linux-kernel - [PATCH v3] perf annotate/report: Remove hist__account

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Sat, 16 Mar 2019 05:16:17 +0800
From:   Jin Yao <yao.jin@...ux.intel.com>
To:     acme@...nel.org, jolsa@...nel.org, peterz@...radead.org,
        mingo@...hat.com, alexander.shishkin@...ux.intel.com
Cc:     Linux-kernel@...r.kernel.org, ak@...ux.intel.com,
        kan.liang@...el.com, yao.jin@...el.com,
        Jin Yao <yao.jin@...ux.intel.com>
Subject: [PATCH v3] perf annotate/report: Remove hist__account_cycles from callback

The hist__account_cycles is executed when the hist_iter__branch_callback
is called. But it looks it's not necessary. In hist__account_cycles, it
already walks on all branch entries.

This patch moves the hist__account_cycles out of callback, now the data
processing is much faster than before.

Previous code has an issue that the ch[offset].num++
(in __symbol__account_cycles) is executed repeatedly since
hist__account_cycles is called in each hist_iter__branch_callback,
so the counting of ch[offset].num is not correct (too big).
With this patch, the issue is fixed. And we don't need the code of
"ch->reset >= ch->num / 2" to check if there are too many overlaps
(in annotation__count_and_fill), otherwise some data would be
hidden.

Now, we can try, for example:

perf record -b ...
perf annotate or perf report -s symbol

The before/after output should be no change.

 v3:
 ---
 Fix the crash in stdio mode.
 Like previous code, it needs the checking of ui__has_annotation()
 before hist__account_cycles()

 v2:
 ---
 1. Cover the similar perf report
 2. Remove the checking code "ch->reset >= ch->num / 2"

Signed-off-by: Jin Yao <yao.jin@...ux.intel.com>
---
 tools/perf/builtin-annotate.c |  4 ++--
 tools/perf/builtin-report.c   | 11 +++++------
 tools/perf/util/annotate.c    |  2 +-
 3 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
index 67f9d9f..77deb3a 100644
--- a/tools/perf/builtin-annotate.c
+++ b/tools/perf/builtin-annotate.c
@@ -159,8 +159,6 @@ static int hist_iter__branch_callback(struct hist_entry_iter *iter,
 	struct perf_evsel *evsel = iter->evsel;
 	int err;
 
-	hist__account_cycles(sample->branch_stack, al, sample, false);
-
 	bi = he->branch_info;
 	err = addr_map_symbol__inc_samples(&bi->from, sample, evsel);
 
@@ -199,6 +197,8 @@ static int process_branch_callback(struct perf_evsel *evsel,
 	if (a.map != NULL)
 		a.map->dso->hit = 1;
 
+	hist__account_cycles(sample->branch_stack, al, sample, false);
+
 	ret = hist_entry_iter__add(&iter, &a, PERF_MAX_STACK_DEPTH, ann);
 	return ret;
 }
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 1921aaa..493e115 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -136,9 +136,6 @@ static int hist_iter__report_callback(struct hist_entry_iter *iter,
 	if (!ui__has_annotation() && !rep->symbol_ipc)
 		return 0;
 
-	hist__account_cycles(sample->branch_stack, al, sample,
-			     rep->nonany_branch_mode);
-
 	if (sort__mode == SORT_MODE__BRANCH) {
 		bi = he->branch_info;
 		err = addr_map_symbol__inc_samples(&bi->from, sample, evsel);
@@ -181,9 +178,6 @@ static int hist_iter__branch_callback(struct hist_entry_iter *iter,
 	if (!ui__has_annotation() && !rep->symbol_ipc)
 		return 0;
 
-	hist__account_cycles(sample->branch_stack, al, sample,
-			     rep->nonany_branch_mode);
-
 	bi = he->branch_info;
 	err = addr_map_symbol__inc_samples(&bi->from, sample, evsel);
 	if (err)
@@ -282,6 +276,11 @@ static int process_sample_event(struct perf_tool *tool,
 	if (al.map != NULL)
 		al.map->dso->hit = 1;
 
+	if (ui__has_annotation() || rep->symbol_ipc) {
+		hist__account_cycles(sample->branch_stack, &al, sample,
+				     rep->nonany_branch_mode);
+	}
+
 	ret = hist_entry_iter__add(&iter, &al, rep->max_stack, rep);
 	if (ret < 0)
 		pr_debug("problem adding hist entry, skipping event\n");
diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 5f6dbbf..e8080c0 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -1015,7 +1015,7 @@ static void annotation__count_and_fill(struct annotation *notes, u64 start, u64
 		float ipc = n_insn / ((double)ch->cycles / (double)ch->num);
 
 		/* Hide data when there are too many overlaps. */
-		if (ch->reset >= 0x7fff || ch->reset >= ch->num / 2)
+		if (ch->reset >= 0x7fff)
 			return;
 
 		for (offset = start; offset <= end; offset++) {
-- 
2.7.4