[Patch v3 7/7] add a new interface to show the memory usage of 1st kernel

[Baoquan He]

On 07/29/14 at 08:43am, Vivek Goyal wrote:
> On Mon, Jul 28, 2014 at 04:20:06PM +0800, Baoquan He wrote:
> > Recently people complained that they don't know how to decide how
> > much disk size need be reserved for kdump. E.g there are lots of
> > machines with different memory size, if the memory usage information
> > of current system can be shown, that can help them to make an estimate
> > how much storage space need be reserved.
> > 
> > In this patch, a new interface is added into makedumpfile. By the
> > help of this, people can know the page number of memory in different
> > use. The implementation is analyzing the "System Ram" and "kernel text"
> > program segment of /proc/kcore excluding the crashkernel range, then
> > calculating the page number of different kind per vmcoreinfo.
> > 
> > The print is like below:
> > ->$ ./makedumpfile  --mem-usage  /proc/kcore
> > Excluding unnecessary pages        : [100.0 %] |
> 
> I think above message is now unnecessary. In fact we are not excluding
> any pages.

I reused the function get_num_dumpable_cyclic(). It will iterate each
pages to check whether it's dumpable or not based on the dump_level
specified. While above message is printed inside a internal function. I
don't think it's very necessary, but also I don't think it will misguide
people to think of too much about it. It just tell the progress of
filtering, and could be a little helpful if it's working on a large
memory, say more than 1T memory.

> 
> > 
> > Page number of memory in different use
> > --------------------------------------------------
> 
> Above is not required.

OK, will remove it.

> 
> 
> > TYPE		PAGES			EXCLUDABLE	DESCRIPTION
> 
> We probably should put dashes under these headers
> 
> TYPE		PAGES			EXCLUDABLE	DESCRIPTION
> ====		=====			==========	===========

I am fine with this, will add dashes to decorate it.


> 
> > ZERO		0               	yes		Pages filled with zero
> > CACHE		562006          	yes		Cache pages
> > CACHE_PRIVATE	353502          	yes		Cache pages + private
> > USER		225780          	yes		User process pages
> > FREE		2761884         	yes		Free pages
> > KERN_DATA	235873          	no		Dumpable kernel data
> 
> What's "Dumpable kernel data" ? Are we saying they are kernel pages which
> can't be filtered?
> 
> Why not simply call them "kernel data" or "kernel pages" 

Yes, it's misled. WIll change.


> 
> 
> > 
> > Total pages on system:	4139045
> 
> How about "Total number of pages".

Will change.

> 
> Otherwise this output looks much better than previous version. Thanks for
> the changes.
> 
> Vivek
> 
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