> [ 0.007779] Code: 7ca507b4 79081764 7d1e4214 8108000c 7f882000
> 409effdc 48000010 38e70001 7ce707b4 4bffffa4 2f8affff 409e0010
> <0fe00000> 3860ffc3 4800004c 7f9b5000
> [ 0.007805] ---[ end trace 0000000000000000 ]---
> [ 0.007997] RCU Tasks Rude: Setting shift to 2 and lim to 1
> rcu_task_cb_adjust=1.
> [ 0.008018] RCU Tasks Trace: Setting shift to 2 and lim to 1
> rcu_task_cb_adjust=1.
> [ 0.008043] POWER10 performance monitor hardware support registered
> [ 0.008071] rcu: Hierarchical SRCU implementation.
> [ 0.008078] rcu: Max phase no-delay instances is 1000.
> [ 0.008516] smp: Bringing up secondary CPUs ...
> [ 0.008735] smp: Brought up 1 node, 2 CPUs
> ...
>
> Note: no warning observed if crashing CPU is 0, 8, 16, 24, 32, ....
>
> Code that generates warning:
>
> File: arch/powerpc/kernel/smp.c
> Function: update_mask_from_threadgroup
> ...
> if (unlikely(i_group_start == -1)) {
> WARN_ON_ONCE(1);
> return -ENODATA;
> }
>
It seems that the crash cpu passed the statements in
init_thread_group_cache_map()
{
if (unlikely(cpu_group_start == -1)) {
WARN_ON_ONCE(1);
return -ENODATA;
}
}
But raising warn in the above snippet. So it means that
get_cpu_thread_group_start(i, tg) for the @first_thread failed in
update_mask_from_threadgroup(). At present, I have no idea about it.
And is this warning observed if only applying [1-2/5] ?
According to my collected data, percpu area will cost 1792 kB per cpu.
Forcing all eight threads in a core online will cost 10752KB more than
the result if applying the whole series. Maybe I can put [3-5/5] aside
as Hari suggested, and try them later if needed.
Thanks,
Pingfan
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