2010-11-29 17:56:37

by Arnaldo Carvalho de Melo

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Subject: [PATCH 0/2] *** SUBJECT HERE ***

*** BLURB HERE ***

Arnaldo Carvalho de Melo (1):
perf symbols: Fix kallsyms kernel/module map splitting

Ming Lei (1):
perf symbols: Figure out start address of kernel map from kallsyms

tools/perf/util/symbol.c | 59 +++++++++++++++++++++++++++++++++++++++++----
1 files changed, 53 insertions(+), 6 deletions(-)


2010-11-29 17:56:25

by Arnaldo Carvalho de Melo

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Subject: [PATCH 1/2] perf symbols: Fix kallsyms kernel/module map splitting

From: Arnaldo Carvalho de Melo <[email protected]>

On ARM, module addresss space is ahead of kernel space, so the module
symbols are handled before kernel symbol in dso__split_kallsyms, then
was causing one map to be created for each kernel symbol.

Reported-by: Ming Lei <[email protected]>
Tested-by: Ming Lei <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Ming Lei <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Tom Zanussi <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
tools/perf/util/symbol.c | 16 +++++++++++-----
1 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 0500895..2af4d7d 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -532,7 +532,7 @@ static int dso__split_kallsyms(struct dso *self, struct map *map,
struct machine *machine = kmaps->machine;
struct map *curr_map = map;
struct symbol *pos;
- int count = 0;
+ int count = 0, moved = 0;
struct rb_root *root = &self->symbols[map->type];
struct rb_node *next = rb_first(root);
int kernel_range = 0;
@@ -590,6 +590,11 @@ static int dso__split_kallsyms(struct dso *self, struct map *map,
char dso_name[PATH_MAX];
struct dso *dso;

+ if (count == 0) {
+ curr_map = map;
+ goto filter_symbol;
+ }
+
if (self->kernel == DSO_TYPE_GUEST_KERNEL)
snprintf(dso_name, sizeof(dso_name),
"[guest.kernel].%d",
@@ -615,7 +620,7 @@ static int dso__split_kallsyms(struct dso *self, struct map *map,
map_groups__insert(kmaps, curr_map);
++kernel_range;
}
-
+filter_symbol:
if (filter && filter(curr_map, pos)) {
discard_symbol: rb_erase(&pos->rb_node, root);
symbol__delete(pos);
@@ -623,8 +628,9 @@ discard_symbol: rb_erase(&pos->rb_node, root);
if (curr_map != map) {
rb_erase(&pos->rb_node, root);
symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
- }
- count++;
+ ++moved;
+ } else
+ ++count;
}
}

@@ -634,7 +640,7 @@ discard_symbol: rb_erase(&pos->rb_node, root);
dso__set_loaded(curr_map->dso, curr_map->type);
}

- return count;
+ return count + moved;
}

int dso__load_kallsyms(struct dso *self, const char *filename,
--
1.6.2.5

2010-11-29 17:56:50

by Arnaldo Carvalho de Melo

[permalink] [raw]
Subject: [PATCH 2/2] perf symbols: Figure out start address of kernel map from kallsyms

From: Ming Lei <[email protected]>

On ARM, module symbol start address is ahead of kernel symbol start address, so
we can't suppose that the start address of kernel map always is zero, otherwise
may cause incorrect .start and .end of kernel map (caused by fixup) when there
are modules loaded, then map_groups__find may return incorrect map for symbol
query.

This patch always figures out the start address of kernel map from
/proc/kallsyms if the file is available, so fix the issues on ARM for module
loaded case.

This patch fixes the following issues on ARM when modules are loaded:

- vmlinux symbol can't be found by kallsyms maps doing 'perf test'
- module symbols are parsed mistakenlly when doing 'perf top'/'perf report'

Cc: Ian Munsie <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Tom Zanussi <[email protected]>
LKML-Reference: <20101125192725.62d31b42@tom-lei>
Signed-off-by: Ming Lei <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
tools/perf/util/symbol.c | 43 ++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 42 insertions(+), 1 deletions(-)

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 2af4d7d..d628c8d 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -2131,14 +2131,55 @@ static struct dso *machine__create_kernel(struct machine *self)
return kernel;
}

+struct process_args {
+ u64 start;
+};
+
+static int symbol__in_kernel(void *arg, const char *name,
+ char type __used, u64 start)
+{
+ struct process_args *args = arg;
+
+ if (strchr(name, '['))
+ return 0;
+
+ args->start = start;
+ return 1;
+}
+
+/* Figure out the start address of kernel map from /proc/kallsyms */
+static u64 machine__get_kernel_start_addr(struct machine *machine)
+{
+ const char *filename;
+ char path[PATH_MAX];
+ struct process_args args;
+
+ if (machine__is_host(machine)) {
+ filename = "/proc/kallsyms";
+ } else {
+ if (machine__is_default_guest(machine))
+ filename = (char *)symbol_conf.default_guest_kallsyms;
+ else {
+ sprintf(path, "%s/proc/kallsyms", machine->root_dir);
+ filename = path;
+ }
+ }
+
+ if (kallsyms__parse(filename, &args, symbol__in_kernel) <= 0)
+ return 0;
+
+ return args.start;
+}
+
int __machine__create_kernel_maps(struct machine *self, struct dso *kernel)
{
enum map_type type;
+ u64 start = machine__get_kernel_start_addr(self);

for (type = 0; type < MAP__NR_TYPES; ++type) {
struct kmap *kmap;

- self->vmlinux_maps[type] = map__new2(0, kernel, type);
+ self->vmlinux_maps[type] = map__new2(start, kernel, type);
if (self->vmlinux_maps[type] == NULL)
return -1;

--
1.6.2.5

2010-11-29 18:54:29

by Arnaldo Carvalho de Melo

[permalink] [raw]
Subject: Re: [PATCH 0/2] perf/urgent fixes

ENOCOFFEE :-\ Sorry

Hi Ingo,

Please pull from:

git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux-2.6 perf/urgent

Regards,

- Arnaldo


Em Mon, Nov 29, 2010 at 03:56:10PM -0200, Arnaldo Carvalho de Melo escreveu:
> *** BLURB HERE ***
>
> Arnaldo Carvalho de Melo (1):
> perf symbols: Fix kallsyms kernel/module map splitting
>
> Ming Lei (1):
> perf symbols: Figure out start address of kernel map from kallsyms
>
> tools/perf/util/symbol.c | 59 +++++++++++++++++++++++++++++++++++++++++----
> 1 files changed, 53 insertions(+), 6 deletions(-)