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perf annotate: Save branch counters for each block

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When annotating a basic block, it's useful to display the occurrences
of other events in the block.

The branch counter feature is only available for newer Intel platforms.

So a dedicated option to display the branch counters is not introduced.

Reuse the existing --total-cycles option, which triggers the annotation
of a basic block and displays the cycle-related annotation.

When the branch counters information is available, the branch counters
are automatically appended after all the cycle-related annotation.

Accounting the branch counters as well when accounting the cycles in
hist__account_cycles().

In 'struct annotated_branch', introduce a br_cntr array to save the
accumulation of each branch counter.

In a sample, all the branch counters for a branch are saved in a u64
space.

Because the saturation of a branch counter is small, e.g., for Intel
Sierra Forest, the saturation is only 3.

Add ANNOTATION__BR_CNTR_SATURATED_FLAG to indicate if a branch counter
once saturated. That can be used to indicate a potential event lost
because of the saturation.

Reviewed-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20240813160208.2493643-5-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Kan Liang
2024-08-13 09:02:03 -07:00
committed by Arnaldo Carvalho de Melo
parent 3a867a6dad
commit 1f2b7fbb04
10 changed files with 80 additions and 22 deletions
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10
tools/perf/util/annotate.h
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@@ -14,6 +14,7 @@
#include "spark.h"
#include "hashmap.h"
#include "disasm.h"
#include "branch.h"
struct hist_browser_timer;
struct hist_entry;
@@ -288,6 +289,9 @@ struct annotated_source {
struct annotation_line *annotated_source__get_line(struct annotated_source *src,
s64 offset);
/* A branch counter once saturated */
#define ANNOTATION__BR_CNTR_SATURATED_FLAG (1ULL << 63)
/**
* struct annotated_branch - basic block and IPC information for a symbol.
*
@@ -297,6 +301,7 @@ struct annotation_line *annotated_source__get_line(struct annotated_source *src,
* @cover_insn: Number of distinct, actually executed instructions.
* @cycles_hist: Array of cyc_hist for each instruction.
* @max_coverage: Maximum number of covered basic block (used for block-range).
* @br_cntr: Array of the occurrences of events (branch counters) during a block.
*
* This struct is used by two different codes when the sample has branch stack
* and cycles information. annotation__compute_ipc() calculates average IPC
@@ -313,6 +318,7 @@ struct annotated_branch {
unsigned int cover_insn;
struct cyc_hist *cycles_hist;
u64 max_coverage;
u64 *br_cntr;
};
struct LOCKABLE annotation {
@@ -383,7 +389,9 @@ struct annotated_branch *annotation__get_branch(struct annotation *notes);
int addr_map_symbol__account_cycles(struct addr_map_symbol *ams,
struct addr_map_symbol *start,
unsigned cycles);
unsigned cycles,
struct evsel *evsel,
u64 br_cntr);
int hist_entry__inc_addr_samples(struct hist_entry *he, struct perf_sample *sample,
struct evsel *evsel, u64 addr);