[RFC PATCH v2 0/10] makedumpfile: cyclic processing to keep memory consumption.

[Atsushi Kumagai]

Hello Vivek,

On Wed, 8 Aug 2012 09:25:10 -0400
Vivek Goyal <vgoyal at redhat.com> wrote:

> On Wed, Aug 08, 2012 at 02:14:00PM +0900, Atsushi Kumagai wrote:
> > Hello Vivek,
> > 
> > On Mon, 6 Aug 2012 16:47:31 -0400
> > Vivek Goyal <vgoyal at redhat.com> wrote:
> > 
> > > On Fri, Jun 29, 2012 at 11:13:20AM +0900, Atsushi Kumagai wrote:
> > > > Hello,
> > > > 
> > > > I improved prototype of cyclic processing as version 2.
> > > > If there is no objection to basic idea, I want to consider the things
> > > > related to performance as next step. (Concretely, buffer size and the patch set
> > > > HATAYAMA-san sent a short time ago.) 
> > > 
> > > Hi Atsushi San,
> > > 
> > > Just checking that what's the state of these patches now. Are they ready
> > > to be included in makedumpfile?
> > 
> > Yes, v2 patches with some fixes are ready to be merged into mainline.
> > At this time, makedumpfile can work in constant memory space.
> > (To make sure it's correct, we need to see the result of HATAYAMA-san's benchmark.)
> > 
> > > I would love to see new makedumpfile where memory usage does not grow
> > > by physical memory present in the system. (Assuming computig overhead
> > > of cycles is bearable).
> > 
> > I planed to release the next version with the new method to exclude free pages
> > (based on HATAYAMA-san's RFC patches). This method looks up members of each page
> > instead of free_list, it's only for performance.
> > 
> >   http://lists.infradead.org/pipermail/kexec/2012-June/006441.html
> > 
> > But, this method need more time for consideration, review and test.
> > 
> > 
> > If you need the new makedumpfile which can work in constant memory space soon,
> > shall I release the new version as soon as possible ? 
> > (But, this version still looks up free_list to exclude free pages same as v1.4.4.)
> > 
> 
> I think once Hatayama's testing is done, it is a good idea to merge cyclic
> patches and make a release. And soon after review and testing, merge
> hatayama's other patches of walking through mem_map array. My understanding
> is that walking through mem_map array will save us cpu cycles in fixed
> memory usage mode.

OK, I start to prepare for the release of the next version with cyclic patches.

Your understanding of walking through mem_map array is correct, it's expected
to reduce wasteful process in fixed memory usage mode.

  http://lists.infradead.org/pipermail/kexec/2012-July/006543.html


Thanks 
Atsushi Kumagai