From: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: venkatesh.pallipadi@intel.com, ak@muc.de, rdreier@cisco.com,
torvalds@linux-foundation.org, gregkh@suse.de, airlied@skynet.ie,
davej@redhat.com, mingo@elte.hu, tglx@linutronix.de,
hpa@zytor.com, akpm@linux-foundation.org, arjan@infradead.org,
jesse.barnes@intel.com, linux-kernel@vger.kernel.org,
Suresh Siddha <suresh.b.siddha@intel.com>
Subject: Re: [RFC PATCH 02/12] PAT 64b: Basic PAT implementation
Date: Fri, 14 Dec 2007 13:10:39 -0800 [thread overview]
Message-ID: <20071214211039.GB717@linux-os.sc.intel.com> (raw)
In-Reply-To: <m1wsrhq4zl.fsf@ebiederm.dsl.xmission.com>
On Thu, Dec 13, 2007 at 09:23:26PM -0700, Eric W. Biederman wrote:
> ebiederm@xmission.com (Eric W. Biederman) writes:
> Ok. My analysis here was wrong. Currently pgprot_noncached and
> ioremap_nocache are out of sync. With ioremap_nocache only specifying
> _PAGE_PCD and pgprot_noncached specifying _PAGE_PCD | _PAGE_PWT.
>
> So I don't have a clue how someone could reprogram the mtrrs currently
> and expect things to work.
>
> ...
>
> If we bother to ask ioremap for memory that is not cached, the last
> thing in the world we want is the MTRRs upgrading that to write combining.
> So ioremap_nocache has been slightly buggy for ages. ioremap_nocache
> and PAGE_KERNEL_NOCACHE should get _PAGE_PWT added to their
> definitions.
>
> Could we please get a cleanup patch at the beginning of this patchset
> or that comes before it that fixes ioremap_nocache on x86?
>
> That will make us a lot more git-bisect safe.
Ok. I will send a separate patch fixing ioremap_nocache on x86.
thanks,
suresh
next prev parent reply other threads:[~2007-12-14 21:11 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-13 23:55 [RFC PATCH 00/12] PAT 64b: PAT support for X86_64 venkatesh.pallipadi
2007-12-13 23:55 ` [RFC PATCH 01/12] PAT 64b: Add cpu_shutdown() support venkatesh.pallipadi
2007-12-13 23:55 ` [RFC PATCH 02/12] PAT 64b: Basic PAT implementation venkatesh.pallipadi
2007-12-14 0:42 ` Andi Kleen
2007-12-14 18:31 ` Venki Pallipadi
2007-12-18 4:50 ` Eric W. Biederman
2007-12-14 3:48 ` Eric W. Biederman
2007-12-14 4:23 ` Eric W. Biederman
2007-12-14 21:10 ` Siddha, Suresh B [this message]
2007-12-14 23:34 ` Siddha, Suresh B
2007-12-15 7:55 ` Ingo Molnar
2007-12-14 10:25 ` Andi Kleen
2007-12-14 19:45 ` H. Peter Anvin
2007-12-18 4:42 ` Eric W. Biederman
2007-12-14 21:06 ` Siddha, Suresh B
2007-12-13 23:55 ` [RFC PATCH 03/12] PAT 64b: drm driver changes for PAT venkatesh.pallipadi
2007-12-13 23:55 ` [RFC PATCH 04/12] PAT 64b: reserve_mattr and free_mattr " venkatesh.pallipadi
2007-12-13 23:55 ` [RFC PATCH 05/12] PAT 64b: pci mmap conlfict patch venkatesh.pallipadi
2007-12-13 23:55 ` [RFC PATCH 06/12] PAT 64b: Add ioremap_wc support venkatesh.pallipadi
2007-12-14 4:17 ` Roland Dreier
2007-12-14 4:28 ` Eric W. Biederman
2007-12-14 4:32 ` Roland Dreier
2007-12-14 4:48 ` Eric W. Biederman
2007-12-14 21:40 ` Siddha, Suresh B
2007-12-14 23:19 ` Andi Kleen
2007-12-18 8:29 ` Eric W. Biederman
2007-12-13 23:55 ` [RFC PATCH 07/12] PAT 64b: dev mem chanegs for pat venkatesh.pallipadi
2007-12-13 23:55 ` [RFC PATCH 08/12] PAT 64b: coherent mmap and sysfs bin ioctl venkatesh.pallipadi
2007-12-14 0:19 ` Greg KH
2007-12-14 0:35 ` David Miller
2007-12-14 6:34 ` Greg KH
2007-12-16 21:57 ` Paul Mackerras
2007-12-17 12:41 ` Andi Kleen
2007-12-18 4:30 ` Eric W. Biederman
2007-12-18 4:51 ` H. Peter Anvin
2007-12-18 9:35 ` Andi Kleen
2007-12-18 13:48 ` Eric W. Biederman
2007-12-14 0:43 ` Andi Kleen
2007-12-14 0:54 ` Jesse Barnes
2007-12-14 3:59 ` Eric W. Biederman
2007-12-14 6:02 ` Greg KH
2007-12-14 6:04 ` Eric W. Biederman
2007-12-14 10:19 ` Andi Kleen
2007-12-13 23:55 ` [RFC PATCH 09/12] PAT 64b: map only usable memory in identity mapping venkatesh.pallipadi
2007-12-13 23:55 ` [RFC PATCH 10/12] PAT 64b: Make acpi use early map instead of assuming identity map venkatesh.pallipadi
2007-12-13 23:55 ` [RFC PATCH 11/12] PAT 64b: devmem do not read pages not mapped in " venkatesh.pallipadi
2007-12-13 23:55 ` [RFC PATCH 12/12] PAT 64b: skip attr tracking for RAM venkatesh.pallipadi
2007-12-14 0:28 ` [RFC PATCH 00/12] PAT 64b: PAT support for X86_64 Dave Airlie
2007-12-14 22:00 ` Siddha, Suresh B
2007-12-14 22:27 ` Dave Airlie
2007-12-14 22:32 ` H. Peter Anvin
2007-12-14 22:37 ` Dave Airlie
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