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* qemu core dump and filtering guest pages
@ 2012-05-22 21:05 Christian Borntraeger
  2012-05-23  8:37 ` Avi Kivity
  0 siblings, 1 reply; 2+ messages in thread
From: Christian Borntraeger @ 2012-05-22 21:05 UTC (permalink / raw)
  To: Avi Kivity, Marcelo Tosatti, KVM list, Linux Kernel Mailing List
  Cc: Oleg Nesterov

Folks,

today we discussed the situation of a qemu crash (with coredump) and big guests.
Quite often the guest pages are not needed but make the core file pretty big.

The most appealing proposal that we had was to adopt the core file code in the 
kernel to have an option for discarding guest pages (e.g. /proc/sys/core_guest).
do_corefile would have a callback into the kvm module that could use its memory 
slot infrastructure to decide if this page should be saved or not.

Would you consider such a change be ok? Any better idea?
Thanks

Christian



^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: qemu core dump and filtering guest pages
  2012-05-22 21:05 qemu core dump and filtering guest pages Christian Borntraeger
@ 2012-05-23  8:37 ` Avi Kivity
  0 siblings, 0 replies; 2+ messages in thread
From: Avi Kivity @ 2012-05-23  8:37 UTC (permalink / raw)
  To: Christian Borntraeger
  Cc: Marcelo Tosatti, KVM list, Linux Kernel Mailing List,
	Oleg Nesterov

On 05/23/2012 12:05 AM, Christian Borntraeger wrote:
> Folks,
> 
> today we discussed the situation of a qemu crash (with coredump) and big guests.
> Quite often the guest pages are not needed but make the core file pretty big.
> 
> The most appealing proposal that we had was to adopt the core file code in the 
> kernel to have an option for discarding guest pages (e.g. /proc/sys/core_guest).
> do_corefile would have a callback into the kvm module that could use its memory 
> slot infrastructure to decide if this page should be saved or not.
> 
> Would you consider such a change be ok? Any better idea?


There's MADV_DONTDUMP which can be used to control this on a per-guest
basis.


-- 
error compiling committee.c: too many arguments to function

^ permalink raw reply	[flat|nested] 2+ messages in thread

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