tracing: add global-clock option to provide cross CPU clock to traces (af4617bd) · Commits · 戴 / test

kernel/trace/trace.c

+30 −4

Original line number	Diff line number	Diff line
		@@ -315,6 +315,7 @@ static const char *trace_options[] = {
		"printk-msg-only",
		"context-info",
		"latency-format",
		"global-clock",
		NULL
		};

		@@ -2251,6 +2252,34 @@ static int set_tracer_option(struct tracer trace, char cmp, int neg)
		return 0;
		}

		static void set_tracer_flags(unsigned int mask, int enabled)
		{
		/* do nothing if flag is already set */
		if (!!(trace_flags & mask) == !!enabled)
		return;

		if (enabled)
		trace_flags \|= mask;
		else
		trace_flags &= ~mask;

		if (mask == TRACE_ITER_GLOBAL_CLK) {
		u64 (*func)(void);

		if (enabled)
		func = trace_clock_global;
		else
		func = trace_clock_local;

		mutex_lock(&trace_types_lock);
		ring_buffer_set_clock(global_trace.buffer, func);

		if (max_tr.buffer)
		ring_buffer_set_clock(max_tr.buffer, func);
		mutex_unlock(&trace_types_lock);
		}
		}

		static ssize_t
		tracing_trace_options_write(struct file filp, const char __user ubuf,
		size_t cnt, loff_t *ppos)
		@@ -2278,10 +2307,7 @@ tracing_trace_options_write(struct file filp, const char __user ubuf,
		int len = strlen(trace_options[i]);

		if (strncmp(cmp, trace_options[i], len) == 0) {
		if (neg)
		trace_flags &= ~(1 << i);
		else
		trace_flags \|= (1 << i);
		set_tracer_flags(1 << i, !neg);
		break;
		}
		}

+1 −0

Original line number	Diff line number	Diff line
		@@ -667,6 +667,7 @@ enum trace_iterator_flags {
		TRACE_ITER_PRINTK_MSGONLY = 0x10000,
		TRACE_ITER_CONTEXT_INFO = 0x20000, /* Print pid/cpu/time */
		TRACE_ITER_LATENCY_FMT = 0x40000,
		TRACE_ITER_GLOBAL_CLK = 0x80000,
		};

		/*