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Commit aa62afd7 authored by Adrian Hunter's avatar Adrian Hunter Committed by Arnaldo Carvalho de Melo
Browse files

perf intel-pt: Add LBR information to synthesized PEBS sample 



Add LBR information from PEBS data in the Intel PT trace to the
synthesized PEBS sample.

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20190610072803.10456-10-adrian.hunter@intel.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 143d34a6

tools/perf/util/intel-pt.c

+72 −0
Original line number Diff line number Diff line
@@ -1628,6 +1628,58 @@ static void intel_pt_add_xmm(struct regs_dump *intr_regs, u64 *pos, 
	}

}



#define LBR_INFO_MISPRED	(1ULL << 63)

#define LBR_INFO_IN_TX		(1ULL << 62)

#define LBR_INFO_ABORT		(1ULL << 61)

#define LBR_INFO_CYCLES		0xffff



/* Refer kernel's intel_pmu_store_pebs_lbrs() */

static u64 intel_pt_lbr_flags(u64 info)

{

	union {

		struct branch_flags flags;

		u64 result;

	} u = {

		.flags = {

			.mispred	= !!(info & LBR_INFO_MISPRED),

			.predicted	= !(info & LBR_INFO_MISPRED),

			.in_tx		= !!(info & LBR_INFO_IN_TX),

			.abort		= !!(info & LBR_INFO_ABORT),

			.cycles		= info & LBR_INFO_CYCLES,

		}

	};



	return u.result;

}



static void intel_pt_add_lbrs(struct branch_stack *br_stack,

			      const struct intel_pt_blk_items *items)

{

	u64 *to;

	int i;



	br_stack->nr = 0;



	to = &br_stack->entries[0].from;



	for (i = INTEL_PT_LBR_0_POS; i <= INTEL_PT_LBR_2_POS; i++) {

		u32 mask = items->mask[i];

		const u64 *from = items->val[i];



		for (; mask; mask >>= 3, from += 3) {

			if ((mask & 7) == 7) {

				*to++ = from[0];

				*to++ = from[1];

				*to++ = intel_pt_lbr_flags(from[2]);

				br_stack->nr += 1;

			}

		}

	}

}



/* INTEL_PT_LBR_0, INTEL_PT_LBR_1 and INTEL_PT_LBR_2 */

#define LBRS_MAX (INTEL_PT_BLK_ITEM_ID_CNT * 3)



static int intel_pt_synth_pebs_sample(struct intel_pt_queue *ptq)

{

	const struct intel_pt_blk_items *items = &ptq->state->items;
@@ -1694,6 +1746,26 @@ static int intel_pt_synth_pebs_sample(struct intel_pt_queue *ptq) 
		intel_pt_add_xmm(&sample.intr_regs, pos, items, regs_mask);

	}



	if (sample_type & PERF_SAMPLE_BRANCH_STACK) {

		struct {

			struct branch_stack br_stack;

			struct branch_entry entries[LBRS_MAX];

		} br;



		if (items->mask[INTEL_PT_LBR_0_POS] ||

		    items->mask[INTEL_PT_LBR_1_POS] ||

		    items->mask[INTEL_PT_LBR_2_POS]) {

			intel_pt_add_lbrs(&br.br_stack, items);

			sample.branch_stack = &br.br_stack;

		} else if (pt->synth_opts.last_branch) {

			intel_pt_copy_last_branch_rb(ptq);

			sample.branch_stack = ptq->last_branch;

		} else {

			br.br_stack.nr = 0;

			sample.branch_stack = &br.br_stack;

		}

	}



	return intel_pt_deliver_synth_event(pt, ptq, event, &sample, sample_type);

}