[Crash-utility] crash version 4.0-3.1 is available

[Ken'ichi Ohmichi]

Hi, Dave.

2006/08/04 13:55:33 -0400, Dave Anderson <anderson at redhat.com> wrote:
>- Fix to address 2.6.18 and later Fedora 2.6.17-based kernel data
>  structure name change from "runqueue" to "rq".  This would cause
>  crash to fail during initialization with a "crash: cannot determine
>  idle task addresses from init_tasks[] or runqueues[]" message,
>  followed by a red herring message: "crash: cannot resolve
>  init_task_union".  (haren at us.ibm.com)
I tried doing "kmem -p" for the kdump dumpfile of linux-2.6.17 on 
a x86_64smp system. As a result, crash command displayed the
following log. 

-- log ------------------------------------------------------
 crash> kmem -p
       PAGE       PHYSICAL      MAPPING       INDEX CNT FLAGS
 kmem: WARNING: mem_map[] from 0 to 8000 not accessible
 kmem: WARNING: mem_map[] from 1000 to 8000 not accessible
 kmem: WARNING: mem_map[] from 2000 to 8000 not accessible
 kmem: WARNING: mem_map[] from 3000 to 8000 not accessible
 kmem: WARNING: mem_map[] from 4000 to 8000 not accessible
 kmem: WARNING: mem_map[] from 5000 to 8000 not accessible
 kmem: WARNING: mem_map[] from 6000 to 8000 not accessible
 kmem: WARNING: mem_map[] from 7000 to 8000 not accessible
 0                       0      -------       -----   0 0
 40                   1000      -------       -----   0 0
 80                   2000      -------       -----   0 0
 c0                   3000      -------       -----   0 0
 100                  4000      -------       -----   0 0
 140                  5000      -------       -----   0 0
 180                  6000      -------       -----   0 0
-------------------------------------------------------------

This problem occurred on a linux-2.6.18-rc3 system (x86_64smp).

nt->mem_map in dump_mem_map() was zero, because the above-mentioned
kernel didn't have necessary symbols(mem_map, pgdat_list, mem_section).
A symbol "pgdat_list" was removed by the following patch.
 [PATCH] for_each_online_pgdat (take2) [5/5] remove pgdat_list
 http://lkml.org/lkml/2006/2/25/8

But this kernel had two symbols(node_online_map, node_data).
Can we get the node_mem_map of each node by using these symbols?

Kernel gets the pglist_data of online nodes in next_online_pgdat() by
the following method.
1. get the online NODE-IDs from "node_online_map".
2. get "node_data[NODE_ID]" as the pglist_data of online nodes.

Thanks
Ken'ichi Ohmichi