silo overflows -- what can I do about this?

[Joseph Garcia]

Matthew Dillon wrote:
:Okay, so I was working via the console port (i.e. DFly box connected to 
:  Firewall via serial port) of my PIX firewall and I kept getting these 
:errors. These errors made it quite impossible to configure the firewall 
:because I was unable to recieve the output from the PIX device.
:
:Error Messages (/var/log/messages):
:Oct 17 17:40:04 dfly kernel: sio1: 2 more silo overflows (total 23)
:Oct 17 17:40:06 dfly kernel: sio1: 4 more silo overflows (total 27)
:Oct 17 17:41:22 dfly kernel: sio1: 7 more silo overflows (total 34)
:Oct 17 17:41:24 dfly kernel: sio1: 9 more silo overflows (total 43)
:Oct 17 17:41:25 dfly kernel: sio1: 4 more silo overflows (total 47)
:Oct 17 17:41:38 dfly kernel: sio1: 2 more silo overflows (total 49)
:Oct 17 17:49:36 dfly kernel: sio1: 1 more silo overflow (total 50)
:Oct 17 17:49:53 dfly kernel: sio1: 1 more silo overflow (total 51)
:Oct 17 17:49:57 dfly kernel: sio1: 1 more silo overflow (total 52)
:Oct 17 17:50:02 dfly kernel: sio1: 1 more silo overflow (total 53)
:
:Is there anything I can do about these errors? The man page for sio says 
:that it's an interupt problem. Any help would be appreciated.
:
:Thanks!
:
:Joey

    It may be possible to reduce the instances of the problem
    by using a different fifo trigger point, but there is always
    going to be an issue of some sort, especially if the IRQ
    used by the serial port is shared with another device. 

    Try changing FIFO_RX_MEDH to FIFO_RX_LOW around line 2281
    of /usr/src/sys/dev/serial/sio/sio.c.
    Also post your 'dmesg' output.

					-Matt
					Matthew Dillon 
					<dillon at xxxxxxxxxxxxx>
If I change that line in that file, do I only need to recompile the kernel?

Here's the dmesg output:

Copyright (c) 2003, 2004, 2005, 2006 The DragonFly Project.
Copyright (c) 1992-2003 The FreeBSD Project.
Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
	The Regents of the University of California. All rights reserved.
DragonFly 1.6.1-RELEASE #2: Tue Sep 19 16:08:22 PDT 2006
    bear at xxxxxxxxxxxxxxxxxxxxxxxx:/usr/obj/usr/src/sys/GENERIC
TSC clock: 866340703 Hz, i8254 clock: 1193202 Hz
CPU: Intel Pentium III (866.33-MHz 686-class CPU)
  Origin = "GenuineIntel"  Id = 0x686  Stepping = 6
Features=0x387f9ff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,PN,MMX,FXSR,SSE>
real memory  = 536805376 (524224K bytes) avail memory = 508997632 
(497068K bytes) Preloaded elf kernel "/kernel" at 0xc073c000.
Preloaded elf module "/modules/vesa.ko" at 0xc073c1e8.
Preloaded elf module "/modules/acpi.ko" at 0xc073c290.
Pentium Pro MTRR support enabled
md0: Malloc disk
pcibios: BIOS version 2.10
Using $PIR table, 6 entries at 0xc00fdce0
npx0: <math processor> on motherboard
npx0: INT 16 interface
Using MMX optimized bcopy/copyin/copyout
acpi0: <VT694X AWRDACPI> on motherboard
acpi0: Power Button (fixed)
Warning: ACPI is disabling APM's device.  You can't run both
acpi_timer0: <24-bit timer at 3.579545MHz> port 0x4008-0x400b on acpi0
cpu0: <ACPI CPU (3 Cx states)> on acpi0
acpi_button0: <Power Button> on acpi0
compare 0
legacypci0 on motherboard
pcib0: <Host to PCI bridge> on legacypci0
pci0: <PCI bus> on pcib0
agp0: <VIA 82C691 (Apollo Pro) host to PCI bridge> mem 
0xe0000000-0xe3ffffff at device 0.0 on pci0
pcib1: <VIA 82C598MVP (Apollo MVP3) PCI-PCI (AGP) bridge> at device 1.0 
on pci0
pci1: <PCI bus> on pcib1
pci1: <ATI model 5046 graphics accelerator> at 0.0 irq 11
isab0: <VIA 82C686 PCI-ISA bridge> at device 7.0 on pci0
isa0: <ISA bus> on isab0
atapci0: <VIA 82C686 ATA66 controller> port 0x6400-0x640f at device 7.1 
on pci0
ata0: at 0x1f0 irq 14 on atapci0
ata1: at 0x170 irq 15 on atapci0
uhci0: <VIA 83C572 USB controller> port 0x6800-0x681f irq 10 at device 
7.2 on pci0
usb0: <VIA 83C572 USB controller> on uhci0
usb0: USB revision 1.0
uhub0: VIA UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub0: 2 ports with 2 removable, self powered
uhub0: port error, restarting port 1
uhub0: port error, giving up port 1
uhci1: <VIA 83C572 USB controller> port 0x6c00-0x6c1f irq 10 at device 
7.3 on pci0
usb1: <VIA 83C572 USB controller> on uhci1
usb1: USB revision 1.0
uhub1: VIA UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub1: 2 ports with 2 removable, self powered
uhub1: port error, restarting port 1
uhub1: port error, giving up port 1
pci0: <VIA 82C686 AC97 Audio> at 7.5 irq 5
sym0: <875> port 0x7c00-0x7cff mem 
0xec122000-0xec122fff,0xec121000-0xec1210ff irq 10 at device 9.0 on pci0
sym0: No NVRAM, ID 7, Fast-20, SE, parity checking
sym1: <875> port 0x8000-0x80ff mem 
0xec125000-0xec125fff,0xec124000-0xec1240ff irq 5 at device 10.0 on pci0
sym1: No NVRAM, ID 7, Fast-20, SE, parity checking
fxp0: <Intel 82550 Pro/100 Ethernet> port 0x8400-0x843f mem 
0xec100000-0xec11ffff,0xec120000-0xec120fff irq 9 at device 11.0 on pci0
miibus0: <MII bus> on fxp0
inphy0: <i82555 10/100 media interface> on miibus0
inphy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
fxp0: MAC address: 00:02:b3:2d:aa:8f
fxp1: <Intel 82559 Pro/100 Ethernet> port 0x8800-0x883f mem 
0xec000000-0xec0fffff,0xec123000-0xec123fff irq 11 at device 12.0 on pci0
miibus1: <MII bus> on fxp1
inphy1: <i82555 10/100 media interface> on miibus1
inphy1:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
fxp1: MAC address: 00:d0:b7:25:f9:b8
orm0: <Option ROMs> at iomem 
0xc0000-0xcafff,0xcb000-0xcc7ff,0xcd000-0xce7ff,0xcf000-0xd2fff on isa0 
pmtimer0 on isa0
fdc0: <NEC 72065B or clone> at port 0x3f0-0x3f5,0x3f7 irq 6 drq 2 on isa0
fdc0: FIFO enabled, 8 bytes threshold
fd0: <1440-KB 3.5" drive> on fdc0 drive 0
atkbdc0: <Keyboard controller (i8042)> at port 0x60,0x64 on isa0
atkbd0: <AT Keyboard> flags 0x1 irq 1 on atkbdc0 kbd0 at atkbd0
psm0: <PS/2 Mouse> irq 12 on atkbdc0
psm0: model IntelliMouse Explorer, device ID 4
vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on isa0
sc0: <System console> at flags 0x100 on isa0
sc0: VGA <16 virtual consoles, flags=0x300> sio0 at port 0x3f8-0x3ff irq 
4 flags 0x10 on isa0
sio0: type 16550A
sio1 at port 0x2f8-0x2ff irq 3 on isa0
sio1: type 16550A
ppc0: <Parallel port> at port 0x378-0x37f irq 7 on isa0
ppc0: Generic chipset (EPP/NIBBLE) in COMPATIBLE mode
ppbus0: <Parallel port bus> on ppc0
plip0: <PLIP network interface> on ppbus0
lpt0: <Printer> on ppbus0
lpt0: Interrupt-driven port
ppi0: <Parallel I/O> on ppbus0
acpi_cpu: throttling enabled, 2 steps (100% to 50.0%), currently 100.0%
ad0: 19092MB <WDC WD200EB-11BHF0> [38792/16/63] at ata0-master UDMA66
acd0: DVD-ROM <DVD-ROM DDU1621> at ata1-master PIO4 Waiting 5 seconds 
for SCSI devices to settle Mounting root from ufs:/dev/ad0s1a cd0 at 
ata1 bus 0 target 0 lun 0
cd0: <SONY DVD-ROM DDU1621 S3.3> Removable CD-ROM SCSI-0 device
cd0: 16.000MB/s transfers
cd0: Attempt to query device size failed: NOT READY, Medium not present 
da0 at sym1 bus 0 target 1 lun 0
da0: <COMPAQ ST34371W 0682> Fixed Direct Access SCSI-2 device
da0: 40.000MB/s transfers (20.000MHz, offset 15, 16bit), Tagged Queueing 
Enabled
da0: 4094MB (8386000 512 byte sectors: 255H 63S/T 522C)
sio1: 1 more silo overflow (total 1)
sio1: 4 more silo overflows (total 5)
sio1: 6 more silo overflows (total 11)
sio1: 1 more silo overflow (total 12)
sio1: 3 more silo overflows (total 15)
sio1: 2 more silo overflows (total 17)
sio1: 1 more silo overflow (total 18)
sio1: 1 more silo overflow (total 19)
sio1: 1 more silo overflow (total 20)
sio1: 1 more silo overflow (total 21)
sio1: 2 more silo overflows (total 23)
sio1: 4 more silo overflows (total 27)
sio1: 7 more silo overflows (total 34)
sio1: 9 more silo overflows (total 43)
sio1: 4 more silo overflows (total 47)
sio1: 2 more silo overflows (total 49)
sio1: 1 more silo overflow (total 50)
sio1: 1 more silo overflow (total 51)
sio1: 1 more silo overflow (total 52)
sio1: 1 more silo overflow (total 53)