Re: The 32-bit powerpc FreeBSD early-boot "tfo_ccache_bucket panic" on (2 socket?) G5s: visible at -r356118, not happening at -r356109

[Brandon Bergren]

Yeah, this is the crash that I've been banging my head on for days.

On Fri, Jan 3, 2020, at 4:35 PM, Mark Millard wrote:
> This is based on testing artifact.ci.freebsd.org
> 32-bit powerpc materials on some (2 socket) G5s.
> It is the later FreeBSD head revision that causes
> an earlier boot-failure than the other one that I
> recently reported.
> 
> There are no 32-bit powerpc artifacts between
> -r356109 and -r356118 (non-inclusive of either end).
> This limits how specific the evidence is -- but also
> avoids getting my personal builds involved as a
> potential problem source.
> 
> I'll note that -r356111 was for:
> 
> Use LLVM as default toolchain for all PowerPC targets
> 
> and -r356014 was for:
> 
> [PowerPC] enable atomic.c in compiler_rt and do not check and forces
>   lock/lock_free decisions in compiled time
> 
> (and would start to be put to use by -r356111 and
> later).
> 
> This suggests the possibility of atomic-activity
> that is insufficient on the example G5 machines.
> (I only have access to dual socket G5s.) But I've
> no specific evidence about the llvm generated
> code leads to the tfo_ccache_bucket panic.
> 
> The crashes look like (typed from a screen
> shot):
> 
> . . .
> Timecounters tick every 1.000 msec
> firewire0: w nodes, maxhop <= 1 cable IRM irm(1) (me)
> firewire0: bus manager 1
> . . . (1 or 2 lines that only sometimes show up, then) . . .
> panic: lock "tfo_ccache_bucket" 0xd2858008 already initialized
> cpuid = 0
> time = 1
> KDB: stack backtrace
> 0xd00048b0: at kdb_backtrace+0x64
> 0xd0004910: at vpanic+0x200
> 0xd0004980: at panic+0x64
> 0xd00049c0: at lock_init+0x200
> 0xd00049d0: at _mtx_init+0x7c
> 0xd00049f0: at tcp_fastopen_init+0x1e8
> 0xd0004a20: at tcp_init+0x234
> 0xd0004a50: at protosv_init+0x1d4
> 0xd0004a60: at vnet_domain_init+0x5c
> 0xd0004a80: at vnet_register_sysinit+0x154
> 0xd0004ab0: at mi_startup+0x280
> 0xd0004af0: at btext+0x74
> KDB: enter: panic
> [ thread pid 0 tid 100000 ]
> Stopped at kdb_enter+0x74: addi r3,r0,0x0
> db> 
> 
> 
> ===
> Mark Millard
> marklmi at yahoo.com
> ( dsl-only.net went
> away in early 2018-Mar)
> 
>

-- 
  Brandon Bergren
  bdragon at imap.cc