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Message-ID: <aNo-U0KquRbcJam9@google.com>
Date: Mon, 29 Sep 2025 17:07:47 +0900
From: Namhyung Kim <namhyung@...nel.org>
To: "Li, Tianyou" <tianyou.li@...el.com>
Cc: Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>,
Arnaldo Carvalho de Melo <acme@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
Jiri Olsa <jolsa@...nel.org>, Ian Rogers <irogers@...gle.com>,
Adrian Hunter <adrian.hunter@...el.com>,
Kan Liang <kan.liang@...ux.intel.com>, wangyang.guo@...el.com,
pan.deng@...el.com, zhiguo.zhou@...el.com, jiebin.sun@...el.com,
thomas.falcon@...el.com, dapeng1.mi@...el.com,
linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4] perf tools c2c: Add annotation support to perf c2c
report
Hello,
On Sun, Sep 28, 2025 at 04:16:16PM +0800, Li, Tianyou wrote:
> Rebased with latest perf-tools-next. Looking forward to your review
> comments. Thanks.
Sorry for the delay, I was on vacation.
> On 9/28/2025 5:02 PM, Tianyou Li wrote:
> > Perf c2c report currently specified the code address and source:line
> > information in the cacheline browser, while it is lack of annotation
> > support like perf report to directly show the disassembly code for
> > the particular symbol shared that same cacheline. This patches add
> > a key 'a' binding to the cacheline browser which reuse the annotation
> > browser to show the disassembly view for easier analysis of cacheline
> > contentions. By default, the 'TAB' key navigate to the code address
> > where the contentions detected.
> >
> > Signed-off-by: Tianyou Li <tianyou.li@...el.com>
> > Reviewed-by: Dapeng Mi <dapeng1.mi@...ux.intel.com>
> > Reviewed-by: Thomas Falcon <thomas.falcon@...el.com>
> > Reviewed-by: Jiebin Sun <jiebin.sun@...el.com>
> > Reviewed-by: Pan Deng <pan.deng@...el.com>
> > Reviewed-by: Zhiguo Zhou <zhiguo.zhou@...el.com>
> > Reviewed-by: Wangyang Guo <wangyang.guo@...el.com>
> > ---
> > tools/perf/builtin-annotate.c | 2 +-
> > tools/perf/builtin-c2c.c | 130 ++++++++++++++++++++++++++++--
> > tools/perf/ui/browsers/annotate.c | 41 +++++++++-
> > tools/perf/ui/browsers/hists.c | 2 +-
> > tools/perf/util/annotate.c | 2 +-
> > tools/perf/util/annotate.h | 2 +
> > tools/perf/util/hist.h | 6 +-
> > 7 files changed, 171 insertions(+), 14 deletions(-)
> >
> > diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
> > index 646f43b0f7c4..f977e97a9c96 100644
> > --- a/tools/perf/builtin-annotate.c
> > +++ b/tools/perf/builtin-annotate.c
> > @@ -519,7 +519,7 @@ static void hists__find_annotations(struct hists *hists,
> > /* skip missing symbols */
> > nd = rb_next(nd);
> > } else if (use_browser == 1) {
> > - key = hist_entry__tui_annotate(he, evsel, NULL);
> > + key = hist_entry__tui_annotate(he, evsel, NULL, NO_INITIAL_IP);
> > switch (key) {
> > case -1:
> > diff --git a/tools/perf/builtin-c2c.c b/tools/perf/builtin-c2c.c
> > index 9e9ff471ddd1..bf2136d062ef 100644
> > --- a/tools/perf/builtin-c2c.c
> > +++ b/tools/perf/builtin-c2c.c
> > @@ -45,6 +45,8 @@
> > #include "pmus.h"
> > #include "string2.h"
> > #include "util/util.h"
> > +#include "util/symbol.h"
> > +#include "util/annotate.h"
> > struct c2c_hists {
> > struct hists hists;
> > @@ -62,6 +64,7 @@ struct compute_stats {
> > struct c2c_hist_entry {
> > struct c2c_hists *hists;
> > + struct evsel *evsel;
> > struct c2c_stats stats;
> > unsigned long *cpuset;
> > unsigned long *nodeset;
> > @@ -225,6 +228,12 @@ he__get_c2c_hists(struct hist_entry *he,
> > return hists;
> > }
> > +static void c2c_he__set_evsel(struct c2c_hist_entry *c2c_he,
> > + struct evsel *evsel)
> > +{
> > + c2c_he->evsel = evsel;
> > +}
> > +
> > static void c2c_he__set_cpu(struct c2c_hist_entry *c2c_he,
> > struct perf_sample *sample)
> > {
> > @@ -334,6 +343,7 @@ static int process_sample_event(const struct perf_tool *tool __maybe_unused,
> > c2c_he__set_cpu(c2c_he, sample);
> > c2c_he__set_node(c2c_he, sample);
> > + c2c_he__set_evsel(c2c_he, evsel);
> > hists__inc_nr_samples(&c2c_hists->hists, he->filtered);
> > ret = hist_entry__append_callchain(he, sample);
> > @@ -371,6 +381,7 @@ static int process_sample_event(const struct perf_tool *tool __maybe_unused,
> > c2c_he__set_cpu(c2c_he, sample);
> > c2c_he__set_node(c2c_he, sample);
> > + c2c_he__set_evsel(c2c_he, evsel);
> > hists__inc_nr_samples(&c2c_hists->hists, he->filtered);
> > ret = hist_entry__append_callchain(he, sample);
> > @@ -2550,6 +2561,35 @@ static void perf_c2c__hists_fprintf(FILE *out, struct perf_session *session)
> > }
> > #ifdef HAVE_SLANG_SUPPORT
> > +
> > +static int perf_c2c__toggle_annotation(struct hist_browser *browser)
> > +{
> > + struct hist_entry *he = browser->he_selection;
> > + struct symbol *sym = NULL;
> > + struct c2c_hist_entry *c2c_he = NULL;
> > + struct annotated_source *src = NULL;
> > +
> > + if (he == NULL) {
> > + ui_browser__help_window(&browser->b, "No entry selected for annotation");
> > + return 0;
> > + }
> > + sym = (&he->ms)->sym;
> > +
> > + if (sym == NULL) {
> > + ui_browser__help_window(&browser->b, "Can not annotate, no symbol found");
> > + return 0;
> > + }
> > +
> > + src = symbol__hists(sym, 0);
> > + if (src == NULL) {
> > + ui_browser__help_window(&browser->b, "Failed to initialize annotation source");
> > + return 0;
> > + }
> > +
> > + c2c_he = container_of(he, struct c2c_hist_entry, he);
> > + return hist_entry__tui_annotate(he, c2c_he->evsel, NULL, he->ip);
I'm skeptical about using he->ip. An hist_entry can collapse multiple
samples with different IP in a symbol (even if hpp_list has symbol sort
key). That means he->ip cannot represent the entry is from the specific
point in the function. This might lead users to an inaccurate place in
the annotation browser. I'd recommend not passing IP.
> > +}
> > +
> > static void c2c_browser__update_nr_entries(struct hist_browser *hb)
> > {
> > u64 nr_entries = 0;
> > @@ -2617,6 +2657,7 @@ static int perf_c2c__browse_cacheline(struct hist_entry *he)
> > " ENTER Toggle callchains (if present) \n"
> > " n Toggle Node details info \n"
> > " s Toggle full length of symbol and source line columns \n"
> > + " a Toggle annotation view \n"
> > " q Return back to cacheline list \n";
> > if (!he)
> > @@ -2651,6 +2692,9 @@ static int perf_c2c__browse_cacheline(struct hist_entry *he)
> > c2c.node_info = (c2c.node_info + 1) % 3;
> > setup_nodes_header();
> > break;
> > + case 'a':
> > + perf_c2c__toggle_annotation(browser);
> > + break;
> > case 'q':
> > goto out;
> > case '?':
> > @@ -2989,6 +3033,11 @@ static int setup_coalesce(const char *coalesce, bool no_source)
> > return 0;
> > }
> > +static bool perf_c2c__has_annotation(void)
> > +{
> > + return use_browser == 1;
Please check if it has symbol dimension in the c2c_hists->list like in
the ui__has_annotation(). Maybe you need to add this in the
c2c_hists__init_sort().
if (dim == &dim_symbol)
hpp_list->sym = 1;
Thanks,
Namhyung
> > +}
> > +
> > static int perf_c2c__report(int argc, const char **argv)
> > {
> > struct itrace_synth_opts itrace_synth_opts = {
> > @@ -3006,6 +3055,7 @@ static int perf_c2c__report(int argc, const char **argv)
> > const char *display = NULL;
> > const char *coalesce = NULL;
> > bool no_source = false;
> > + const char *disassembler_style = NULL, *objdump_path = NULL, *addr2line_path = NULL;
> > const struct option options[] = {
> > OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
> > "file", "vmlinux pathname"),
> > @@ -3033,6 +3083,12 @@ static int perf_c2c__report(int argc, const char **argv)
> > OPT_BOOLEAN(0, "stitch-lbr", &c2c.stitch_lbr,
> > "Enable LBR callgraph stitching approach"),
> > OPT_BOOLEAN(0, "double-cl", &chk_double_cl, "Detect adjacent cacheline false sharing"),
> > + OPT_STRING('M', "disassembler-style", &disassembler_style, "disassembler style",
> > + "Specify disassembler style (e.g. -M intel for intel syntax)"),
> > + OPT_STRING(0, "objdump", &objdump_path, "path",
> > + "objdump binary to use for disassembly and annotations"),
> > + OPT_STRING(0, "addr2line", &addr2line_path, "path",
> > + "addr2line binary to use for line numbers"),
> > OPT_PARENT(c2c_options),
> > OPT_END()
> > };
> > @@ -3040,6 +3096,12 @@ static int perf_c2c__report(int argc, const char **argv)
> > const char *output_str, *sort_str = NULL;
> > struct perf_env *env;
> > + annotation_options__init();
> > +
> > + err = hists__init();
> > + if (err < 0)
> > + goto out;
> > +
> > argc = parse_options(argc, argv, options, report_c2c_usage,
> > PARSE_OPT_STOP_AT_NON_OPTION);
> > if (argc)
> > @@ -3052,6 +3114,36 @@ static int perf_c2c__report(int argc, const char **argv)
> > if (c2c.stats_only)
> > c2c.use_stdio = true;
> > + /**
> > + * Annotation related options
> > + * disassembler_style, objdump_path, addr2line_path
> > + * are set in the c2c_options, so we can use them here.
> > + */
> > + if (disassembler_style) {
> > + annotate_opts.disassembler_style = strdup(disassembler_style);
> > + if (!annotate_opts.disassembler_style) {
> > + err = -ENOMEM;
> > + pr_err("Failed to allocate memory for annotation options\n");
> > + goto out;
> > + }
> > + }
> > + if (objdump_path) {
> > + annotate_opts.objdump_path = strdup(objdump_path);
> > + if (!annotate_opts.objdump_path) {
> > + err = -ENOMEM;
> > + pr_err("Failed to allocate memory for annotation options\n");
> > + goto out;
> > + }
> > + }
> > + if (addr2line_path) {
> > + symbol_conf.addr2line_path = strdup(addr2line_path);
> > + if (!symbol_conf.addr2line_path) {
> > + err = -ENOMEM;
> > + pr_err("Failed to allocate memory for annotation options\n");
> > + goto out;
> > + }
> > + }
> > +
> > err = symbol__validate_sym_arguments();
> > if (err)
> > goto out;
> > @@ -3126,6 +3218,38 @@ static int perf_c2c__report(int argc, const char **argv)
> > if (err)
> > goto out_mem2node;
> > + if (c2c.use_stdio)
> > + use_browser = 0;
> > + else
> > + use_browser = 1;
> > +
> > + /*
> > + * Only in the TUI browser we are doing integrated annotation,
> > + * so don't allocate extra space that won't be used in the stdio
> > + * implementation.
> > + */
> > + if (perf_c2c__has_annotation()) {
> > + int ret = symbol__annotation_init();
> > +
> > + if (ret < 0)
> > + goto out_mem2node;
> > + /*
> > + * For searching by name on the "Browse map details".
> > + * providing it only in verbose mode not to bloat too
> > + * much struct symbol.
> > + */
> > + if (verbose > 0) {
> > + /*
> > + * XXX: Need to provide a less kludgy way to ask for
> > + * more space per symbol, the u32 is for the index on
> > + * the ui browser.
> > + * See symbol__browser_index.
> > + */
> > + symbol_conf.priv_size += sizeof(u32);
> > + }
> > + annotation_config__init();
> > + }
> > +
> > if (symbol__init(env) < 0)
> > goto out_mem2node;
> > @@ -3135,11 +3259,6 @@ static int perf_c2c__report(int argc, const char **argv)
> > goto out_mem2node;
> > }
> > - if (c2c.use_stdio)
> > - use_browser = 0;
> > - else
> > - use_browser = 1;
> > -
> > setup_browser(false);
> > err = perf_session__process_events(session);
> > @@ -3210,6 +3329,7 @@ static int perf_c2c__report(int argc, const char **argv)
> > out_session:
> > perf_session__delete(session);
> > out:
> > + annotation_options__exit();
> > return err;
> > }
> > diff --git a/tools/perf/ui/browsers/annotate.c b/tools/perf/ui/browsers/annotate.c
> > index 8fe699f98542..63d0e28fb991 100644
> > --- a/tools/perf/ui/browsers/annotate.c
> > +++ b/tools/perf/ui/browsers/annotate.c
> > @@ -605,7 +605,7 @@ static bool annotate_browser__callq(struct annotate_browser *browser,
> > target_ms.map = ms->map;
> > target_ms.sym = dl->ops.target.sym;
> > annotation__unlock(notes);
> > - __hist_entry__tui_annotate(browser->he, &target_ms, evsel, hbt);
> > + __hist_entry__tui_annotate(browser->he, &target_ms, evsel, hbt, NO_INITIAL_IP);
> > /*
> > * The annotate_browser above changed the title with the target function
> > @@ -864,6 +864,7 @@ static int annotate_browser__run(struct annotate_browser *browser,
> > const char *help = "Press 'h' for help on key bindings";
> > int delay_secs = hbt ? hbt->refresh : 0;
> > char *br_cntr_text = NULL;
> > + u64 init_ip = NO_INITIAL_IP;
> > char title[256];
> > int key;
> > @@ -873,6 +874,13 @@ static int annotate_browser__run(struct annotate_browser *browser,
> > annotate_browser__calc_percent(browser, evsel);
> > + /* the selection are intentionally even not from the sample percentage */
> > + if (browser->entries.rb_node == NULL && browser->selection) {
> > + init_ip = sym->start + browser->selection->offset;
> > + disasm_rb_tree__insert(browser, browser->selection);
> > + browser->curr_hot = rb_last(&browser->entries);
> > + }
> > +
> > if (browser->curr_hot) {
> > annotate_browser__set_rb_top(browser, browser->curr_hot);
> > browser->b.navkeypressed = false;
> > @@ -973,6 +981,18 @@ static int annotate_browser__run(struct annotate_browser *browser,
> > ui_helpline__puts(help);
> > annotate__scnprintf_title(hists, title, sizeof(title));
> > annotate_browser__show(browser, title, help);
> > + /* Previous RB tree may not valid, need refresh according to new entries*/
> > + if (init_ip != NO_INITIAL_IP) {
> > + struct disasm_line *dl = find_disasm_line(sym, init_ip, true);
> > +
> > + browser->curr_hot = NULL;
> > + browser->entries.rb_node = NULL;
> > + if (dl != NULL) {
> > + disasm_rb_tree__insert(browser, &dl->al);
> > + browser->curr_hot = rb_last(&browser->entries);
> > + }
> > + nd = browser->curr_hot;
> > + }
> > continue;
> > case 'o':
> > annotate_opts.use_offset = !annotate_opts.use_offset;
> > @@ -1106,22 +1126,23 @@ static int annotate_browser__run(struct annotate_browser *browser,
> > }
> > int hist_entry__tui_annotate(struct hist_entry *he, struct evsel *evsel,
> > - struct hist_browser_timer *hbt)
> > + struct hist_browser_timer *hbt, u64 init_ip)
> > {
> > /* reset abort key so that it can get Ctrl-C as a key */
> > SLang_reset_tty();
> > SLang_init_tty(0, 0, 0);
> > SLtty_set_suspend_state(true);
> > - return __hist_entry__tui_annotate(he, &he->ms, evsel, hbt);
> > + return __hist_entry__tui_annotate(he, &he->ms, evsel, hbt, init_ip);
> > }
> > int __hist_entry__tui_annotate(struct hist_entry *he, struct map_symbol *ms,
> > struct evsel *evsel,
> > - struct hist_browser_timer *hbt)
> > + struct hist_browser_timer *hbt, u64 init_ip)
> > {
> > struct symbol *sym = ms->sym;
> > struct annotation *notes = symbol__annotation(sym);
> > + struct disasm_line *dl = NULL;
> > struct annotate_browser browser = {
> > .b = {
> > .refresh = annotate_browser__refresh,
> > @@ -1173,6 +1194,18 @@ int __hist_entry__tui_annotate(struct hist_entry *he, struct map_symbol *ms,
> > browser.he = &annotate_he;
> > }
> > + /*
> > + * If init_ip is set, it means that there should be a line
> > + * intentionally selected, not based on the percentages
> > + * which caculated by the event sampling. In this case, we
> > + * convey this information into the browser selection, where
> > + * the selection in other cases should be empty.
> > + */
> > + if (init_ip != NO_INITIAL_IP) {
> > + dl = find_disasm_line(sym, init_ip, false);
> > + browser.selection = &dl->al;
> > + }
> > +
> > ui_helpline__push("Press ESC to exit");
> > if (annotate_opts.code_with_type) {
> > diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
> > index 487c0b08c003..3675a703de11 100644
> > --- a/tools/perf/ui/browsers/hists.c
> > +++ b/tools/perf/ui/browsers/hists.c
> > @@ -2485,7 +2485,7 @@ do_annotate(struct hist_browser *browser, struct popup_action *act)
> > evsel = hists_to_evsel(browser->hists);
> > he = hist_browser__selected_entry(browser);
> > - err = __hist_entry__tui_annotate(he, &act->ms, evsel, browser->hbt);
> > + err = __hist_entry__tui_annotate(he, &act->ms, evsel, browser->hbt, NO_INITIAL_IP);
> > /*
> > * offer option to annotate the other branch source or target
> > * (if they exists) when returning from annotate
> > diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
> > index c9b220d9f924..937effbeda69 100644
> > --- a/tools/perf/util/annotate.c
> > +++ b/tools/perf/util/annotate.c
> > @@ -2622,7 +2622,7 @@ int annotate_get_insn_location(struct arch *arch, struct disasm_line *dl,
> > return 0;
> > }
> > -static struct disasm_line *find_disasm_line(struct symbol *sym, u64 ip,
> > +struct disasm_line *find_disasm_line(struct symbol *sym, u64 ip,
> > bool allow_update)
> > {
> > struct disasm_line *dl;
> > diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h
> > index eaf6c8aa7f47..bbe67588bbdd 100644
> > --- a/tools/perf/util/annotate.h
> > +++ b/tools/perf/util/annotate.h
> > @@ -170,6 +170,8 @@ static inline struct disasm_line *disasm_line(struct annotation_line *al)
> > return al ? container_of(al, struct disasm_line, al) : NULL;
> > }
> > +struct disasm_line *find_disasm_line(struct symbol *sym, u64 ip, bool allow_update);
> > +
> > /*
> > * Is this offset in the same function as the line it is used?
> > * asm functions jump to other functions, for instance.
> > diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
> > index c64005278687..e544e1795f19 100644
> > --- a/tools/perf/util/hist.h
> > +++ b/tools/perf/util/hist.h
> > @@ -713,12 +713,14 @@ struct block_hist {
> > #include "../ui/keysyms.h"
> > void attr_to_script(char *buf, struct perf_event_attr *attr);
> > +#define NO_INITIAL_IP 0
> > +
> > int __hist_entry__tui_annotate(struct hist_entry *he, struct map_symbol *ms,
> > struct evsel *evsel,
> > - struct hist_browser_timer *hbt);
> > + struct hist_browser_timer *hbt, u64 init_ip);
> > int hist_entry__tui_annotate(struct hist_entry *he, struct evsel *evsel,
> > - struct hist_browser_timer *hbt);
> > + struct hist_browser_timer *hbt, u64 init_ip);
> > int evlist__tui_browse_hists(struct evlist *evlist, const char *help, struct hist_browser_timer *hbt,
> > float min_pcnt, struct perf_env *env, bool warn_lost_event);
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