perf annotate: Add comments in the data structures

Reviewed-by: Ian Rogers <irogers@google.com>
Reviewed-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240304230815.1440583-5-namhyung@kernel.org
This commit is contained in:
Namhyung Kim 2024-03-04 15:08:15 -08:00
parent f59e3660cd
commit 0f66dfe7b9

View file

@ -239,11 +239,42 @@ int disasm_line__scnprintf(struct disasm_line *dl, char *bf, size_t size, bool r
size_t disasm__fprintf(struct list_head *head, FILE *fp);
void symbol__calc_percent(struct symbol *sym, struct evsel *evsel);
/**
* struct sym_hist - symbol histogram information for an event
*
* @nr_samples: Total number of samples.
* @period: Sum of sample periods.
*/
struct sym_hist {
u64 nr_samples;
u64 period;
};
/**
* struct cyc_hist - (CPU) cycle histogram for a basic block
*
* @start: Start address of current block (if known).
* @cycles: Sum of cycles for the longest basic block.
* @cycles_aggr: Total cycles for this address.
* @cycles_max: Max cycles for this address.
* @cycles_min: Min cycles for this address.
* @cycles_spark: History of cycles for the longest basic block.
* @num: Number of samples for the longest basic block.
* @num_aggr: Total number of samples for this address.
* @have_start: Whether the current branch info has a start address.
* @reset: Number of resets due to a different start address.
*
* If sample has branch_stack and cycles info, it can construct basic blocks
* between two adjacent branches. It'd have start and end addresses but
* sometimes the start address may not be available. So the cycles are
* accounted at the end address. If multiple basic blocks end at the same
* address, it will take the longest one.
*
* The @start, @cycles, @cycles_spark and @num fields are used for the longest
* block only. Other fields are used for all cases.
*
* See __symbol__account_cycles().
*/
struct cyc_hist {
u64 start;
u64 cycles;
@ -258,18 +289,24 @@ struct cyc_hist {
u16 reset;
};
/** struct annotated_source - symbols with hits have this attached as in sannotation
/**
* struct annotated_source - symbols with hits have this attached as in annotation
*
* @histograms: Array of addr hit histograms per event being monitored
* nr_histograms: This may not be the same as evsel->evlist->core.nr_entries if
* @source: List head for annotated_line (embeded in disasm_line).
* @histograms: Array of symbol histograms per event to maintain the total number
* of samples and period.
* @nr_histograms: This may not be the same as evsel->evlist->core.nr_entries if
* we have more than a group in a evlist, where we will want
* to see each group separately, that is why symbol__annotate2()
* sets src->nr_histograms to evsel->nr_members.
* @lines: If 'print_lines' is specified, per source code line percentages
* @source: source parsed from a disassembler like objdump -dS
* @cyc_hist: Average cycles per basic block
* @offsets: Array of annotation_line to be accessed by offset.
* @samples: Hash map of sym_hist_entry. Keyed by event index and offset in symbol.
* @nr_entries: Number of annotated_line in the source list.
* @nr_asm_entries: Number of annotated_line with actual asm instruction in the
* source list.
* @max_line_len: Maximum length of objdump output in an annotated_line.
*
* lines is allocated, percentages calculated and all sorted by percentage
* disasm_lines are allocated, percentages calculated and all sorted by percentage
* when the annotation is about to be presented, so the percentages are for
* one of the entries in the histogram array, i.e. for the event/counter being
* presented. It is deallocated right after symbol__{tui,tty,etc}_annotate
@ -286,6 +323,24 @@ struct annotated_source {
u16 max_line_len;
};
/**
* struct annotated_branch - basic block and IPC information for a symbol.
*
* @hit_cycles: Total executed cycles.
* @hit_insn: Total number of instructions executed.
* @total_insn: Number of instructions in the function.
* @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).
*
* This struct is used by two different codes when the sample has branch stack
* and cycles information. annotation__compute_ipc() calculates average IPC
* using @hit_insn / @hit_cycles. The actual coverage can be calculated using
* @cover_insn / @total_insn. The @cycles_hist can give IPC for each (longest)
* basic block ends at the given address.
* process_basic_block() calculates coverage of instructions (or basic blocks)
* in the function.
*/
struct annotated_branch {
u64 hit_cycles;
u64 hit_insn;