Messages in this thread | | | Subject | Re: [PATCH] powerpc/kdump: fix kdump kernel hangup issue with hot add CPUs | From | Sourabh Jain <> | Date | Fri, 16 Apr 2021 16:57:55 +0530 |
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On 16/04/21 3:03 pm, Hari Bathini wrote: > > > On 16/04/21 12:17 pm, Sourabh Jain wrote: >> With the kexec_file_load system call when system crashes on the hot add >> CPU the capture kernel hangs and failed to collect the vmcore. >> >> Kernel panic - not syncing: sysrq triggered crash >> CPU: 24 PID: 6065 Comm: echo Kdump: loaded Not tainted >> 5.12.0-rc5upstream #54 >> Call Trace: >> [c0000000e590fac0] [c0000000007b2400] dump_stack+0xc4/0x114 >> (unreliable) >> [c0000000e590fb00] [c000000000145290] panic+0x16c/0x41c >> [c0000000e590fba0] [c0000000008892e0] sysrq_handle_crash+0x30/0x40 >> [c0000000e590fc00] [c000000000889cdc] __handle_sysrq+0xcc/0x1f0 >> [c0000000e590fca0] [c00000000088a538] write_sysrq_trigger+0xd8/0x178 >> [c0000000e590fce0] [c0000000005e9b7c] proc_reg_write+0x10c/0x1b0 >> [c0000000e590fd10] [c0000000004f26d0] vfs_write+0xf0/0x330 >> [c0000000e590fd60] [c0000000004f2aec] ksys_write+0x7c/0x140 >> [c0000000e590fdb0] [c000000000031ee0] >> system_call_exception+0x150/0x290 >> [c0000000e590fe10] [c00000000000ca5c] system_call_common+0xec/0x278 >> --- interrupt: c00 at 0x7fff905b9664 >> NIP: 00007fff905b9664 LR: 00007fff905320c4 CTR: 0000000000000000 >> REGS: c0000000e590fe80 TRAP: 0c00 Not tainted (5.12.0-rc5upstream) >> MSR: 800000000280f033 <SF,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE> CR: >> 28000242 >> XER: 00000000 >> IRQMASK: 0 >> GPR00: 0000000000000004 00007ffff5fedf30 00007fff906a7300 >> 0000000000000001 >> GPR04: 000001002a7355b0 0000000000000002 0000000000000001 >> 00007ffff5fef616 >> GPR08: 0000000000000001 0000000000000000 0000000000000000 >> 0000000000000000 >> GPR12: 0000000000000000 00007fff9073a160 0000000000000000 >> 0000000000000000 >> GPR16: 0000000000000000 0000000000000000 0000000000000000 >> 0000000000000000 >> GPR20: 0000000000000000 00007fff906a4ee0 0000000000000002 >> 0000000000000001 >> GPR24: 00007fff906a0898 0000000000000000 0000000000000002 >> 000001002a7355b0 >> GPR28: 0000000000000002 00007fff906a1790 000001002a7355b0 >> 0000000000000002 >> NIP [00007fff905b9664] 0x7fff905b9664 >> LR [00007fff905320c4] 0x7fff905320c4 >> --- interrupt: c00 > > <SNIP> > > I will update the commit message. > >> /** >> * setup_new_fdt_ppc64 - Update the flattend device-tree of the kernel >> * being loaded. >> @@ -1020,6 +1113,13 @@ int setup_new_fdt_ppc64(const struct kimage >> *image, void *fdt, >> } >> } >> + /* Update cpus nodes information to account hotplug CPUs. */ >> + if (image->type == KEXEC_TYPE_CRASH) { > > Shouldn't this apply to regular kexec_file_load case as well? Yeah, > there won't be a hang in regular kexec_file_load case but for > correctness, that kernel should also not see stale CPU info in FDT? > > Yes better to update the fdt for both kexec and kdump. > > Thanks for the review Hari. > > - Sourabh Jain
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