Re: [PATCH 03/32] timens: Introduce CLOCK_MONOTONIC offsets
From: Thomas Gleixner <hidden>
Date: 2019-02-07 21:41:25
Also in:
lkml
On Wed, 6 Feb 2019, Dmitry Safonov wrote:
quoted hunk ↗ jump to hunk
#include "timekeeping.h" #include "posix-timers.h"@@ -1041,6 +1042,9 @@ SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock, error = kc->clock_get(which_clock, &kernel_tp); + if (!error && kc->clock_timens_adjust) + timens_clock_from_host(which_clock, &kernel_tp);
Why are you adding this conditional instead of sticking the offset magic into the affected ->clock_get() implementations? That spares you the switch() and the !offsets conditional.
+static void clock_timens_fixup(int clockid, struct timespec64 *val, bool to_ns)
+{
+ struct timens_offsets *ns_offsets = current->nsproxy->time_ns->offsets;
+ struct timespec64 *offsets = NULL;
+
+ if (!ns_offsets)
+ return;
+
+ if (val->tv_sec == 0 && val->tv_nsec == 0)
+ return;I have no idea why 0/0 is special.
+
+ switch (clockid) {
+ case CLOCK_MONOTONIC:
+ case CLOCK_MONOTONIC_RAW:
+ case CLOCK_MONOTONIC_COARSE:
+ offsets = &ns_offsets->monotonic_time_offset;
+ break;
+ }
+
+ if (!offsets)
+ return;
+
+ if (to_ns)
+ *val = timespec64_add(*val, *offsets);
+ else
+ *val = timespec64_sub(*val, *offsets);
+}
+
+void timens_clock_to_host(int clockid, struct timespec64 *val)
Does this really need to be an out of line call? If you stick this into the
clock_get() implementations then it boils down to:
static inline void timens_add_monotonic(struct timespec64 *ts)
{
struct timens_offsets *ns_offsets = current->nsproxy->time_ns->offsets;
if (ns_offsets)
*ts = timespec64_add(*ts, ns_offsets->monotonic_time_offset);
}
and
static int posix_ktime_get_ts(clockid_t which_clock, struct timespec64 *tp)
{
ktime_get_ts64(tp);
timens_add_monotonic(tp);
return 0;
}
Hmm?
Thanks,
tglx