Sekhar, My patch also initialized the read in the structure with read function which caused the crash. I think the reason for the dummy is to allow early call of sched_clock(). I have tested your patch and it seems to work fine so far (2 hours of test). Could you push this to upstream?
[ 6913.964051] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 6924.057637] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 6934.154051] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 6944.244104] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 6954.334119] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 INIT: Id "1" respawning too fast: disabled for 5 minutes [ 7265.037501] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 7275.134251] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 7285.224238] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 7295.314279] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 7305.404428] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 7315.494298] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 7325.588130] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 7335.684288] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 7345.774308] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 7355.864308] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 INIT: Id "1" respawning too fast: disabled for 5 minutes [ 7667.566695] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 7677.664666] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 7687.754515] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 7697.844583] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 7707.934504] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 7718.024714] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 7728.118240] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 7738.214555] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 7748.304595] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 [ 7758.394574] jprobe: clone_flags = 0x1200011, stack_size = 0x0, regs = 0xc7825fb0 INIT: Id "1" respawning too fast: disabled for 5 minutes Murali Karicheri Software Design Engineer email: m-kariche...@ti.com Phone: (301) 407 9583 >> -----Original Message----- >> From: davinci-linux-open-source-boun...@linux.davincidsp.com [mailto:davinci- >> linux-open-source-boun...@linux.davincidsp.com] On Behalf Of Karicheri, >> Muralidharan >> Sent: Tuesday, December 20, 2011 10:15 AM >> To: Nori, Sekhar >> Cc: davinci-linux-open-source@linux.davincidsp.com >> Subject: RE: Log time stamp wraps around to 25 >> >> Sekhar, >> >> I had implemented the same fix yesterday after discussion with Russell in the >> ARM mailing list. I got a crash in the sched_init() as given below. I am not >> sure why this is not happening on your platform. I haven't root caused the >> reason for this crash, but from Russell's email, it seems timer is to be >> initialized using early_init() of machine callback so that sched_init() will >> be able to call sched_clock early. I will debug the root cause of the crash, >> but what you think on moving timer initialization to early_init() machine >> callback? >> >> Murali >> >> [ 0.000000] Memory: 128MB = 128MB total >> [ 0.000000] Memory: 126552k/126552k available, 4520k reserved, 0K highmem >> [ 0.000000] Virtual kernel memory layout: >> [ 0.000000] vector : 0xffff0000 - 0xffff1000 ( 4 kB) >> [ 0.000000] fixmap : 0xfff00000 - 0xfffe0000 ( 896 kB) >> [ 0.000000] DMA : 0xff000000 - 0xffe00000 ( 14 MB) >> [ 0.000000] vmalloc : 0xc8800000 - 0xfe600000 ( 862 MB) >> [ 0.000000] lowmem : 0xc0000000 - 0xc8000000 ( 128 MB) >> [ 0.000000] modules : 0xbf000000 - 0xc0000000 ( 16 MB) >> [ 0.000000] .text : 0xc0008000 - 0xc02edf7c (2968 kB) >> [ 0.000000] .init : 0xc02ee000 - 0xc030a000 ( 112 kB) >> [ 0.000000] .data : 0xc030a000 - 0xc032f600 ( 150 kB) >> [ 0.000000] .bss : 0xc032f624 - 0xc03470d8 ( 95 kB) >> [ 0.000000] SLUB: Genslabs=11, HWalign=64, Order=0-3, MinObjects=0, >> CPUs=1, >> Nodes=1 >> [ 0.000000] Unable to handle kernel NULL pointer dereference at virtual >> address 00000000 >> [ 0.000000] pgd = c0004000 >> [ 0.000000] [00000000] *pgd=00000000 >> [ 0.000000] Internal error: Oops: 5 [#1] PREEMPT >> [ 0.000000] Modules linked in: >> [ 0.000000] CPU: 0 Not tainted (3.1.0-00032-g5dc3d4f-dirty #4) >> [ 0.000000] PC is at sched_clock+0x1c/0x64 >> [ 0.000000] LR is at 0x0 >> [ 0.000000] pc : [<c001e034>] lr : [<00000000>] psr: 400001d3 >> [ 0.000000] sp : c030bf90 ip : 00000000 fp : c030bfac >> [ 0.000000] r10: c0313030 r9 : c0311bf0 r8 : c032fcc0 >> [ 0.000000] r7 : 00000000 r6 : 389fd980 r5 : c030dd48 r4 : 400001d3 >> [ 0.000000] r3 : 00000000 r2 : c032f910 r1 : 00000000 r0 : c030dd48 >> [ 0.000000] Flags: nZcv IRQs off FIQs off Mode SVC_32 ISA ARM Segment >> kernel >> [ 0.000000] Control: 10c5287b Table: 80004019 DAC: 00000015 >> [ 0.000000] Process swapper (pid: 0, stack limit = 0xc030a2e8) >> [ 0.000000] Stack: (0xc030bf90 to 0xc030c000) >> [ 0.000000] bf80: 400001d3 c030dd48 >> 389fd980 c030385c >> [ 0.000000] bfa0: c030a000 00000000 c030bfd4 c02f49fc c030c160 c032f640 >> c030515c c0305158 >> [ 0.000000] bfc0: c030ed84 80004059 413fc082 00000000 00000000 c02ee650 >> c02ee2c0 00000000 >> [ 0.000000] bfe0: 00000000 c030515c 00000000 10c52c79 c030c040 8000803c >> 00000000 00000000 >> [ 0.000000] [<c001e034>] (sched_clock+0x1c/0x64) from [<c030385c>] >> (init_idle+0x3c/0xa0) >> [ 0.000000] [<c030385c>] (init_idle+0x3c/0xa0) from [<c02f49fc>] >> (sched_init+0x190/0x1ec) >> [ 0.000000] [<c02f49fc>] (sched_init+0x190/0x1ec) from [<c02ee650>] >> (start_kernel+0x150/0x2fc) >> [ 0.000000] [<c02ee650>] (start_kernel+0x150/0x2fc) from [<8000803c>] >> (0x8000803c) >> [ 0.000000] Code: e5931068 e5933064 e592e014 e592c010 (e7932001) >> [ 0.000000] ---[ end trace 1b75b31a2719ed1c ]--- >> [ 0.000000] Kernel panic - not syncing: Attempted to kill the idle task! >> [ 0.000000] [<c0018084>] (unwind_backtrace+0x0/0xec) from [<c021afdc>] >> (panic+0x6c/0x1a4) >> [ 0.000000] [<c021afdc>] (panic+0x6c/0x1a4) from [<c002b05c>] >> (do_exit+0x9c/0x6a0) >> [ 0.000000] [<c002b05c>] (do_exit+0x9c/0x6a0) from [<c001656c>] >> (die+0x1b8/0x1e0) >> [ 0.000000] [<c001656c>] (die+0x1b8/0x1e0) from [<c001b4e4>] >> (__do_kernel_fault+0x64/0x84) >> [ 0.000000] [<c001b4e4>] (__do_kernel_fault+0x64/0x84) from [<c021edcc>] >> (do_page_fault+0x2f0/0x314) >> [ 0.000000] [<c021edcc>] (do_page_fault+0x2f0/0x314) from [<c00084cc>] >> (do_DataAbort+0x34/0x94) >> [ 0.000000] [<c00084cc>] (do_DataAbort+0x34/0x94) from [<c021d558>] >> (__dabt_svc+0x38/0x60) >> [ 0.000000] Exception stack(0xc030bf48 to 0xc030bf90) >> [ 0.000000] bf40: c030dd48 00000000 c032f910 00000000 >> 400001d3 c030dd48 >> [ 0.000000] bf60: 389fd980 00000000 c032fcc0 c0311bf0 c0313030 c030bfac >> 00000000 c030bf90 >> [ 0.000000] bf80: 00000000 c001e034 400001d3 ffffffff >> [ 0.000000] [<c021d558>] (__dabt_svc+0x38/0x60) from [<c001e034>] >> (sched_clock+0x1c/0x64) >> [ 0.000000] [<c001e034>] (sched_clock+0x1c/0x64) from [<c030385c>] >> (init_idle+0x3c/0xa0) >> [ 0.000000] [<c030385c>] (init_idle+0x3c/0xa0) from [<c02f49fc>] >> (sched_init+0x190/0x1ec) >> [ 0.000000] [<c02f49fc>] (sched_init+0x190/0x1ec) from [<c02ee650>] >> (start_kernel+0x150/0x2fc) >> [ 0.000000] [<c02ee650>] (start_kernel+0x150/0x2fc) from [<8000803c>] >> (0x8000803c) >> Uncompressing Linux... done, booting the kernel. >> [ 0.000000] Linux version 3.1.0-00032-g5dc3d4f (murali@murali-laptop) (gcc >> version 4.3.3 (Sourcery G+ >> + Lite 2009q1-203) ) #6 PREEMPT Mon Dec 19 14:57:22 EST 2011 >> [ 0.000000] CPU: ARMv7 Processor [413fc082] revision 2 (ARMv7), >> cr=10c52c7b >> [ 0.000000] CPU: VIPT nonaliasing data cache, VIPT aliasing instruction >> cache >> >> >> Murali Karicheri >> Software Design Engineer >> email: m-kariche...@ti.com >> Phone: (301) 407 9583 >> >> >> >> -----Original Message----- >> >> From: Nori, Sekhar >> >> Sent: Monday, December 19, 2011 2:15 PM >> >> To: Karicheri, Muralidharan >> >> Cc: davinci-linux-open-source@linux.davincidsp.com; Chemparathy, Cyril >> >> Subject: RE: Log time stamp wraps around to 25 >> >> >> >> Hi Murali, >> >> >> >> On Fri, Dec 16, 2011 at 04:50:54, Karicheri, Muralidharan wrote: >> >> > Sekhar, >> >> > >> >> > I made some searches on the internet. The schedule_clock() must return a >> >> monotonous clock. One way to do this is to use cnt32_to_63() to convert >> >> the >> >> 32bit clock count value to a 64bit value. I have tried this and it seems >> >> to >> >> work. I am just curious as to how this is working on other davinci >> platforms? >> >> So any response from you will be helpful. >> >> > >> >> >> >> I checked this on AM18x and the clock there wraps around in about >> >> 180 seconds which is consistent with your observation given that >> >> we have a 24 MHz timer clock there. >> >> >> >> I did a quick implementation of sched_clock using the common sched_clock >> >> infrastructure in arch/arm/kernel/sched_clock.c and that seemed to have >> >> fixed the issue in some limited testing. Attached is the patch, can you >> >> give it a shot? >> >> >> >> Thanks, >> >> Sekhar >> >> >> >> ----8<----- >> >> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig >> >> index e084b7e..b5b630a 100644 >> >> --- a/arch/arm/Kconfig >> >> +++ b/arch/arm/Kconfig >> >> @@ -924,6 +924,7 @@ config ARCH_DAVINCI >> >> select ARCH_REQUIRE_GPIOLIB >> >> select ZONE_DMA >> >> select HAVE_IDE >> >> + select HAVE_SCHED_CLOCK >> >> select CLKDEV_LOOKUP >> >> select GENERIC_ALLOCATOR >> >> select GENERIC_IRQ_CHIP >> >> diff --git a/arch/arm/mach-davinci/time.c b/arch/arm/mach-davinci/time.c >> >> index e1969ce..8396ba8 100644 >> >> --- a/arch/arm/mach-davinci/time.c >> >> +++ b/arch/arm/mach-davinci/time.c >> >> @@ -22,6 +22,7 @@ >> >> #include <mach/hardware.h> >> >> #include <asm/mach/irq.h> >> >> #include <asm/mach/time.h> >> >> +#include <asm/sched_clock.h> >> >> #include <mach/cputype.h> >> >> #include <mach/time.h> >> >> #include "clock.h" >> >> @@ -292,12 +293,18 @@ static struct clocksource clocksource_davinci = { >> >> /* >> >> * Overwrite weak default sched_clock with something more precise >> >> */ >> >> +static DEFINE_CLOCK_DATA(cd); >> >> + >> >> unsigned long long notrace sched_clock(void) >> >> { >> >> - const cycle_t cyc = clocksource_davinci.read(&clocksource_davinci); >> >> + u32 cyc = clocksource_davinci.read(&clocksource_davinci); >> >> + return cyc_to_sched_clock(&cd, cyc, (u32)~0); >> >> +} >> >> >> >> - return clocksource_cyc2ns(cyc, clocksource_davinci.mult, >> >> - clocksource_davinci.shift); >> >> +static void notrace davinci_update_sched_clock(void) >> >> +{ >> >> + u32 cyc = clocksource_davinci.read(&clocksource_davinci); >> >> + update_sched_clock(&cd, cyc, (u32)~0); >> >> } >> >> >> >> /* >> >> @@ -399,6 +406,8 @@ static void __init davinci_timer_init(void) >> >> /* setup clocksource */ >> >> clocksource_davinci.read = read_cycles; >> >> clocksource_davinci.name = id_to_name[clocksource_id]; >> >> + init_sched_clock(&cd, davinci_update_sched_clock, 32, >> >> + davinci_clock_tick_rate); >> >> if (clocksource_register_hz(&clocksource_davinci, >> >> davinci_clock_tick_rate)) >> >> printk(err, clocksource_davinci.name); >> >> _______________________________________________ >> Davinci-linux-open-source mailing list >> Davinci-linux-open-source@linux.davincidsp.com >> http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source _______________________________________________ Davinci-linux-open-source mailing list Davinci-linux-open-source@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
