Hi Mikulas,
On 14.06.2016 18:20, Mikulas Patocka wrote:
> There is another bug: when you enable CONFIG_DEBUG_TIMEKEEPING, parisc
> boot gets stuck with these messages.
Nice catch!
> (but it is not caused by the patch
> 54b668009076caddbede8fde513ca2c982590bfe, because this bug happens even in
> kernel 4.6).
Seems to be a generic upstream problem.
Would be nice to know if it happens on x86_64 as well.
I tried this patch (copy&pasted):
diff --git a/arch/parisc/kernel/time.c b/arch/parisc/kernel/time.c
index 31ec99a..85e7bb7 100644
--- a/arch/parisc/kernel/time.c
+++ b/arch/parisc/kernel/time.c
@@ -217,9 +217,16 @@ static struct clocksource clocksource_cr16 = {
.rating = 300,
.read = read_cr16,
.mask = CLOCKSOURCE_MASK(BITS_PER_LONG),
+ .mult = 1000,
+ .shift = 12,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
+struct clocksource * __init clocksource_default_clock(void)
+{
+ return &clocksource_cr16;
+}
+
int update_cr16_clocksource(void)
{
/* since the cr16 cycle counters are not synchronized across CPUs,
which gives:
[ 0.000000] clocksource: cr16: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 29863444473 ns
[ 0.000000] Console: colour dummy device 128x48
[ 0.012938] Calibrating delay loop... 63.07 BogoMIPS (lpj=315392)
[ 0.012938] pid_max: default: 32768 minimum: 301
[ 0.014235] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.014235] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.019359] Adjusting cr16 more than 11% (1000 vs -1967128576)
[ 0.019359] Brought up 1 CPUs
[ 0.020634] devtmpfs: initialized
[ 0.022716] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
[ 0.022716] NET: Registered protocol family 16
Still puzzled...
Helge
> Mikulas
>
> [ 0.000000] Memory: 7201556K/7337984K available (4096K kernel code, 1419K rwdata, 883K rodata, 176K init, 2296K bss, 136428K reserved, 0K cma-reserved)
> [ 0.000000] virtual kernel memory layout:
> [ 0.000000] vmalloc : 0x0000000000008000 - 0x000000003f000000 (1007 MB)
> [ 0.000000] memory : 0x0000000040000000 - 0x0000004140000000 (266240 MB)
> [ 0.000000] .init : 0x0000000040100000 - 0x000000004012c000 ( 176 kB)
> [ 0.000000] .data : 0x000000004052c000 - 0x000000004076bb60 (2302 kB)
> [ 0.000000] .text : 0x000000004012c000 - 0x000000004052c000 (4096 kB)
> [ 0.000000] SLUB: HWalign=16, Order=0-3, MinObjects=0, CPUs=4, Nodes=8
> [ 0.000000] Hierarchical RCU implementation.
> [ 0.000000] Build-time adjustment of leaf fanout to 64.
> [ 0.000000] NR_IRQS:80
> [ 0.000000] clocksource: cr16: mask: 0xffffffffffffffff max_cycles: 0x1cd42e4dffb, max_idle_ns: 881590591483 ns
> [ 0.133333] WARNING: timekeeping: Cycle offset (40) is larger than allowed by the 'jiffies' clock's max_cycles value (10): time overflow danger
> [ 0.133333] timekeeping: Your kernel is sick, but tries to cope by capping time updates
> [ 0.133333] Console: colour dummy device 160x64
> [ 0.303333] WARNING: timekeeping: Cycle offset (51) is larger than allowed by the 'jiffies' clock's max_cycles value (10): time overflow danger
> [ 0.303333] timekeeping: Your kernel is sick, but tries to cope by capping time updates
> [ 0.423333] WARNING: timekeeping: Cycle offset (36) is larger than allowed by the 'jiffies' clock's max_cycles value (10): time overflow danger
> [ 0.423333] timekeeping: Your kernel is sick, but tries to cope by capping time updates
> [ 0.483333] WARNING: timekeeping: Cycle offset (18) is larger than allowed by the 'jiffies' clock's max_cycles value (10): time overflow danger
> [ 0.483333] timekeeping: Your kernel is sick, but tries to cope by capping time updates
> [ 0.653333] WARNING: timekeeping: Cycle offset (51) is larger than allowed by the 'jiffies' clock's max_cycles value (10): time overflow danger
> [ 0.653333] timekeeping: Your kernel is sick, but tries to cope by capping time updates
> [ 0.769999] WARNING: timekeeping: Cycle offset (35) is larger than allowed by the 'jiffies' clock's max_cycles value (10): time overflow danger
> [ 0.769999] timekeeping: Your kernel is sick, but tries to cope by capping time updates
> [ 0.943333] WARNING: timekeeping: Cycle offset (52) is larger than allowed by the 'jiffies' clock's max_cycles value (10): time overflow danger
> [ 0.943333] timekeeping: Your kernel is sick, but tries to cope by capping time updates
>
>
> On Wed, 1 Jun 2016, Helge Deller wrote:
>
>> * Mikulas Patocka <mpatocka@xxxxxxxxxx>:
>>> Hi
>>>
>>> With the kernel 4.7-rc1, I get corrupted printk times when the machine
>>> boots. The kernel is compiled with "Show timing information on printks"
>>> (CONFIG_PRINTK_TIME) enabled. There are no other negative effects.
>>>
>>> Bisecting shows that it is caused by the patch
>>> 54b668009076caddbede8fde513ca2c982590bfe ("parisc: Add native
>>> high-resolution sched_clock() implementation").
>>>
>>> [ 0.000000] NR_IRQS:80
>>> [ 0.000000] clocksource: cr16: mask: 0xffffffffffffffff max_cycles: 0x1cd42e4dffb, max_idle_ns: 881590591483 ns
>>> [ 0.000000] Console: colour dummy device 160x64
>>> [ 90.122205] Calibrating delay loop... 1991.60 BogoMIPS (lpj=3317760)
>>> [ 90.224168] pid_max: default: 32768 minimum: 301
>>> ....
>>> [ 92.235878] 13. Crestone Peak Core RS-232 at 0xfffffff0f05e2000 [18] { 10, 0x0, 0x076, 0x000ad }
>>> [ 92.708000] Releasing cpu 1 now, hpa=fffffffffe781000
>>> [ 92.818803] FP[1] enabled: Rev 1 Model 20
>>> [ 2.917508] Releasing cpu 2 now, hpa=fffffffffe798000
>>> [ 0.196666] FP[2] enabled: Rev 1 Model 20
>>> [ 3.116794] Releasing cpu 3 now, hpa=fffffffffe799000
>>> [ 0.196666] FP[3] enabled: Rev 1 Model 20
>>> [ 3.296942] CPU(s): 4 out of 4 PA8900 (Shortfin) at 1000.000000 MHz online
>>> [ 3.447762] Setting cache flush threshold to 65536 kB
>>> [ 3.450548] Setting TLB flush threshold to 1020 kB
>>
>> Please try attached patch.
>>
>> It fixes the problem mostly for me, there is just one little glitch
>> left, which is that the lines "FP[x] enabled" will still print an
>> invalid time. I assume it's because when this text is printed, the
>> clock/interrupts for the just booted CPU aren't enabled yet.
>>
>> I'm not sure it's worth trying to fix that.
>> One could print out that info at a later time, or just disabled it.
>>
>> Helge
>>
>> [ 5.720014] Enabling PDC_PAT chassis codes support v0.05
>> [ 6.644542] Releasing cpu 1 now, hpa=fffffffffe781000
>> [ 0.196000] FP[1] enabled: Rev 1 Model 20
>> [ 7.088432] CPU(s): 2 out of 2 PA8800 (Mako) at 900.000000 MHz online
>>
>> -----------
>>
>> [PATCH] parisc: Fix printk time during boot
>>
>> Signed-off-by: Helge Deller <deller@xxxxxx>
>>
>> diff --git a/arch/parisc/kernel/time.c b/arch/parisc/kernel/time.c
>> index 58dd680..31ec99a 100644
>> --- a/arch/parisc/kernel/time.c
>> +++ b/arch/parisc/kernel/time.c
>> @@ -309,11 +309,6 @@ void __init time_init(void)
>> clocks_calc_mult_shift(&cyc2ns_mul, &cyc2ns_shift, current_cr16_khz,
>> NSEC_PER_MSEC, 0);
>>
>> -#if defined(CONFIG_HAVE_UNSTABLE_SCHED_CLOCK) && defined(CONFIG_64BIT)
>> - /* At bootup only one 64bit CPU is online and cr16 is "stable" */
>> - set_sched_clock_stable();
>> -#endif
>> -
>> start_cpu_itimer(); /* get CPU 0 started */
>>
>> /* register at clocksource framework */
>>
--
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