kdb: use ktime_get_mono_fast_ns() instead of ktime_get_ts()

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.

Baolin Wang committed 8 years ago

Commit 40b90ef1 parent 33f765f1 file · +3 −3Browse files

Showing the changes to kernel/debug (1 of 1 file). Show all

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kernel/debug/kdb/kdb_main.c+3−3

@@ -2512,10 +2512,10 @@ static int kdb_kill(int argc, const char **argv) · 2511 unmodified lines
2512	2512	*/
2513	2513	static void kdb_sysinfo(struct sysinfo *val)
2514	2514	{
2515		− struct timespec uptime;
2516		− ktime_get_ts(&uptime);
	2515	+ u64 uptime = ktime_get_mono_fast_ns();
	2516	+
2517	2517	memset(val, 0, sizeof(*val));
2518		− val->uptime = uptime.tv_sec;
	2518	+ val->uptime = div_u64(uptime, NSEC_PER_SEC);
2519	2519	val->loads[0] = avenrun[0];
2520	2520	val->loads[1] = avenrun[1];
2521	2521	val->loads[2] = avenrun[2];