Re: [PATCH] atmel_tc clocksource/clockevent code

["Remy Bohmer" <linux@bohmer.net>]

[-- Attachment #1: Type: text/plain, Size: 3217 bytes --]

Hello David,

> Could you elaborate on where that 50-100 usec gets spent?

Attached I have put a screendump of my ETM debugger. It shows a
complete flow of kernel function-calls of what happens on a timer
interrupt. In this example the complete sequence takes about 154 us.
Notice that the ETM is non-intrusive, and that the times are real and
accurate in this trace. (you can even see the effects of CPU-caches,
sometimes the same code just runs faster)
It is based on 2.6.23.12-rt14, with a ticking kernel, I have attached
the .config of the kernel under trace also. The CPU is running at
160/80Mhz.
I have some custom patches to the kernel, but none of them effect this
particular trace.

> Does the same issue happpen with the $SUBJECT patch (if you tweak the
>  clocksource ratings to use its clockevents on rm9200)?

not tested yet, but I will generate a trace for it, I will post it later.

>  I'd not think the timer IRQ logic accounts for much of that time,
>  and the rest of the instruction cycles would seem to be either
>  in genirq or gentime.

There is more to it than just the genIRQ mechanism. The softirqs are
kicked, the scheduler is triggered and so on. It is a waterfall of
events that happen, just by having a timer interrupt.

> Unless the issue is that accessing that
>  particular hardware is slow, with clockdomain crossing etc ...
>  or that AT91 has way too many handlers sitting on IRQ-1.
>  If it's a gentime or genirq issue, that's somewhat amenable to
>  fixing ... and it would also impact the $SUBJECT patch both on
>  other AT91 ARM9 cores and on the AVR32 AP7 cores.

>  > So, a higher resolution than 30usec is useless on these cores, and
>  > setting timers on a frequency that high will just choke the processor
>  > in only handling timers...
> Should the min_delta_ns be increased in at91rm9200_time.c then?

Maybe it should be configurable for these kinds of CPUs?

If a CPU is infinite fast, one could probably want a HRT resolution of zero.
But, no CPUs are that fast, and I assume there is always a need to get
a good balance between timer resolution compared to CPU load.
We probably do not want to cause a DoS by building some application
that starts (periodic) timers that fast, that the CPU is doing nothing
more than just that. To me, it appears that the HRT framework is going
that route here. It seems to me now, that if it is technically
possible to create a microsec accurate timer-framework, we make them,
regardless of it fits the rest of the system.
Notice that I also fell in this pitfall while using HRT, and I only
wanted an application that made a 1ms accurate timer... Other
processes/daemons in the system also uses timers, which eventually
resulted in intervals in the sub-millisec range, and thus due to the
overhead that will bring tot the system, the CPU-load just goes
sky-high, doing actually nothing really special.

So, hires timestamps -> really really welcome.
hires timers -> there should be a (configurable) minimal resolution
that fits the hardware to not overload the CPU.

>  Right now, as you probably recall, it's at the lowest value
>  needed for correctness:  a smidgeon over two ticks (~ 72 nsec).

I remember...

Kind Regards,

Remy

[-- Attachment #2: trace-timer-interrupt-rm9200.png --]
[-- Type: image/png, Size: 126791 bytes --]

[-- Attachment #3: .config --]
[-- Type: application/octet-stream, Size: 18005 bytes --]

#
# Automatically generated make config: don't edit
# Linux kernel version: 2.6.23.12-rt14
# Wed Mar  5 09:09:39 2008
#
CONFIG_ARM=y
CONFIG_SYS_SUPPORTS_APM_EMULATION=y
CONFIG_GENERIC_GPIO=y
CONFIG_GENERIC_TIME=y
CONFIG_GENERIC_CLOCKEVENTS=y
CONFIG_STACKTRACE_SUPPORT=y
CONFIG_MMU=y
# CONFIG_NO_IOPORT is not set
CONFIG_GENERIC_HARDIRQS=y
CONFIG_LOCKDEP_SUPPORT=y
CONFIG_TRACE_IRQFLAGS_SUPPORT=y
CONFIG_HARDIRQS_SW_RESEND=y
CONFIG_GENERIC_IRQ_PROBE=y
CONFIG_RWSEM_GENERIC_SPINLOCK=y
# CONFIG_ARCH_HAS_ILOG2_U32 is not set
# CONFIG_ARCH_HAS_ILOG2_U64 is not set
CONFIG_GENERIC_HWEIGHT=y
CONFIG_GENERIC_CALIBRATE_DELAY=y
CONFIG_ZONE_DMA=y
CONFIG_VECTORS_BASE=0xffff0000
CONFIG_DEFCONFIG_LIST="/lib/modules/$UNAME_RELEASE/.config"

#
# General setup
#
CONFIG_EXPERIMENTAL=y
CONFIG_BROKEN_ON_SMP=y
CONFIG_LOCK_KERNEL=y
CONFIG_INIT_ENV_ARG_LIMIT=32
CONFIG_LOCALVERSION=""
# CONFIG_LOCALVERSION_AUTO is not set
# CONFIG_SWAP is not set
CONFIG_SYSVIPC=y
CONFIG_SYSVIPC_SYSCTL=y
# CONFIG_POSIX_MQUEUE is not set
# CONFIG_BSD_PROCESS_ACCT is not set
# CONFIG_TASKSTATS is not set
# CONFIG_USER_NS is not set
# CONFIG_AUDIT is not set
CONFIG_IKCONFIG=y
CONFIG_IKCONFIG_PROC=y
CONFIG_LOG_BUF_SHIFT=14
CONFIG_SYSFS_DEPRECATED=y
CONFIG_RELAY=y
CONFIG_BLK_DEV_INITRD=y
CONFIG_INITRAMFS_SOURCE=""
CONFIG_CC_OPTIMIZE_FOR_SIZE=y
CONFIG_SYSCTL=y
# CONFIG_RADIX_TREE_CONCURRENT is not set
CONFIG_EMBEDDED=y
# CONFIG_UID16 is not set
CONFIG_SYSCTL_SYSCALL=y
CONFIG_KALLSYMS=y
# CONFIG_KALLSYMS_EXTRA_PASS is not set
CONFIG_HOTPLUG=y
CONFIG_PRINTK=y
CONFIG_BUG=y
CONFIG_ELF_CORE=y
CONFIG_BASE_FULL=y
CONFIG_FUTEX=y
CONFIG_ANON_INODES=y
CONFIG_EPOLL=y
CONFIG_SIGNALFD=y
CONFIG_EVENTFD=y
# CONFIG_SHMEM is not set
CONFIG_VM_EVENT_COUNTERS=y
CONFIG_SLAB=y
# CONFIG_SLUB is not set
# CONFIG_SLOB is not set
CONFIG_RT_MUTEXES=y
CONFIG_TINY_SHMEM=y
CONFIG_BASE_SMALL=0
CONFIG_MODULES=y
CONFIG_MODULE_UNLOAD=y
CONFIG_MODULE_FORCE_UNLOAD=y
CONFIG_MODVERSIONS=y
# CONFIG_MODULE_SRCVERSION_ALL is not set
CONFIG_KMOD=y
CONFIG_BLOCK=y
# CONFIG_LBD is not set
# CONFIG_BLK_DEV_IO_TRACE is not set
# CONFIG_LSF is not set
# CONFIG_BLK_DEV_BSG is not set

#
# IO Schedulers
#
CONFIG_IOSCHED_NOOP=y
CONFIG_IOSCHED_AS=y
# CONFIG_IOSCHED_DEADLINE is not set
# CONFIG_IOSCHED_CFQ is not set
CONFIG_DEFAULT_AS=y
# CONFIG_DEFAULT_DEADLINE is not set
# CONFIG_DEFAULT_CFQ is not set
# CONFIG_DEFAULT_NOOP is not set
CONFIG_DEFAULT_IOSCHED="anticipatory"

#
# System Type
#
# CONFIG_ARCH_AAEC2000 is not set
# CONFIG_ARCH_INTEGRATOR is not set
# CONFIG_ARCH_REALVIEW is not set
# CONFIG_ARCH_VERSATILE is not set
CONFIG_ARCH_AT91=y
# CONFIG_ARCH_CLPS7500 is not set
# CONFIG_ARCH_CLPS711X is not set
# CONFIG_ARCH_CO285 is not set
# CONFIG_ARCH_EBSA110 is not set
# CONFIG_ARCH_EP93XX is not set
# CONFIG_ARCH_FOOTBRIDGE is not set
# CONFIG_ARCH_NETX is not set
# CONFIG_ARCH_H720X is not set
# CONFIG_ARCH_IMX is not set
# CONFIG_ARCH_IOP13XX is not set
# CONFIG_ARCH_IOP32X is not set
# CONFIG_ARCH_IOP33X is not set
# CONFIG_ARCH_IXP23XX is not set
# CONFIG_ARCH_IXP2000 is not set
# CONFIG_ARCH_IXP4XX is not set
# CONFIG_ARCH_L7200 is not set
# CONFIG_ARCH_KS8695 is not set
# CONFIG_ARCH_NS9XXX is not set
# CONFIG_ARCH_MXC is not set
# CONFIG_ARCH_PNX4008 is not set
# CONFIG_ARCH_PXA is not set
# CONFIG_ARCH_RPC is not set
# CONFIG_ARCH_SA1100 is not set
# CONFIG_ARCH_S3C2410 is not set
# CONFIG_ARCH_SHARK is not set
# CONFIG_ARCH_LH7A40X is not set
# CONFIG_ARCH_DAVINCI is not set
# CONFIG_ARCH_OMAP is not set

#
# Boot options
#

#
# Power management
#

#
# Atmel AT91 System-on-Chip
#
CONFIG_ARCH_AT91RM9200=y
# CONFIG_ARCH_AT91SAM9260 is not set
# CONFIG_ARCH_AT91SAM9261 is not set
# CONFIG_ARCH_AT91SAM9263 is not set
# CONFIG_ARCH_AT91SAM9RL is not set

#
# AT91RM9200 Board Type
#
# CONFIG_MACH_ONEARM is not set
# CONFIG_ARCH_AT91RM9200DK is not set
# CONFIG_MACH_AT91RM9200EK is not set
CONFIG_MACH_OCEARMTEST=y
# CONFIG_MACH_CSB337 is not set
# CONFIG_MACH_CSB637 is not set
# CONFIG_MACH_CARMEVA is not set
# CONFIG_MACH_ATEB9200 is not set
# CONFIG_MACH_KB9200 is not set
# CONFIG_MACH_PICOTUX2XX is not set
# CONFIG_MACH_KAFA is not set
# CONFIG_MACH_CHUB is not set
# CONFIG_MACH_HOMEMATIC is not set
# CONFIG_MACH_ECBAT91 is not set
# CONFIG_MACH_SWEDATMS is not set

#
# AT91 Board Options
#

#
# AT91 Feature Selections
#
# CONFIG_AT91_PROGRAMMABLE_CLOCKS is not set
CONFIG_ATMEL_TCLIB=y
CONFIG_AT91_TC_CLOCKSOURCE=y
CONFIG_AT91_TIMER_HZ=100

#
# Processor Type
#
CONFIG_CPU_32=y
CONFIG_CPU_ARM920T=y
CONFIG_CPU_32v4T=y
CONFIG_CPU_ABRT_EV4T=y
CONFIG_CPU_CACHE_V4WT=y
CONFIG_CPU_CACHE_VIVT=y
CONFIG_CPU_COPY_V4WB=y
CONFIG_CPU_TLB_V4WBI=y
CONFIG_CPU_CP15=y
CONFIG_CPU_CP15_MMU=y

#
# Processor Features
#
# CONFIG_ARM_THUMB is not set
# CONFIG_CPU_ICACHE_DISABLE is not set
# CONFIG_CPU_DCACHE_DISABLE is not set
# CONFIG_CPU_DCACHE_WRITETHROUGH is not set
# CONFIG_OUTER_CACHE is not set

#
# Bus support
#
# CONFIG_PCI_SYSCALL is not set
# CONFIG_ARCH_SUPPORTS_MSI is not set

#
# PCCARD (PCMCIA/CardBus) support
#
# CONFIG_PCCARD is not set

#
# Kernel Features
#
# CONFIG_TICK_ONESHOT is not set
# CONFIG_NO_HZ is not set
# CONFIG_HIGH_RES_TIMERS is not set
CONFIG_GENERIC_CLOCKEVENTS_BUILD=y
# CONFIG_PREEMPT_NONE is not set
# CONFIG_PREEMPT_VOLUNTARY is not set
# CONFIG_PREEMPT_DESKTOP is not set
CONFIG_PREEMPT_RT=y
CONFIG_PREEMPT=y
CONFIG_PREEMPT_SOFTIRQS=y
CONFIG_PREEMPT_HARDIRQS=y
CONFIG_PREEMPT_BKL=y
# CONFIG_CLASSIC_RCU is not set
CONFIG_PREEMPT_RCU=y
# CONFIG_PREEMPT_RCU_BOOST is not set
# CONFIG_RCU_TRACE is not set
CONFIG_HZ=100
CONFIG_AEABI=y
# CONFIG_OABI_COMPAT is not set
# CONFIG_ARCH_DISCONTIGMEM_ENABLE is not set
CONFIG_SELECT_MEMORY_MODEL=y
CONFIG_FLATMEM_MANUAL=y
# CONFIG_DISCONTIGMEM_MANUAL is not set
# CONFIG_SPARSEMEM_MANUAL is not set
CONFIG_FLATMEM=y
CONFIG_FLAT_NODE_MEM_MAP=y
# CONFIG_SPARSEMEM_STATIC is not set
CONFIG_SPLIT_PTLOCK_CPUS=4096
# CONFIG_RESOURCES_64BIT is not set
CONFIG_ZONE_DMA_FLAG=1
CONFIG_BOUNCE=y
CONFIG_VIRT_TO_BUS=y
CONFIG_LEDS=y
CONFIG_LEDS_CPU=y
CONFIG_ALIGNMENT_TRAP=y

#
# Boot options
#
CONFIG_ZBOOT_ROM_TEXT=0x0
CONFIG_ZBOOT_ROM_BSS=0x0
CONFIG_CMDLINE=""
# CONFIG_XIP_KERNEL is not set
# CONFIG_KEXEC is not set

#
# Floating point emulation
#

#
# At least one emulation must be selected
#

#
# Userspace binary formats
#
CONFIG_BINFMT_ELF=y
# CONFIG_BINFMT_AOUT is not set
# CONFIG_BINFMT_MISC is not set

#
# Power management options
#
# CONFIG_PM is not set
CONFIG_SUSPEND_UP_POSSIBLE=y

#
# Networking
#
CONFIG_NET=y

#
# Networking options
#
CONFIG_PACKET=y
# CONFIG_PACKET_MMAP is not set
CONFIG_UNIX=y
# CONFIG_NET_KEY is not set
CONFIG_INET=y
# CONFIG_IP_MULTICAST is not set
# CONFIG_IP_ADVANCED_ROUTER is not set
CONFIG_IP_FIB_HASH=y
CONFIG_IP_PNP=y
# CONFIG_IP_PNP_DHCP is not set
CONFIG_IP_PNP_BOOTP=y
CONFIG_IP_PNP_RARP=y
# CONFIG_NET_IPIP is not set
# CONFIG_NET_IPGRE is not set
# CONFIG_ARPD is not set
# CONFIG_SYN_COOKIES is not set
# CONFIG_INET_AH is not set
# CONFIG_INET_ESP is not set
# CONFIG_INET_IPCOMP is not set
# CONFIG_INET_XFRM_TUNNEL is not set
# CONFIG_INET_TUNNEL is not set
# CONFIG_INET_XFRM_MODE_TRANSPORT is not set
# CONFIG_INET_XFRM_MODE_TUNNEL is not set
# CONFIG_INET_XFRM_MODE_BEET is not set
# CONFIG_INET_DIAG is not set
# CONFIG_TCP_CONG_ADVANCED is not set
CONFIG_TCP_CONG_CUBIC=y
CONFIG_DEFAULT_TCP_CONG="cubic"
# CONFIG_TCP_MD5SIG is not set
# CONFIG_IPV6 is not set
# CONFIG_INET6_XFRM_TUNNEL is not set
# CONFIG_INET6_TUNNEL is not set
# CONFIG_NETWORK_SECMARK is not set
# CONFIG_NETFILTER is not set
# CONFIG_IP_DCCP is not set
# CONFIG_IP_SCTP is not set
# CONFIG_TIPC is not set
# CONFIG_ATM is not set
# CONFIG_BRIDGE is not set
# CONFIG_VLAN_8021Q is not set
# CONFIG_DECNET is not set
# CONFIG_LLC2 is not set
# CONFIG_IPX is not set
# CONFIG_ATALK is not set
# CONFIG_X25 is not set
# CONFIG_LAPB is not set
# CONFIG_ECONET is not set
# CONFIG_WAN_ROUTER is not set

#
# QoS and/or fair queueing
#
# CONFIG_NET_SCHED is not set

#
# Network testing
#
# CONFIG_NET_PKTGEN is not set
# CONFIG_HAMRADIO is not set
# CONFIG_IRDA is not set
# CONFIG_BT is not set
# CONFIG_AF_RXRPC is not set

#
# Wireless
#
# CONFIG_CFG80211 is not set
# CONFIG_WIRELESS_EXT is not set
# CONFIG_MAC80211 is not set
# CONFIG_IEEE80211 is not set
# CONFIG_RFKILL is not set
# CONFIG_NET_9P is not set

#
# Device Drivers
#

#
# Oce Custom Driver support
#
CONFIG_OCE_ARMIO=y
CONFIG_OCE_ARMIO_TC_BLOCK_TIME_BASE=y
CONFIG_OCE_ARMIO_DEBUG_ENABLED=y
# CONFIG_OCE_ARMIO_DEBUG_LEVEL_RW is not set
# CONFIG_OCE_ARMIO_DEBUG_LEVEL_IRQ is not set
# CONFIG_OCE_ARMIO_DEBUG_LEVEL_OTHER is not set

#
# Rose RTS support
#
CONFIG_ROSE_RTS=y
# CONFIG_ROSE_RTS_DEBUG is not set

#
# Generic Driver Options
#
CONFIG_STANDALONE=y
CONFIG_PREVENT_FIRMWARE_BUILD=y
# CONFIG_FW_LOADER is not set
# CONFIG_SYS_HYPERVISOR is not set
# CONFIG_CONNECTOR is not set
CONFIG_MTD=y
# CONFIG_MTD_DEBUG is not set
CONFIG_MTD_CONCAT=y
CONFIG_MTD_PARTITIONS=y
# CONFIG_MTD_REDBOOT_PARTS is not set
CONFIG_MTD_CMDLINE_PARTS=y
# CONFIG_MTD_AFS_PARTS is not set

#
# User Modules And Translation Layers
#
CONFIG_MTD_CHAR=y
CONFIG_MTD_BLKDEVS=y
CONFIG_MTD_BLOCK=y
# CONFIG_FTL is not set
# CONFIG_NFTL is not set
# CONFIG_INFTL is not set
# CONFIG_RFD_FTL is not set
# CONFIG_SSFDC is not set

#
# RAM/ROM/Flash chip drivers
#
CONFIG_MTD_CFI=y
# CONFIG_MTD_JEDECPROBE is not set
CONFIG_MTD_GEN_PROBE=y
# CONFIG_MTD_CFI_ADV_OPTIONS is not set
CONFIG_MTD_MAP_BANK_WIDTH_1=y
CONFIG_MTD_MAP_BANK_WIDTH_2=y
CONFIG_MTD_MAP_BANK_WIDTH_4=y
# CONFIG_MTD_MAP_BANK_WIDTH_8 is not set
# CONFIG_MTD_MAP_BANK_WIDTH_16 is not set
# CONFIG_MTD_MAP_BANK_WIDTH_32 is not set
CONFIG_MTD_CFI_I1=y
CONFIG_MTD_CFI_I2=y
# CONFIG_MTD_CFI_I4 is not set
# CONFIG_MTD_CFI_I8 is not set
CONFIG_MTD_CFI_INTELEXT=y
CONFIG_MTD_CFI_AMDSTD=y
CONFIG_MTD_CFI_STAA=y
CONFIG_MTD_CFI_UTIL=y
CONFIG_MTD_RAM=y
CONFIG_MTD_ROM=y
CONFIG_MTD_ABSENT=y

#
# Mapping drivers for chip access
#
CONFIG_MTD_COMPLEX_MAPPINGS=y
CONFIG_MTD_PHYSMAP=y
CONFIG_MTD_PHYSMAP_START=0x8000000
CONFIG_MTD_PHYSMAP_LEN=0
CONFIG_MTD_PHYSMAP_BANKWIDTH=2
# CONFIG_MTD_ARM_INTEGRATOR is not set
# CONFIG_MTD_PLATRAM is not set

#
# Self-contained MTD device drivers
#
# CONFIG_MTD_SLRAM is not set
# CONFIG_MTD_PHRAM is not set
# CONFIG_MTD_MTDRAM is not set
# CONFIG_MTD_BLOCK2MTD is not set

#
# Disk-On-Chip Device Drivers
#
# CONFIG_MTD_DOC2000 is not set
# CONFIG_MTD_DOC2001 is not set
# CONFIG_MTD_DOC2001PLUS is not set
# CONFIG_MTD_NAND is not set
# CONFIG_MTD_ONENAND is not set

#
# UBI - Unsorted block images
#
# CONFIG_MTD_UBI is not set
# CONFIG_PARPORT is not set
CONFIG_BLK_DEV=y
# CONFIG_BLK_DEV_COW_COMMON is not set
# CONFIG_BLK_DEV_LOOP is not set
# CONFIG_BLK_DEV_NBD is not set
CONFIG_BLK_DEV_RAM=y
CONFIG_BLK_DEV_RAM_COUNT=1
CONFIG_BLK_DEV_RAM_SIZE=8192
CONFIG_BLK_DEV_RAM_BLOCKSIZE=1024
# CONFIG_CDROM_PKTCDVD is not set
# CONFIG_ATA_OVER_ETH is not set

#
# SCSI device support
#
# CONFIG_RAID_ATTRS is not set
# CONFIG_SCSI is not set
# CONFIG_SCSI_DMA is not set
# CONFIG_SCSI_NETLINK is not set
# CONFIG_ATA is not set
# CONFIG_MD is not set
CONFIG_NETDEVICES=y
# CONFIG_NETDEVICES_MULTIQUEUE is not set
# CONFIG_DUMMY is not set
# CONFIG_BONDING is not set
# CONFIG_MACVLAN is not set
# CONFIG_EQUALIZER is not set
# CONFIG_TUN is not set
# CONFIG_PHYLIB is not set
CONFIG_NET_ETHERNET=y
CONFIG_MII=y
CONFIG_ARM_AT91_ETHER=y
# CONFIG_AX88796 is not set
# CONFIG_SMC91X is not set
# CONFIG_DM9000 is not set
# CONFIG_NETDEV_1000 is not set
# CONFIG_NETDEV_10000 is not set

#
# Wireless LAN
#
# CONFIG_WLAN_PRE80211 is not set
# CONFIG_WLAN_80211 is not set
# CONFIG_WAN is not set
# CONFIG_PPP is not set
# CONFIG_SLIP is not set
# CONFIG_SHAPER is not set
# CONFIG_NETCONSOLE is not set
# CONFIG_NETPOLL is not set
# CONFIG_NET_POLL_CONTROLLER is not set
# CONFIG_ISDN is not set

#
# Input device support
#
CONFIG_INPUT=y
# CONFIG_INPUT_FF_MEMLESS is not set
# CONFIG_INPUT_POLLDEV is not set

#
# Userland interfaces
#
# CONFIG_INPUT_MOUSEDEV is not set
# CONFIG_INPUT_JOYDEV is not set
# CONFIG_INPUT_TSDEV is not set
# CONFIG_INPUT_EVDEV is not set
# CONFIG_INPUT_EVBUG is not set

#
# Input Device Drivers
#
# CONFIG_INPUT_KEYBOARD is not set
# CONFIG_INPUT_MOUSE is not set
# CONFIG_INPUT_JOYSTICK is not set
# CONFIG_INPUT_TABLET is not set
# CONFIG_INPUT_TOUCHSCREEN is not set
# CONFIG_INPUT_MISC is not set

#
# Hardware I/O ports
#
# CONFIG_SERIO is not set
# CONFIG_GAMEPORT is not set

#
# Character devices
#
CONFIG_VT=y
CONFIG_VT_CONSOLE=y
CONFIG_HW_CONSOLE=y
# CONFIG_VT_HW_CONSOLE_BINDING is not set
# CONFIG_SERIAL_NONSTANDARD is not set

#
# Serial drivers
#
# CONFIG_SERIAL_8250 is not set

#
# Non-8250 serial port support
#
CONFIG_SERIAL_ATMEL=y
CONFIG_SERIAL_ATMEL_CONSOLE=y
CONFIG_SERIAL_ATMEL_PDC=y
# CONFIG_SERIAL_ATMEL_TTYAT is not set
CONFIG_SERIAL_CORE=y
CONFIG_SERIAL_CORE_CONSOLE=y
CONFIG_UNIX98_PTYS=y
# CONFIG_LEGACY_PTYS is not set
# CONFIG_IPMI_HANDLER is not set
# CONFIG_WATCHDOG is not set
# CONFIG_HW_RANDOM is not set
# CONFIG_NVRAM is not set
# CONFIG_R3964 is not set
# CONFIG_RAW_DRIVER is not set
# CONFIG_TCG_TPM is not set
# CONFIG_RMEM is not set
# CONFIG_ALLOC_RTSJ_MEM is not set
# CONFIG_AT91_SPI is not set
# CONFIG_I2C is not set

#
# SPI support
#
CONFIG_SPI=y
# CONFIG_SPI_MASTER is not set

#
# SPI Slave Controller Drivers
#
CONFIG_CEI=y
# CONFIG_W1 is not set
# CONFIG_HWMON is not set
# CONFIG_MISC_DEVICES is not set

#
# Multifunction device drivers
#
# CONFIG_MFD_SM501 is not set
# CONFIG_NEW_LEDS is not set

#
# Multimedia devices
#
# CONFIG_VIDEO_DEV is not set
# CONFIG_DVB_CORE is not set
# CONFIG_DAB is not set

#
# Graphics support
#
# CONFIG_BACKLIGHT_LCD_SUPPORT is not set

#
# Display device support
#
# CONFIG_DISPLAY_SUPPORT is not set
# CONFIG_VGASTATE is not set
# CONFIG_VIDEO_OUTPUT_CONTROL is not set
# CONFIG_FB is not set

#
# Console display driver support
#
# CONFIG_VGA_CONSOLE is not set
CONFIG_DUMMY_CONSOLE=y

#
# Sound
#
# CONFIG_SOUND is not set
# CONFIG_HID_SUPPORT is not set
# CONFIG_USB_SUPPORT is not set
# CONFIG_MMC is not set
CONFIG_RTC_LIB=y
# CONFIG_RTC_CLASS is not set

#
# DMA Engine support
#
# CONFIG_DMA_ENGINE is not set

#
# DMA Clients
#

#
# DMA Devices
#

#
# File systems
#
CONFIG_EXT2_FS=y
# CONFIG_EXT2_FS_XATTR is not set
# CONFIG_EXT2_FS_XIP is not set
# CONFIG_EXT3_FS is not set
# CONFIG_EXT4DEV_FS is not set
# CONFIG_REISERFS_FS is not set
# CONFIG_JFS_FS is not set
CONFIG_FS_POSIX_ACL=y
# CONFIG_XFS_FS is not set
# CONFIG_GFS2_FS is not set
# CONFIG_OCFS2_FS is not set
# CONFIG_MINIX_FS is not set
# CONFIG_ROMFS_FS is not set
# CONFIG_INOTIFY is not set
# CONFIG_QUOTA is not set
CONFIG_DNOTIFY=y
# CONFIG_AUTOFS_FS is not set
# CONFIG_AUTOFS4_FS is not set
# CONFIG_FUSE_FS is not set

#
# CD-ROM/DVD Filesystems
#
# CONFIG_ISO9660_FS is not set
# CONFIG_UDF_FS is not set

#
# DOS/FAT/NT Filesystems
#
# CONFIG_MSDOS_FS is not set
# CONFIG_VFAT_FS is not set
# CONFIG_NTFS_FS is not set

#
# Pseudo filesystems
#
CONFIG_PROC_FS=y
CONFIG_PROC_SYSCTL=y
CONFIG_SYSFS=y
CONFIG_TMPFS=y
# CONFIG_TMPFS_POSIX_ACL is not set
# CONFIG_HUGETLB_PAGE is not set
CONFIG_RAMFS=y
# CONFIG_CONFIGFS_FS is not set

#
# Miscellaneous filesystems
#
# CONFIG_ADFS_FS is not set
# CONFIG_AFFS_FS is not set
# CONFIG_HFS_FS is not set
# CONFIG_HFSPLUS_FS is not set
# CONFIG_BEFS_FS is not set
# CONFIG_BFS_FS is not set
# CONFIG_EFS_FS is not set
CONFIG_JFFS2_FS=y
CONFIG_JFFS2_FS_DEBUG=0
CONFIG_JFFS2_FS_WRITEBUFFER=y
# CONFIG_JFFS2_SUMMARY is not set
CONFIG_JFFS2_FS_XATTR=y
CONFIG_JFFS2_FS_POSIX_ACL=y
CONFIG_JFFS2_FS_SECURITY=y
# CONFIG_JFFS2_COMPRESSION_OPTIONS is not set
CONFIG_JFFS2_ZLIB=y
CONFIG_JFFS2_RTIME=y
# CONFIG_JFFS2_RUBIN is not set
# CONFIG_CRAMFS is not set
# CONFIG_VXFS_FS is not set
# CONFIG_HPFS_FS is not set
# CONFIG_QNX4FS_FS is not set
# CONFIG_SYSV_FS is not set
# CONFIG_UFS_FS is not set

#
# Network File Systems
#
CONFIG_NFS_FS=y
CONFIG_NFS_V3=y
# CONFIG_NFS_V3_ACL is not set
# CONFIG_NFS_V4 is not set
# CONFIG_NFS_DIRECTIO is not set
# CONFIG_NFSD is not set
CONFIG_ROOT_NFS=y
CONFIG_LOCKD=y
CONFIG_LOCKD_V4=y
CONFIG_NFS_COMMON=y
CONFIG_SUNRPC=y
# CONFIG_SUNRPC_BIND34 is not set
# CONFIG_RPCSEC_GSS_KRB5 is not set
# CONFIG_RPCSEC_GSS_SPKM3 is not set
# CONFIG_SMB_FS is not set
# CONFIG_CIFS is not set
# CONFIG_NCP_FS is not set
# CONFIG_CODA_FS is not set
# CONFIG_AFS_FS is not set

#
# Partition Types
#
# CONFIG_PARTITION_ADVANCED is not set
CONFIG_MSDOS_PARTITION=y

#
# Native Language Support
#
# CONFIG_NLS is not set

#
# Distributed Lock Manager
#
# CONFIG_DLM is not set

#
# Profiling support
#
# CONFIG_PROFILING is not set

#
# Instrumentation Support
#
# CONFIG_IMMEDIATE is not set
CONFIG_MARKERS=y
CONFIG_LTT=y
CONFIG_LTT_TRACER=m
CONFIG_LTT_RELAY=m
CONFIG_LTT_SERIALIZE=m
# CONFIG_LTT_ALIGNMENT is not set
# CONFIG_LTT_HEARTBEAT is not set
# CONFIG_LTT_USERSPACE_GENERIC is not set
CONFIG_LTT_NETLINK_CONTROL=m
CONFIG_LTT_STATEDUMP=m

#
# Probes
#
CONFIG_LTT_PROBE_CORE=m
CONFIG_LTT_PROBE_FS=m
CONFIG_LTT_PROBE_KERNEL=m
CONFIG_LTT_PROBE_ARCH=m
CONFIG_LTT_PROBE_MM=m
CONFIG_LTT_PROBE_NET=m
CONFIG_LTT_PROBE_LIST=m

#
# Kernel hacking
#
CONFIG_PRINTK_TIME=y
CONFIG_ENABLE_MUST_CHECK=y
# CONFIG_MAGIC_SYSRQ is not set
# CONFIG_UNUSED_SYMBOLS is not set
CONFIG_DEBUG_FS=y
# CONFIG_HEADERS_CHECK is not set
# CONFIG_DEBUG_KERNEL is not set
# CONFIG_EVENT_TRACE is not set
# CONFIG_FUNCTION_TRACE is not set
# CONFIG_WAKEUP_TIMING is not set
# CONFIG_CRITICAL_PREEMPT_TIMING is not set
# CONFIG_CRITICAL_IRQSOFF_TIMING is not set
# CONFIG_DEBUG_BUGVERBOSE is not set
CONFIG_FRAME_POINTER=y
CONFIG_DEBUG_USER=y

#
# Security options
#
# CONFIG_KEYS is not set
# CONFIG_SECURITY is not set
# CONFIG_CRYPTO is not set

#
# Library routines
#
CONFIG_BITREVERSE=y
# CONFIG_CRC_CCITT is not set
# CONFIG_CRC16 is not set
# CONFIG_CRC_ITU_T is not set
CONFIG_CRC32=y
# CONFIG_CRC7 is not set
# CONFIG_LIBCRC32C is not set
CONFIG_ZLIB_INFLATE=y
CONFIG_ZLIB_DEFLATE=y
CONFIG_PLIST=y
CONFIG_HAS_IOMEM=y
CONFIG_HAS_IOPORT=y
CONFIG_HAS_DMA=y