-----Message d'origine----- De : HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab@xxxxxxx> Envoyé : mercredi 6 avril 2022 10:06 À : Agrain Patrick <patrick.agrain@xxxxxxxxxxxxxxxxx> Cc : kexec@xxxxxxxxxxxxxxxxxxx; Discussion list for crash utility usage, maintenance and development <crash-utility@xxxxxxxxxx> 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 -- Crash-utility mailing list Crash-utility@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/crash-utility Contribution Guidelines: https://github.com/crash-utility/crash/wiki
