linux-kernel - [tip:perf/core] perf report: Make max_stack value allow for synthesized callchains

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

Date:	Tue, 29 Sep 2015 01:46:15 -0700
From:	tip-bot for Adrian Hunter <tipbot@...or.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	mingo@...nel.org, acme@...hat.com, linux-kernel@...r.kernel.org,
	jolsa@...hat.com, adrian.hunter@...el.com, tglx@...utronix.de,
	hpa@...or.com
Subject: [tip:perf/core] perf report:
  Make max_stack value allow for synthesized callchains

Commit-ID:  188bb5e2ce112463428994f91291e5df6fc05521
Gitweb:     http://git.kernel.org/tip/188bb5e2ce112463428994f91291e5df6fc05521
Author:     Adrian Hunter <adrian.hunter@...el.com>
AuthorDate: Fri, 25 Sep 2015 16:15:46 +0300
Committer:  Arnaldo Carvalho de Melo <acme@...hat.com>
CommitDate: Mon, 28 Sep 2015 17:03:20 -0300

perf report: Make max_stack value allow for synthesized callchains

perf report has an option (--max-stack) to set the maximum stack depth
when processing callchains.  The option defaults to the hard-coded
maximum definition PERF_MAX_STACK_DEPTH which is 127.  The intention of
the option is to allow the user to reduce the processing time by
reducing the amount of the callchain that is processed.

It is also possible, when processing instruction traces, to synthesize
callchains.  Synthesized callchains do not have the kernel size
limitation and are whatever size the user requests, although validation
presently prevents the user requested a value greater that 1024.  The
default value is 16.

To allow for synthesized callchains, make the max_stack value at least
the same size as the synthesized callchain size.

Signed-off-by: Adrian Hunter <adrian.hunter@...el.com>
Cc: Jiri Olsa <jolsa@...hat.com>
Link: http://lkml.kernel.org/r/1443186956-18718-16-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>
---
 tools/perf/builtin-report.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index e94e5c7..37c9f51 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -809,6 +809,10 @@ int cmd_report(int argc, const char **argv, const char *prefix __maybe_unused)
 	if (report.inverted_callchain)
 		callchain_param.order = ORDER_CALLER;
 
+	if (itrace_synth_opts.callchain &&
+	    (int)itrace_synth_opts.callchain_sz > report.max_stack)
+		report.max_stack = itrace_synth_opts.callchain_sz;
+
 	if (!input_name || !strlen(input_name)) {
 		if (!fstat(STDIN_FILENO, &st) && S_ISFIFO(st.st_mode))
 			input_name = "-";
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/