From: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
To: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
linux-kernel@vger.kernel.org, Andi Kleen <ak@linux.intel.com>,
Dave Hansen <dave.hansen@intel.com>,
Andy Lutomirski <luto@amacapital.net>,
Michal Hocko <mhocko@suse.com>,
linux-arch@vger.kernel.org, linux-mm@kvack.org
Subject: Re: Question on the five-level page table support patches
Date: Mon, 24 Apr 2017 22:37:40 +0200 [thread overview]
Message-ID: <fdc80e3c-6909-cf39-fe0b-6f1c012571e4@physik.fu-berlin.de> (raw)
In-Reply-To: <20170424161959.c5ba2nhnxyy57wxe@node.shutemov.name>
On 04/24/2017 06:19 PM, Kirill A. Shutemov wrote:
> In proposed implementation, we also use hint address, but in different
> way: by default, if hint address is NULL, kernel would not create mappings
> above 47-bits, preserving compatibility.
Ooooh, that would solve a lot of problems actually if it were to be available
on all architectures. On SPARC, the situation is really annoying and I have
been discussing a solution with the Qt developers and they suggested a
similar approach, just one that would also apply to brk() [1].
> If an application wants to have access to larger address space, it has to
> specify hint addess above 47-bits.
>
> See details here:
>
> http://lkml.kernel.org/r/20170420162147.86517-10-kirill.shutemov@linux.intel.com
Thanks. I'll have a read. Although from your message I'm reading out that
this particular proposal got rejected.
Would be really nice to able to have a canonical solution for this issue,
it's been biting us on SPARC for quite a while now due to the fact that
virtual address space has been 52 bits on SPARC for a while now.
Adrian
> [1] https://bugreports.qt.io/browse/QTBUG-56264
--
.''`. John Paul Adrian Glaubitz
: :' : Debian Developer - glaubitz@debian.org
`. `' Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de
`- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913
next prev parent reply other threads:[~2017-04-24 20:38 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-23 10:53 Question on the five-level page table support patches John Paul Adrian Glaubitz
2017-04-24 5:11 ` Andy Lutomirski
2017-04-24 13:03 ` Andi Kleen
2017-04-24 20:33 ` John Paul Adrian Glaubitz
2017-04-24 16:19 ` Kirill A. Shutemov
2017-04-24 20:37 ` John Paul Adrian Glaubitz [this message]
2017-04-24 22:01 ` Kirill A. Shutemov
2017-04-24 22:09 ` David Miller
2017-04-25 7:25 ` Jon Masters
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