On 6 January 2015 at 07:55, Ian Lepore <i...@freebsd.org> wrote: > On Tue, 2015-01-06 at 09:37 -0500, John Baldwin wrote: >> On 1/5/15 8:18 AM, Hans Petter Selasky wrote: >> > Hi, >> > >> > There is a limitiation on the number of interrupt vectors available when >> > only a single processor is running. To have more interrupts available we >> > need to start SMP earlier when building a monotolith kernel and not >> > loading drivers as modules. The driver in question is a network driver >> > and because it cannot be started after SI_SUB_ROOT_CONF due to PXE >> > support I see no other option than to move SI_SUB_SMP earlier. >> > >> > Suggested patch: >> > >> >>[...] >> > >> > This fixes a problem for Mellanox drivers in the OFED layer. Possibly we >> > need to move the SMP even earlier to not miss the generic FreeBSD PCI >> > device enumeration or maybe this is not possible. Does anyone know how >> > early we can start SMP? >> >> We need a lot more work before this is ready. This is one of the goals >> of the multipass new-bus stuff. In particular, we have to enumerate >> enough devices to bring event timer hardware up so that timer interrupts >> work so that tsleep() will actually sleep. In addition, we also need >> idle threads created and working before APs are started as otherwise >> they will have no thread to run initially. This is certainly a desired >> feature, but it is not as simple as moving the sysinit up I'm afraid. >> > > Just an FYI, the ARM world is now using the multipass newbus stuff. It > works well, with some quirks... > > The predefined pass names don't always makes sense for the arm world. > There aren't enough predefined pass names and even though the number > space for them is 4 billion wide all the predefined names are in the > range < 100 and separated by only 10 so it's tricky to wedge things > between the existing names.
Maybe we need a RENUM script? :) -adrian > > The strangest bit is when you have interdependent drivers at different > early pass numbers. Sometimes it's necessary to do almost nothing in > the attach() routine and do all the real attach-time type stuff in a > bus_new_pass() routine after the pass number becomes high enough that > your co-dependent driver peers are available. > > -- Ian > > > _______________________________________________ > firstname.lastname@example.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org" _______________________________________________ email@example.com mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"