6 files changed, 80 insertions, 10 deletions
diff --git a/pkg/sentry/time/BUILD b/pkg/sentry/time/BUILD
index 1f617ca8f..36d999c47 100644
--- a/pkg/sentry/time/BUILD
+++ b/pkg/sentry/time/BUILD
@@ -8,7 +8,7 @@ go_template_instance(
     out = "seqatomic_parameters_unsafe.go",
     package = "time",
     suffix = "Parameters",
-    template = "//pkg/sync:generic_seqatomic",
+    template = "//pkg/sync/seqatomic:generic_seqatomic",
     types = {
         "Value": "Parameters",
     },
@@ -25,6 +25,8 @@ go_library(
         "muldiv_arm64.s",
         "parameters.go",
         "sampler.go",
+        "sampler_amd64.go",
+        "sampler_arm64.go",
         "sampler_unsafe.go",
         "seqatomic_parameters_unsafe.go",
         "tsc_amd64.s",
@@ -32,6 +34,7 @@ go_library(
     ],
     visibility = ["//:sandbox"],
     deps = [
+        "//pkg/errors/linuxerr",
         "//pkg/gohacks",
         "//pkg/log",
         "//pkg/metric",
diff --git a/pkg/sentry/time/calibrated_clock.go b/pkg/sentry/time/calibrated_clock.go
index 39bf1e0de..eed74f6bd 100644
--- a/pkg/sentry/time/calibrated_clock.go
+++ b/pkg/sentry/time/calibrated_clock.go
@@ -19,10 +19,10 @@ package time
 import (
 	"time"
 
+	"gvisor.dev/gvisor/pkg/errors/linuxerr"
 	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/pkg/metric"
 	"gvisor.dev/gvisor/pkg/sync"
-	"gvisor.dev/gvisor/pkg/syserror"
 )
 
 // CalibratedClock implements a clock that tracks a reference clock.
@@ -259,6 +259,6 @@ func (c *CalibratedClocks) GetTime(id ClockID) (int64, error) {
 	case Realtime:
 		return c.realtime.GetTime()
 	default:
-		return 0, syserror.EINVAL
+		return 0, linuxerr.EINVAL
 	}
 }
diff --git a/pkg/sentry/time/sampler.go b/pkg/sentry/time/sampler.go
index 4ac9c4474..24a47f5d5 100644
--- a/pkg/sentry/time/sampler.go
+++ b/pkg/sentry/time/sampler.go
@@ -21,13 +21,6 @@ import (
 )
 
 const (
-	// defaultOverheadTSC is the default estimated syscall overhead in TSC cycles.
-	// It is further refined as syscalls are made.
-	defaultOverheadCycles = 1 * 1000
-
-	// maxOverheadCycles is the maximum allowed syscall overhead in TSC cycles.
-	maxOverheadCycles = 100 * defaultOverheadCycles
-
 	// maxSampleLoops is the maximum number of times to try to get a clock sample
 	// under the expected overhead.
 	maxSampleLoops = 5
diff --git a/pkg/sentry/time/sampler_amd64.go b/pkg/sentry/time/sampler_amd64.go
new file mode 100644
index 000000000..9f1b4b2fb
--- /dev/null
+++ b/pkg/sentry/time/sampler_amd64.go
@@ -0,0 +1,26 @@
+// Copyright 2018 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//+build amd64
+
+package time
+
+const (
+	// defaultOverheadTSC is the default estimated syscall overhead in TSC cycles.
+	// It is further refined as syscalls are made.
+	defaultOverheadCycles = 1 * 1000
+
+	// maxOverheadCycles is the maximum allowed syscall overhead in TSC cycles.
+	maxOverheadCycles = 100 * defaultOverheadCycles
+)
diff --git a/pkg/sentry/time/sampler_arm64.go b/pkg/sentry/time/sampler_arm64.go
new file mode 100644
index 000000000..4c8d33ae4
--- /dev/null
+++ b/pkg/sentry/time/sampler_arm64.go
@@ -0,0 +1,42 @@
+// Copyright 2018 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//+build arm64
+
+package time
+
+// getCNTFRQ get ARM counter-timer frequency
+func getCNTFRQ() TSCValue
+
+// getDefaultArchOverheadCycles get default OverheadCycles based on
+// ARM counter-timer frequency. Usually ARM counter-timer frequency
+// is range from 1-50Mhz which is much less than that on x86, so we
+// calibrate defaultOverheadCycles for ARM.
+func getDefaultArchOverheadCycles() TSCValue {
+	// estimated the clock frequency on x86 is 1Ghz.
+	// 1Ghz devided by counter-timer frequency of ARM to get
+	// frqRatio. defaultOverheadCycles of ARM equals to that on
+	// x86 devided by frqRatio
+	cntfrq := getCNTFRQ()
+	frqRatio := 1000000000 / cntfrq
+	overheadCycles := (1 * 1000) / frqRatio
+	return overheadCycles
+}
+
+// defaultOverheadTSC is the default estimated syscall overhead in TSC cycles.
+// It is further refined as syscalls are made.
+var defaultOverheadCycles = getDefaultArchOverheadCycles()
+
+// maxOverheadCycles is the maximum allowed syscall overhead in TSC cycles.
+var maxOverheadCycles = 100 * defaultOverheadCycles
diff --git a/pkg/sentry/time/tsc_arm64.s b/pkg/sentry/time/tsc_arm64.s
index da9fa4112..711349fa1 100644
--- a/pkg/sentry/time/tsc_arm64.s
+++ b/pkg/sentry/time/tsc_arm64.s
@@ -20,3 +20,9 @@ TEXT ·Rdtsc(SB),NOSPLIT,$0-8
 	WORD	$0xd53be040     //MRS	CNTVCT_EL0, R0
 	MOVD	R0, ret+0(FP)
 	RET
+
+TEXT ·getCNTFRQ(SB),NOSPLIT,$0-8
+	// Get the virtual counter frequency.
+	WORD	$0xd53be000     //MRS	CNTFRQ_EL0, R0
+	MOVD	R0, ret+0(FP)
+	RET