Re: [Crash-utility] EXT: RE: crash: read error on type: "memory section root table"
-----Message d'origine-----
De : HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab(a)nec.com>
Envoyé : mercredi 6 avril 2022 10:06
À : Agrain Patrick <patrick.agrain(a)al-enterprise.com>
Cc : kexec(a)lists.infradead.org; Discussion list for crash utility usage, maintenance and
development <crash-utility(a)redhat.com>
Objet : RE: EXT: RE: crash: read error on type: "memory section root table"
-----Original Message-----
-----Original Message-----
> Hello,
>
> Suggested trace above gives following information after a crash -d 8 command:
> <...>
> kernel NR_CPUS: 2
> <readmem: ffffffffa4925820, KVADDR, "high_memory", 8, (FOE),
> 56017b542648>
> <read_diskdump: addr: ffffffffa4925820 paddr: 12925820 cnt: 8>
> read_diskdump: paddr/pfn: 12925820/12925 -> cache physical page:
> 12925000
> GETBUF(328 -> 0)
> FREEBUF(0)
> GETBUF(328 -> 0)
> FREEBUF(0)
> PAGESIZE=4096
> mem_section_size = 16384
> NR_SECTION_ROOTS = 2048
> NR_MEM_SECTIONS = 524288
> SECTIONS_PER_ROOT = 256
> SECTION_ROOT_MASK = 0xff
> PAGES_PER_SECTION = 32768
> <readmem: ffffffffa4926db0, KVADDR, "mem_section", 8, (FOE),
> 7ffd1b6bb000>
> <read_diskdump: addr: ffffffffa4926db0 paddr: 12926db0 cnt: 8>
> read_diskdump: paddr/pfn: 12926db0/12926 -> cache physical page:
> 12926000
> <readmem: ffff904c7f7fc000, KVADDR, "memory section root table",
> 16384, (FOE), 56017da26fd0>
> <read_diskdump: addr: ffff904c7f7fc000 paddr: 3f7fc000 cnt: 4096>
> read_diskdump: paddr/pfn: 3f7fc000/3f7fc -> cache physical page:
> 3f7fc000
> crash: PAG3 - errno=2 r=0 pd.size=49
> read_diskdump: READ_ERROR: cannot cache page: 3f7fc000
> crash: read error: kernel virtual address: ffff904c7f7fc000 type: "memory
section root table"
hmm, r=0 means end of file, can you check again whether pd.offset
exceeds the dumpfile size? If so, somehow the dumpfile is shorter than expected.
I think a RHEL-based kexec-tools does "sync" after makedumpfile, but
can you check?
> Note 2: The debug message of makedumpfile report 'Write
bytes : 17364943', but the file is ~5MB for '-d 31' opton.
This also looks the same situation.
Does cp command always work on your machine to capture /proc/vmcore?
e.g. with a RHEL-based kexec-tools:
core_collector cp
The size of a vmcore should become almost same as memory size.
Yes, if I'm using the /proc/vmcore instead, crash has no problem to read it... except
that in a very few number of cases, the /proc/vmcore has less bytes than expected
(1031389184 bytes on a 1GB RAM system) and then crash also fails.
Thanks,
Kazu