Question

无论我运行Sysrq处理程序多少次，代码中特定点的寄存器似乎永远不会改变。

Answer 1

神奇的SysRq转储寄存器功能的目的是什么？

正如您可能期望的那样，目的是显示系统的当前状态。它永远不会改变你的必须是由于实现或你如何运行Sysrq处理程序（也许echo p >/proc/sysrq-trigger）。在这里的系统上，当我从控制台执行SysRq P 时，我会得到不同的输出，例如： G：

SysRq : Show Regs
NIP: c0010c9c LR: 00000000 CTR: 00000000
REGS: c049d2c0 TRAP: 0000   Not tainted  (2.6.34)
MSR: 00009032 <EE,ME,IR,DR>  CR: 00000000  XER: 00000000
TASK = cf852760[194] 'gatekeeper/0' THREAD: cfaba000
GPR00: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
GPR08: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
GPR24: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
NIP [c0010c8c] __delay+0x40/0x84
LR [00000000] (null)
Call Trace:
[cfabbcd0] [c0009a74] show_stack+0xac/0x1d8 (unreliable)
[cfabbd20] [c000a1bc] show_regs+0x1c8/0x310
[cfabbd50] [c026d190] sysrq_handle_showregs+0x34/0x50
[cfabbd60] [c026d61c] __handle_sysrq+0xcc/0x1a8
[cfabbd90] [c026d7bc] handle_sysrq+0x44/0x5c
[cfabbdb0] [c02735e4] mpc52xx_psc_handle_irq+0x538/0x604
[cfabbe10] [c0272d78] mpc52xx_uart_int+0x38/0x50
[cfabbe20] [c0070b04] handle_IRQ_event+0x90/0x1f8
[cfabbe50] [c0073ca4] handle_level_irq+0x74/0xf0
[cfabbe70] [c0006864] handle_one_irq+0x40/0x58
[cfabbe90] [c000d180] __ipipe_do_IRQ+0x48/0x68
[cfabbeb0] [c0076c08] __ipipe_sync_stage+0x1f0/0x24c
[cfabbee0] [c007722c] __ipipe_unstall_root+0x50/0x74
[cfabbef0] [c002ad80] finish_task_switch+0x40/0xb8
[cfabbf10] [c03935c8] schedule+0x240/0x4c8
[cfabbf60] [c00afe34] gatekeeper_thread+0x190/0x1e0
[cfabbfc0] [c0054bf0] kthread+0x88/0x8c
[cfabbff0] [c0015648] kernel_thread+0x4c/0x68
Instruction dump:
81698020 800b000c 70090040 41820040 7d2c42e6 7c0c42e6 7c090050 7f801840
409c0018 7c210b78 <7c0c42e6> 7c090050 7f830040 419dfff0 7c421378 81610000

或

SysRq : Show Regs
NIP: c0010c88 LR: 00000000 CTR: 00000000
REGS: c049d2c0 TRAP: 0000   Not tainted  (2.6.34)
MSR: 00009032 <EE,ME,IR,DR>  CR: 00000000  XER: 00000000
TASK = c049c4b0[0] 'swapper' THREAD: c04c0000
GPR00: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
GPR08: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
GPR24: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
NIP [c0010cf0] udelay+0x20/0x3c
LR [00000000] (null)
Call Trace:
[c04c1c50] [c0009a74] show_stack+0xac/0x1d8 (unreliable)
[c04c1ca0] [c000a1bc] show_regs+0x1c8/0x310
[c04c1cd0] [c026d190] sysrq_handle_showregs+0x34/0x50
[c04c1ce0] [c026d61c] __handle_sysrq+0xcc/0x1a8
[c04c1d10] [c026d7bc] handle_sysrq+0x44/0x5c
[c04c1d30] [c02735e4] mpc52xx_psc_handle_irq+0x538/0x604
[c04c1d90] [c0272d78] mpc52xx_uart_int+0x38/0x50
[c04c1da0] [c0070b04] handle_IRQ_event+0x90/0x1f8
[c04c1dd0] [c0073ca4] handle_level_irq+0x74/0xf0
[c04c1df0] [c0006864] handle_one_irq+0x40/0x58
[c04c1e10] [c000d180] __ipipe_do_IRQ+0x48/0x68
[c04c1e30] [c0076c08] __ipipe_sync_stage+0x1f0/0x24c
[c04c1e60] [c0076e5c] __ipipe_walk_pipeline+0x104/0x128
[c04c1e80] [c000cc9c] __ipipe_handle_irq+0x154/0x16c
[c04c1eb0] [c000cdd4] __ipipe_grab_irq+0x4c/0x8c
[c04c1ec0] [c0016168] __ipipe_ret_from_except+0x0/0xc
--- Exception: 501 at cpu_idle+0xac/0xf0
    LR = cpu_idle+0xac/0xf0
[c04c1f80] [c000ad18] cpu_idle+0x6c/0xf0 (unreliable)
[c04c1fa0] [c0003e90] rest_init+0x70/0xa0
[c04c1fb0] [c045da04] start_kernel+0x2c8/0x2e0
[c04c1ff0] [00003438] 0x3438
Instruction dump:
3d20c04d 93e1000c 7c3f0b78 81698020 800b000c 70090040 41820040 7d2c42e6
7c0c42e6 7c090050 7f801840 409c0018 <7c210b78> 7c0c42e6 7c090050 7f830040

神奇的SysRq转储寄存器功能的目的是什么？

1 个答案: