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Commit 00f0ad73 authored Mar 25, 2009 by Peter Zijlstra Committed by Ingo Molnar Apr 06, 2009

perf_counter: kerneltop: output event support



Teach kerneltop about the new output ABI.

XXX: anybody fancy integrating the PID/TID data into the output?

Bump the mmap_data pages a little because we bloated the output and
have to be more careful about overruns with structured data.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Orig-LKML-Reference: <20090325113317.192910290@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent 4c4ba21d

Documentation/perf_counter/kerneltop.c

+59 −6

Original line number	Diff line number	Diff line
		@@ -134,6 +134,11 @@
		#endif

		#define unlikely(x) __builtin_expect(!!(x), 0)
		#define min(x, y) ({ \
		typeof(x) _min1 = (x); \
		typeof(y) _min2 = (y); \
		(void) (&_min1 == &_min2); \
		_min1 < _min2 ? _min1 : _min2; })

		asmlinkage int sys_perf_counter_open(
		struct perf_counter_hw_event *hw_event_uptr __user,
		@@ -178,7 +183,7 @@ static int nr_cpus = 0;
		static int nmi = 1;
		static int group = 0;
		static unsigned int page_size;
		static unsigned int mmap_pages = 4;
		static unsigned int mmap_pages = 16;

		static char *vmlinux;

		@@ -1147,28 +1152,75 @@ static void mmap_read(struct mmap_data *md)
		unsigned int head = mmap_read_head(md);
		unsigned int old = md->prev;
		unsigned char *data = md->base + page_size;
		int diff;

		gettimeofday(&this_read, NULL);

		if (head - old > md->mask) {
		/*
		* If we're further behind than half the buffer, there's a chance
		* the writer will bite our tail and screw up the events under us.
		*
		* If we somehow ended up ahead of the head, we got messed up.
		*
		* In either case, truncate and restart at head.
		*/
		diff = head - old;
		if (diff > md->mask / 2 \|\| diff < 0) {
		struct timeval iv;
		unsigned long msecs;

		timersub(&this_read, &last_read, &iv);
		msecs = iv.tv_sec*1000 + iv.tv_usec/1000;

		fprintf(stderr, "WARNING: failed to keep up with mmap data. Last read %lu msecs ago.\n", msecs);
		fprintf(stderr, "WARNING: failed to keep up with mmap data."
		" Last read %lu msecs ago.\n", msecs);

		/*
		* head points to a known good entry, start there.
		*/
		old = head;
		}

		last_read = this_read;

		for (; old != head;) {
		__u64 ptr = (__u64 )&data[old & md->mask];
		old += sizeof(__u64);
		struct event_struct {
		struct perf_event_header header;
		__u64 ip;
		__u32 pid, tid;
		} event = (struct event_struct )&data[old & md->mask];
		struct event_struct event_copy;

		unsigned int size = event->header.size;

		process_event(*ptr, md->counter);
		/*
		* Event straddles the mmap boundary -- header should always
		* be inside due to u64 alignment of output.
		*/
		if ((old & md->mask) + size != ((old + size) & md->mask)) {
		unsigned int offset = old;
		unsigned int len = sizeof(*event), cpy;
		void *dst = &event_copy;

		do {
		cpy = min(md->mask + 1 - (offset & md->mask), len);
		memcpy(dst, &data[offset & md->mask], cpy);
		offset += cpy;
		dst += cpy;
		len -= cpy;
		} while (len);

		event = &event_copy;
		}

		old += size;

		switch (event->header.type) {
		case PERF_EVENT_IP:
		case PERF_EVENT_IP \| __PERF_EVENT_TID:
		process_event(event->ip, md->counter);
		break;
		}
		}

		md->prev = old;
		@@ -1214,6 +1266,7 @@ int main(int argc, char *argv[])
		hw_event.irq_period = event_count[counter];
		hw_event.record_type = PERF_RECORD_IRQ;
		hw_event.nmi = nmi;
		hw_event.include_tid = 1;

		fd[i][counter] = sys_perf_counter_open(&hw_event, tid, cpu, group_fd, 0);
		if (fd[i][counter] < 0) {