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authorTony Luck <tony.luck@intel.com>2006-02-07 15:25:57 -0800
committerTony Luck <tony.luck@intel.com>2006-02-07 15:25:57 -0800
commitd6e56a2a088935f3c1feee5ff5a06c67f2ec6002 (patch)
treeab9fd17a56f81a7662aab8f135be7ed0f3c707c5 /arch/ia64/kernel/time.c
parent9d78f43d1fd3e028bfd37510ce847d0896f71f78 (diff)
downloadblackbird-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.c27
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;
+}
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