From: arnd@arndb.de (Arnd Bergmann)
To: linux-arm-kernel@lists.infradead.org
Subject: PMD update corruption (sync question)
Date: Tue, 03 Mar 2015 10:06:48 +0100 [thread overview]
Message-ID: <8866266.2EELEveYhm@wuerfel> (raw)
In-Reply-To: <54F4E266.8090709@redhat.com>
On Monday 02 March 2015 17:21:26 Jon Masters wrote:
> On 03/02/2015 05:50 AM, Catalin Marinas wrote:
> > On Mon, Mar 02, 2015 at 12:58:36AM -0500, Jon Masters wrote:
>
> >> Test kernels running with an explicit DSB in all PTE update cases now
> >> running overnight. Just in case.
>
> ...and stay up after 19 hours. But that's just timing I'm sure.
>
> > It could be hiding some other problems.
>
> I checked my GDB macros and they were correct BUT my debugger went out
> to lunch soon after that dump so I suspect it was just garbage
>
> Instead, for my immediate issue, I have a much more likely suspect. For
> anyone interested in the followup, you should know that hardware page
> table walkers generally do respond well when you feed them Makefiles:
>
> 0x43e81c0000: 20230a23 656b614d 656c6966 726f6620 : #.# Makefile for
> 0x43e81c0010: 65687420 462d4920 6563726f 69726420 : the I-Force dri
> 0x43e81c0020: 0a726576 20230a23 4a207942 6e61686f : ver.#.# By Johan
> 0x43e81c0030: 6544206e 7875656e 6f6a3c20 6e6e6168 : n Deneux <johann
> 0x43e81c0040: 6e65642e 40787565 69616d67 6f632e6c : .deneux at gmail.co
> 0x43e81c0050: 230a3e6d 626f0a0a 28242d6a 464e4f43 : m>.#..obj-$(CONF
> 0x43e81c0060: 4a5f4749 5453594f 5f4b4349 524f4649 : IG_JOYSTICK_IFOR
> 0x43e81c0070: 09294543 69203d2b 63726f66 0a6f2e65 : CE).+= iforce.o.
> 0x43e81c0080: 6f66690a 2d656372 3d3a2079 6f666920 : .iforce-y := ifo
> 0x43e81c0090: 2d656372 6f2e6666 6f666920 2d656372 : rce-ff.o iforce-
> 0x43e81c00a0: 6e69616d 69206f2e 63726f66 61702d65 : main.o iforce-pa
> 0x43e81c00b0: 74656b63 0a6f2e73 726f6669 242d6563 : ckets.o.iforce-$
> 0x43e81c00c0: 4e4f4328 5f474946 53594f4a 4b434954 : (CONFIG_JOYSTICK
> 0x43e81c00d0: 4f46495f 5f454352 29323332 203d2b09 : _IFORCE_232).+=
> 0x43e81c00e0: 726f6669 732d6563 6f697265 690a6f2e : iforce-serio.o.i
> 0x43e81c00f0: 63726f66 28242d65 464e4f43 4a5f4749 : force-$(CONFIG_J
> 0x43e81c0100: 5453594f 5f4b4349 524f4649 555f4543 : OYSTICK_IFORCE_U
> 0x43e81c0110: 09294253 69203d2b 63726f66 73752d65 : SB).+= iforce-us
> 0x43e81c0120: 0a6f2e62 00000000 00000000 00000000 : b.o.............
>
> So that explains why things were falling over. It is likely indeed the
> bad DMA I have been craving all along. And this time it was so gracious
> as to give me the answer in plain ASCII I suspect there will be a
> patch for a certain AHCI driver in the not too distant future.
I hope this kind of problem becomes easier to debug once we have
full iommu support working on arm64. When we had problems like this
on PowerPC, using iommu=force to ensure DMA would only be done to
pages that are currently mapped to the device was really helpful.
Arnd
next prev parent reply other threads:[~2015-03-03 9:06 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-26 14:03 [PATCH V4 0/6] RCU get_user_pages_fast and __get_user_pages_fast Steve Capper
2014-09-26 14:03 ` [PATCH V4 1/6] mm: Introduce a general RCU get_user_pages_fast Steve Capper
2014-09-29 21:51 ` Hugh Dickins
2014-10-01 11:11 ` Catalin Marinas
2014-10-02 16:00 ` Steve Capper
2014-10-02 12:19 ` Andrea Arcangeli
2014-10-02 16:18 ` Steve Capper
2014-10-02 16:54 ` Andrea Arcangeli
2014-10-13 5:15 ` Aneesh Kumar K.V
2014-10-13 5:21 ` David Miller
2014-10-13 11:44 ` Steve Capper
2014-10-13 16:06 ` David Miller
2014-10-14 12:38 ` Steve Capper
2014-10-14 16:30 ` David Miller
2014-10-13 17:04 ` Aneesh Kumar K.V
2014-10-13 6:22 ` Aneesh Kumar K.V
2014-09-26 14:03 ` [PATCH V4 2/6] arm: mm: Introduce special ptes for LPAE Steve Capper
2014-09-26 14:03 ` [PATCH V4 3/6] arm: mm: Enable HAVE_RCU_TABLE_FREE logic Steve Capper
2014-09-26 14:03 ` [PATCH V4 4/6] arm: mm: Enable RCU fast_gup Steve Capper
2014-09-26 14:03 ` [PATCH V4 5/6] arm64: mm: Enable HAVE_RCU_TABLE_FREE logic Steve Capper
2014-09-26 14:03 ` [PATCH V4 6/6] arm64: mm: Enable RCU fast_gup Steve Capper
2015-02-27 12:42 ` [PATCH V4 0/6] RCU get_user_pages_fast and __get_user_pages_fast Jon Masters
2015-02-27 13:20 ` Mark Rutland
2015-03-02 14:16 ` Mark Rutland
[not found] ` <54F3C6AD.50300@redhat.com>
2015-03-02 5:58 ` PMD update corruption (sync question) Jon Masters
2015-03-02 10:50 ` Catalin Marinas
2015-03-02 11:06 ` Jon Masters
2015-03-02 12:31 ` Peter Zijlstra
2015-03-02 12:40 ` Geert Uytterhoeven
2015-03-02 22:21 ` Jon Masters
2015-03-02 22:29 ` Jon Masters
2015-03-03 9:06 ` Arnd Bergmann [this message]
2015-03-03 15:46 ` Jon Masters
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