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Date:   Thu, 15 Nov 2018 12:10:23 +0100
From:   Borislav Petkov <bp@alien8.de>
To:     Dave Young <dyoung@redhat.com>
Cc:     David Hildenbrand <david@redhat.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
        devel@linuxdriverproject.org, linux-fsdevel@vger.kernel.org,
        linux-pm@vger.kernel.org, xen-devel@lists.xenproject.org,
        Andrew Morton <akpm@linux-foundation.org>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Baoquan He <bhe@redhat.com>, Omar Sandoval <osandov@fb.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Matthew Wilcox <willy@infradead.org>,
        Michal Hocko <mhocko@suse.com>,
        Lianbo Jiang <lijiang@redhat.com>,
        "Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [PATCH RFC 3/6] kexec: export PG_offline to VMCOREINFO
Message-ID: <20181115111023.GC26448@zn.tnic>
References: <20181114211704.6381-1-david@redhat.com>
 <20181114211704.6381-4-david@redhat.com>
 <20181115061923.GA3971@dhcp-128-65.nay.redhat.com>
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On Thu, Nov 15, 2018 at 02:19:23PM +0800, Dave Young wrote:
> It would be good to copy some background info from cover letter to the
> patch description so that we can get better understanding why this is
> needed now.
> 
> BTW, Lianbo is working on a documentation of the vmcoreinfo exported
> fields. Ccing him so that he is aware of this.
> 
> Also cc Boris,  although I do not want the doc changes blocks this
> he might have different opinion :)

Yeah, my initial reaction is that exporting an mm-internal flag to
userspace is a no-no.

What would be better, IMHO, is having a general method of telling the
kdump kernel - maybe ranges of physical addresses - which to skip.

Because the moment there's a set of pages which do not have PG_offline
set but kdump would still like to skip, this breaks.

But that's mm guys' call.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.