Red Hat Bugzilla – Bug 604808
kexec-tools: Output memory usage stats during kdump boot
Last modified: 2013-09-29 22:17:00 EDT
Description of problem:
Very often we run into discussion of how much memory is sufficient for kdump kernel and nobody knows and we do guess work.
Neil recently tweaked kdump initrd to run "free" command at some checkpoints to
monitor memory usage as we execute kdump initrd.
I think we can polish that patch to make it a production environment thing and output "used" and "free" memory stat in kdump kernel at select checkpoints. This should help a user/developer to keep track that whether reserved memory is sufficient or not and also how our memory requirement is growing over time as
we pull in more patches in kernel and do changes to initrd/initramfs infrastructure.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
Created attachment 424560 [details]
patch to periodically dump memory stats to console
amerigo, this is completely untested, but I think something like this would satisfy viveks request.
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux major release. Product Management has requested further
review of this request by Red Hat Engineering, for potential inclusion in a Red
Hat Enterprise Linux Major release. This request is not yet committed for
Are you sure this is for a real production not a debug version??
In fact, I plan to add some debug option into kdump.conf, so that our developers and QA could use it for debugging.
I'll leave that decision to you. Vivek thought it would be good to have this data available, and I wrote the patch. You certainly can gate it with a debug option if you like
I will say that, given everything that gets dumped to the console during boot, I don't think customers would really care if they saw it consistently.
(In reply to comment #5)
> I'll leave that decision to you. Vivek thought it would be good to have this
> data available, and I wrote the patch. You certainly can gate it with a debug
> option if you like
> I will say that, given everything that gets dumped to the console during boot,
> I don't think customers would really care if they saw it consistently.
I _wanted_ to add a debug option so that we can debug info during booting the second, however, it seems that msh of busybox doesn't have something like 'set -x', so this will be not necessary any more.
I will directly apply this patch.
Verified with -133.el6:
Free memory/Total memory (free %): 227492 / 249652 ( 91.1236 )
Scanning logical volumes
Reading all physical volumes. This may take a while...
Found volume group "vg_hpml370g401" using metadata type lvm2
Activating logical volumes
2 logical volume(s) in volume group "vg_hpml370g401" now active
Free memory/Total memory (free %): 226984 / 249652 ( 90.9202 )
Change status to VERIFIED.
Red Hat Enterprise Linux 6.0 is now available and should resolve
the problem described in this bug report. This report is therefore being closed
with a resolution of CURRENTRELEASE. You may reopen this bug report if the
solution does not work for you.