linux-kernel - Re: [PATCH V2 0/2] kexec: Make a pair of map/unmap reserved pages in error path

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Date:	Wed, 23 Mar 2016 16:23:44 +0800
From:	Baoquan He <bhe@...hat.com>
To:	xlpang@...hat.com
Cc:	mhuang@...hat.com, kexec@...ts.infradead.org,
	linux-kernel@...r.kernel.org, Minfei Huang <mnfhuang@...il.com>,
	akpm@...ux-foundation.org, ebiederm@...ssion.com
Subject: Re: [PATCH V2 0/2] kexec: Make a pair of map/unmap reserved pages in
 error path

On 03/23/16 at 11:32am, Xunlei Pang wrote:
> On 2016/03/23 at 10:48, Baoquan He wrote:
> > On 03/01/16 at 05:53pm, Xunlei Pang wrote:
> >> This is a bug fix.
> >>
> >> After this, I will try to do a cleanup for crash_unmap/map_reserved_pages()
> >> (only used by S390) to consolidate it with arch_kexec_unprotect/protect_crashkres().
> > Hi Xunlei, Minfei,
> >
> > I think you need discuss together about how to do clean up codes in this
> > place. From my point of view, arch_map/unmap_reserved_pages and
> > arch_kexec_protect/unprotect_crashkres() are for the same goal but by
> > different ways on different arch. So for Xunlei's patchset, you might
> > need to rethink your implementation, the name of function. I personally
> > think you just implement a x86 specific arch_map/unmap_reserved_pages.
> > It may need a more generic name, and then add your x86 arch specific
> > implementation. Sorry I can't see your patches on my mail client,
> 
> Like what you said, I think arch_kexec_unprotect/protect_crashkres() are
> generic enough, but any other better name is welcome :-)
> 
> It also covered the newly-added kexec file path, and we can easily transfer
> arch_map/unmap_reserved_pages into this new interface.

I don't know the status of your patchset. If possible I think the 1st
patch in your patchset shoule rename arch_map/unmap_reserved_pages to
arch_kexec_protect/unprotect_crashkres, 2nd patch is to add your x86
specific patch.

> 
> I was planning doing that, but sick recently, I will try to send a patch
> doing that later.

Yeah, totally understand. This is not urgent, please take care of
yourself.

> 
> Regards,
> Xunlei
> 
> > Xunlei. Since Andrew asked, I just checked these.
> >
> > I am fine with Minfei's patch 1/2. But for patch 2/2, it's a little
> > comfortable to me. Is it really necessary to abstract code block from
> > kexec_load, then wrap them into a newly added function do_kexec_load()?
> > Without this wrapping is there a way to do your bug fix? Is there
> > possibility that do_kexec_load will be called in other places? What's
> > the benefit to wrap it into do_kexec_load against not wrapping?
> >
> > Thanks
> > Baoquan
> >
> >> Regards,
> >> Xunlei
> >>
> >> On 03/01/2016 at 04:02 PM, Minfei Huang wrote:
> >>> v1:
> >>> - Bisect the patch according to Andrew Morton's suggestion
> >>>
> >>> Minfei Huang (2):
> >>>   kexec: Make a pair of map/unmap reserved pages in error path
> >>>   kexec: Do a cleanup for function kexec_load
> >>>
> >>>  kernel/kexec.c | 112 ++++++++++++++++++++++++++++++++-------------------------
> >>>  1 file changed, 63 insertions(+), 49 deletions(-)
> >>>
> >>
> >> _______________________________________________
> >> kexec mailing list
> >> kexec@...ts.infradead.org
> >> http://lists.infradead.org/mailman/listinfo/kexec
> 
> 
> _______________________________________________
> kexec mailing list
> kexec@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec

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