Benefits of cryptographic hash functions for uniquely identifing Vulkan shaders.

[abel.bernabeu at gmail.com]

Two cents, sorry if too obvious.

If you want to try to squeeze more performance here, it seems valid to try
to fallback to full comparison in case of collision. The algorithm will be
correct irrespective of your (bad luck) with hash collisions, and at worst,
with an insignificant probability, the time cost is O(n*n), but the typical
cost will remain close to always O(n).

That way you try cheaper hashing algorithms without worry.

Regards.



On Thu, 29 Jun 2023 at 13:35, Marek Olšák <maraeo at gmail.com> wrote:

> If there is a hash collision, it will cause a GPU hang. A cryptographic
> hash function reduces that chance to practically zero.
>
> Marek
>
> On Thu, Jun 29, 2023, 07:04 mikolajlubiak1337 <mikolajlubiak1337 at proton.me>
> wrote:
>
>> Hi,
>> I have recently read Phoronix article[1] about you switching to BLAKE3
>> instead of SHA1.
>> If BLAKE3 is a cryptographic hash function wouldn't it be faster to use a
>> non cryptographic hash function or even a checksum function? Do you need
>> the benefits of cryptographic hash functions over other hash/checksum
>> functions for the purpose of uniquely identifing Vulkan shaders?
>>
>> [1]: https://www.phoronix.com/news/Mesa-BLAKE3-Shader-Hashing
>>
>> -- me
>>
>>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/mesa-dev/attachments/20230703/d263b7df/attachment.htm>