> On 13 Jun 2020, at 3:20 pm, Theo Buehler wrote:
>
> On Sat, Jun 13, 2020 at 11:35:42AM +1000, David Gwynne wrote:
>> On Fri, Jun 12, 2020 at 03:37:59PM +0200, Theo Buehler wrote:
>>> I finally found the time to think about the mathematics of this some
>>> more and I'm now convinced that
> On 14 Jun 2020, at 10:59 pm, Miod Vallat wrote:
>
>
>>> Others have pointed out off-list that one can use __builtin_popcount(),
>>> but __builtin_parity() is exactly what I want. Is it available on all
>>> architectures?
>>
>> I don't think it is available on gcc 3.x for m88k but someone
>> Others have pointed out off-list that one can use __builtin_popcount(),
>> but __builtin_parity() is exactly what I want. Is it available on all
>> architectures?
>
> I don't think it is available on gcc 3.x for m88k but someone with
> an m88k should confirm.
__builtin_popcount() does not
On 6/13/20 2:47 PM, Theo Buehler wrote:
>>> Yes. The thing is that you need to convince yourself that this is still
>>> uniformly distributed over the wanted numbers. But it's correct. In
>>> fact, it's enough to flip a fixed bit, so you can get away with one call
>>> to arc4random().
>>
>> Its
On 6/13/20 9:19 AM, Theo Buehler wrote:
> On Sat, Jun 13, 2020 at 08:46:13AM -0400, David Higgs wrote:
>> On Fri, Jun 12, 2020 at 9:41 AM Theo Buehler wrote:
>>
>>> I finally found the time to think about the mathematics of this some
>>> more and I'm now convinced that it's a sound construction.
On Sat, Jun 13, 2020 at 07:10:50PM -, Christian Weisgerber wrote:
> On 2020-06-13, Theo Buehler wrote:
>
> > Others have pointed out off-list that one can use __builtin_popcount(),
> > but __builtin_parity() is exactly what I want. Is it available on all
> > architectures?
>
> The standard
On 2020-06-13, Theo Buehler wrote:
> Others have pointed out off-list that one can use __builtin_popcount(),
> but __builtin_parity() is exactly what I want. Is it available on all
> architectures?
The standard implementation will be perfectly fine, no need to resort
to magic compiler
> > Yes. The thing is that you need to convince yourself that this is still
> > uniformly distributed over the wanted numbers. But it's correct. In
> > fact, it's enough to flip a fixed bit, so you can get away with one call
> > to arc4random().
>
> Its not immediately obvious because this is not
On Sat, 13 Jun 2020 15:19:28 +0200, Theo Buehler wrote:
> Others have pointed out off-list that one can use __builtin_popcount(),
> but __builtin_parity() is exactly what I want. Is it available on all
> architectures?
I don't think it is available on gcc 3.x for m88k but someone with
an m88k
On Sat, Jun 13, 2020 at 08:46:13AM -0400, David Higgs wrote:
> On Fri, Jun 12, 2020 at 9:41 AM Theo Buehler wrote:
>
> > I finally found the time to think about the mathematics of this some
> > more and I'm now convinced that it's a sound construction. I hope that
> > one or the other
On Fri, Jun 12, 2020 at 9:41 AM Theo Buehler wrote:
> I finally found the time to think about the mathematics of this some
> more and I'm now convinced that it's a sound construction. I hope that
> one or the other observation below will be useful for you.
>
> The hash as it is now can be proved
On Sat, Jun 13, 2020 at 11:35:42AM +1000, David Gwynne wrote:
> On Fri, Jun 12, 2020 at 03:37:59PM +0200, Theo Buehler wrote:
> > I finally found the time to think about the mathematics of this some
> > more and I'm now convinced that it's a sound construction. I hope that
> > one or the other
On Fri, Jun 12, 2020 at 03:37:59PM +0200, Theo Buehler wrote:
> I finally found the time to think about the mathematics of this some
> more and I'm now convinced that it's a sound construction. I hope that
> one or the other observation below will be useful for you.
Yes, I read everything below
I finally found the time to think about the mathematics of this some
more and I'm now convinced that it's a sound construction. I hope that
one or the other observation below will be useful for you.
The hash as it is now can be proved to produce values in the full range
of uint16_t, so that's
> At the end of this loop, key[b] contains two copies of the cyclically
> permuted skey next to each other. When building the cache, you scan
> through the bits of val, xor the corresponding keys in if they're set
> and then throw away half of the 32 bits when assigning
> scache->bytes[val] = res;
On Fri, May 29, 2020 at 02:41:07PM +1000, David Gwynne wrote:
> This is another bit of the puzzle for supporting multiple rx rings
> and receive side scaling (RSS) on nics. It borrows heavily from
> DragonflyBSD, but I've made some tweaks on the way.
>
> For background on the dfly side, I
This is another bit of the puzzle for supporting multiple rx rings
and receive side scaling (RSS) on nics. It borrows heavily from
DragonflyBSD, but I've made some tweaks on the way.
For background on the dfly side, I recommend having a look at
17 matches
Mail list logo
