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Commit c75841a3 authored by Robert Richter's avatar Robert Richter Committed by Ingo Molnar
Browse files

perf/x86-ibs: Fix update of period 



The last sw period was not correctly updated on overflow and thus led
to wrong distribution of events. We always need to properly initialize
data.period in struct perf_sample_data.

Signed-off-by: default avatarRobert Richter <robert.richter@amd.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1333390758-10893-2-git-send-email-robert.richter@amd.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent ad8537cd

arch/x86/kernel/cpu/perf_event_amd_ibs.c

+14 −13
Original line number Diff line number Diff line
@@ -386,7 +386,21 @@ static int perf_ibs_handle_irq(struct perf_ibs *perf_ibs, struct pt_regs *iregs) 
	if (!(*buf++ & perf_ibs->valid_mask))

		return 0;



	/*

	 * Emulate IbsOpCurCnt in MSRC001_1033 (IbsOpCtl), not

	 * supported in all cpus. As this triggered an interrupt, we

	 * set the current count to the max count.

	 */

	config = ibs_data.regs[0];

	if (perf_ibs == &perf_ibs_op && !(ibs_caps & IBS_CAPS_RDWROPCNT)) {

		config &= ~IBS_OP_CUR_CNT;

		config |= (config & IBS_OP_MAX_CNT) << 36;

	}



	perf_ibs_event_update(perf_ibs, event, config);

	perf_sample_data_init(&data, 0);

	data.period = event->hw.last_period;



	if (event->attr.sample_type & PERF_SAMPLE_RAW) {

		ibs_data.caps = ibs_caps;

		size = 1;
@@ -405,19 +419,6 @@ static int perf_ibs_handle_irq(struct perf_ibs *perf_ibs, struct pt_regs *iregs) 


	regs = *iregs; /* XXX: update ip from ibs sample */



	/*

	 * Emulate IbsOpCurCnt in MSRC001_1033 (IbsOpCtl), not

	 * supported in all cpus. As this triggered an interrupt, we

	 * set the current count to the max count.

	 */

	config = ibs_data.regs[0];

	if (perf_ibs == &perf_ibs_op && !(ibs_caps & IBS_CAPS_RDWROPCNT)) {

		config &= ~IBS_OP_CUR_CNT;

		config |= (config & IBS_OP_MAX_CNT) << 36;

	}



	perf_ibs_event_update(perf_ibs, event, config);



	overflow = perf_ibs_set_period(perf_ibs, hwc, &config);

	reenable = !(overflow && perf_event_overflow(event, &data, &regs));

	config = (config >> 4) | (reenable ? perf_ibs->enable_mask : 0);