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author | Tony Luck <tony.luck@intel.com> | 2006-02-07 15:25:57 -0800 |
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committer | Tony Luck <tony.luck@intel.com> | 2006-02-07 15:25:57 -0800 |
commit | d6e56a2a088935f3c1feee5ff5a06c67f2ec6002 (patch) | |
tree | ab9fd17a56f81a7662aab8f135be7ed0f3c707c5 /arch/ia64/kernel/time.c | |
parent | 9d78f43d1fd3e028bfd37510ce847d0896f71f78 (diff) | |
download | blackbird-op-linux-d6e56a2a088935f3c1feee5ff5a06c67f2ec6002.tar.gz blackbird-op-linux-d6e56a2a088935f3c1feee5ff5a06c67f2ec6002.zip |
[IA64] Fix CONFIG_PRINTK_TIME
There were two problems with enabling the PRINTK_TIME config
option:
1) The first calls to printk() occur before per-cpu data virtual
address is pinned into the TLB, so sched_clock() can fault.
2) sched_clock() is based on ar.itc, which may not be synchronized
across cpus.
Ken Chen started this patch, Tony Luck tinkered with it, and Jes
Sorensen perfected it.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch/ia64/kernel/time.c')
-rw-r--r-- | arch/ia64/kernel/time.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c index 028a2b95936c..a094ec49ccfa 100644 --- a/arch/ia64/kernel/time.c +++ b/arch/ia64/kernel/time.c @@ -278,3 +278,30 @@ udelay (unsigned long usecs) } } EXPORT_SYMBOL(udelay); + +static unsigned long long ia64_itc_printk_clock(void) +{ + if (ia64_get_kr(IA64_KR_PER_CPU_DATA)) + return sched_clock(); + return 0; +} + +static unsigned long long ia64_default_printk_clock(void) +{ + return (unsigned long long)(jiffies_64 - INITIAL_JIFFIES) * + (1000000000/HZ); +} + +unsigned long long (*ia64_printk_clock)(void) = &ia64_default_printk_clock; + +unsigned long long printk_clock(void) +{ + return ia64_printk_clock(); +} + +void __init +ia64_setup_printk_clock(void) +{ + if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) + ia64_printk_clock = ia64_itc_printk_clock; +} |