Re: [PATCH 4/4] percpu: add tracepoint support for percpu memory

From: Levin, Alexander (Sasha Levin)
Date: Wed Jun 21 2017 - 12:24:07 EST


On Mon, Jun 19, 2017 at 07:28:32PM -0400, Dennis Zhou wrote:
>Add support for tracepoints to the following events: chunk allocation,
>chunk free, area allocation, area free, and area allocation failure.
>This should let us replay percpu memory requests and evaluate
>corresponding decisions.

This patch breaks boot for me:

[ 0.000000] DEBUG_LOCKS_WARN_ON(unlikely(early_boot_irqs_disabled))
[ 0.000000] ------------[ cut here ]------------
[ 0.000000] WARNING: CPU: 0 PID: 0 at kernel/locking/lockdep.c:2741 trace_hardirqs_on_caller.cold.58+0x47/0x4e
[ 0.000000] Modules linked in:
[ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.12.0-rc6-next-20170621+ #155
[ 0.000000] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.1-1ubuntu1 04/01/2014
[ 0.000000] task: ffffffffb7831180 task.stack: ffffffffb7800000
[ 0.000000] RIP: 0010:trace_hardirqs_on_caller.cold.58+0x47/0x4e
[ 0.000000] RSP: 0000:ffffffffb78079d0 EFLAGS: 00010086 ORIG_RAX: 0000000000000000
[ 0.000000] RAX: 0000000000000037 RBX: 0000000000000003 RCX: 0000000000000000
[ 0.000000] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 1ffffffff6f00ef6
[ 0.000000] RBP: ffffffffb78079e0 R08: 0000000000000000 R09: ffffffffb7831180
[ 0.000000] R10: 0000000000000000 R11: ffffffffb24e96ce R12: ffffffffb6b39b87
[ 0.000000] R13: 00000000001f0001 R14: ffffffffb85603a0 R15: 0000000000002000
[ 0.000000] FS: 0000000000000000(0000) GS:ffffffffb81be000(0000) knlGS:0000000000000000
[ 0.000000] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 0.000000] CR2: ffff88007fbff000 CR3: 000000006b828000 CR4: 00000000000406b0
[ 0.000000] Call Trace:
[ 0.000000] trace_hardirqs_on+0xd/0x10
[ 0.000000] _raw_spin_unlock_irq+0x27/0x50
[ 0.000000] pcpu_setup_first_chunk+0x19c2/0x1c27
[ 0.000000] ? pcpu_free_alloc_info+0x4b/0x4b
[ 0.000000] ? vprintk_emit+0x403/0x480
[ 0.000000] ? __down_trylock_console_sem+0xb7/0xc0
[ 0.000000] ? __down_trylock_console_sem+0x6e/0xc0
[ 0.000000] ? vprintk_emit+0x362/0x480
[ 0.000000] ? vprintk_default+0x28/0x30
[ 0.000000] ? printk+0xb2/0xdd
[ 0.000000] ? snapshot_ioctl.cold.1+0x19/0x19
[ 0.000000] ? __alloc_bootmem_node_nopanic+0x88/0x96
[ 0.000000] pcpu_embed_first_chunk+0x7b0/0x8ef
[ 0.000000] ? pcpup_populate_pte+0xb/0xb
[ 0.000000] setup_per_cpu_areas+0x105/0x6d9
[ 0.000000] ? find_last_bit+0xa6/0xd0
[ 0.000000] start_kernel+0x25e/0x78f
[ 0.000000] ? thread_stack_cache_init+0xb/0xb
[ 0.000000] ? early_idt_handler_common+0x3b/0x52
[ 0.000000] ? early_idt_handler_array+0x120/0x120
[ 0.000000] ? early_idt_handler_array+0x120/0x120
[ 0.000000] x86_64_start_reservations+0x24/0x26
[ 0.000000] x86_64_start_kernel+0x143/0x166
[ 0.000000] secondary_startup_64+0x9f/0x9f
[ 0.000000] Code: c6 a0 49 c6 b6 48 c7 c7 e0 49 c6 b6 e8 43 34 00 00 0f ff e9 ed 71 ce ff 48 c7 c6 c0 79 c6 b6 48 c7 c7 e0 49 c6 b6 e8 29 34 00 00 <0f> ff e9 d3 71 ce ff 48 c7 c6 20 7c c6 b6 48 c7 c7 e0 49 c6 b6
[ 0.000000] random: print_oops_end_marker+0x30/0x50 get_random_bytes called with crng_init=0
[ 0.000000] ---[ end trace f68728a0d3053b52 ]---
[ 0.000000] BUG: unable to handle kernel paging request at 00000000ffffffff
[ 0.000000] IP: native_write_msr+0x6/0x30
[ 0.000000] PGD 0
[ 0.000000] P4D 0
[ 0.000000]
[ 0.000000] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN
[ 0.000000] Modules linked in:
[ 0.000000] CPU: 0 PID: 0 Comm: swapper Tainted: G W 4.12.0-rc6-next-20170621+ #155
[ 0.000000] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.1-1ubuntu1 04/01/2014
[ 0.000000] task: ffffffffb7831180 task.stack: ffffffffb7800000
[ 0.000000] RIP: 0010:native_write_msr+0x6/0x30
[ 0.000000] RSP: 0000:ffffffffb7807dc8 EFLAGS: 00010202
[ 0.000000] RAX: 000000003ea15d43 RBX: ffff88003ea15d40 RCX: 000000004b564d02
[ 0.000000] RDX: 0000000000000000 RSI: 000000003ea15d43 RDI: 000000004b564d02
[ 0.000000] RBP: ffffffffb7807df0 R08: 0000000000000040 R09: 0000000000000000
[ 0.000000] R10: 0000000000007100 R11: 000000007ffd6f00 R12: 0000000000000000
[ 0.000000] R13: 1ffffffff6f00fc3 R14: ffffffffb7807eb8 R15: dffffc0000000000
[ 0.000000] FS: 0000000000000000(0000) GS:ffff88003ea00000(0000) knlGS:0000000000000000
[ 0.000000] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 0.000000] CR2: 00000000ffffffff CR3: 000000006b828000 CR4: 00000000000406b0
[ 0.000000] Call Trace:
[ 0.000000] ? kvm_guest_cpu_init+0x155/0x220
[ 0.000000] kvm_smp_prepare_boot_cpu+0x9/0x10
[ 0.000000] start_kernel+0x28c/0x78f
[ 0.000000] ? thread_stack_cache_init+0xb/0xb
[ 0.000000] ? early_idt_handler_common+0x3b/0x52
[ 0.000000] ? early_idt_handler_array+0x120/0x120
[ 0.000000] ? early_idt_handler_array+0x120/0x120
[ 0.000000] x86_64_start_reservations+0x24/0x26
[ 0.000000] x86_64_start_kernel+0x143/0x166
[ 0.000000] secondary_startup_64+0x9f/0x9f
[ 0.000000] Code: c3 0f 21 c8 5d c3 0f 21 d0 5d c3 0f 21 d8 5d c3 0f 21 f0 5d c3 0f 0b 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00 89 f9 89 f0 0f 30 <0f> 1f 44 00 00 c3 48 89 d6 55 89 c2 48 c1 e6 20 48 89 e5 48 09
[ 0.000000] RIP: native_write_msr+0x6/0x30 RSP: ffffffffb7807dc8
[ 0.000000] CR2: 00000000ffffffff
[ 0.000000] ---[ end trace f68728a0d3053b53 ]---
[ 0.000000] Kernel panic - not syncing: Fatal exception
[ 0.000000] ---[ end Kernel panic - not syncing: Fatal exception

--

Thanks,
Sasha