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authorChristian Ehrhardt <ehrhardt@linux.vnet.ibm.com>2008-07-14 08:00:01 -0400
committerAvi Kivity <avi@qumranet.com>2008-10-15 04:15:15 -0400
commit3f7f95c65ef6a89472a28da1b9436eaeee288831 (patch)
treed453af46dceb3fcce512a110573cd2e8e4341cfa /virt
parente32c8f2c0720fb21c6f4a5f6ccbebdadc878f707 (diff)
KVM: kvmtrace: replace get_cycles with ktime_get v3
The current kvmtrace code uses get_cycles() while the interpretation would be easier using using nanoseconds. ktime_get() should give at least the same accuracy as get_cycles on all architectures (even better on 32bit archs) but at a better unit (e.g. comparable between hosts with different frequencies. [avi: avoid ktime_t in public header] Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/kvm_trace.c19
1 files changed, 10 insertions, 9 deletions
diff --git a/virt/kvm/kvm_trace.c b/virt/kvm/kvm_trace.c
index 9acb78b3cc9f..41dcc845f78c 100644
--- a/virt/kvm/kvm_trace.c
+++ b/virt/kvm/kvm_trace.c
@@ -17,6 +17,7 @@
17#include <linux/module.h> 17#include <linux/module.h>
18#include <linux/relay.h> 18#include <linux/relay.h>
19#include <linux/debugfs.h> 19#include <linux/debugfs.h>
20#include <linux/ktime.h>
20 21
21#include <linux/kvm_host.h> 22#include <linux/kvm_host.h>
22 23
@@ -35,16 +36,16 @@ static struct kvm_trace *kvm_trace;
35struct kvm_trace_probe { 36struct kvm_trace_probe {
36 const char *name; 37 const char *name;
37 const char *format; 38 const char *format;
38 u32 cycle_in; 39 u32 timestamp_in;
39 marker_probe_func *probe_func; 40 marker_probe_func *probe_func;
40}; 41};
41 42
42static inline int calc_rec_size(int cycle, int extra) 43static inline int calc_rec_size(int timestamp, int extra)
43{ 44{
44 int rec_size = KVM_TRC_HEAD_SIZE; 45 int rec_size = KVM_TRC_HEAD_SIZE;
45 46
46 rec_size += extra; 47 rec_size += extra;
47 return cycle ? rec_size += KVM_TRC_CYCLE_SIZE : rec_size; 48 return timestamp ? rec_size += KVM_TRC_CYCLE_SIZE : rec_size;
48} 49}
49 50
50static void kvm_add_trace(void *probe_private, void *call_data, 51static void kvm_add_trace(void *probe_private, void *call_data,
@@ -69,20 +70,20 @@ static void kvm_add_trace(void *probe_private, void *call_data,
69 WARN_ON(!(extra <= KVM_TRC_EXTRA_MAX)); 70 WARN_ON(!(extra <= KVM_TRC_EXTRA_MAX));
70 extra = min_t(u32, extra, KVM_TRC_EXTRA_MAX); 71 extra = min_t(u32, extra, KVM_TRC_EXTRA_MAX);
71 72
72 rec.rec_val |= TRACE_REC_TCS(p->cycle_in) 73 rec.rec_val |= TRACE_REC_TCS(p->timestamp_in)
73 | TRACE_REC_NUM_DATA_ARGS(extra); 74 | TRACE_REC_NUM_DATA_ARGS(extra);
74 75
75 if (p->cycle_in) { 76 if (p->timestamp_in) {
76 rec.u.cycle.cycle_u64 = get_cycles(); 77 rec.u.timestamp.timestamp = ktime_to_ns(ktime_get());
77 78
78 for (i = 0; i < extra; i++) 79 for (i = 0; i < extra; i++)
79 rec.u.cycle.extra_u32[i] = va_arg(*args, u32); 80 rec.u.timestamp.extra_u32[i] = va_arg(*args, u32);
80 } else { 81 } else {
81 for (i = 0; i < extra; i++) 82 for (i = 0; i < extra; i++)
82 rec.u.nocycle.extra_u32[i] = va_arg(*args, u32); 83 rec.u.notimestamp.extra_u32[i] = va_arg(*args, u32);
83 } 84 }
84 85
85 size = calc_rec_size(p->cycle_in, extra * sizeof(u32)); 86 size = calc_rec_size(p->timestamp_in, extra * sizeof(u32));
86 relay_write(kt->rchan, &rec, size); 87 relay_write(kt->rchan, &rec, size);
87} 88}
88 89