[Mesa-dev] [PATCH] anv: change BLOCK_POOL_MEMFD_SIZE to exactly 2GB

[Tapani Pälli]

On 03/07/2017 07:16 PM, Emil Velikov wrote:
> On 7 March 2017 at 15:53, Eero Tamminen <eero.t.tamminen at intel.com> wrote:
>> Hi,
>>
>> On 07.03.2017 17:08, Jason Ekstrand wrote:
>>> Interesting... This must only affect android for some weird reason
>>> because 32-bit builds have been working on regular Linux for some time
>>> now.
>>
>> There are couple of issues...
>>
>>  From "ftruncate" manual page:
>>         int ftruncate(int fd, off_t length);
>> ...
>>         The original Linux truncate() and ftruncate() system calls were not
>> designed to handle large file offsets.  Consequently, Linux 2.4 added
>> truncate64() and ftruncate64() system calls that handle large files.
>> However, these details can be ignored by applications using glibc, whose
>> wrapper functions  transparently  employ the more recent system calls where
>> they are available.
>>
>>         On some 32-bit architectures, the calling signature for these system
>> calls differ, for the reasons described in syscall(2).
>>
>>
>> And from "ftello" manual page:
>>         On some architectures, both off_t and long are 32-bit types, but
>> defining _FILE_OFFSET_BITS with the value 64 (before including any header
>> files) will turn off_t into a 64-bit type.
>>
>>
>> Not sure which one Android libc/build hits.
>>
> Afaict 32bit Android has been ... what's a nicer word than broken...
> See the fun experience we have in gallium [1] to w/a their fun mmap
> implementation ;-)
>
> Tapani, cannot comment on the patch itself but do take a look at [1]
> and move/reuse it _everywhere_. Mauro can you lend a hand to Tapani ?

OK, that's interesting. Will need to check if we have issues with mmap.

> -Emil
> [1] src/gallium/auxiliary/os/os_mman.h
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// Tapani