Re: [PATCH RFC 0/6] mm/kdump: allow to exclude pages that are logically offline

From: Julien Freche <jfreche@vmware.com>
To: Nadav Amit <namit@vmware.com>,
	David Hildenbrand <david@redhat.com>,
	linux-mm <linux-mm@kvack.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
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	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
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	xen-devel <xen-devel@lists.xenproject.org>,
	Alexander Duyck <alexander.h.duyck@linux.intel.com>,
	Alexey Dobriyan <adobriyan@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
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	Vlastimil Babka <vbabka@suse.cz>
Subject: Re: [PATCH RFC 0/6] mm/kdump: allow to exclude pages that are logically offline
Date: Thu, 15 Nov 2018 01:42:30 +0000	[thread overview]
Message-ID: <B6456717-0A6F-4957-A7F2-11599701226A@vmware.com> (raw)
In-Reply-To: <63214D36-14FD-4080-8E35-CF2A392D6507@vmware.com>

>On 11/14/18, 3:41 PM, "Nadav Amit" <namit@vmware.com> wrote:
>>From: David Hildenbrand
>>Sent: November 14, 2018 at 11:05:38 PM GMT
>> Subject: Re: [PATCH RFC 0/6] mm/kdump: allow to exclude pages that are logically offline
>> 
>> 
>> Can you share if something like this is also desired for vmware's
>> implementation? (I tagged this as RFC to get some more feedback)
>> 
>> It should in theory be as simple as adding a handful of
>> _SetPageOffline()/_ClearPageOffline() at the right spots.
>    
> Thanks, I was just suspecting it is personal ;-)
>
> I would obviously prefer that your changes would be done on top of those
> that were skipped. This patch-set sounds very reasonable to me, but I prefer
> that Julien (cc’d) would also give his opinion.

I think this is desirable for VMware's implementation also. You are right,
dumping data that is not relevant is a waste :-) 
I haven't heard of any panic/issue due to this but that's still a good optimization.

Nadav or I could help to test that on ESX if required.

Regards,

-- 
Julien Freche