[PATCH v3] x86/vdso: Handle clock_gettime(CLOCK_TAI) in vDSO
Process clock_gettime(CLOCK_TAI) in vDSO.
This makes the call about as fast as CLOCK_REALTIME and CLOCK_MONOTONIC:
nanoseconds
before after clockname
- -
23387 CLOCK_TAI
9693 CLOCK_REALTIME
8887 CLOCK_MONOTONIC
Signed-off-by: Matt Rickard
---
arch/x86/entry/vdso/vclock_gettime.c| 25 +
arch/x86/entry/vsyscall/vsyscall_gtod.c | 2 ++
arch/x86/include/asm/vgtod.h| 1 +
3 files changed, 28 insertions(+)
diff --git a/arch/x86/entry/vdso/vclock_gettime.c
b/arch/x86/entry/vdso/vclock_gettime.c
index f19856d95c60..91ed1bb2a3bb 100644
--- a/arch/x86/entry/vdso/vclock_gettime.c
+++ b/arch/x86/entry/vdso/vclock_gettime.c
@@ -246,6 +246,27 @@ notrace static int __always_inline do_monotonic(struct
timespec *ts)
return mode;
}
+notrace static int __always_inline do_tai(struct timespec *ts)
+{
+ unsigned long seq;
+ u64 ns;
+ int mode;
+
+ do {
+ seq = gtod_read_begin(gtod);
+ mode = gtod->vclock_mode;
+ ts->tv_sec = gtod->tai_time_sec;
+ ns = gtod->wall_time_snsec;
+ ns += vgetsns(&mode);
+ ns >>= gtod->shift;
+ } while (unlikely(gtod_read_retry(gtod, seq)));
+
+ ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
+ ts->tv_nsec = ns;
+
+ return mode;
+}
+
notrace static void do_realtime_coarse(struct timespec *ts)
{
unsigned long seq;
@@ -277,6 +298,10 @@ notrace int __vdso_clock_gettime(clockid_t clock, struct
timespec *ts)
if (do_monotonic(ts) == VCLOCK_NONE)
goto fallback;
break;
+ case CLOCK_TAI:
+ if (do_tai(ts) == VCLOCK_NONE)
+ goto fallback;
+ break;
case CLOCK_REALTIME_COARSE:
do_realtime_coarse(ts);
break;
diff --git a/arch/x86/entry/vsyscall/vsyscall_gtod.c
b/arch/x86/entry/vsyscall/vsyscall_gtod.c
index e1216dd95c04..d61392fe17f6 100644
--- a/arch/x86/entry/vsyscall/vsyscall_gtod.c
+++ b/arch/x86/entry/vsyscall/vsyscall_gtod.c
@@ -53,6 +53,8 @@ void update_vsyscall(struct timekeeper *tk)
vdata->monotonic_time_snsec = tk->tkr_mono.xtime_nsec
+ ((u64)tk->wall_to_monotonic.tv_nsec
<< tk->tkr_mono.shift);
+ vdata->tai_time_sec = tk->xtime_sec
+ + tk->tai_offset;
while (vdata->monotonic_time_snsec >=
(((u64)NSEC_PER_SEC) <<
tk->tkr_mono.shift)) {
vdata->monotonic_time_snsec -=
diff --git a/arch/x86/include/asm/vgtod.h b/arch/x86/include/asm/vgtod.h
index fb856c9f0449..adc9f7b20b9c 100644
--- a/arch/x86/include/asm/vgtod.h
+++ b/arch/x86/include/asm/vgtod.h
@@ -32,6 +32,7 @@ struct vsyscall_gtod_data {
gtod_long_t wall_time_coarse_nsec;
gtod_long_t monotonic_time_coarse_sec;
gtod_long_t monotonic_time_coarse_nsec;
+ gtod_long_t tai_time_sec;
int tz_minuteswest;
int tz_dsttime;
[RESEND PATCH] x86/vdso: Handle clock_gettime(CLOCK_TAI) in vDSO
Process clock_gettime(CLOCK_TAI) in vDSO. This makes the call about as fast as
CLOCK_REALTIME instead of taking about four times as long.
Signed-off-by: Matt Rickard
---
arch/x86/entry/vdso/vclock_gettime.c| 25 +
arch/x86/entry/vsyscall/vsyscall_gtod.c | 2 ++
arch/x86/include/asm/vgtod.h| 1 +
3 files changed, 28 insertions(+)
diff --git a/arch/x86/entry/vdso/vclock_gettime.c
b/arch/x86/entry/vdso/vclock_gettime.c
index f19856d95c60..91ed1bb2a3bb 100644
--- a/arch/x86/entry/vdso/vclock_gettime.c
+++ b/arch/x86/entry/vdso/vclock_gettime.c
@@ -246,6 +246,27 @@ notrace static int __always_inline do_monotonic(struct
timespec *ts)
return mode;
}
+notrace static int __always_inline do_tai(struct timespec *ts)
+{
+ unsigned long seq;
+ u64 ns;
+ int mode;
+
+ do {
+ seq = gtod_read_begin(gtod);
+ mode = gtod->vclock_mode;
+ ts->tv_sec = gtod->tai_time_sec;
+ ns = gtod->wall_time_snsec;
+ ns += vgetsns(&mode);
+ ns >>= gtod->shift;
+ } while (unlikely(gtod_read_retry(gtod, seq)));
+
+ ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
+ ts->tv_nsec = ns;
+
+ return mode;
+}
+
notrace static void do_realtime_coarse(struct timespec *ts)
{
unsigned long seq;
@@ -277,6 +298,10 @@ notrace int __vdso_clock_gettime(clockid_t clock, struct
timespec *ts)
if (do_monotonic(ts) == VCLOCK_NONE)
goto fallback;
break;
+ case CLOCK_TAI:
+ if (do_tai(ts) == VCLOCK_NONE)
+ goto fallback;
+ break;
case CLOCK_REALTIME_COARSE:
do_realtime_coarse(ts);
break;
diff --git a/arch/x86/entry/vsyscall/vsyscall_gtod.c
b/arch/x86/entry/vsyscall/vsyscall_gtod.c
index e1216dd95c04..d61392fe17f6 100644
--- a/arch/x86/entry/vsyscall/vsyscall_gtod.c
+++ b/arch/x86/entry/vsyscall/vsyscall_gtod.c
@@ -53,6 +53,8 @@ void update_vsyscall(struct timekeeper *tk)
vdata->monotonic_time_snsec = tk->tkr_mono.xtime_nsec
+ ((u64)tk->wall_to_monotonic.tv_nsec
<< tk->tkr_mono.shift);
+ vdata->tai_time_sec = tk->xtime_sec
+ + tk->tai_offset;
while (vdata->monotonic_time_snsec >=
(((u64)NSEC_PER_SEC) <<
tk->tkr_mono.shift)) {
vdata->monotonic_time_snsec -=
diff --git a/arch/x86/include/asm/vgtod.h b/arch/x86/include/asm/vgtod.h
index fb856c9f0449..adc9f7b20b9c 100644
--- a/arch/x86/include/asm/vgtod.h
+++ b/arch/x86/include/asm/vgtod.h
@@ -32,6 +32,7 @@ struct vsyscall_gtod_data {
gtod_long_t wall_time_coarse_nsec;
gtod_long_t monotonic_time_coarse_sec;
gtod_long_t monotonic_time_coarse_nsec;
+ gtod_long_t tai_time_sec;
int tz_minuteswest;
int tz_dsttime;
[RESEND PATCH] x86/vdso: Handle clock_gettime(CLOCK_TAI) in vDSO
Process clock_gettime(CLOCK_TAI) in vDSO. This makes the call about as fast as CLOCK_REALTIME instead of taking about four times as long. Signed-off-by: Matt Rickard --- 0 files changed
