Hi Morten,
On 16/03/2020 14:39, Morten Brørup wrote:
From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Vladimir Medvedkin
Sent: Monday, March 16, 2020 2:38 PM
Currently DPDK has a special implementation of a hash table for
4 byte keys which is called FBK hash. Unfortunately its main drawback
is that it only supports 2 byte values.
The new implementation called DWK (double word key) hash
supports 8 byte values, which is enough to store a pointer.
It would also be nice to get feedback on whether to leave the old FBK
and new DWK implementations, or whether to deprecate the old one?
<rant on>
Who comes up with these names?!?
FBK (Four Byte Key) and DWK (Double Word Key) is supposed to mean the same.
Could you use 32 somewhere in the name instead, like in int32_t, instead of
using a growing list of creative synonyms for the same thing? Pretty please,
with a cherry on top!
That's true, at first I named it as fbk2, but then it was decided to
rename it "dwk", so that there was no confusion with the existing FBK
library. Naming suggestions are welcome!
And if the value size is fixed too, perhaps the name should also indicate the
value size.
<rant off>
It's a shame we don't have C++ class templates available in DPDK...
In other news, Mellanox has sent an RFC for an "indexed memory pool" library
[1] to conserve memory by using uintXX_t instead of pointers, so perhaps a variant of a
32 bit key hash library with 32 bit values (in addition to 16 bit values in FBK and 64
bit in DWK) would be nice combination with that library.
[1]: http://mails.dpdk.org/archives/dev/2019-October/147513.html
Med venlig hilsen / kind regards
- Morten Brørup
--
Regards,
Vladimir
