Messages in this thread | | | Date | Tue, 30 Jan 2018 09:48:41 +0000 | From | Daniel Thompson <> | Subject | Re: [PATCH v2] kdb: use ktime_get_mono_fast_ns() instead of ktime_get_ts() |
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On Mon, Jan 29, 2018 at 10:22:51AM +0800, Baolin Wang wrote: > The kdb code will print the monotonic time by ktime_get_ts(), but > the ktime_get_ts() will be protected by a sequence lock, that will > introduce one deadlock risk if the lock was already held in the > context from which we entered the debugger. > > Thus we can use the ktime_get_mono_fast_ns() to get the monotonic > time, which is NMI safe access to clock monotonic. Moreover we can > remove the 'struct timespec', which is not y2038 safe. > > Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
> --- > Changes since v1: > - Use ktime_get_mono_fast_ns() instead of ktime_get_seconds(). > --- > kernel/debug/kdb/kdb_main.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c > index 69e70f4..bf1d0e0 100644 > --- a/kernel/debug/kdb/kdb_main.c > +++ b/kernel/debug/kdb/kdb_main.c > @@ -2486,10 +2486,10 @@ static int kdb_kill(int argc, const char **argv) > */ > static void kdb_sysinfo(struct sysinfo *val) > { > - struct timespec uptime; > - ktime_get_ts(&uptime); > + u64 uptime = ktime_get_mono_fast_ns(); > + > memset(val, 0, sizeof(*val)); > - val->uptime = uptime.tv_sec; > + val->uptime = div_u64(uptime, NSEC_PER_SEC); > val->loads[0] = avenrun[0]; > val->loads[1] = avenrun[1]; > val->loads[2] = avenrun[2]; > -- > 1.7.9.5 >
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