[PATCH] 2.6.17-rt add clockevent to ixp4xx

[PATCH] 2.6.17-rt add clockevent to ixp4xx

[Milan Svoboda]

[-- Attachment #1: Type: text/plain, Size: 4904 bytes --]

Hello,

there are patches that enable clock event on ixp4xx platform. This should
enable high resolution timers... Option for hrtimers in menuconfig is 
also enabled.

I tested it on nanosleep test program (included in attachments) and obtained
this results:

requested: 899000 us, got: 899159 us, diff: -159 us
requested: 897000 us, got: 897209 us, diff: -209 us
requested: 895000 us, got: 899803 us, diff: -4803 us
requested: 893000 us, got: 899425 us, diff: -6425 us
requested: 891000 us, got: 899806 us, diff: -8806 us
requested: 889000 us, got: 890142 us, diff: -1142 us
requested: 887000 us, got: 889873 us, diff: -2873 us
requested: 885000 us, got: 888096 us, diff: -3096 us
requested: 883000 us, got: 883323 us, diff: -323 us
requested: 881000 us, got: 883395 us, diff: -2395 us
requested: 879000 us, got: 883026 us, diff: -4026 us
requested: 877000 us, got: 877838 us, diff: -838 us
requested: 875000 us, got: 876975 us, diff: -1975 us
requested: 873000 us, got: 873585 us, diff: -585 us
requested: 871000 us, got: 871699 us, diff: -699 us
requested: 869000 us, got: 869747 us, diff: -747 us
requested: 867000 us, got: 869771 us, diff: -2771 us
requested: 865000 us, got: 869777 us, diff: -4777 us
requested: 863000 us, got: 869774 us, diff: -6774 us
requested: 861000 us, got: 869744 us, diff: -8744 us
requested: 859000 us, got: 861180 us, diff: -2180 us
requested: 857000 us, got: 857108 us, diff: -108 us
requested: 855000 us, got: 860986 us, diff: -5986 us
requested: 853000 us, got: 858383 us, diff: -5383 us
requested: 851000 us, got: 855234 us, diff: -4234 us
requested: 849000 us, got: 850261 us, diff: -1261 us
requested: 847000 us, got: 848729 us, diff: -1729 us
requested: 845000 us, got: 845926 us, diff: -926 us
requested: 843000 us, got: 844059 us, diff: -1059 us
requested: 841000 us, got: 841498 us, diff: -498 us
requested: 839000 us, got: 839758 us, diff: -758 us
requested: 837000 us, got: 839748 us, diff: -2748 us
requested: 835000 us, got: 839727 us, diff: -4727 us
requested: 833000 us, got: 834417 us, diff: -1417 us
requested: 831000 us, got: 834710 us, diff: -3710 us
requested: 829000 us, got: 834696 us, diff: -5696 us
requested: 827000 us, got: 830714 us, diff: -3714 us
requested: 825000 us, got: 830543 us, diff: -5543 us
requested: 823000 us, got: 830812 us, diff: -7812 us
requested: 821000 us, got: 828395 us, diff: -7395 us
requested: 819000 us, got: 819855 us, diff: -855 us
requested: 817000 us, got: 818855 us, diff: -1855 us
requested: 815000 us, got: 817711 us, diff: -2711 us
requested: 813000 us, got: 813312 us, diff: -312 us
requested: 811000 us, got: 811901 us, diff: -901 us
requested: 809000 us, got: 809804 us, diff: -804 us
requested: 807000 us, got: 809790 us, diff: -2790 us
requested: 805000 us, got: 809798 us, diff: -4798 us
requested: 803000 us, got: 809243 us, diff: -6243 us
requested: 801000 us, got: 801482 us, diff: -482 us
requested: 799000 us, got: 799772 us, diff: -772 us
requested: 797000 us, got: 801161 us, diff: -4161 us
requested: 795000 us, got: 798107 us, diff: -3107 us
requested: 793000 us, got: 795470 us, diff: -2470 us
requested: 791000 us, got: 793550 us, diff: -2550 us
requested: 789000 us, got: 789249 us, diff: -249 us
requested: 787000 us, got: 789163 us, diff: -2163 us
requested: 785000 us, got: 785329 us, diff: -329 us
requested: 783000 us, got: 783539 us, diff: -539 us
requested: 781000 us, got: 781949 us, diff: -949 us
requested: 779000 us, got: 779836 us, diff: -836 us
requested: 777000 us, got: 779785 us, diff: -2785 us
requested: 775000 us, got: 779804 us, diff: -4804 us
requested: 773000 us, got: 779805 us, diff: -6805 us
requested: 771000 us, got: 779811 us, diff: -8811 us
requested: 769000 us, got: 769796 us, diff: -796 us
requested: 767000 us, got: 769803 us, diff: -2803 us
requested: 765000 us, got: 769030 us, diff: -4030 us
requested: 763000 us, got: 771035 us, diff: -8035 us
requested: 761000 us, got: 761268 us, diff: -268 us
requested: 759000 us, got: 759746 us, diff: -746 us
requested: 757000 us, got: 757719 us, diff: -719 us
requested: 755000 us, got: 757442 us, diff: -2442 us
requested: 753000 us, got: 754198 us, diff: -1198 us
requested: 751000 us, got: 751350 us, diff: -350 us
requested: 749000 us, got: 749765 us, diff: -765 us
requested: 747000 us, got: 749758 us, diff: -2758 us

Results are far better than on standart kernel, but...

My question is: are these numbers expected? I hoped that with
hrtimers get better numbers, something about hundrets of us, instead
of thoushands...

The CONFIG_HIGH_RES_RESOLUTION is 100000 but
numbers were roughly the same with the default 1000. Numbers are
the same also when nanosleep and kernel threads are boosted to use
rt round-robin priority...

The system is running only this program.

Patch is against 2.6.17-rt7.

Feedback and comments are highly appreciated.

Signed-off-by: Milan Svoboda <msvoboda@ra.rockwell.com>
---


[-- Attachment #2: arm_add_hrtimer_option.patch --]
[-- Type: text/plain, Size: 414 bytes --]

diff -uprN -X rt/Documentation/dontdiff rt/arch/arm/Kconfig rt_new/arch/arm/Kconfig
--- rt/arch/arm/Kconfig	2006-07-12 11:35:52.000000000 +0000
+++ rt_new/arch/arm/Kconfig	2006-07-10 10:45:53.000000000 +0000
@@ -474,6 +474,8 @@ config HZ
 	default OMAP_32K_TIMER_HZ if ARCH_OMAP && OMAP_32K_TIMER
 	default 100
 
+source "kernel/time/Kconfig"
+
 config AEABI
 	bool "Use the ARM EABI to compile the kernel"
 	help

[-- Attachment #3: hrtimer_add_clockevent_hz2mult.patch --]
[-- Type: text/plain, Size: 650 bytes --]

diff -uprN -X rt/Documentation/dontdiff rt/include/linux/clockchips.h rt_new/include/linux/clockchips.h
--- rt/include/linux/clockchips.h	2006-07-12 11:35:52.000000000 +0000
+++ rt_new/include/linux/clockchips.h	2006-07-12 14:39:14.000000000 +0000
@@ -90,7 +90,19 @@ struct clock_event {
 	void *priv;
 };
 
+static inline u32 clockevent_hz2mult(u32 hz, u32 shift)
+{
+	u64 tmp = (u64) hz << shift;
+	do_div(tmp, 1000000000);
+	return (u32) tmp;
+}
 
+static inline u32 clockevent_khz2mult(u32 khz, u32 shift)
+{
+	u64 tmp = (u64) khz << shift;
+	do_div(tmp, 1000000);
+	return (u32) tmp;
+}
 
 /*
  * Calculate a multiplication factor with shift=32

[-- Attachment #4: ixp4xx_add_clock_event.patch --]
[-- Type: text/plain, Size: 2077 bytes --]

diff -uprN -X rt/Documentation/dontdiff rt/arch/arm/mach-ixp4xx/common.c rt_new/arch/arm/mach-ixp4xx/common.c
--- rt/arch/arm/mach-ixp4xx/common.c	2006-07-12 11:35:52.000000000 +0000
+++ rt_new/arch/arm/mach-ixp4xx/common.c	2006-07-13 10:26:06.000000000 +0000
@@ -28,6 +28,7 @@
 #include <linux/time.h>
 #include <linux/timex.h>
 #include <linux/clocksource.h>
+#include <linux/clockchips.h>
 
 #include <asm/hardware.h>
 #include <asm/uaccess.h>
@@ -255,15 +256,32 @@ void __init ixp4xx_init_irq(void)
 
 static unsigned volatile last_jiffy_time;
 
-#define CLOCK_TICKS_PER_USEC	((CLOCK_TICK_RATE + USEC_PER_SEC/2) / USEC_PER_SEC)
+#ifdef CONFIG_HIGH_RES_TIMERS
+static void ixp4xx_set_next_event(unsigned long evt, void *priv)
+{
+	*IXP4XX_OSRT1 = (evt & ~IXP4XX_OST_RELOAD_MASK) | IXP4XX_OST_ENABLE;
+}
+
+static struct clock_event clockevent_ixp4xx = {
+	.name		= "OSTS clock event interface",
+	.capabilities	= CLOCK_CAP_NEXTEVT | CLOCK_CAP_TICK |
+				 CLOCK_HAS_IRQHANDLER,
+	.shift		= 32,
+	.set_next_event	= ixp4xx_set_next_event,
+};
+#endif
 
 static irqreturn_t ixp4xx_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 {
-	write_seqlock(&xtime_lock);
-
 	/* Clear Pending Interrupt by writing '1' to it */
 	*IXP4XX_OSST = IXP4XX_OSST_TIMER_1_PEND;
 
+#ifdef CONFIG_HIGH_RES_TIMERS
+	if (clockevent_ixp4xx.event_handler)
+		clockevent_ixp4xx.event_handler(regs, NULL);
+#endif
+	write_seqlock(&xtime_lock);
+
 	/*
 	 * Catch up with the real idea of time
 	 */
@@ -379,5 +397,20 @@ static int __init ixp4xx_clocksource_ini
 
 	return 0;
 }
-
 device_initcall(ixp4xx_clocksource_init);
+
+#ifdef CONFIG_HIGH_RES_TIMERS
+static int __init ixp4xx_clockevent_init(void)
+{
+	clockevent_ixp4xx.mult =
+		clockevent_hz2mult(FREQ, clockevent_ixp4xx.shift);
+	clockevent_ixp4xx.max_delta_ns =
+		clockevent_delta2ns(0xfffffffe, &clockevent_ixp4xx);
+	clockevent_ixp4xx.min_delta_ns =
+		clockevent_delta2ns(0xf, &clockevent_ixp4xx);
+	setup_local_clockevent(&clockevent_ixp4xx, CPU_MASK_NONE);
+
+	return 0;
+}
+device_initcall(ixp4xx_clockevent_init);
+#endif

[-- Attachment #5: ixp4xx_make_clock_accurate.patch --]
[-- Type: text/plain, Size: 455 bytes --]

diff -uprN -X rt/Documentation/dontdiff rt/arch/arm/mach-ixp4xx/common.c rt_new/arch/arm/mach-ixp4xx/common.c
--- rt/arch/arm/mach-ixp4xx/common.c	2006-07-12 11:35:52.000000000 +0000
+++ rt_new/arch/arm/mach-ixp4xx/common.c	2006-07-12 11:37:27.000000000 +0000
@@ -364,7 +364,7 @@ static struct clocksource clocksource_ix
 	.rating		= 200,
 	.read		= ixp4xx_get_cycles,
 	.mask		= 0xFFFFFFFF,
-	.shift 		= 10,
+	.shift 		= 20,
 	.is_continuous 	= 1,
 };
 

[-- Attachment #6: nanosleep.c --]
[-- Type: text/plain, Size: 775 bytes --]

#include <time.h>
#include <sys/time.h>

int main(int argc, char **argv)
{
	int i, r;
	unsigned long delta;
	struct timeval beg, end;
	struct timespec ts;
	struct timespec rest;
	
	ts.tv_sec  = 0;
	ts.tv_nsec = 900000000;
	
	// > 1 msec
	//
	while (ts.tv_nsec > 1000000)
	{
		r = gettimeofday(&beg, NULL);
		if (r < 0)
			break;
	
		r = nanosleep(&ts, &rest);
		if (r < 0)
			break;

		r = gettimeofday(&end, NULL);
		if (r < 0)
			break;
	
		delta = (end.tv_sec - beg.tv_sec) * 1000 * 1000;
		delta = delta + (end.tv_usec - beg.tv_usec);
		
		printf("requested: %lu us, got: %lu us, diff: %li us\n",
			(ts.tv_nsec / 1000),
			delta,
			delta - (ts.tv_nsec / 1000));
			
		// 1 msec
		//
		ts.tv_nsec -= 1000000;
	}

	printf("ts.tv_nsec: %lu\n", ts.tv_nsec);	

	return 0;
}

[-- Attachment #7: .config --]
[-- Type: text/plain, Size: 18044 bytes --]

#
# Automatically generated make config: don't edit
# Linux kernel version: 2.6.17-rt7
# Thu Jul 13 10:09:57 2006
#
CONFIG_ARM=y
CONFIG_MMU=y
CONFIG_GENERIC_TIME=y
CONFIG_GENERIC_HARDIRQS=y
CONFIG_HARDIRQS_SW_RESEND=y
CONFIG_GENERIC_IRQ_PROBE=y
CONFIG_RWSEM_GENERIC_SPINLOCK=y
CONFIG_GENERIC_HWEIGHT=y
CONFIG_GENERIC_CALIBRATE_DELAY=y
CONFIG_VECTORS_BASE=0xffff0000

#
# Code maturity level options
#
CONFIG_EXPERIMENTAL=y
CONFIG_BROKEN_ON_SMP=y
CONFIG_LOCK_KERNEL=y
CONFIG_INIT_ENV_ARG_LIMIT=32

#
# General setup
#
CONFIG_LOCALVERSION=""
# CONFIG_LOCALVERSION_AUTO is not set
# CONFIG_SWAP is not set
# CONFIG_SYSVIPC is not set
# CONFIG_POSIX_MQUEUE is not set
# CONFIG_BSD_PROCESS_ACCT is not set
CONFIG_SYSCTL=y
# CONFIG_AUDIT is not set
# CONFIG_IKCONFIG is not set
# CONFIG_RELAY is not set
CONFIG_INITRAMFS_SOURCE=""
CONFIG_UID16=y
# CONFIG_CC_OPTIMIZE_FOR_SIZE is not set
# CONFIG_EMBEDDED is not set
CONFIG_KALLSYMS=y
# CONFIG_KALLSYMS_ALL is not set
# 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_RT_MUTEXES=y
CONFIG_FUTEX=y
CONFIG_EPOLL=y
CONFIG_SHMEM=y
CONFIG_SLAB=y
# CONFIG_TINY_SHMEM is not set
CONFIG_BASE_SMALL=0
# CONFIG_SLOB is not set
CONFIG_OBSOLETE_INTERMODULE=y

#
# Loadable module support
#
CONFIG_MODULES=y
CONFIG_MODULE_UNLOAD=y
# CONFIG_MODULE_FORCE_UNLOAD is not set
# CONFIG_MODVERSIONS is not set
# CONFIG_MODULE_SRCVERSION_ALL is not set
# CONFIG_KMOD is not set

#
# Block layer
#
# CONFIG_BLK_DEV_IO_TRACE is not set

#
# IO Schedulers
#
CONFIG_IOSCHED_NOOP=y
CONFIG_IOSCHED_AS=y
CONFIG_IOSCHED_DEADLINE=y
CONFIG_IOSCHED_CFQ=y
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_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_INTEGRATOR is not set
# CONFIG_ARCH_IOP3XX is not set
CONFIG_ARCH_IXP4XX=y
# CONFIG_ARCH_IXP2000 is not set
# CONFIG_ARCH_IXP23XX is not set
# CONFIG_ARCH_L7200 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_OMAP is not set
# CONFIG_ARCH_VERSATILE is not set
# CONFIG_ARCH_REALVIEW is not set
# CONFIG_ARCH_IMX is not set
# CONFIG_ARCH_H720X is not set
# CONFIG_ARCH_AAEC2000 is not set
# CONFIG_ARCH_AT91RM9200 is not set
CONFIG_ARCH_SUPPORTS_BIG_ENDIAN=y

#
# Intel IXP4xx Implementation Options
#

#
# IXP4xx Platforms
#
# CONFIG_MACH_NSLU2 is not set
# CONFIG_ARCH_AVILA is not set
# CONFIG_ARCH_ADI_COYOTE is not set
# CONFIG_ARCH_IXDP425 is not set
# CONFIG_MACH_IXDPG425 is not set
CONFIG_MACH_IXDP465=y
# CONFIG_ARCH_PRPMC1100 is not set
# CONFIG_MACH_NAS100D is not set
CONFIG_ARCH_IXDP4XX=y
CONFIG_CPU_IXP46X=y
# CONFIG_MACH_GTWX5715 is not set

#
# IXP4xx Options
#
CONFIG_DMABOUNCE=y
# CONFIG_IXP4XX_INDIRECT_PCI is not set

#
# Processor Type
#
CONFIG_CPU_32=y
CONFIG_CPU_XSCALE=y
CONFIG_CPU_32v5=y
CONFIG_CPU_ABRT_EV5T=y
CONFIG_CPU_CACHE_VIVT=y
CONFIG_CPU_TLB_V4WBI=y

#
# Processor Features
#
# CONFIG_ARM_THUMB is not set
CONFIG_CPU_BIG_ENDIAN=y
CONFIG_XSCALE_PMU=y

#
# Bus support
#
CONFIG_PCI=y
# CONFIG_PCI_DEBUG is not set

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

#
# Kernel Features
#
# 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_RCU_STATS is not set
# CONFIG_NO_IDLE_HZ is not set
CONFIG_HZ=100
CONFIG_HIGH_RES_TIMERS=y
CONFIG_HIGH_RES_RESOLUTION=100000
# CONFIG_AEABI 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_ALIGNMENT_TRAP=y

#
# Boot options
#
CONFIG_ZBOOT_ROM_TEXT=0
CONFIG_ZBOOT_ROM_BSS=0
CONFIG_CMDLINE="console=ttyS0,115200 root=/dev/nfs ip=bootp mem=128M"
# CONFIG_XIP_KERNEL is not set

#
# Floating point emulation
#

#
# At least one emulation must be selected
#
# CONFIG_FPE_NWFPE is not set
# CONFIG_FPE_FASTFPE is not set

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

#
# Power management options
#
CONFIG_PM=y
# CONFIG_PM_LEGACY is not set
CONFIG_PM_DEBUG=y
# CONFIG_APM is not set

#
# Networking
#
CONFIG_NET=y

#
# Networking options
#
# CONFIG_NETDEBUG is not set
CONFIG_PACKET=y
# CONFIG_PACKET_MMAP is not set
CONFIG_UNIX=y
# CONFIG_NET_KEY is not set
CONFIG_INET=y
CONFIG_IP_MULTICAST=y
# CONFIG_IP_ADVANCED_ROUTER is not set
CONFIG_IP_FIB_HASH=y
CONFIG_IP_PNP=y
CONFIG_IP_PNP_DHCP=y
CONFIG_IP_PNP_BOOTP=y
# CONFIG_IP_PNP_RARP is not set
# CONFIG_NET_IPIP is not set
# CONFIG_NET_IPGRE is not set
# CONFIG_IP_MROUTE 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_DIAG=y
CONFIG_INET_TCP_DIAG=y
# CONFIG_TCP_CONG_ADVANCED is not set
CONFIG_TCP_CONG_BIC=y
# CONFIG_IPV6 is not set
# CONFIG_INET6_XFRM_TUNNEL is not set
# CONFIG_INET6_TUNNEL is not set
# CONFIG_NETFILTER is not set

#
# DCCP Configuration (EXPERIMENTAL)
#
# CONFIG_IP_DCCP is not set

#
# SCTP Configuration (EXPERIMENTAL)
#
# CONFIG_IP_SCTP is not set

#
# TIPC Configuration (EXPERIMENTAL)
#
# 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_NET_DIVERT 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_IEEE80211 is not set

#
# Device Drivers
#

#
# Generic Driver Options
#
# CONFIG_STANDALONE is not set
# CONFIG_PREVENT_FIRMWARE_BUILD is not set
CONFIG_FW_LOADER=y
# CONFIG_DEBUG_DRIVER is not set

#
# Connector - unified userspace <-> kernelspace linker
#
# CONFIG_CONNECTOR is not set

#
# Memory Technology Devices (MTD)
#
CONFIG_MTD=y
# CONFIG_MTD_DEBUG is not set
# CONFIG_MTD_CONCAT is not set
CONFIG_MTD_PARTITIONS=y
CONFIG_MTD_REDBOOT_PARTS=y
CONFIG_MTD_REDBOOT_DIRECTORY_BLOCK=-1
# CONFIG_MTD_REDBOOT_PARTS_UNALLOCATED is not set
CONFIG_MTD_REDBOOT_PARTS_READONLY=y
# CONFIG_MTD_CMDLINE_PARTS is not set
# CONFIG_MTD_AFS_PARTS is not set

#
# User Modules And Translation Layers
#
CONFIG_MTD_CHAR=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

#
# 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 is not set
# CONFIG_MTD_CFI_STAA is not set
CONFIG_MTD_CFI_UTIL=y
# CONFIG_MTD_RAM is not set
# CONFIG_MTD_ROM is not set
# CONFIG_MTD_ABSENT is not set
# CONFIG_MTD_OBSOLETE_CHIPS is not set

#
# Mapping drivers for chip access
#
CONFIG_MTD_COMPLEX_MAPPINGS=y
# CONFIG_MTD_PHYSMAP is not set
# CONFIG_MTD_ARM_INTEGRATOR is not set
CONFIG_MTD_IXP4XX=y
# CONFIG_MTD_PCI is not set
# CONFIG_MTD_PLATRAM is not set

#
# Self-contained MTD device drivers
#
# CONFIG_MTD_PMC551 is not set
# 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

#
# NAND Flash Device Drivers
#
# CONFIG_MTD_NAND is not set

#
# OneNAND Flash Device Drivers
#
# CONFIG_MTD_ONENAND is not set

#
# Parallel port support
#
# CONFIG_PARPORT is not set

#
# Plug and Play support
#

#
# Block devices
#
# CONFIG_BLK_CPQ_DA is not set
# CONFIG_BLK_CPQ_CISS_DA is not set
# CONFIG_BLK_DEV_DAC960 is not set
# CONFIG_BLK_DEV_UMEM is not set
# 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_SX8 is not set
CONFIG_BLK_DEV_RAM=y
CONFIG_BLK_DEV_RAM_COUNT=16
CONFIG_BLK_DEV_RAM_SIZE=8192
CONFIG_BLK_DEV_INITRD=y
# CONFIG_CDROM_PKTCDVD is not set
# CONFIG_ATA_OVER_ETH is not set

#
# ATA/ATAPI/MFM/RLL support
#
# CONFIG_IDE is not set

#
# SCSI device support
#
# CONFIG_RAID_ATTRS is not set
# CONFIG_SCSI is not set

#
# Multi-device support (RAID and LVM)
#
# CONFIG_MD is not set

#
# Fusion MPT device support
#
# CONFIG_FUSION is not set

#
# IEEE 1394 (FireWire) support
#
# CONFIG_IEEE1394 is not set

#
# I2O device support
#
# CONFIG_I2O is not set

#
# Network device support
#
CONFIG_NETDEVICES=y
# CONFIG_DUMMY is not set
# CONFIG_BONDING is not set
# CONFIG_EQUALIZER is not set
# CONFIG_TUN is not set

#
# ARCnet devices
#
# CONFIG_ARCNET is not set

#
# PHY device support
#
# CONFIG_PHYLIB is not set

#
# Ethernet (10 or 100Mbit)
#
CONFIG_NET_ETHERNET=y
CONFIG_MII=y
# CONFIG_HAPPYMEAL is not set
# CONFIG_SUNGEM is not set
# CONFIG_CASSINI is not set
# CONFIG_NET_VENDOR_3COM is not set
# CONFIG_SMC91X is not set
# CONFIG_DM9000 is not set

#
# Tulip family network device support
#
# CONFIG_NET_TULIP is not set
# CONFIG_HP100 is not set
CONFIG_NET_PCI=y
# CONFIG_PCNET32 is not set
# CONFIG_AMD8111_ETH is not set
# CONFIG_ADAPTEC_STARFIRE is not set
# CONFIG_B44 is not set
# CONFIG_FORCEDETH is not set
# CONFIG_DGRS is not set
# CONFIG_EEPRO100 is not set
CONFIG_E100=y
# CONFIG_FEALNX is not set
# CONFIG_NATSEMI is not set
# CONFIG_NE2K_PCI is not set
# CONFIG_8139CP is not set
# CONFIG_8139TOO is not set
# CONFIG_SIS900 is not set
# CONFIG_EPIC100 is not set
# CONFIG_SUNDANCE is not set
# CONFIG_TLAN is not set
# CONFIG_VIA_RHINE is not set

#
# Ethernet (1000 Mbit)
#
# CONFIG_ACENIC is not set
# CONFIG_DL2K is not set
# CONFIG_E1000 is not set
# CONFIG_NS83820 is not set
# CONFIG_HAMACHI is not set
# CONFIG_YELLOWFIN is not set
# CONFIG_R8169 is not set
# CONFIG_SIS190 is not set
# CONFIG_SKGE is not set
# CONFIG_SKY2 is not set
# CONFIG_SK98LIN is not set
# CONFIG_VIA_VELOCITY is not set
# CONFIG_TIGON3 is not set
# CONFIG_BNX2 is not set

#
# Ethernet (10000 Mbit)
#
# CONFIG_CHELSIO_T1 is not set
# CONFIG_IXGB is not set
# CONFIG_S2IO is not set

#
# Token Ring devices
#
# CONFIG_TR is not set

#
# Wireless LAN (non-hamradio)
#
# CONFIG_NET_RADIO is not set

#
# Wan interfaces
#
# CONFIG_WAN is not set
# CONFIG_FDDI is not set
# CONFIG_HIPPI 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

#
# ISDN subsystem
#
# CONFIG_ISDN is not set

#
# Input device support
#
CONFIG_INPUT=y

#
# Userland interfaces
#
CONFIG_INPUT_MOUSEDEV=y
# CONFIG_INPUT_MOUSEDEV_PSAUX is not set
CONFIG_INPUT_MOUSEDEV_SCREEN_X=1024
CONFIG_INPUT_MOUSEDEV_SCREEN_Y=768
# 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_TOUCHSCREEN is not set
# CONFIG_INPUT_MISC is not set

#
# Hardware I/O ports
#
CONFIG_SERIO=y
CONFIG_SERIO_SERPORT=y
# CONFIG_SERIO_PCIPS2 is not set
# CONFIG_SERIO_RAW is not set
# CONFIG_GAMEPORT is not set

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

#
# Serial drivers
#
CONFIG_SERIAL_8250=y
CONFIG_SERIAL_8250_CONSOLE=y
CONFIG_SERIAL_8250_PCI=y
CONFIG_SERIAL_8250_NR_UARTS=2
CONFIG_SERIAL_8250_RUNTIME_UARTS=2
# CONFIG_SERIAL_8250_EXTENDED is not set

#
# Non-8250 serial port support
#
CONFIG_SERIAL_CORE=y
CONFIG_SERIAL_CORE_CONSOLE=y
# CONFIG_SERIAL_JSM is not set
CONFIG_UNIX98_PTYS=y
CONFIG_LEGACY_PTYS=y
CONFIG_LEGACY_PTY_COUNT=256

#
# IPMI
#
# CONFIG_IPMI_HANDLER is not set

#
# Watchdog Cards
#
# CONFIG_WATCHDOG is not set
# CONFIG_NVRAM is not set
# CONFIG_DTLK is not set
# CONFIG_R3964 is not set
# CONFIG_APPLICOM is not set

#
# Ftape, the floppy tape device driver
#
# CONFIG_DRM is not set
# CONFIG_RAW_DRIVER is not set

#
# TPM devices
#
# CONFIG_TCG_TPM is not set
# CONFIG_TELCLOCK is not set

#
# I2C support
#
# CONFIG_I2C is not set

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

#
# Dallas's 1-wire bus
#
# CONFIG_W1 is not set

#
# Hardware Monitoring support
#
CONFIG_HWMON=y
# CONFIG_HWMON_VID is not set
# CONFIG_SENSORS_F71805F is not set
# CONFIG_HWMON_DEBUG_CHIP is not set

#
# Misc devices
#

#
# LED devices
#
# CONFIG_NEW_LEDS is not set

#
# LED drivers
#

#
# LED Triggers
#

#
# Multimedia devices
#
# CONFIG_VIDEO_DEV is not set
CONFIG_VIDEO_V4L2=y

#
# Digital Video Broadcasting Devices
#
# CONFIG_DVB is not set

#
# Graphics support
#
# 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

#
# USB support
#
CONFIG_USB_ARCH_HAS_HCD=y
CONFIG_USB_ARCH_HAS_OHCI=y
CONFIG_USB_ARCH_HAS_EHCI=y
# CONFIG_USB is not set

#
# NOTE: USB_STORAGE enables SCSI, and 'SCSI disk support'
#

#
# USB Gadget Support
#
CONFIG_USB_GADGET=m
# CONFIG_USB_GADGET_DEBUG_FILES is not set
CONFIG_USB_GADGET_SELECTED=y
# CONFIG_USB_GADGET_NET2280 is not set
CONFIG_USB_GADGET_PXA2XX=y
CONFIG_USB_PXA2XX=m
CONFIG_USB_PXA2XX_SMALL=y
# CONFIG_USB_GADGET_GOKU is not set
# CONFIG_USB_GADGET_LH7A40X is not set
# CONFIG_USB_GADGET_OMAP is not set
# CONFIG_USB_GADGET_AT91 is not set
# CONFIG_USB_GADGET_DUMMY_HCD is not set
# CONFIG_USB_GADGET_DUALSPEED is not set
CONFIG_USB_ZERO=m
# CONFIG_USB_ETH is not set
CONFIG_USB_GADGETFS=m
# CONFIG_USB_FILE_STORAGE is not set
# CONFIG_USB_G_SERIAL is not set

#
# MMC/SD Card support
#
# CONFIG_MMC is not set

#
# Real Time Clock
#
CONFIG_RTC_LIB=y
# CONFIG_RTC_CLASS is not set

#
# 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_REISERFS_FS is not set
# CONFIG_JFS_FS is not set
# CONFIG_FS_POSIX_ACL is not set
# CONFIG_XFS_FS is not set
# CONFIG_OCFS2_FS is not set
# CONFIG_MINIX_FS is not set
# CONFIG_ROMFS_FS is not set
CONFIG_INOTIFY=y
# 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_SYSFS=y
CONFIG_TMPFS=y
# 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_JFFS_FS is not set
# CONFIG_JFFS2_FS 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_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
# CONFIG_9P_FS is not set

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

#
# Native Language Support
#
# CONFIG_NLS is not set

#
# Profiling support
#
# CONFIG_PROFILING is not set

#
# Kernel hacking
#
# CONFIG_PRINTK_TIME is not set
# CONFIG_PRINTK_IGNORE_LOGLEVEL is not set
# CONFIG_MAGIC_SYSRQ is not set
CONFIG_DEBUG_KERNEL=y
CONFIG_LOG_BUF_SHIFT=14
CONFIG_DETECT_SOFTLOCKUP=y
# CONFIG_SCHEDSTATS is not set
# CONFIG_DEBUG_SLAB is not set
CONFIG_DEBUG_PREEMPT=y
CONFIG_DEBUG_RT_MUTEXES=y
CONFIG_DEBUG_PI_LIST=y
CONFIG_RT_MUTEX_TESTER=y
# CONFIG_WAKEUP_TIMING is not set
CONFIG_PREEMPT_TRACE=y
# CONFIG_CRITICAL_PREEMPT_TIMING is not set
# CONFIG_CRITICAL_IRQSOFF_TIMING is not set
# CONFIG_DEBUG_KOBJECT is not set
CONFIG_DEBUG_BUGVERBOSE=y
CONFIG_DEBUG_INFO=y
# CONFIG_DEBUG_FS is not set
# CONFIG_DEBUG_VM is not set
CONFIG_FRAME_POINTER=y
CONFIG_UNWIND_INFO=y
CONFIG_FORCED_INLINING=y
CONFIG_RCU_TORTURE_TEST=m
# CONFIG_DEBUG_USER is not set
CONFIG_DEBUG_WAITQ=y
CONFIG_DEBUG_ERRORS=y
# CONFIG_DEBUG_LL is not set

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

#
# Cryptographic options
#
# CONFIG_CRYPTO is not set

#
# Hardware crypto devices
#

#
# Library routines
#
# CONFIG_CRC_CCITT is not set
# CONFIG_CRC16 is not set
CONFIG_CRC32=y
# CONFIG_LIBCRC32C is not set
CONFIG_PLIST=y

Re: [PATCH] 2.6.17-rt add clockevent to ixp4xx

[Daniel Walker]

On Thu, 2006-07-13 at 10:53 +0000, Milan Svoboda wrote:
> Hello,
> 
> there are patches that enable clock event on ixp4xx platform. This should
> enable high resolution timers... Option for hrtimers in menuconfig is 
> also enabled.
> 
> I tested it on nanosleep test program (included in attachments) and obtained
> this results:
> 
> requested: 899000 us, got: 899159 us, diff: -159 us
> requested: 897000 us, got: 897209 us, diff: -209 us
> requested: 895000 us, got: 899803 us, diff: -4803 us
> requested: 893000 us, got: 899425 us, diff: -6425 us
> requested: 891000 us, got: 899806 us, diff: -8806 us
> requested: 889000 us, got: 890142 us, diff: -1142 us
> requested: 887000 us, got: 889873 us, diff: -2873 us
> requested: 885000 us, got: 888096 us, diff: -3096 us

I'd turn off some of the debugging options, and retest. For instance,
the pi-list debugging option will cause arbitrary latency, which you
seem to show in your results. Normally with PREEMPT_RT turned on you
would expect the timers to trigger within a constant amount of time from
when they are suppose to.

Daniel

Re: [PATCH] 2.6.17-rt add clockevent to ixp4xx

[Thomas Gleixner]

On Thu, 2006-07-13 at 07:41 -0700, Daniel Walker wrote:
> On Thu, 2006-07-13 at 10:53 +0000, Milan Svoboda wrote:
> > Hello,
> > 
> > there are patches that enable clock event on ixp4xx platform. This should
> > enable high resolution timers... Option for hrtimers in menuconfig is 
> > also enabled.
> > 
> > I tested it on nanosleep test program (included in attachments) and obtained
> > this results:
> > 
> > requested: 899000 us, got: 899159 us, diff: -159 us
> > requested: 897000 us, got: 897209 us, diff: -209 us
> > requested: 895000 us, got: 899803 us, diff: -4803 us
> > requested: 893000 us, got: 899425 us, diff: -6425 us
> > requested: 891000 us, got: 899806 us, diff: -8806 us
> > requested: 889000 us, got: 890142 us, diff: -1142 us
> > requested: 887000 us, got: 889873 us, diff: -2873 us
> > requested: 885000 us, got: 888096 us, diff: -3096 us
> 
> I'd turn off some of the debugging options, and retest. For instance,
> the pi-list debugging option will cause arbitrary latency, which you
> seem to show in your results. Normally with PREEMPT_RT turned on you
> would expect the timers to trigger within a constant amount of time from
> when they are suppose to.

No, the time differences looks like the high res mode never gets
switched on. its oszillating between 0 and 10ms, which is the usual
behaviour for a non hrt kernel.

Also I would recommend to test without preempt-rt in the first place.
Preempt-rt on ARM is not really well tested, so you dont fight two
battles at once.

	tglx

Re: [PATCH] 2.6.17-rt add clockevent to ixp4xx

[Kevin Hilman]

[-- Attachment #1: Type: text/plain, Size: 3534 bytes --]

On Thu, 2006-07-13 at 10:53 +0000, Milan Svoboda wrote:

> there are patches that enable clock event on ixp4xx platform. This should
> enable high resolution timers... Option for hrtimers in menuconfig is 
> also enabled.

Milan,

I've also done a clockevent driver for ixp4xx and it looks pretty much
like yours.  I've been waiting to submit as Thomas has recently reworked
the clockevent layer a bit in his -hrt-dyntick patchset.

Here are a couple comments on your patchset

 - since you've registered the clockevent with CAP_TICK, both the 
arch interrupt handler and the clockevent handler are handling the tick
and calling do_timer().  While I don't think this will negatively affect
timekeeping, it's unncessary overhead.

 - why the addition of clockevent_hz2mult()? since shift is 32, you
could use existing div_sc32()

The attached patch is a combination of my patch and yours and addresses
my comments above.  I simply removed the CLOCK_CAP_TICK and removed your
clockevent_hz2mult() and used div_sc32().

Also, below are a few runs of the nanosleep_jitter test that comes with
the sourceforge HRT test suite.  Something strange is that with the
nanosleep_jitter test, I only see max sleeps of ~300-400 usec but with
your test I see max sleeps up to 1.3 msec.

Kevin

root@ixp425:/kjh# gcc -DCLOCK_REALTIME_HR=CLOCK_REALTIME
nanosleep_jitter.c -lposixtime
root@ixp425:/kjh# ./a.out
Doing 10 iterations of sleeping for 50 micro seconds 1000 times
Total time for each iteration should be 0.050000 seconds.
Iteration iter time (secs)           min sleep max sleep
  0        0.075580  0.075575 0.000075    0.000084
  1        0.075526  0.075521 0.000074    0.000082
  2        0.075529  0.075525 0.000074    0.000082
  3        0.075518  0.075514 0.000074    0.000082
  4        0.075526  0.075521 0.000075    0.000082
  5        0.075525  0.075521 0.000074    0.000082
  6        0.075526  0.075521 0.000074    0.000082
  7        0.075519  0.075514 0.000074    0.000082
  8        0.075526  0.075522 0.000075    0.000082
  9        0.244572  0.244564 0.000074    0.000316
root@ixp425:/kjh# ./a.out
Doing 10 iterations of sleeping for 50 micro seconds 1000 times
Total time for each iteration should be 0.050000 seconds.
Iteration iter time (secs)           min sleep max sleep
  0        0.075644  0.075639 0.000075    0.000083
  1        0.075527  0.075523 0.000075    0.000082
  2        0.075518  0.075514 0.000074    0.000082
  3        0.075525  0.075521 0.000075    0.000082
  4        0.075530  0.075525 0.000074    0.000082
  5        0.075526  0.075521 0.000074    0.000082
  6        0.075518  0.075514 0.000074    0.000082
  7        0.075526  0.075521 0.000075    0.000082
  8        0.075526  0.075521 0.000074    0.000082
  9        0.147196  0.147187 0.000074    0.000311
root@ixp425:/kjh# ./a.out
Doing 10 iterations of sleeping for 50 micro seconds 1000 times
Total time for each iteration should be 0.050000 seconds.
Iteration iter time (secs)           min sleep max sleep
  0        0.075588  0.075583 0.000075    0.000084
  1        0.075534  0.075529 0.000074    0.000082
  2        0.075537  0.075533 0.000074    0.000082
  3        0.075526  0.075522 0.000074    0.000082
  4        0.075533  0.075529 0.000075    0.000082
  5        0.075533  0.075529 0.000074    0.000082
  6        0.075594  0.075589 0.000074    0.000083
  7        0.075540  0.075535 0.000074    0.000086
  8        0.075539  0.075534 0.000075    0.000084
  9        0.075527  0.075522 0.000074    0.000083
root@ixp425:/kjh#





[-- Attachment #2: arm-ixp4xx-clockevent2.patch --]
[-- Type: text/x-patch, Size: 2328 bytes --]

ARM: Add HRT clockevent support for IXP4xx platform

Signed-off-by: Milan Svoboda <msvoboda@ra.rockwell.com>
Signed-off-by: Kevin Hilman <khilman@deeprooted.net>

Index: ixp4xx/arch/arm/mach-ixp4xx/common.c
===================================================================
--- ixp4xx.orig/arch/arm/mach-ixp4xx/common.c
+++ ixp4xx/arch/arm/mach-ixp4xx/common.c
@@ -28,6 +28,7 @@
 #include <linux/time.h>
 #include <linux/timex.h>
 #include <linux/clocksource.h>
+#include <linux/clockchips.h>
 
 #include <asm/hardware.h>
 #include <asm/uaccess.h>
@@ -256,15 +257,31 @@ void __init ixp4xx_init_irq(void)
 
 static unsigned volatile last_jiffy_time;
 
-#define CLOCK_TICKS_PER_USEC	((CLOCK_TICK_RATE + USEC_PER_SEC/2) / USEC_PER_SEC)
+#ifdef CONFIG_HIGH_RES_TIMERS
+static void ixp4xx_set_next_event(unsigned long evt, void *priv)
+{
+	*IXP4XX_OSRT1 = (evt & ~IXP4XX_OST_RELOAD_MASK) | IXP4XX_OST_ENABLE;
+}
+
+static struct clock_event clockevent_ixp4xx = {
+	.name		= "OSTS clock event interface",
+	.capabilities	= CLOCK_CAP_NEXTEVT |  CLOCK_HAS_IRQHANDLER,
+	.shift		= 32,
+	.set_next_event	= ixp4xx_set_next_event,
+};
+#endif
 
 static irqreturn_t ixp4xx_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 {
-	write_seqlock(&xtime_lock);
-
 	/* Clear Pending Interrupt by writing '1' to it */
 	*IXP4XX_OSST = IXP4XX_OSST_TIMER_1_PEND;
 
+#ifdef CONFIG_HIGH_RES_TIMERS
+	if (clockevent_ixp4xx.event_handler)
+		clockevent_ixp4xx.event_handler(regs, NULL);
+#endif
+	write_seqlock(&xtime_lock);
+
 	/*
 	 * Catch up with the real idea of time
 	 */
@@ -404,7 +421,7 @@ static struct clocksource clocksource_ix
 	.rating		= 200,
 	.read		= ixp4xx_get_cycles,
 	.mask		= 0xFFFFFFFF,
-	.shift 		= 10,
+	.shift 		= 20,
 	.is_continuous 	= 1,
 };
 
@@ -419,5 +436,19 @@ static int __init ixp4xx_clocksource_ini
 
 	return 0;
 }
-
 device_initcall(ixp4xx_clocksource_init);
+
+#ifdef CONFIG_HIGH_RES_TIMERS
+static int __init ixp4xx_clockevent_init(void)
+{
+	clockevent_ixp4xx.mult = div_sc32(FREQ, NSEC_PER_SEC);
+	clockevent_ixp4xx.max_delta_ns =
+		clockevent_delta2ns(0xfffffffe, &clockevent_ixp4xx);
+	clockevent_ixp4xx.min_delta_ns =
+		clockevent_delta2ns(0xf, &clockevent_ixp4xx);
+	setup_local_clockevent(&clockevent_ixp4xx, CPU_MASK_NONE);
+
+	return 0;
+}
+device_initcall(ixp4xx_clockevent_init);
+#endif

Re: [PATCH] 2.6.17-rt add clockevent to ixp4xx

[Kevin Hilman]

On Fri, 2006-07-14 at 12:36 +0200, Milan Svoboda wrote:

> I did patch against -hrt-dyntick (see lkml, this thread) wich is almost 
> the same
> as this one against -rt (for ixp4xx part only) and I found that when timer 
> is
> loaded with IXP4XX_OST_ONE_SHOT the latency time suddenly drops to ~30usec instead
> of ~2000usec! I'd like know what's the reason for this...

You should implement the set_mode method as well and set the
IXP4XX_OST_ONE_SHOT when the clockevent layer mode == CLOCK_EVT_ONESHOT.

Kevin

Re: [PATCH] 2.6.17-rt add clockevent to ixp4xx

[Milan Svoboda]

Kevin,

> On Thu, 2006-07-13 at 10:53 +0000, Milan Svoboda wrote:
> 
> > there are patches that enable clock event on ixp4xx platform. This 
should
> > enable high resolution timers... Option for hrtimers in menuconfig is
> > also enabled.
> 
> Milan,
> 
> I've also done a clockevent driver for ixp4xx and it looks pretty much
> like yours.  I've been waiting to submit as Thomas has recently reworked
> the clockevent layer a bit in his -hrt-dyntick patchset.
> 
> Here are a couple comments on your patchset
> 
> - since you've registered the clockevent with CAP_TICK, both the
> arch interrupt handler and the clockevent handler are handling the tick
> and calling do_timer().  While I don't think this will negatively affect
> timekeeping, it's unncessary overhead.

Yeah, I had a headache from this mistake, I found it a few minutes
after sendig mail ;-)

> - why the addition of clockevent_hz2mult()? since shift is 32, you
> could use existing div_sc32()

I didn't know about div_sc32... Simply, I have no problem with using
div_sc32 now when I know that is exists ;-)

> The attached patch is a combination of my patch and yours and addresses
> my comments above.  I simply removed the CLOCK_CAP_TICK and removed your
> clockevent_hz2mult() and used div_sc32().
> 

Good.

> Also, below are a few runs of the nanosleep_jitter test that comes with
> the sourceforge HRT test suite.  Something strange is that with the
> nanosleep_jitter test, I only see max sleeps of ~300-400 usec but with
> your test I see max sleeps up to 1.3 msec.
> 

Maybe my test program is not as good as nanosleep_jitter :-)

I did patch against -hrt-dyntick (see lkml, this thread) wich is almost 
the same
as this one against -rt (for ixp4xx part only) and I found that when timer 
is
loaded with IXP4XX_OST_ONE_SHOT the latency time suddenly drops to ~30usec instead
of ~2000usec! I'd like know what's the reason for this...

Best regards,
Milan

Re: [PATCH] 2.6.17-rt add clockevent to ixp4xx

[Milan Svoboda]

[-- Attachment #1: Type: text/plain, Size: 2519 bytes --]

> On Thu, 2006-07-13 at 07:41 -0700, Daniel Walker wrote:
> > On Thu, 2006-07-13 at 10:53 +0000, Milan Svoboda wrote:
> > > Hello,
> > > 
> > > there are patches that enable clock event on ixp4xx platform. This 
should
> > > enable high resolution timers... Option for hrtimers in menuconfig 
is 
> > > also enabled.
> > > 
> > > I tested it on nanosleep test program (included in attachments) and 
obtained
> > > this results:
> > > 
> > > requested: 899000 us, got: 899159 us, diff: -159 us
> > > requested: 897000 us, got: 897209 us, diff: -209 us
> > > requested: 895000 us, got: 899803 us, diff: -4803 us
> > > requested: 893000 us, got: 899425 us, diff: -6425 us
> > > requested: 891000 us, got: 899806 us, diff: -8806 us
> > > requested: 889000 us, got: 890142 us, diff: -1142 us
> > > requested: 887000 us, got: 889873 us, diff: -2873 us
> > > requested: 885000 us, got: 888096 us, diff: -3096 us
> > 
> > I'd turn off some of the debugging options, and retest. For instance,
> > the pi-list debugging option will cause arbitrary latency, which you
> > seem to show in your results. Normally with PREEMPT_RT turned on you
> > would expect the timers to trigger within a constant amount of time 
from
> > when they are suppose to.
> 
> No, the time differences looks like the high res mode never gets
> switched on. its oszillating between 0 and 10ms, which is the usual
> behaviour for a non hrt kernel.
> 
> Also I would recommend to test without preempt-rt in the first place.
> Preempt-rt on ARM is not really well tested, so you dont fight two
> battles at once.

Ok ;-), I did what you told me and there is patch agains 
2.6.17-hrt-dyntick5
which enables clocksource and clockevent for ixp4xx. There were
some changes in common code to be able to compile it for arm, I'm
not sure If these changes are correct, can you please check this out?

I tested it with my nanosleep test program and got beautiful
results - differency between requested and real time of sleep
is stable around 30us.

Important thing is to use IXP4XX_OST_ONE_SHOT! Without this set, results
are as bad as I reported previously...

I'm trying to fix -rt to use this, but interface has been changed and I
don't know hot to switch hrtimers to use one-shots. It looks like it wants
to always use cyclic timers...

The bad thing is that I tested it also using timer_create with 
CLOCK_REALTIME
and the best what I got was 100 tick per sec... I'll try to find where is 
problem.

Signed-off-by: Milan Svoboda <msvoboda@ra.rockwell.com>
---


[-- Attachment #2: hrt_ixp4xx.patch --]
[-- Type: application/octet-stream, Size: 7030 bytes --]

diff -uprN -X hrt_orig/Documentation/dontdiff hrt_orig/arch/arm/Kconfig hrt/arch/arm/Kconfig
--- hrt_orig/arch/arm/Kconfig	2006-06-27 13:50:30.000000000 +0000
+++ hrt/arch/arm/Kconfig	2006-07-11 14:45:05.000000000 +0000
@@ -385,6 +385,12 @@ endmenu
 
 menu "Kernel Features"
 
+config GENERIC_TIME
+	bool
+	default y
+
+source "kernel/time/Kconfig"
+
 config SMP
 	bool "Symmetric Multi-Processing (EXPERIMENTAL)"
 	depends on EXPERIMENTAL && REALVIEW_MPCORE
diff -uprN -X hrt_orig/Documentation/dontdiff hrt_orig/arch/arm/mach-ixp4xx/common.c hrt/arch/arm/mach-ixp4xx/common.c
--- hrt_orig/arch/arm/mach-ixp4xx/common.c	2006-06-27 13:50:30.000000000 +0000
+++ hrt/arch/arm/mach-ixp4xx/common.c	2006-07-14 11:53:23.000000000 +0000
@@ -27,6 +27,8 @@
 #include <linux/bitops.h>
 #include <linux/time.h>
 #include <linux/timex.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
 
 #include <asm/hardware.h>
 #include <asm/uaccess.h>
@@ -254,25 +256,38 @@ void __init ixp4xx_init_irq(void)
 
 static unsigned volatile last_jiffy_time;
 
-#define CLOCK_TICKS_PER_USEC	((CLOCK_TICK_RATE + USEC_PER_SEC/2) / USEC_PER_SEC)
+#ifdef CONFIG_HIGH_RES_TIMERS
 
-/* IRQs are disabled before entering here from do_gettimeofday() */
-static unsigned long ixp4xx_gettimeoffset(void)
+static void ixp4xx_set_mode(int mode, struct clock_event *evt)
 {
-	u32 elapsed;
-
-	elapsed = *IXP4XX_OSTS - last_jiffy_time;
+}
 
-	return elapsed / CLOCK_TICKS_PER_USEC;
+static void ixp4xx_set_next_event(unsigned long delta, struct clock_event *evt)
+{
+	*IXP4XX_OSRT1 = (delta & ~IXP4XX_OST_RELOAD_MASK) | IXP4XX_OST_ENABLE |
+		IXP4XX_OST_ONE_SHOT;
 }
 
+static struct clock_event clockevent_ixp4xx = {
+	.name		= "OSTS clock event interface",
+	.capabilities	= CLOCK_CAP_NEXTEVT,
+	.shift		= 32,
+	.set_mode	= ixp4xx_set_mode,
+	.set_next_event	= ixp4xx_set_next_event,
+};
+#endif
+
 static irqreturn_t ixp4xx_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 {
-	write_seqlock(&xtime_lock);
-
 	/* Clear Pending Interrupt by writing '1' to it */
 	*IXP4XX_OSST = IXP4XX_OSST_TIMER_1_PEND;
 
+#ifdef CONFIG_HIGH_RES_TIMERS
+	if (clockevent_ixp4xx.event_handler)
+		clockevent_ixp4xx.event_handler(regs);
+#endif
+	write_seqlock(&xtime_lock);
+
 	/*
 	 * Catch up with the real idea of time
 	 */
@@ -300,8 +315,6 @@ static void __init ixp4xx_timer_init(voi
 	/* Setup the Timer counter value */
 	*IXP4XX_OSRT1 = (LATCH & ~IXP4XX_OST_RELOAD_MASK) | IXP4XX_OST_ENABLE;
 
-	/* Reset time-stamp counter */
-	*IXP4XX_OSTS = 0;
 	last_jiffy_time = 0;
 
 	/* Connect the interrupt handler and enable the interrupt */
@@ -310,7 +323,6 @@ static void __init ixp4xx_timer_init(voi
 
 struct sys_timer ixp4xx_timer = {
 	.init		= ixp4xx_timer_init,
-	.offset		= ixp4xx_gettimeoffset,
 };
 
 static struct resource ixp46x_i2c_resources[] = {
@@ -366,3 +378,46 @@ void __init ixp4xx_sys_init(void)
 			ixp4xx_exp_bus_size >> 20);
 }
 
+cycle_t ixp4xx_get_cycles(void)
+{
+	return *IXP4XX_OSTS;
+}
+
+static struct clocksource clocksource_ixp4xx = {
+	.name 		= "OSTS",
+	.rating		= 200,
+	.read		= ixp4xx_get_cycles,
+	.mask		= 0xFFFFFFFF,
+	.shift 		= 20,
+	.is_continuous 	= 1,
+};
+
+static int __init ixp4xx_clocksource_init(void)
+{
+	/* Reset time-stamp counter */
+	*IXP4XX_OSTS = 0;
+
+	clocksource_ixp4xx.mult =
+		clocksource_khz2mult(66660, clocksource_ixp4xx.shift);
+	clocksource_register(&clocksource_ixp4xx);
+
+	return 0;
+}
+device_initcall(ixp4xx_clocksource_init);
+
+#ifdef CONFIG_HIGH_RES_TIMERS
+static int __init ixp4xx_clockevent_init(void)
+{
+	clockevent_ixp4xx.mult =
+		div_sc(FREQ, NSEC_PER_SEC, clockevent_ixp4xx.shift);
+	clockevent_ixp4xx.max_delta_ns =
+		clockevent_delta2ns(0xfffffffe, &clockevent_ixp4xx);
+	clockevent_ixp4xx.min_delta_ns =
+		clockevent_delta2ns(0xf, &clockevent_ixp4xx);
+	register_local_clockevent(&clockevent_ixp4xx);
+
+	return 0;
+}
+device_initcall(ixp4xx_clockevent_init);
+#endif
+
diff -uprN -X hrt_orig/Documentation/dontdiff hrt_orig/arch/arm/mach-ixp4xx/common-pci.c hrt/arch/arm/mach-ixp4xx/common-pci.c
--- hrt_orig/arch/arm/mach-ixp4xx/common-pci.c	2006-06-28 10:06:33.000000000 +0000
+++ hrt/arch/arm/mach-ixp4xx/common-pci.c	2006-07-11 11:08:43.000000000 +0000
@@ -532,6 +532,8 @@ pci_set_consistent_dma_mask(struct pci_d
 	return -EIO;
 }
 
+EXPORT_SYMBOL(pci_set_dma_mask);
+EXPORT_SYMBOL(pci_set_consistent_dma_mask);
 EXPORT_SYMBOL(ixp4xx_pci_read);
 EXPORT_SYMBOL(ixp4xx_pci_write);
 
diff -uprN -X hrt_orig/Documentation/dontdiff hrt_orig/include/asm-arm/hw_irq.h hrt/include/asm-arm/hw_irq.h
--- hrt_orig/include/asm-arm/hw_irq.h	1970-01-01 00:00:00.000000000 +0000
+++ hrt/include/asm-arm/hw_irq.h	2006-07-11 15:16:14.000000000 +0000
@@ -0,0 +1,9 @@
+/*
+ * Nothing to see here yet
+ */
+#ifndef _ARCH_ARM_HW_IRQ_H
+#define _ARCH_ARM_HW_IRQ_H
+
+#include <asm/mach/irq.h>
+
+#endif
diff -uprN -X hrt_orig/Documentation/dontdiff hrt_orig/include/linux/irq.h hrt/include/linux/irq.h
--- hrt_orig/include/linux/irq.h	2006-06-27 13:50:42.000000000 +0000
+++ hrt/include/linux/irq.h	2006-07-11 15:20:20.000000000 +0000
@@ -68,28 +68,29 @@ typedef struct hw_interrupt_type  hw_irq
  *
  * Pad this out to 32 bytes for cache and indexing reasons.
  */
-typedef struct irq_desc {
-	hw_irq_controller *handler;
-	void *handler_data;
-	struct irqaction *action;	/* IRQ action list */
-	unsigned int status;		/* IRQ status */
-	unsigned int depth;		/* nested irq disables */
-	unsigned int irq_count;		/* For detecting broken interrupts */
-	unsigned int irqs_unhandled;
-	spinlock_t lock;
-#if defined (CONFIG_GENERIC_PENDING_IRQ) || defined (CONFIG_IRQBALANCE)
-	unsigned int move_irq;		/* Flag need to re-target intr dest*/
-#endif
-} ____cacheline_aligned irq_desc_t;
 
-extern irq_desc_t irq_desc [NR_IRQS];
+//typedef struct irq_desc {
+//	hw_irq_controller *handler;
+//	void *handler_data;
+//	struct irqaction *action;	/* IRQ action list */
+//	unsigned int status;		/* IRQ status */
+//	unsigned int depth;		/* nested irq disables */
+//	unsigned int irq_count;		/* For detecting broken interrupts */
+//	unsigned int irqs_unhandled;
+//	spinlock_t lock;
+//#if defined (CONFIG_GENERIC_PENDING_IRQ) || defined (CONFIG_IRQBALANCE)
+//	unsigned int move_irq;		/* Flag need to re-target intr dest*/
+//#endif
+//} ____cacheline_aligned irq_desc_t;
+
+//extern irq_desc_t irq_desc [NR_IRQS];
 
 /* Return a pointer to the irq descriptor for IRQ.  */
-static inline irq_desc_t *
-irq_descp (int irq)
-{
-	return irq_desc + irq;
-}
+//static inline irq_desc_t *
+//irq_descp (int irq)
+//{
+//	return irq_desc + irq;
+//}
 
 #include <asm/hw_irq.h> /* the arch dependent stuff */
 
diff -uprN -X hrt_orig/Documentation/dontdiff hrt_orig/kernel/hrtimer.c hrt/kernel/hrtimer.c
--- hrt_orig/kernel/hrtimer.c	2006-07-14 11:44:08.000000000 +0000
+++ hrt/kernel/hrtimer.c	2006-07-11 15:14:04.000000000 +0000
@@ -40,6 +40,7 @@
 #include <linux/interrupt.h>
 #include <linux/clockchips.h>
 #include <linux/seq_file.h>
+#include <linux/profile.h>
 
 #include <asm/uaccess.h>
 

Re: [PATCH] 2.6.17-rt add clockevent to ixp4xx

[Milan Svoboda]

> > there are patches that enable clock event on ixp4xx platform. This 
should
> > enable high resolution timers... Option for hrtimers in menuconfig is 
> > also enabled.
> > 
> > I tested it on nanosleep test program (included in attachments) and 
obtained
> > this results:
> > 
> > requested: 899000 us, got: 899159 us, diff: -159 us
> > requested: 897000 us, got: 897209 us, diff: -209 us
> > requested: 895000 us, got: 899803 us, diff: -4803 us
> > requested: 893000 us, got: 899425 us, diff: -6425 us
> > requested: 891000 us, got: 899806 us, diff: -8806 us
> > requested: 889000 us, got: 890142 us, diff: -1142 us
> > requested: 887000 us, got: 889873 us, diff: -2873 us
> > requested: 885000 us, got: 888096 us, diff: -3096 us
> 
> I'd turn off some of the debugging options, and retest. For instance,
> the pi-list debugging option will cause arbitrary latency, which you
> seem to show in your results. Normally with PREEMPT_RT turned on you
> would expect the timers to trigger within a constant amount of time from
> when they are suppose to.
> 

Thanks, yes I've seen decrease of latency times with debugging turned off.

Milan