Re: [Cake] [LEDE-DEV] Cake SQM killing my DIR-860L - was: [17.01] Kernel: bump to 4.4.51

2017-03-06 Thread Benjamin Cronce
Depends on how short of a timescale you're talking about. Shared global state that is being read and written to very quickly by multiple threads is bad enough for a single package system, but when you start getting to something like an AMD Ryzen or NUMA, shared global state becomes really

Re: [Cake] [LEDE-DEV] Cake SQM killing my DIR-860L - was: [17.01] Kernel: bump to 4.4.51

2017-03-06 Thread Eric Luehrsen
On 03/02/2017 07:02 PM, Jonathan Morton wrote: >> On 3 Mar, 2017, at 01:55, John Yates wrote: >> >> The virtue of a prime number of buckets is that when you mod >> your 32-bit hash value to get a bucket index you harvest _all_ >> of the entropy in the hash, not just the

Re: [Cake] [LEDE-DEV] Cake SQM killing my DIR-860L - was: [17.01] Kernel: bump to 4.4.51

2017-03-02 Thread Jonathan Morton
> On 3 Mar, 2017, at 06:31, Eric Luehrsen wrote: > > Also with SQM you may not what idealized entropy in your queue > distribution. It is desired by some to have host-connection fairness, > and not so much interest in stream-type fairness. So overlap in a few > hash

Re: [Cake] [LEDE-DEV] Cake SQM killing my DIR-860L - was: [17.01] Kernel: bump to 4.4.51

2017-03-02 Thread Jonathan Morton
> On 3 Mar, 2017, at 01:55, John Yates wrote: > > The virtue of a prime number of buckets is that when you mod > your 32-bit hash value to get a bucket index you harvest _all_ > of the entropy in the hash, not just the entropy in the bits you > preserve. True, but you

Re: [Cake] [LEDE-DEV] Cake SQM killing my DIR-860L - was: [17.01] Kernel: bump to 4.4.51

2017-03-02 Thread Jonathan Morton
> On 3 Mar, 2017, at 01:16, John Yates wrote: > > What are the requirements for this hashing function? > - How much data is being hashed? I am guessing a limited number of bytes > rather than an entire packet payload. Generally it’s what we call the “5-tuple”: two

Re: [Cake] [LEDE-DEV] Cake SQM killing my DIR-860L - was: [17.01] Kernel: bump to 4.4.51

2017-03-02 Thread John Yates
On Thu, Mar 2, 2017 at 4:10 PM, Dave Täht wrote: > As for speeding up hashing, I've been looking over various algorithms to > do that for years now, I'm open to suggestions. The fastest new ones > tend to depend on co-processor support. The fastest I've seen relies on > the CRC32