On Tue, Jan 06, 2015 at 09:37:30AM -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: > > > >> Index: sys/kernel.h > >> =================================================================== > >> --- sys/kernel.h (revision 276691) > >> +++ sys/kernel.h (working copy) > >> _at__at_ -152,6 +152,7 _at__at_ > >> SI_SUB_KPROF = 0x9000000, /* kernel profiling*/ > >> SI_SUB_KICK_SCHEDULER = 0xa000000, /* start the timeout > >> events*/ > >> SI_SUB_INT_CONFIG_HOOKS = 0xa800000, /* Interrupts enabled > >> config */ > >> + SI_SUB_SMP = 0xa850000, /* start the APs*/ > >> SI_SUB_ROOT_CONF = 0xb000000, /* Find root devices */ > >> SI_SUB_DUMP_CONF = 0xb200000, /* Find dump devices */ > >> SI_SUB_RAID = 0xb380000, /* Configure GEOM classes */ > >> _at__at_ -165,7 +166,6 _at__at_ > >> SI_SUB_KTHREAD_BUF = 0xea00000, /* buffer daemon*/ > >> SI_SUB_KTHREAD_UPDATE = 0xec00000, /* update daemon*/ > >> SI_SUB_KTHREAD_IDLE = 0xee00000, /* idle procs*/ > >> - SI_SUB_SMP = 0xf000000, /* start the APs*/ > >> SI_SUB_RACCTD = 0xf100000, /* start racctd*/ > >> SI_SUB_LAST = 0xfffffff /* final initialization */ > >> }; > > > > 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. > I believe that idle threads are still created before the APs start with the patch posted, this was the thing I checked first. It is SUB_SCHED_IDLE, which is done long before even drivers are configured.Received on Tue Jan 06 2015 - 14:12:17 UTC
This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:40:54 UTC