Re: [RFC][PATCH 00/13] SCHED_DEADLINE server infrastructure

[Alessio Balsini]

Hi Peter,

While testing your series (peterz/sched/wip-deadline 7a9e91d3fe951), I ended up
in a panic at boot on a x86_64 kvm guest, would you please have a look?  Here
attached the backtrace.
Happy to test any suggestion that fixes the issue.

Thanks,
Alessio
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[    0.798326] ------------[ cut here ]------------       
[    0.798328] kernel BUG at kernel/sched/deadline.c:1542!            
[    0.798335] invalid opcode: 0000 [#1] SMP PTI                                  
[    0.798339] CPU: 4 PID: 0 Comm: swapper/4 Not tainted 5.3.0-rc6+ #28
[    0.798340] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
[    0.798349] RIP: 0010:enqueue_dl_entity+0x3f8/0x440
[    0.798351] Code: ff 48 8b 85 60 0a 00 00 8b 48 28 85 c9 0f 85 99 fd ff ff c7 40 28 01 00 00 00 e9 8d fd ff ff 85 c0 75 20 f                                                                                                                             
[    0.798353] RSP: 0000:ffffb68e40154f10 EFLAGS: 00010096
[    0.798356] RAX: 0000000000000020 RBX: ffff974bc74d0c00 RCX: ffff974bc751b200
[    0.798358] RDX: 0000000000000001 RSI: ffff974bc7929410 RDI: ffff974bc7929410
[    0.798359] RBP: 0000000000000009 R08: 00000000a73eb274 R09: 00000000000f4887
[    0.798361] R10: 0000000000000000 R11: 0000000000000000 R12: ffff974bc74d0c80
[    0.798362] R13: 0000000000000000 R14: ffff974bc74d0d00 R15: 0000000000000000
[    0.798365] FS:  0000000000000000(0000) GS:ffff974bc7900000(0000) knlGS:0000000000000000
[    0.798371] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033 
[    0.798372] CR2: 00000000ffffffff CR3: 000000000480a000 CR4: 00000000000006e0
[    0.798374] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[    0.798375] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[    0.798376] Call Trace:                       
[    0.798397]  <IRQ>                                                
[    0.798402]  enqueue_task_fair+0xe69/0x11d0   
[    0.798407]  activate_task+0x58/0x90                                
[    0.798412]  ? kvm_sched_clock_read+0xd/0x20              
[    0.798416]  ttwu_do_activate.isra.96+0x3a/0x50                 
[    0.798420]  sched_ttwu_pending+0x5e/0x90                                              
[    0.798424]  scheduler_ipi+0x9f/0x120               
[    0.798430]  reschedule_interrupt+0xf/0x20           
[    0.798432]  </IRQ>                                                                           
[    0.798436] RIP: 0010:default_idle+0x20/0x140   
[    0.798438] Code: 90 90 90 90 90 90 90 90 90 90 41 55 41 54 55 65 8b 2d f4 40 d7 70 53 0f 1f 44 00 00 e9 07 00 00 00 0f 00 5                                                                                                                             
[    0.798440] RSP: 0000:ffffb68e40083ec0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff02
[    0.798442] RAX: ffffffff8f29c250 RBX: 0000000000000004 RCX: ffff974bc7916000               
[    0.798444] RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff974bc791ca80
[    0.798445] RBP: 0000000000000004 R08: 000000009d74022b R09: 0000004d7ebb5820
[    0.798447] R10: 0000000000000400 R11: 0000000000000400 R12: 0000000000000000
[    0.798448] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[    0.798451]  ? __cpuidle_text_start+0x8/0x8 
[    0.798455]  do_idle+0x19e/0x210              
[    0.798458]  cpu_startup_entry+0x14/0x20
[    0.798464]  start_secondary+0x144/0x170                       
[    0.798467]  secondary_startup_64+0xa4/0xb0   
[    0.798469] Modules linked in:              
[    0.798478] ---[ end trace c2be7729c78a55ad ]---
[    0.798482] RIP: 0010:enqueue_dl_entity+0x3f8/0x440                                   
[    0.798484] Code: ff 48 8b 85 60 0a 00 00 8b 48 28 85 c9 0f 85 99 fd ff ff c7 40 28 01 00 00 00 e9 8d fd ff ff 85 c0 75 20 f                                                                                                                             
[    0.798485] RSP: 0000:ffffb68e40154f10 EFLAGS: 00010096
[    0.798487] RAX: 0000000000000020 RBX: ffff974bc74d0c00 RCX: ffff974bc751b200
[    0.798489] RDX: 0000000000000001 RSI: ffff974bc7929410 RDI: ffff974bc7929410
[    0.798490] RBP: 0000000000000009 R08: 00000000a73eb274 R09: 00000000000f4887
[    0.798491] R10: 0000000000000000 R11: 0000000000000000 R12: ffff974bc74d0c80
[    0.798493] R13: 0000000000000000 R14: ffff974bc74d0d00 R15: 0000000000000000
[    0.798495] FS:  0000000000000000(0000) GS:ffff974bc7900000(0000) knlGS:0000000000000000
[    0.798500] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.798501] CR2: 00000000ffffffff CR3: 000000000480a000 CR4: 00000000000006e0
[    0.798502] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[    0.798504] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[    0.798505] Kernel panic - not syncing: Fatal exception in interrupt
[    0.799522] Kernel Offset: 0xd800000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[    0.875144] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---
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