strange network performance degradation 2.6.8-rc3-mm1 -> 2.6.8-rc4-mm1

[Jurriaan <thunder7@xs4all.nl>]

My adsl-line, which is capable of reaching 450 KiB/s with 2.6.8-rc3-mm1
(and earlier kernels) barely gets 6 to 10 KiB/s with 2.6.8-rc4-mm1.
The router, firewall and internet connection are the same in both cases.

I'm using the 8139TOO driver, and it seems to call pci_enable_device()
in drivers/net/8139too.c.
so that should be OK.

The dmesg-output between 2.6.8-rc3-mm1 and 2.6.8-rc4-mm1 differs like
this:

1c1
< Linux version 2.6.8-rc3-mm1 (jurriaan@middle) (gcc version 3.3.4 (Debian 1:3.3.4-7)) #1 SMP Fri Aug 6 07:12:48 CEST 2004
---
> Linux version 2.6.8-rc4-mm1 (jurriaan@middle) (gcc version 3.3.4 (Debian 1:3.3.4-7)) #2 SMP Tue Aug 10 09:40:51 CEST 2004
123,138c123,129
< ACPI: PCI interrupt 0000:00:1d.0[A] -> GSI 16 (level, low) -> IRQ 16
< ACPI: PCI interrupt 0000:00:1d.1[B] -> GSI 19 (level, low) -> IRQ 19
< ACPI: PCI interrupt 0000:00:1d.2[C] -> GSI 18 (level, low) -> IRQ 18
< ACPI: PCI interrupt 0000:00:1d.3[A] -> GSI 16 (level, low) -> IRQ 16
< ACPI: PCI interrupt 0000:00:1d.7[D] -> GSI 23 (level, low) -> IRQ 23
< ACPI: PCI interrupt 0000:00:1f.1[A] -> GSI 18 (level, low) -> IRQ 18
< ACPI: PCI interrupt 0000:00:1f.3[B] -> GSI 17 (level, low) -> IRQ 17
< ACPI: PCI interrupt 0000:00:1f.5[B] -> GSI 17 (level, low) -> IRQ 17
< ACPI: PCI interrupt 0000:01:00.0[A] -> GSI 16 (level, low) -> IRQ 16
< ACPI: PCI interrupt 0000:02:00.0[A] -> GSI 16 (level, low) -> IRQ 16
< ACPI: PCI interrupt 0000:02:00.1[A] -> GSI 16 (level, low) -> IRQ 16
< ACPI: PCI interrupt 0000:02:01.0[A] -> GSI 17 (level, low) -> IRQ 17
< ACPI: PCI interrupt 0000:02:02.0[A] -> GSI 18 (level, low) -> IRQ 18
< ACPI: PCI interrupt 0000:02:05.0[A] -> GSI 21 (level, low) -> IRQ 21
< ACPI: PCI interrupt 0000:02:06.0[A] -> GSI 22 (level, low) -> IRQ 22
< ACPI: PCI interrupt 0000:02:07.0[A] -> GSI 23 (level, low) -> IRQ 23
---
> ** PCI interrupts are no longer routed automatically.  If this
> ** causes a device to stop working, it is probably because the
> ** driver failed to call pci_enable_device().  As a temporary
> ** workaround, the "pci=routeirq" argument restores the old
> ** behavior.  If this argument makes the device work again,
> ** please email the output of "lspci" to bjorn.helgaas@hp.com
> ** so I can fix the driver.

[obviously uninteresting lines about different cpu temperatures
snipped]

This behaviour happens both with /proc/sys/net/ipv4/tcp_window_scaling
set to 0 or 1 (setting it to 0 or 1 doesn't matter with 2.6.8-rc3-mm1).

What could be the problem here?

2.6.8-rc4-mm1 .config:
CONFIG_X86=y
CONFIG_MMU=y
CONFIG_UID16=y
CONFIG_GENERIC_ISA_DMA=y
CONFIG_EXPERIMENTAL=y
CONFIG_BROKEN=y
CONFIG_BROKEN_ON_SMP=y
CONFIG_SWAP=y
CONFIG_SYSVIPC=y
CONFIG_SYSCTL=y
CONFIG_LOG_BUF_SHIFT=16
CONFIG_IKCONFIG=y
CONFIG_IKCONFIG_PROC=y
CONFIG_KALLSYMS=y
CONFIG_KALLSYMS_ALL=y
CONFIG_FUTEX=y
CONFIG_EPOLL=y
CONFIG_IOSCHED_NOOP=y
CONFIG_IOSCHED_AS=y
CONFIG_IOSCHED_DEADLINE=y
CONFIG_IOSCHED_CFQ=y
CONFIG_MODULES=y
CONFIG_MODULE_UNLOAD=y
CONFIG_OBSOLETE_MODPARM=y
CONFIG_KMOD=y
CONFIG_STOP_MACHINE=y
CONFIG_X86_PC=y
CONFIG_MPENTIUM4=y
CONFIG_X86_CMPXCHG=y
CONFIG_X86_XADD=y
CONFIG_X86_L1_CACHE_SHIFT=7
CONFIG_RWSEM_XCHGADD_ALGORITHM=y
CONFIG_X86_WP_WORKS_OK=y
CONFIG_X86_INVLPG=y
CONFIG_X86_BSWAP=y
CONFIG_X86_POPAD_OK=y
CONFIG_X86_GOOD_APIC=y
CONFIG_X86_INTEL_USERCOPY=y
CONFIG_X86_USE_PPRO_CHECKSUM=y
CONFIG_HPET_TIMER=y
CONFIG_HPET_EMULATE_RTC=y
CONFIG_SMP=y
CONFIG_NR_CPUS=2
CONFIG_SCHED_SMT=y
CONFIG_PREEMPT=y
CONFIG_X86_LOCAL_APIC=y
CONFIG_X86_IO_APIC=y
CONFIG_X86_TSC=y
CONFIG_X86_MCE=y
CONFIG_X86_MCE_NONFATAL=y
CONFIG_X86_MCE_P4THERMAL=y
CONFIG_MICROCODE=y
CONFIG_X86_MSR=y
CONFIG_X86_CPUID=y
CONFIG_HIGHMEM4G=y
CONFIG_HIGHMEM=y
CONFIG_HIGHPTE=y
CONFIG_MTRR=y
CONFIG_HAVE_DEC_LOCK=y
CONFIG_REGPARM=y
CONFIG_PM=y
CONFIG_ACPI=y
CONFIG_ACPI_BOOT=y
CONFIG_ACPI_INTERPRETER=y
CONFIG_ACPI_SLEEP=y
CONFIG_ACPI_SLEEP_PROC_FS=y
CONFIG_ACPI_AC=y
CONFIG_ACPI_BUTTON=y
CONFIG_ACPI_FAN=y
CONFIG_ACPI_PROCESSOR=y
CONFIG_ACPI_THERMAL=y
CONFIG_ACPI_BUS=y
CONFIG_ACPI_EC=y
CONFIG_ACPI_POWER=y
CONFIG_ACPI_PCI=y
CONFIG_ACPI_SYSTEM=y
CONFIG_X86_PM_TIMER=y
CONFIG_PCI=y
CONFIG_PCI_GOANY=y
CONFIG_PCI_BIOS=y
CONFIG_PCI_DIRECT=y
CONFIG_PCI_MMCONFIG=y
CONFIG_PCI_NAMES=y
CONFIG_ISA=y
CONFIG_BINFMT_ELF=y
CONFIG_BINFMT_AOUT=y
CONFIG_BINFMT_MISC=y
CONFIG_PREVENT_FIRMWARE_BUILD=y
CONFIG_PARPORT=y
CONFIG_PARPORT_PC=y
CONFIG_PARPORT_PC_CML1=y
CONFIG_PARPORT_1284=y
CONFIG_BLK_DEV_FD=y
CONFIG_BLK_DEV_LOOP=y
CONFIG_IDE=y
CONFIG_BLK_DEV_IDE=y
CONFIG_BLK_DEV_IDEDISK=y
CONFIG_BLK_DEV_IDECD=y
CONFIG_BLK_DEV_IDESCSI=y
CONFIG_IDE_GENERIC=y
CONFIG_BLK_DEV_IDEPCI=y
CONFIG_IDEPCI_SHARE_IRQ=y
CONFIG_BLK_DEV_IDEDMA_PCI=y
CONFIG_IDEDMA_PCI_AUTO=y
CONFIG_BLK_DEV_ADMA=y
CONFIG_BLK_DEV_AMD74XX=y
CONFIG_BLK_DEV_HPT366=y
CONFIG_BLK_DEV_PIIX=y
CONFIG_BLK_DEV_PDC202XX_OLD=y
CONFIG_BLK_DEV_VIA82CXXX=y
CONFIG_BLK_DEV_IDEDMA=y
CONFIG_IDEDMA_AUTO=y
CONFIG_SCSI=y
CONFIG_SCSI_PROC_FS=y
CONFIG_BLK_DEV_SD=y
CONFIG_CHR_DEV_ST=y
CONFIG_BLK_DEV_SR=y
CONFIG_CHR_DEV_SG=y
CONFIG_SCSI_MULTI_LUN=y
CONFIG_SCSI_CONSTANTS=y
CONFIG_SCSI_SPI_ATTRS=y
CONFIG_SCSI_SYM53C8XX_2=y
CONFIG_SCSI_SYM53C8XX_DMA_ADDRESSING_MODE=1
CONFIG_SCSI_SYM53C8XX_DEFAULT_TAGS=16
CONFIG_SCSI_SYM53C8XX_MAX_TAGS=64
CONFIG_SCSI_QLA2XXX=y
CONFIG_MD=y
CONFIG_BLK_DEV_MD=y
CONFIG_MD_LINEAR=y
CONFIG_MD_RAID0=y
CONFIG_MD_RAID1=y
CONFIG_MD_RAID5=y
CONFIG_NET=y
CONFIG_PACKET=y
CONFIG_UNIX=y
CONFIG_INET=y
CONFIG_IP_MULTICAST=y
CONFIG_IP_ADVANCED_ROUTER=y
CONFIG_IP_ROUTE_VERBOSE=y
CONFIG_SYN_COOKIES=y
CONFIG_IPV6=y
CONFIG_NETFILTER=y
CONFIG_IP6_NF_IPTABLES=y
CONFIG_IP6_NF_MATCH_LIMIT=y
CONFIG_IP6_NF_MATCH_MAC=y
CONFIG_IP6_NF_MATCH_RT=y
CONFIG_IP6_NF_MATCH_OPTS=y
CONFIG_IP6_NF_MATCH_FRAG=y
CONFIG_IP6_NF_MATCH_HL=y
CONFIG_IP6_NF_MATCH_MULTIPORT=y
CONFIG_IP6_NF_MATCH_OWNER=y
CONFIG_IP6_NF_MATCH_MARK=y
CONFIG_IP6_NF_MATCH_IPV6HEADER=y
CONFIG_IP6_NF_MATCH_AHESP=y
CONFIG_IP6_NF_MATCH_LENGTH=y
CONFIG_IP6_NF_MATCH_EUI64=y
CONFIG_IP6_NF_FILTER=y
CONFIG_IP6_NF_TARGET_LOG=y
CONFIG_IP6_NF_MANGLE=y
CONFIG_IP6_NF_TARGET_MARK=y
CONFIG_IP6_NF_RAW=y
CONFIG_NETDEVICES=y
CONFIG_DUMMY=y
CONFIG_NET_ETHERNET=y
CONFIG_MII=y
CONFIG_NET_TULIP=y
CONFIG_TULIP=y
CONFIG_TULIP_MWI=y
CONFIG_TULIP_MMIO=y
CONFIG_NET_PCI=y
CONFIG_8139TOO=y
CONFIG_E1000=y
CONFIG_TIGON3=y
CONFIG_INPUT=y
CONFIG_INPUT_MOUSEDEV=y
CONFIG_INPUT_MOUSEDEV_PSAUX=y
CONFIG_INPUT_MOUSEDEV_SCREEN_X=1024
CONFIG_INPUT_MOUSEDEV_SCREEN_Y=768
CONFIG_SOUND_GAMEPORT=y
CONFIG_SERIO=y
CONFIG_SERIO_I8042=y
CONFIG_SERIO_SERPORT=y
CONFIG_INPUT_KEYBOARD=y
CONFIG_KEYBOARD_ATKBD=y
CONFIG_INPUT_MOUSE=y
CONFIG_MOUSE_PS2=y
CONFIG_INPUT_MISC=y
CONFIG_INPUT_PCSPKR=y
CONFIG_VT=y
CONFIG_VT_CONSOLE=y
CONFIG_HW_CONSOLE=y
CONFIG_SERIAL_8250=y
CONFIG_SERIAL_8250_NR_UARTS=4
CONFIG_SERIAL_CORE=y
CONFIG_UNIX98_PTYS=y
CONFIG_LEGACY_PTYS=y
CONFIG_LEGACY_PTY_COUNT=256
CONFIG_PRINTER=y
CONFIG_WATCHDOG=y
CONFIG_SOFT_WATCHDOG=y
CONFIG_HW_RANDOM=y
CONFIG_RTC=y
CONFIG_AGP=y
CONFIG_AGP_INTEL=y
CONFIG_DRM=y
CONFIG_DRM_RADEON=y
CONFIG_DRM_MGA=y
CONFIG_HANGCHECK_TIMER=y
CONFIG_I2C=y
CONFIG_I2C_CHARDEV=m
CONFIG_I2C_ALGOBIT=y
CONFIG_I2C_ISA=m
CONFIG_I2C_VIAPRO=m
CONFIG_I2C_SENSOR=m
CONFIG_SENSORS_VIA686A=m
CONFIG_SENSORS_W83781D=m
CONFIG_SENSORS_EEPROM=m
CONFIG_FB=y
CONFIG_FB_MODE_HELPERS=y
CONFIG_VIDEO_SELECT=y
CONFIG_FB_MATROX=y
CONFIG_FB_MATROX_G450=y
CONFIG_FB_MATROX_G100=y
CONFIG_FB_RADEON=y
CONFIG_FB_RADEON_I2C=y
CONFIG_VGA_CONSOLE=y
CONFIG_DUMMY_CONSOLE=y
CONFIG_FRAMEBUFFER_CONSOLE=y
CONFIG_FONTS=y
CONFIG_FONT_SUN12x22=y
CONFIG_LOGO=y
CONFIG_LOGO_LINUX_MONO=y
CONFIG_LOGO_LINUX_VGA16=y
CONFIG_LOGO_LINUX_CLUT224=y
CONFIG_SOUND=y
CONFIG_SND=y
CONFIG_SND_TIMER=y
CONFIG_SND_PCM=y
CONFIG_SND_HWDEP=y
CONFIG_SND_RAWMIDI=y
CONFIG_SND_SEQUENCER=y
CONFIG_SND_OSSEMUL=y
CONFIG_SND_MIXER_OSS=y
CONFIG_SND_PCM_OSS=y
CONFIG_SND_SEQUENCER_OSS=y
CONFIG_SND_RTCTIMER=y
CONFIG_SND_MPU401_UART=y
CONFIG_SND_OPL3_LIB=y
CONFIG_SND_AC97_CODEC=y
CONFIG_SND_EMU10K1=y
CONFIG_SND_CMIPCI=y
CONFIG_SND_INTEL8X0=y
CONFIG_SND_VIA82XX=y
CONFIG_USB=y
CONFIG_USB_DEVICEFS=y
CONFIG_USB_EHCI_HCD=y
CONFIG_USB_UHCI_HCD=y
CONFIG_USB_PRINTER=y
CONFIG_USB_HID=y
CONFIG_USB_HIDINPUT=y
CONFIG_EXT2_FS=y
CONFIG_EXT3_FS=y
CONFIG_EXT3_FS_XATTR=y
CONFIG_JBD=y
CONFIG_FS_MBCACHE=y
CONFIG_REISERFS_FS=y
CONFIG_XFS_FS=y
CONFIG_ISO9660_FS=y
CONFIG_JOLIET=y
CONFIG_UDF_FS=y
CONFIG_UDF_NLS=y
CONFIG_FAT_FS=y
CONFIG_VFAT_FS=y
CONFIG_FAT_DEFAULT_CODEPAGE=437
CONFIG_FAT_DEFAULT_IOCHARSET="iso8859-1"
CONFIG_NTFS_FS=y
CONFIG_PROC_FS=y
CONFIG_PROC_KCORE=y
CONFIG_SYSFS=y
CONFIG_TMPFS=y
CONFIG_RAMFS=y
CONFIG_NFS_FS=y
CONFIG_NFS_V3=y
CONFIG_LOCKD=y
CONFIG_LOCKD_V4=y
CONFIG_SUNRPC=y
CONFIG_MSDOS_PARTITION=y
CONFIG_NLS=y
CONFIG_NLS_DEFAULT="iso8859-1"
CONFIG_NLS_CODEPAGE_437=y
CONFIG_NLS_ISO8859_1=y
CONFIG_DEBUG_KERNEL=y
CONFIG_EARLY_PRINTK=y
CONFIG_MAGIC_SYSRQ=y
CONFIG_FRAME_POINTER=y
CONFIG_SCHEDSTATS=y
CONFIG_X86_FIND_SMP_CONFIG=y
CONFIG_X86_MPPARSE=y
CONFIG_CRC32=y
CONFIG_X86_SMP=y
CONFIG_X86_HT=y
CONFIG_X86_BIOS_REBOOT=y
CONFIG_X86_TRAMPOLINE=y
CONFIG_PC=y

Thanks,
Jurriaan
-- 
Whatever women do they must do twice as well as men
to be thought of as half as good. Luckily, this is not difficult.
        Charlotte Whitton
Debian (Unstable) GNU/Linux 2.6.8-rc3-mm1 2x6078 bogomips load 0.04