perf report: Use properly build_id kernel binaries

If we bring the recorded perf data together with kernel binary from another machine using: on server A: perf archive on server B: tar xjvf perf.data.tar.bz2 -C ~/.debug the build_id kernel dso is not properly recognized during the "perf report" command on server B. The reason is, that build_id dsos are added during the session initialization, while the kernel maps are created during the sample event processing. The machine__create_kernel_maps functions ends up creating new dso object for kernel, but it does not check if we already have one added by build_id processing. Also the build_id reading ABI quirk added in commit: - commit b25114817a73bbd2b84ce9dba02ee1ef8989a947 perf build-id: Add quirk to deal with perf.data file format breakage populates the "struct build_id_event::pid" with 0, which is later interpreted as DEFAULT_GUEST_KERNEL_ID. This is not always correct, so it's better to guess the pid value based on the "struct build_id_event::header::misc" value. - Tested with data generated on x86 kernel version v2.6.34 and reported back on x86_64 current kernel. - Not tested for guest kernel case. Note the problem stays for PERF_RECORD_MMAP events recorded by perf that does not use proper pid (HOST_KERNEL_ID/DEFAULT_GUEST_KERNEL_ID). They are misinterpreted within the current perf code. Probably there's not much we can do about that. Cc: Avi Kivity <avi@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com> Link: http://lkml.kernel.org/r/20110601194346.GB1934@jolsa.brq.redhat.com Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf report: Use properly build_id kernel binaries
If we bring the recorded perf data together with kernel binary from another machine using: on server A: perf archive on server B: tar xjvf perf.data.tar.bz2 -C ~/.debug the build_id kernel dso is not properly recognized during the "perf report" command on server B. The reason is, that build_id dsos are added during the session initialization, while the kernel maps are created during the sample event processing. The machine__create_kernel_maps functions ends up creating new dso object for kernel, but it does not check if we already have one added by build_id processing. Also the build_id reading ABI quirk added in commit: - commit b25114817a73bbd2b84ce9dba02ee1ef8989a947 perf build-id: Add quirk to deal with perf.data file format breakage populates the "struct build_id_event::pid" with 0, which is later interpreted as DEFAULT_GUEST_KERNEL_ID. This is not always correct, so it's better to guess the pid value based on the "struct build_id_event::header::misc" value. - Tested with data generated on x86 kernel version v2.6.34 and reported back on x86_64 current kernel. - Not tested for guest kernel case. Note the problem stays for PERF_RECORD_MMAP events recorded by perf that does not use proper pid (HOST_KERNEL_ID/DEFAULT_GUEST_KERNEL_ID). They are misinterpreted within the current perf code. Probably there's not much we can do about that. Cc: Avi Kivity <avi@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com> Link: http://lkml.kernel.org/r/20110601194346.GB1934@jolsa.brq.redhat.com Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Jiri Olsa · Arnaldo Carvalho de Melo
1 parent fc8ed7be73
Showing 3 changed files with 42 additions and 27 deletions Side-by-side Diff
tools/perf/util/header.c
tools/perf/util/symbol.c
tools/perf/util/symbol.h
@@ -726,7 +726,16 @@
 			return -1;
  
 		bev.header = old_bev.header;
-		bev.pid	   = 0;
+
+		/*
+		 * As the pid is the missing value, we need to fill
+		 * it properly. The header.misc value give us nice hint.
+		 */
+		bev.pid	= HOST_KERNEL_ID;
+		if (bev.header.misc == PERF_RECORD_MISC_GUEST_USER ||
+		    bev.header.misc == PERF_RECORD_MISC_GUEST_KERNEL)
+			bev.pid	= DEFAULT_GUEST_KERNEL_ID;
+
 		memcpy(bev.build_id, old_bev.build_id, sizeof(bev.build_id));
 		__event_process_build_id(&bev, filename, session);
  
@@ -2181,32 +2181,27 @@
 	return ret;
 }
  
-struct dso *dso__new_kernel(const char *name)
+static struct dso*
+dso__kernel_findnew(struct machine *machine, const char *name,
+		    const char *short_name, int dso_type)
 {
-	struct dso *dso = dso__new(name ?: "[kernel.kallsyms]");
+	/*
+	 * The kernel dso could be created by build_id processing.
+	 */
+	struct dso *dso = __dsos__findnew(&machine->kernel_dsos, name);
  
+	/*
+	 * We need to run this in all cases, since during the build_id
+	 * processing we had no idea this was the kernel dso.
+	 */
 	if (dso != NULL) {
-		dso__set_short_name(dso, "[kernel]");
-		dso->kernel = DSO_TYPE_KERNEL;
+		dso__set_short_name(dso, short_name);
+		dso->kernel = dso_type;
 	}
  
 	return dso;
 }
  
-static struct dso *dso__new_guest_kernel(struct machine *machine,
-					const char *name)
-{
-	char bf[PATH_MAX];
-	struct dso *dso = dso__new(name ?: machine__mmap_name(machine, bf,
-							      sizeof(bf)));
-	if (dso != NULL) {
-		dso__set_short_name(dso, "[guest.kernel]");
-		dso->kernel = DSO_TYPE_GUEST_KERNEL;
-	}
-
-	return dso;
-}
-
 void dso__read_running_kernel_build_id(struct dso *dso, struct machine *machine)
 {
 	char path[PATH_MAX];
  
  
  
  
  
@@ -2219,24 +2214,36 @@
 		dso->has_build_id = true;
 }
  
-static struct dso *machine__create_kernel(struct machine *machine)
+static struct dso *machine__get_kernel(struct machine *machine)
 {
 	const char *vmlinux_name = NULL;
 	struct dso *kernel;
  
 	if (machine__is_host(machine)) {
 		vmlinux_name = symbol_conf.vmlinux_name;
-		kernel = dso__new_kernel(vmlinux_name);
+		if (!vmlinux_name)
+			vmlinux_name = "[kernel.kallsyms]";
+
+		kernel = dso__kernel_findnew(machine, vmlinux_name,
+					     "[kernel]",
+					     DSO_TYPE_KERNEL);
 	} else {
+		char bf[PATH_MAX];
+
 		if (machine__is_default_guest(machine))
 			vmlinux_name = symbol_conf.default_guest_vmlinux_name;
-		kernel = dso__new_guest_kernel(machine, vmlinux_name);
+		if (!vmlinux_name)
+			vmlinux_name = machine__mmap_name(machine, bf,
+							  sizeof(bf));
+
+		kernel = dso__kernel_findnew(machine, vmlinux_name,
+					     "[guest.kernel]",
+					     DSO_TYPE_GUEST_KERNEL);
 	}
  
-	if (kernel != NULL) {
+	if (kernel != NULL && (!kernel->has_build_id))
 		dso__read_running_kernel_build_id(kernel, machine);
-		dsos__add(&machine->kernel_dsos, kernel);
-	}
+
 	return kernel;
 }
  
@@ -2340,7 +2347,7 @@
  
 int machine__create_kernel_maps(struct machine *machine)
 {
-	struct dso *kernel = machine__create_kernel(machine);
+	struct dso *kernel = machine__get_kernel(machine);
  
 	if (kernel == NULL ||
 	    __machine__create_kernel_maps(machine, kernel) < 0)
@@ -155,7 +155,6 @@
 };
  
 struct dso *dso__new(const char *name);
-struct dso *dso__new_kernel(const char *name);
 void dso__delete(struct dso *dso);
  
 int dso__name_len(const struct dso *dso);
...	...	@@ -726,7 +726,16 @@
726	726	return -1;
727	727
728	728	bev.header = old_bev.header;
729		- bev.pid = 0;
	729	+
	730	+ /*
	731	+ * As the pid is the missing value, we need to fill
	732	+ * it properly. The header.misc value give us nice hint.
	733	+ */
	734	+ bev.pid = HOST_KERNEL_ID;
	735	+ if (bev.header.misc == PERF_RECORD_MISC_GUEST_USER \|\|
	736	+ bev.header.misc == PERF_RECORD_MISC_GUEST_KERNEL)
	737	+ bev.pid = DEFAULT_GUEST_KERNEL_ID;
	738	+
730	739	memcpy(bev.build_id, old_bev.build_id, sizeof(bev.build_id));
731	740	__event_process_build_id(&bev, filename, session);
732	741
...	...	@@ -2181,32 +2181,27 @@
2181	2181	return ret;
2182	2182	}
2183	2183
2184		-struct dso dso__new_kernel(const char name)
	2184	+static struct dso*
	2185	+dso__kernel_findnew(struct machine machine, const char name,
	2186	+ const char *short_name, int dso_type)
2185	2187	{
2186		- struct dso *dso = dso__new(name ?: "[kernel.kallsyms]");
	2188	+ /*
	2189	+ * The kernel dso could be created by build_id processing.
	2190	+ */
	2191	+ struct dso *dso = __dsos__findnew(&machine->kernel_dsos, name);
2187	2192
	2193	+ /*
	2194	+ * We need to run this in all cases, since during the build_id
	2195	+ * processing we had no idea this was the kernel dso.
	2196	+ */
2188	2197	if (dso != NULL) {
2189		- dso__set_short_name(dso, "[kernel]");
2190		- dso->kernel = DSO_TYPE_KERNEL;
	2198	+ dso__set_short_name(dso, short_name);
	2199	+ dso->kernel = dso_type;
2191	2200	}
2192	2201
2193	2202	return dso;
2194	2203	}
2195	2204
2196		-static struct dso dso__new_guest_kernel(struct machine machine,
2197		- const char *name)
2198		-{
2199		- char bf[PATH_MAX];
2200		- struct dso *dso = dso__new(name ?: machine__mmap_name(machine, bf,
2201		- sizeof(bf)));
2202		- if (dso != NULL) {
2203		- dso__set_short_name(dso, "[guest.kernel]");
2204		- dso->kernel = DSO_TYPE_GUEST_KERNEL;
2205		- }
2206		-
2207		- return dso;
2208		-}
2209		-
2210	2205	void dso__read_running_kernel_build_id(struct dso dso, struct machine machine)
2211	2206	{
2212	2207	char path[PATH_MAX];
2213	2208
2214	2209
2215	2210
2216	2211
2217	2212
...	...	@@ -2219,24 +2214,36 @@
2219	2214	dso->has_build_id = true;
2220	2215	}
2221	2216
2222		-static struct dso machine__create_kernel(struct machine machine)
	2217	+static struct dso machine__get_kernel(struct machine machine)
2223	2218	{
2224	2219	const char *vmlinux_name = NULL;
2225	2220	struct dso *kernel;
2226	2221
2227	2222	if (machine__is_host(machine)) {
2228	2223	vmlinux_name = symbol_conf.vmlinux_name;
2229		- kernel = dso__new_kernel(vmlinux_name);
	2224	+ if (!vmlinux_name)
	2225	+ vmlinux_name = "[kernel.kallsyms]";
	2226	+
	2227	+ kernel = dso__kernel_findnew(machine, vmlinux_name,
	2228	+ "[kernel]",
	2229	+ DSO_TYPE_KERNEL);
2230	2230	} else {
	2231	+ char bf[PATH_MAX];
	2232	+
2231	2233	if (machine__is_default_guest(machine))
2232	2234	vmlinux_name = symbol_conf.default_guest_vmlinux_name;
2233		- kernel = dso__new_guest_kernel(machine, vmlinux_name);
	2235	+ if (!vmlinux_name)
	2236	+ vmlinux_name = machine__mmap_name(machine, bf,
	2237	+ sizeof(bf));
	2238	+
	2239	+ kernel = dso__kernel_findnew(machine, vmlinux_name,
	2240	+ "[guest.kernel]",
	2241	+ DSO_TYPE_GUEST_KERNEL);
2234	2242	}
2235	2243
2236		- if (kernel != NULL) {
	2244	+ if (kernel != NULL && (!kernel->has_build_id))
2237	2245	dso__read_running_kernel_build_id(kernel, machine);
2238		- dsos__add(&machine->kernel_dsos, kernel);
2239		- }
	2246	+
2240	2247	return kernel;
2241	2248	}
2242	2249
...	...	@@ -2340,7 +2347,7 @@
2340	2347
2341	2348	int machine__create_kernel_maps(struct machine *machine)
2342	2349	{
2343		- struct dso *kernel = machine__create_kernel(machine);
	2350	+ struct dso *kernel = machine__get_kernel(machine);
2344	2351
2345	2352	if (kernel == NULL \|\|
2346	2353	__machine__create_kernel_maps(machine, kernel) < 0)
...	...	@@ -155,7 +155,6 @@
155	155	};
156	156
157	157	struct dso dso__new(const char name);
158		-struct dso dso__new_kernel(const char name);
159	158	void dso__delete(struct dso *dso);
160	159
161	160	int dso__name_len(const struct dso *dso);