CLOCK_REALTIME_ALARM behaves exactly as CLOCK_REALTIME as far as the vDSO is concerned. The vDSO library can handle it automatically correctly. Only the basetime needs to be maintained during the tick.
Reuse the CLOCK_REALTIME basetime for CLOCK_REALTIME_ALARM and update the userspace hres clock mask to include CLOCK_REALTIME_ALARM. Signed-off-by: Thomas Weißschuh <[email protected]> --- include/vdso/datapage.h | 1 + kernel/time/vsyscall.c | 4 ++++ 2 files changed, 5 insertions(+) diff --git a/include/vdso/datapage.h b/include/vdso/datapage.h index 33297b5e2521..0aa28a484dcd 100644 --- a/include/vdso/datapage.h +++ b/include/vdso/datapage.h @@ -33,6 +33,7 @@ struct vdso_arch_data { #define VDSO_BASES (CLOCK_TAI + 1) #define VDSO_BASE_AUX 0 #define VDSO_HRES (BIT(CLOCK_REALTIME) | \ + BIT(CLOCK_REALTIME_ALARM) | \ BIT(CLOCK_MONOTONIC) | \ BIT(CLOCK_BOOTTIME) | \ BIT(CLOCK_BOOTTIME_ALARM) | \ diff --git a/kernel/time/vsyscall.c b/kernel/time/vsyscall.c index bb412ad1782f..0cf4eadf6996 100644 --- a/kernel/time/vsyscall.c +++ b/kernel/time/vsyscall.c @@ -69,6 +69,10 @@ static inline void update_vdso_time_data(struct vdso_time_data *vdata, struct ti vdso_ts = &vc[CS_HRES_COARSE].basetime[CLOCK_TAI]; vdso_ts->sec = tk->xtime_sec + (s64)tk->tai_offset; vdso_ts->nsec = tk->tkr_mono.xtime_nsec; + + /* CLOCK_REALTIME_ALARM, copy of CLOCK_REALTIME */ + vdso_ts = &vc[CS_HRES_COARSE].basetime[CLOCK_REALTIME_ALARM]; + *vdso_ts = vc[CS_HRES_COARSE].basetime[CLOCK_REALTIME]; } void update_vsyscall(struct timekeeper *tk) -- 2.55.0
