renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-20 19:23:57 +08:00
Code

perf report: Use properly build_id kernel binaries

Browse Source 
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 b25114817a
   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>
This commit is contained in:
Jiri Olsa 2011-06-01 21:43:46 +02:00 committed by Arnaldo Carvalho de Melo
parent fc8ed7be73
commit f57b05ed53
3 changed files with 42 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
tools/perf/util/header.c
View File

@ -726,7 +726,16 @@ static int perf_header__read_build_ids_abi_quirk(struct perf_header *header,
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);

57
tools/perf/util/symbol.c
View File

@ -2181,27 +2181,22 @@ size_t machines__fprintf_dsos_buildid(struct rb_root *machines,
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;
}
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;
dso__set_short_name(dso, short_name);
dso->kernel = dso_type;
}
return dso;
@ -2219,24 +2214,36 @@ void dso__read_running_kernel_build_id(struct dso *dso, struct machine *machine)
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 @@ void machine__destroy_kernel_maps(struct machine *machine)
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)

1
tools/perf/util/symbol.h
View File

@ -155,7 +155,6 @@ struct dso {
};
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);