Re: [PATCH v6 03/19] kernel: Unify update_vsyscall implementation

Vincenzo Frascino
2019-06-14T12:14:33Z

Hi Thomas,

On 6/14/19 12:10 PM, Thomas Gleixner wrote:
> On Thu, 30 May 2019, Vincenzo Frascino wrote:
>> +
>> + if (__arch_use_vsyscall(vdata)) {
>> + vdata[CS_HRES_COARSE].cycle_last =
>> + tk->tkr_mono.cycle_last;
>> + vdata[CS_HRES_COARSE].mask =
>> + tk->tkr_mono.mask;
>> + vdata[CS_HRES_COARSE].mult =
>> + tk->tkr_mono.mult;
>
> These line breaks make it really hard to read. Can you fold in the patch
> below please?
>

Thanks for this. I will do it in v7.

> Thanks,
>
> tglx
> 8<-----------
> --- a/kernel/vdso/vsyscall.c
> +++ b/kernel/vdso/vsyscall.c
> @@ -11,6 +11,66 @@
> #include <vdso/helpers.h>
> #include <vdso/vsyscall.h>
>
> +static inline void udpate_vdata(struct vdso_data *vdata, struct timekeeper *tk)
> +{
> + struct vdso_timestamp *vdso_ts;
> + u64 nsec;
> +
> + vdata[CS_HRES_COARSE].cycle_last = tk->tkr_mono.cycle_last;
> + vdata[CS_HRES_COARSE].mask = tk->tkr_mono.mask;
> + vdata[CS_HRES_COARSE].mult = tk->tkr_mono.mult;
> + vdata[CS_HRES_COARSE].shift = tk->tkr_mono.shift;
> + vdata[CS_RAW].cycle_last = tk->tkr_raw.cycle_last;
> + vdata[CS_RAW].mask = tk->tkr_raw.mask;
> + vdata[CS_RAW].mult = tk->tkr_raw.mult;
> + vdata[CS_RAW].shift = tk->tkr_raw.shift;
> +
> + /* CLOCK_REALTIME */
> + vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_REALTIME];
> + vdso_ts->sec = tk->xtime_sec;
> + vdso_ts->nsec = tk->tkr_mono.xtime_nsec;
> +
> + /* CLOCK_MONOTONIC */
> + vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC];
> + vdso_ts->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
> +
> + nsec = tk->tkr_mono.xtime_nsec;
> + nsec += ((u64)tk->wall_to_monotonic.tv_nsec << tk->tkr_mono.shift);
> + while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
> + nsec -= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift);
> + vdso_ts->sec++;
> + }
> + vdso_ts->nsec = nsec;
> +
> + /* CLOCK_MONOTONIC_RAW */
> + vdso_ts = &vdata[CS_RAW].basetime[CLOCK_MONOTONIC_RAW];
> + vdso_ts->sec = tk->raw_sec;
> + vdso_ts->nsec = tk->tkr_raw.xtime_nsec;
> +
> + /* CLOCK_BOOTTIME */
> + vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_BOOTTIME];
> + vdso_ts->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
> + nsec = tk->tkr_mono.xtime_nsec;
> + nsec += ((u64)(tk->wall_to_monotonic.tv_nsec +
> + ktime_to_ns(tk->offs_boot)) << tk->tkr_mono.shift);
> + while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
> + nsec -= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift);
> + vdso_ts->sec++;
> + }
> + vdso_ts->nsec = nsec;
> +
> + /* CLOCK_TAI */
> + vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_TAI];
> + vdso_ts->sec = tk->xtime_sec + (s64)tk->tai_offset;
> + vdso_ts->nsec = tk->tkr_mono.xtime_nsec;
> +
> + /*
> + * Read without the seqlock held by clock_getres().
> + * Note: No need to have a second copy.
> + */
> + WRITE_ONCE(vdata[CS_HRES_COARSE].hrtimer_res, hrtimer_resolution);
> +}
> +
> void update_vsyscall(struct timekeeper *tk)
> {
> struct vdso_data *vdata = __arch_get_k_vdso_data();
> @@ -32,92 +92,23 @@ void update_vsyscall(struct timekeeper *
> vdata[CS_RAW].clock_mode = __arch_get_clock_mode(tk);
>
> /* CLOCK_REALTIME_COARSE */
> - vdso_ts =
> - &vdata[CS_HRES_COARSE].basetime[CLOCK_REALTIME_COARSE];
> - vdso_ts->sec = tk->xtime_sec;
> - vdso_ts->nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;
> + vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_REALTIME_COARSE];
> + vdso_ts->sec = tk->xtime_sec;
> + vdso_ts->nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;
> +
> /* CLOCK_MONOTONIC_COARSE */
> - vdso_ts =
> - &vdata[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC_COARSE];
> - vdso_ts->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
> - nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;
> - nsec = nsec + tk->wall_to_monotonic.tv_nsec;
> + vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC_COARSE];
> + vdso_ts->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
> + nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;
> + nsec = nsec + tk->wall_to_monotonic.tv_nsec;
> while (nsec >= NSEC_PER_SEC) {
> nsec = nsec - NSEC_PER_SEC;
> vdso_ts->sec++;
> }
> - vdso_ts->nsec = nsec;
> + vdso_ts->nsec = nsec;
>
> - if (__arch_use_vsyscall(vdata)) {
> - vdata[CS_HRES_COARSE].cycle_last =
> - tk->tkr_mono.cycle_last;
> - vdata[CS_HRES_COARSE].mask =
> - tk->tkr_mono.mask;
> - vdata[CS_HRES_COARSE].mult =
> - tk->tkr_mono.mult;
> - vdata[CS_HRES_COARSE].shift =
> - tk->tkr_mono.shift;
> - vdata[CS_RAW].cycle_last =
> - tk->tkr_raw.cycle_last;
> - vdata[CS_RAW].mask =
> - tk->tkr_raw.mask;
> - vdata[CS_RAW].mult =
> - tk->tkr_raw.mult;
> - vdata[CS_RAW].shift =
> - tk->tkr_raw.shift;
> - /* CLOCK_REALTIME */
> - vdso_ts =
> - &vdata[CS_HRES_COARSE].basetime[CLOCK_REALTIME];
> - vdso_ts->sec = tk->xtime_sec;
> - vdso_ts->nsec = tk->tkr_mono.xtime_nsec;
> - /* CLOCK_MONOTONIC */
> - vdso_ts =
> - &vdata[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC];
> - vdso_ts->sec = tk->xtime_sec +
> - tk->wall_to_monotonic.tv_sec;
> - nsec = tk->tkr_mono.xtime_nsec;
> - nsec = nsec +
> - ((u64)tk->wall_to_monotonic.tv_nsec <<
> - tk->tkr_mono.shift);
> - while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
> - nsec = nsec -
> - (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift);
> - vdso_ts->sec++;
> - }
> - vdso_ts->nsec = nsec;
> - /* CLOCK_MONOTONIC_RAW */
> - vdso_ts =
> - &vdata[CS_RAW].basetime[CLOCK_MONOTONIC_RAW];
> - vdso_ts->sec = tk->raw_sec;
> - vdso_ts->nsec = tk->tkr_raw.xtime_nsec;
> - /* CLOCK_BOOTTIME */
> - vdso_ts =
> - &vdata[CS_HRES_COARSE].basetime[CLOCK_BOOTTIME];
> - vdso_ts->sec = tk->xtime_sec +
> - tk->wall_to_monotonic.tv_sec;
> - nsec = tk->tkr_mono.xtime_nsec;
> - nsec = nsec +
> - ((u64)(tk->wall_to_monotonic.tv_nsec +
> - ktime_to_ns(tk->offs_boot)) <<
> - tk->tkr_mono.shift);
> - while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
> - nsec = nsec -
> - (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift);
> - vdso_ts->sec++;
> - }
> - vdso_ts->nsec = nsec;
> - /* CLOCK_TAI */
> - vdso_ts =
> - &vdata[CS_HRES_COARSE].basetime[CLOCK_TAI];
> - vdso_ts->sec = tk->xtime_sec + (s64)tk->tai_offset;
> - vdso_ts->nsec = tk->tkr_mono.xtime_nsec;
> -
> - /*
> - * Read without the seqlock held by clock_getres().
> - * Note: No need to have a second copy.
> - */
> - WRITE_ONCE(vdata[CS_HRES_COARSE].hrtimer_res, hrtimer_resolution);
> - }
> + if (__arch_use_vsyscall(vdata))
> + update_vdata(vdata, tk);
>
> __arch_update_vsyscall(vdata, tk);
>
>

--
Regards,
Vincenzo