why is perf-report asking for objdump path?

DISCUSSION David Ahern 2 participants 3 messages Nov 1, 2012 – Nov 2, 2012 perf events

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David Ahern

author

2012-11-01 21:09 UTC #0 lore raw

$ /tmp/pbuild/perf report -i perf.data --kallsyms kallsyms
Error:
Please install objdump for i686.
You can add it to PATH, set CROSS_COMPILE or override the default using --objdump.

And worse it refuses to run without it. If I was running the annotate command I could understand the request -- but this is the report path.

Furthermore objdump exists:

$ which objdump
/usr/bin/objdump

yes, the file was created on an i686 target, but I should be able to use the x86_64 host objdump if I were doing an annotate.

David

Namhyung Kim

maintainer

2012-11-02 01:12 UTC #1 lore raw

Hi David,

Quoted 8 lines · David Ahern

$ /tmp/pbuild/perf report -i perf.data --kallsyms kallsyms
Error:
Please install objdump for i686.
You can add it to PATH, set CROSS_COMPILE or override the default
using --objdump.
And worse it refuses to run without it. If I was running the annotate command I could understand the request -- but this is the report path.

Agreed. It should not affect when no annotation was used.

Quoted 8 lines

Furthermore objdump exists:
$ which objdump
/usr/bin/objdump
yes, the file was created on an i686 target, but I should be able to use the x86_64 host objdump if I were doing an annotate.

Could you test the below patch? It'd great if you can do it in a reverse situation - using x86_64 target on i686 host.

Quoted 1 line

From f0a9d6303f83452c8b6f81081abae8fdf9c81778 Mon Sep 17 00:00:00 2001

From: Namhyung Kim <[email protected]>
Date: Fri, 2 Nov 2012 09:48:17 +0900
Subject: [PATCH] perf tools: Use normalized arch name for searching objdump
path

David reported that perf report for i686 target data on x86_64 host failed to work because it tried to find out cross-compiled objdump.

However objdump for x86_64 is compatible to i686 so that it doesn't need to do it at all. To prevent similar artifacts, normalize arch name when comparing host and file architectures.

Reported-by David Ahern <[email protected]>

Cc Irina Tirdea <[email protected]>

Signed-off-by Namhyung Kim <[email protected]>

---
 tools/perf/arch/common.c | 40 +++++++++++++++++++++++++++++++++-------
 1 file changed, 33 insertions(+), 7 deletions(-)

tools/perf/arch/common.c +33 -7

index 2367b253f039..5683529135b1 100644
@@ -93,16 +93,46 @@ static int lookup_triplets(const char *const *triplets, const char *name)
 	return -1;
 }
 
+/*
+ * Return architecture name in a normalized form.
+ * The conversion logic comes from the Makefile.
+ */
+static const char *normalize_arch(char *arch)
+{
+	if (!strcmp(arch, "x86_64"))
+		return "x86";
+	if (arch[0] == 'i' && arch[2] == '8' && arch[3] == '6')
+		return "x86";
+	if (!strcmp(arch, "sun4u") || !strncmp(arch, "sparc", 5))
+		return "sparc";
+	if (!strncmp(arch, "arm", 3) || !strcmp(arch, "sa110"))
+		return "arm";
+	if (!strncmp(arch, "s390", 4))
+		return "s390";
+	if (!strncmp(arch, "parisc", 6))
+		return "parisc";
+	if (!strncmp(arch, "powerpc", 7) || !strncmp(arch, "ppc", 3))
+		return "powerpc";
+	if (!strncmp(arch, "mips", 4))
+		return "mips";
+	if (!strncmp(arch, "sh", 2) && isdigit(arch[2]))
+		return "sh";
+
+	return arch;
+}
+
 static int perf_session_env__lookup_binutils_path(struct perf_session_env *env,
 						  const char *name,
 						  const char **path)
 {
 	int idx;
-	char *arch, *cross_env;
+	const char *arch, *cross_env;
 	struct utsname uts;
 	const char *const *path_list;
 	char *buf = NULL;
 
+	arch = normalize_arch(env->arch);
+
 	if (uname(&uts) < 0)
 		goto out;

@@ -110,7 +140,7 @@ static int perf_session_env__lookup_binutils_path(struct perf_session_env *env,
 	 * We don't need to try to find objdump path for native system.
 	 * Just use default binutils path (e.g.: "objdump").
 	 */
-	if (!strcmp(uts.machine, env->arch))
+	if (!strcmp(normalize_arch(uts.machine), arch))
 		goto out;
 
 	cross_env = getenv("CROSS_COMPILE");

@@ -127,8 +157,6 @@ static int perf_session_env__lookup_binutils_path(struct perf_session_env *env,
 		free(buf);
 	}
 
-	arch = env->arch;
-
 	if (!strcmp(arch, "arm"))
 		path_list = arm_triplets;
 	else if (!strcmp(arch, "powerpc"))

@@ -139,9 +167,7 @@ static int perf_session_env__lookup_binutils_path(struct perf_session_env *env,
 		path_list = s390_triplets;
 	else if (!strcmp(arch, "sparc"))
 		path_list = sparc_triplets;
-	else if (!strcmp(arch, "x86") || !strcmp(arch, "i386") ||
-		 !strcmp(arch, "i486") || !strcmp(arch, "i586") ||
-		 !strcmp(arch, "i686"))
+	else if (!strcmp(arch, "x86"))
 		path_list = x86_triplets;
 	else if (!strcmp(arch, "mips"))
 		path_list = mips_triplets;

Signature · 1 line

1.7.11.7

David Ahern

author

2012-11-02 03:37 UTC #2 lore raw

Quoted 6 lines · Namhyung Kim

From f0a9d6303f83452c8b6f81081abae8fdf9c81778 Mon Sep 17 00:00:00 2001
From: Namhyung Kim<[email protected]>
Date: Fri, 2 Nov 2012 09:48:17 +0900
Subject: [PATCH] perf tools: Use normalized arch name for searching objdump
path

Quoted 7 lines

David reported that perf report for i686 target data on x86_64 host failed to work because it tried to find out cross-compiled objdump.
However objdump for x86_64 is compatible to i686 so that it doesn't need to do it at all. To prevent similar artifacts, normalize arch name when comparing host and file architectures.

This fixes the i686 perf.data file analyzed on x86_64. I don't have time for the reverse - partly because I needed to verify my other point on this bug report: why does objdump path matter for non-annotate commands? Before this patch I can analyze 32-bit ppc files on x86 (an important use case on my end). After the objdump patch it fails -- or rather, I have to add the --objdump argument which is awkward. I don't want to have to educate users to add a non-sensical argument to perf-report (and other specialized commands).

David