lkml.org 
[lkml]   [2015]   [May]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH] perf: fix wrong DEBUG configuration
On 05/20/2015 04:55 PM, Ingo Molnar wrote:
>
> * Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
>
>> Em Wed, May 20, 2015 at 03:29:37PM +0200, Martin Liška escreveu:
>>> On 05/20/2015 03:17 PM, Arnaldo Carvalho de Melo wrote:
>>>> Em Wed, May 20, 2015 at 03:07:39PM +0200, Martin Liška escreveu:
>>>>> Currently, GCC optimizes -O6 same as -O3 level. Right optimize debugging
>>>>> experience is given by passing -Og to compiler.
>>
>>>> Is this is this -Og available in old gcc versions? When was it
>>>> introduced? Do you know?
>>
>>> GCC 4.8.0 is the first version capable of the option: https://gcc.gnu.org/gcc-4.8/changes.html.
>>> That can be problematic, which GCC version do you support in linux/perf?
>>
>> So the rule has been: What are the kernel requirements for the
>> toolchain? tools/perf/ should build with that.
>
> So we could use -Og if it works, like Kbuild does it:
>
> KBUILD_CFLAGS += $(call cc-option,-mno-fp-ret-in-387)
>
> the 'cc-option' Make function does some magic of silently calling GCC
> with that option and observing the result.
>
> See:
>
> scripts/Kbuild.include:cc-option = $(call try-run,\
>
> et al.
>
> Thanks,
>
> Ingo
>

Hi.

I am sorry, I did mistake in understanding of DEBUG variable.
Following patch should be fixed, except missing auto-detection
of -Og option.

Unfortunately, following hunk does not work, no -Ox is added to CFLAGS?

-- CFLAGS += -Og
++ CFLAGS += $(call cc-option,-Og,-O0)


Thanks,
Martin
From 98ef10fcb27afc3ae7aaab3ebd157ab90b3b1afe Mon Sep 17 00:00:00 2001
From: mliska <mliska@suse.cz>
Date: Thu, 2 Apr 2015 15:24:49 +0200
Subject: [PATCH] perf: fix wrong DEBUG configuration

Currently, GCC optimizes -O6 same as -O3 level, thus change the value
to -O6.
Right optimize debugging experience is given by passing -Og to compiler.
Assign default value for pointers that are identified by compiler as
non-initialized.

Signed-off-by: Martin Liska <mliska@suse.cz>
---
tools/perf/arch/common.c | 2 +-
tools/perf/config/Makefile | 4 +++-
tools/perf/util/symbol.c | 2 +-
tools/perf/util/trace-event-parse.c | 2 +-
4 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/tools/perf/arch/common.c b/tools/perf/arch/common.c
index 49776f1..b7bb42c 100644
--- a/tools/perf/arch/common.c
+++ b/tools/perf/arch/common.c
@@ -61,7 +61,7 @@ const char *const mips_triplets[] = {
static bool lookup_path(char *name)
{
bool found = false;
- char *path, *tmp;
+ char *path, *tmp = NULL;
char buf[PATH_MAX];
char *env = getenv("PATH");

diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
index e3b3724..6a29320 100644
--- a/tools/perf/config/Makefile
+++ b/tools/perf/config/Makefile
@@ -129,7 +129,9 @@ ifndef DEBUG
endif

ifeq ($(DEBUG),0)
- CFLAGS += -O6
+ CFLAGS += -O3
+else
+ CFLAGS += -Og
endif

ifdef PARSER_DEBUG
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 82a31fd..a19fbd4 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -400,7 +400,7 @@ static struct symbol *symbols__find_by_name(struct rb_root *symbols,
const char *name)
{
struct rb_node *n;
- struct symbol_name_rb_node *s;
+ struct symbol_name_rb_node *s = NULL;

if (symbols == NULL)
return NULL;
diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
index 25d6c73..d495741 100644
--- a/tools/perf/util/trace-event-parse.c
+++ b/tools/perf/util/trace-event-parse.c
@@ -173,7 +173,7 @@ void parse_ftrace_printk(struct pevent *pevent,
char *line;
char *next = NULL;
char *addr_str;
- char *fmt;
+ char *fmt = NULL;

line = strtok_r(file, "\n", &next);
while (line) {
--
2.1.4
\
 
 \ /
  Last update: 2015-05-20 18:41    [W:0.086 / U:0.268 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site