Re: Request for Testing: TCP RACK
Mike Karels <[email protected]>
| Newsgroups | gmane.os.freebsd.devel.net |
|---|---|
| Message-ID | <[email protected]> |
On 18 Mar 2024, at 7:04, [email protected] wrote: >> On 18. Mar 2024, at 12:42, Nuno Teixeira <[email protected]> wrote: >> >> Hello all! >> >> It works just fine! >> System performance is OK. >> Using patch on main-n268841-b0aaf8beb126(-dirty). >> >> --- >> net.inet.tcp.functions_available: >> Stack D Alias PCB count >> freebsd freebsd 0 >> rack * rack 38 >> --- >> >> It would be so nice that we can have a sysctl tunnable for this patch >> so we could do more tests without recompiling kernel. > Thanks for testing! > > @gallatin: can you come up with a patch that is acceptable for Netflix > and allows to mitigate the performance regression. Ideally, tcphpts could enable this automatically when it starts to be used (enough?), but a sysctl could select auto/on/off. Mike > Best regards > Michael >> >> Thanks all! >> Really happy here :) >> >> Cheers, >> >> Nuno Teixeira <[email protected]> escreveu (domingo, 17/03/2024 à(s) 20:26): >>> >>> Hello, >>> >>>> I don't have the full context, but it seems like the complaint is a performance regression in bonnie++ and perhaps other things when tcp_hpts is loaded, even when it is not used. Is that correct? >>>> >>>> If so, I suspect its because we drive the tcp_hpts_softclock() routine from userret(), in order to avoid tons of timer interrupts and context switches. To test this theory, you could apply a patch like: >>> >>> It's affecting overall system performance, bonnie was just a way to >>> get some numbers to compare. >>> >>> Tomorrow I will test patch. >>> >>> Thanks! >>> >>> -- >>> Nuno Teixeira >>> FreeBSD Committer (ports) >> >> >> >> -- >> Nuno Teixeira >> FreeBSD Committer (ports)