[alsa-devel] USB transfer_buffer allocations on 64bit systems

Pedro Ribeiro pedrib at gmail.com
Wed Apr 14 12:47:33 CEST 2010


On 14 April 2010 11:09, Daniel Mack <daniel at caiaq.de> wrote:

> Thanks! So the only thing I can do for now is submit exactly this patch.
> At least, it helps you and it shouldn't break anything. The question
> remains whether this type of memory should be used for all
> transfer_buffers.
>

Is there any chance you could push this to -stable? I don't care
because I always use the latest kernel, but the next Debian stable and
Ubuntu LTS are going to use 2.6.32.

>> Any idea why is mem=4096m different than a regular boot since I have 4GB anyway?
>
> On Fri, Apr 09, 2010 at 04:11:52PM -0600, Robert Hancock wrote:
>> If you have 4GB of RAM then almost certainly you have memory located
>> at addresses over 4GB. If you look at the e820 memory map printed at
>> the start of dmesg on bootup and see entries with addresses of
>> 100000000 or higher reported as usable, then this is the case.
>
> Could you post the these e820 line from your dmesg when booted with
> mem=4096?
>
> Daniel
>
>

This is the e820 WITHOUT mem=4096m:

[    0.000000] BIOS-provided physical RAM map:
[    0.000000]  BIOS-e820: 0000000000000000 - 000000000009ec00 (usable)
[    0.000000]  BIOS-e820: 000000000009ec00 - 00000000000a0000 (reserved)
[    0.000000]  BIOS-e820: 00000000000dc000 - 0000000000100000 (reserved)
[    0.000000]  BIOS-e820: 0000000000100000 - 00000000bd4a1000 (usable)
[    0.000000]  BIOS-e820: 00000000bd4a1000 - 00000000bd4a7000 (reserved)
[    0.000000]  BIOS-e820: 00000000bd4a7000 - 00000000bd5b8000 (usable)
[    0.000000]  BIOS-e820: 00000000bd5b8000 - 00000000bd60f000 (reserved)
[    0.000000]  BIOS-e820: 00000000bd60f000 - 00000000bd6c6000 (usable)
[    0.000000]  BIOS-e820: 00000000bd6c6000 - 00000000bd6d1000 (ACPI NVS)
[    0.000000]  BIOS-e820: 00000000bd6d1000 - 00000000bd6d4000 (ACPI data)
[    0.000000]  BIOS-e820: 00000000bd6d4000 - 00000000bd6d8000 (reserved)
[    0.000000]  BIOS-e820: 00000000bd6d8000 - 00000000bd6dc000 (ACPI NVS)
[    0.000000]  BIOS-e820: 00000000bd6dc000 - 00000000bd6df000 (reserved)
[    0.000000]  BIOS-e820: 00000000bd6df000 - 00000000bd706000 (ACPI NVS)
[    0.000000]  BIOS-e820: 00000000bd706000 - 00000000bd708000 (ACPI data)
[    0.000000]  BIOS-e820: 00000000bd708000 - 00000000bd90f000 (reserved)
[    0.000000]  BIOS-e820: 00000000bd90f000 - 00000000bd99f000 (ACPI NVS)
[    0.000000]  BIOS-e820: 00000000bd99f000 - 00000000bd9ff000 (ACPI data)
[    0.000000]  BIOS-e820: 00000000bd9ff000 - 00000000bda00000 (usable)
[    0.000000]  BIOS-e820: 00000000bdc00000 - 00000000c0000000 (reserved)
[    0.000000]  BIOS-e820: 00000000e0000000 - 00000000f0000000 (reserved)
[    0.000000]  BIOS-e820: 00000000fec00000 - 00000000fec10000 (reserved)
[    0.000000]  BIOS-e820: 00000000fed00000 - 00000000fed00400 (reserved)
[    0.000000]  BIOS-e820: 00000000fed10000 - 00000000fed14000 (reserved)
[    0.000000]  BIOS-e820: 00000000fed18000 - 00000000fed1a000 (reserved)
[    0.000000]  BIOS-e820: 00000000fed1c000 - 00000000fed90000 (reserved)
[    0.000000]  BIOS-e820: 00000000fee00000 - 00000000fee01000 (reserved)
[    0.000000]  BIOS-e820: 00000000ff800000 - 0000000100000000 (reserved)
[    0.000000]  BIOS-e820: 0000000100000000 - 000000013c000000 (usable)



This is the e820 output WITH mem=4096m

[    0.000000] BIOS-provided physical RAM map:
[    0.000000]  BIOS-e820: 0000000000000000 - 000000000009ec00 (usable)
[    0.000000]  BIOS-e820: 000000000009ec00 - 00000000000a0000 (reserved)
[    0.000000]  BIOS-e820: 00000000000dc000 - 0000000000100000 (reserved)
[    0.000000]  BIOS-e820: 0000000000100000 - 00000000bd4a1000 (usable)
[    0.000000]  BIOS-e820: 00000000bd4a1000 - 00000000bd4a7000 (reserved)
[    0.000000]  BIOS-e820: 00000000bd4a7000 - 00000000bd5b8000 (usable)
[    0.000000]  BIOS-e820: 00000000bd5b8000 - 00000000bd60f000 (reserved)
[    0.000000]  BIOS-e820: 00000000bd60f000 - 00000000bd6c6000 (usable)
[    0.000000]  BIOS-e820: 00000000bd6c6000 - 00000000bd6d1000 (ACPI NVS)
[    0.000000]  BIOS-e820: 00000000bd6d1000 - 00000000bd6d4000 (ACPI data)
[    0.000000]  BIOS-e820: 00000000bd6d4000 - 00000000bd6d8000 (reserved)
[    0.000000]  BIOS-e820: 00000000bd6d8000 - 00000000bd6dc000 (ACPI NVS)
[    0.000000]  BIOS-e820: 00000000bd6dc000 - 00000000bd6df000 (reserved)
[    0.000000]  BIOS-e820: 00000000bd6df000 - 00000000bd706000 (ACPI NVS)
[    0.000000]  BIOS-e820: 00000000bd706000 - 00000000bd708000 (ACPI data)
[    0.000000]  BIOS-e820: 00000000bd708000 - 00000000bd90f000 (reserved)
[    0.000000]  BIOS-e820: 00000000bd90f000 - 00000000bd99f000 (ACPI NVS)
[    0.000000]  BIOS-e820: 00000000bd99f000 - 00000000bd9ff000 (ACPI data)
[    0.000000]  BIOS-e820: 00000000bd9ff000 - 00000000bda00000 (usable)
[    0.000000]  BIOS-e820: 00000000bdc00000 - 00000000c0000000 (reserved)
[    0.000000]  BIOS-e820: 00000000e0000000 - 00000000f0000000 (reserved)
[    0.000000]  BIOS-e820: 00000000fec00000 - 00000000fec10000 (reserved)
[    0.000000]  BIOS-e820: 00000000fed00000 - 00000000fed00400 (reserved)
[    0.000000]  BIOS-e820: 00000000fed10000 - 00000000fed14000 (reserved)
[    0.000000]  BIOS-e820: 00000000fed18000 - 00000000fed1a000 (reserved)
[    0.000000]  BIOS-e820: 00000000fed1c000 - 00000000fed90000 (reserved)
[    0.000000]  BIOS-e820: 00000000fee00000 - 00000000fee01000 (reserved)
[    0.000000]  BIOS-e820: 00000000ff800000 - 0000000100000000 (reserved)
[    0.000000]  BIOS-e820: 0000000100000000 - 000000013c000000 (usable)
[    0.000000] NX (Execute Disable) protection: active
[    0.000000] user-defined physical RAM map:
[    0.000000]  user: 0000000000000000 - 000000000009ec00 (usable)
[    0.000000]  user: 000000000009ec00 - 00000000000a0000 (reserved)
[    0.000000]  user: 00000000000dc000 - 0000000000100000 (reserved)
[    0.000000]  user: 0000000000100000 - 00000000bd4a1000 (usable)
[    0.000000]  user: 00000000bd4a1000 - 00000000bd4a7000 (reserved)
[    0.000000]  user: 00000000bd4a7000 - 00000000bd5b8000 (usable)
[    0.000000]  user: 00000000bd5b8000 - 00000000bd60f000 (reserved)
[    0.000000]  user: 00000000bd60f000 - 00000000bd6c6000 (usable)
[    0.000000]  user: 00000000bd6c6000 - 00000000bd6d1000 (ACPI NVS)
[    0.000000]  user: 00000000bd6d1000 - 00000000bd6d4000 (ACPI data)
[    0.000000]  user: 00000000bd6d4000 - 00000000bd6d8000 (reserved)
[    0.000000]  user: 00000000bd6d8000 - 00000000bd6dc000 (ACPI NVS)
[    0.000000]  user: 00000000bd6dc000 - 00000000bd6df000 (reserved)
[    0.000000]  user: 00000000bd6df000 - 00000000bd706000 (ACPI NVS)
[    0.000000]  user: 00000000bd706000 - 00000000bd708000 (ACPI data)
[    0.000000]  user: 00000000bd708000 - 00000000bd90f000 (reserved)
[    0.000000]  user: 00000000bd90f000 - 00000000bd99f000 (ACPI NVS)
[    0.000000]  user: 00000000bd99f000 - 00000000bd9ff000 (ACPI data)
[    0.000000]  user: 00000000bd9ff000 - 00000000bda00000 (usable)
[    0.000000]  user: 00000000bdc00000 - 00000000c0000000 (reserved)
[    0.000000]  user: 00000000e0000000 - 00000000f0000000 (reserved)
[    0.000000]  user: 00000000fec00000 - 00000000fec10000 (reserved)
[    0.000000]  user: 00000000fed00000 - 00000000fed00400 (reserved)
[    0.000000]  user: 00000000fed10000 - 00000000fed14000 (reserved)
[    0.000000]  user: 00000000fed18000 - 00000000fed1a000 (reserved)
[    0.000000]  user: 00000000fed1c000 - 00000000fed90000 (reserved)
[    0.000000]  user: 00000000fee00000 - 00000000fee01000 (reserved)
[    0.000000]  user: 00000000ff800000 - 0000000100000000 (reserved)

So basically the BIOS is incorrectly reporting
BIOS-e820: 0000000100000000 - 000000013c000000 (usable)

right?

Thanks,
Pedro


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