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

[Pedro Ribeiro]

On 14 April 2010 11:47, Pedro Ribeiro <pedrib at gmail.com> wrote:
> 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
>

(sorry for the spam)

Actually this can't be right, because booting with mem=4096m only
gives me 3047008 kb of usable memory, versus 3949684 kb without
mem=4096m.

Pedro