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perf symbols: Don't try to find a vmlinux file when looking for kernel modules

PATCH Applied Arnaldo Carvalho de Melo 3 participants 5 messages Mar 2, 2020 – Mar 4, 2020 perf events

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#0 lore raw

PATCH 1/1 perf symbols: Don't try to find a vmlinux file when looking for kernel modules

The dso->kernel value is now set to everything that is in machine->kmaps, but that was being used to decide if vmlinux lookup is needed, which ended up making that lookup be made for kernel modules, that now have dso->kernel set, leading to these kinds of warnings when running on a machine with compressed kernel modules, like fedora:31:

[root@five ~]# perf record -F 10000 -a sleep 2
[ perf record: Woken up 1 times to write data ]
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory' [ perf record: Captured and wrote 1.024 MB perf.data (1366 samples) ]
[root@five ~]#

This happens when collecting the buildid, when we find samples for kernel modules, fix it by checking if the looked up DSO is a kernel module by other means.

Fixes 02213cec64bb ("perf maps: Mark module DSOs with kernel type")
Cc Alexander Shishkin <[email protected]>
Cc Jiri Olsa <[email protected]>
Cc Kim Phillips <[email protected]>
Cc Michael Petlan <[email protected]>
Cc Namhyung Kim <[email protected]>
Cc Ravi Bangoria <[email protected]>

---

tools/perf/util/symbol.c +6 -7
index 1077013d8ce2..26bc6a0096ce 100644
@@ -1622,7 +1622,12 @@ int dso__load(struct dso *dso, struct map *map)
 		goto out;
 	}
 
-	if (dso->kernel) {
+	kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
+		dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
+		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
+		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
+
+	if (dso->kernel && !kmod) {
 		if (dso->kernel == DSO_TYPE_KERNEL)
 			ret = dso__load_kernel_sym(dso, map);
 		else if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
@@ -1650,12 +1655,6 @@ int dso__load(struct dso *dso, struct map *map)
 	if (!name)
 		goto out;
 
-	kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
-		dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
-		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
-		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
-
-
 	/*
 	 * Read the build id if possible. This is required for
 	 * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
#1 lore raw
Quoted 36 lines · Arnaldo Carvalho de Melo

The dso->kernel value is now set to everything that is in machine->kmaps, but that was being used to decide if vmlinux lookup is needed, which ended up making that lookup be made for kernel modules, that now have dso->kernel set, leading to these kinds of warnings when running on a machine with compressed kernel modules, like fedora:31:

[root@five ~]# perf record -F 10000 -a sleep 2
[ perf record: Woken up 1 times to write data ]
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory' [ perf record: Captured and wrote 1.024 MB perf.data (1366 samples) ]
[root@five ~]#

Quoted 3 lines

This happens when collecting the buildid, when we find samples for kernel modules, fix it by checking if the looked up DSO is a kernel module by other means.

cool, I just saw your other email and was going to check on it ;-) ging to check on this and review

jirka

Quoted 44 lines
Fixes 02213cec64bb ("perf maps: Mark module DSOs with kernel type")
Cc Alexander Shishkin <[email protected]>
Cc Jiri Olsa <[email protected]>
Cc Kim Phillips <[email protected]>
Cc Michael Petlan <[email protected]>
Cc Namhyung Kim <[email protected]>
Cc Ravi Bangoria <[email protected]>

---

tools/perf/util/symbol.c +6 -7
index 1077013d8ce2..26bc6a0096ce 100644
@@ -1622,7 +1622,12 @@ int dso__load(struct dso *dso, struct map *map)
 		goto out;
 	}
 
-	if (dso->kernel) {
+	kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
+		dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
+		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
+		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
+
+	if (dso->kernel && !kmod) {
 		if (dso->kernel == DSO_TYPE_KERNEL)
 			ret = dso__load_kernel_sym(dso, map);
 		else if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
@@ -1650,12 +1655,6 @@ int dso__load(struct dso *dso, struct map *map)
 	if (!name)
 		goto out;
 
-	kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
-		dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
-		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
-		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
-
-
 	/*
 	 * Read the build id if possible. This is required for
 	 * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
#2 lore raw
In reply to Arnaldo Carvalho de Melo
Quoted 36 lines · Arnaldo Carvalho de Melo

The dso->kernel value is now set to everything that is in machine->kmaps, but that was being used to decide if vmlinux lookup is needed, which ended up making that lookup be made for kernel modules, that now have dso->kernel set, leading to these kinds of warnings when running on a machine with compressed kernel modules, like fedora:31:

[root@five ~]# perf record -F 10000 -a sleep 2
[ perf record: Woken up 1 times to write data ]
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory' [ perf record: Captured and wrote 1.024 MB perf.data (1366 samples) ]
[root@five ~]#

Quoted 5 lines

This happens when collecting the buildid, when we find samples for kernel modules, fix it by checking if the looked up DSO is a kernel module by other means.

Fixes 02213cec64bb ("perf maps: Mark module DSOs with kernel type")

ok, I couldn't see that because kcore took over the modules, for some reason you don't have it enabled on your system?

because I had to disable it manualy in the code.. I think we should add some --no-kcore option for record

the fix is working for me:

Tested/Acked-by: Jiri Olsa <[email protected]>

thanks,
jirka

#3 lore raw

Em Mon, Mar 02, 2020 at 09:02:49PM +0100, Jiri Olsa escreveu:

Quoted 37 lines · Arnaldo Carvalho de Melo
Quoted 36 lines

The dso->kernel value is now set to everything that is in machine->kmaps, but that was being used to decide if vmlinux lookup is needed, which ended up making that lookup be made for kernel modules, that now have dso->kernel set, leading to these kinds of warnings when running on a machine with compressed kernel modules, like fedora:31:

[root@five ~]# perf record -F 10000 -a sleep 2
[ perf record: Woken up 1 times to write data ]
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory' [ perf record: Captured and wrote 1.024 MB perf.data (1366 samples) ]
[root@five ~]#

Quoted 8 lines
Quoted 5 lines

This happens when collecting the buildid, when we find samples for kernel modules, fix it by checking if the looked up DSO is a kernel module by other means.

Fixes 02213cec64bb ("perf maps: Mark module DSOs with kernel type")

ok, I couldn't see that because kcore took over the modules, for some reason you don't have it enabled on your system?

Humm, maybe you don't have a reachable vmlinux so it ends up using /proc/kcore? I even think we should make the default... :-)

Quoted 6 lines

because I had to disable it manualy in the code.. I think we should add some --no-kcore option for record

the fix is working for me:

Tested/Acked-by: Jiri Olsa <[email protected]>

Thanks, for checking!

Quoted 3 lines

thanks,
jirka

Signature · 1 line
- Arnaldo
#4 lore raw
In reply to Arnaldo Carvalho de Melo
The following commit has been merged into the perf/urgent branch of tip:

The following commit has been merged into the perf/urgent branch of tip:

Commit-ID:     b5c0951860ba98cfe1936b5c0739450875d51451
Gitweb:        https://git.kernel.org/tip/b5c0951860ba98cfe1936b5c0739450875d51451
Author:        Arnaldo Carvalho de Melo <[email protected]>
AuthorDate:    Mon, 02 Mar 2020 16:03:34 -03:00
Committer:     Arnaldo Carvalho de Melo <[email protected]>
CommitterDate: Tue, 03 Mar 2020 16:20:01 -03:00

perf symbols: Don't try to find a vmlinux file when looking for kernel modules

The dso->kernel value is now set to everything that is in machine->kmaps, but that was being used to decide if vmlinux lookup is needed, which ended up making that lookup be made for kernel modules, that now have dso->kernel set, leading to these kinds of warnings when running on a machine with compressed kernel modules, like fedora:31:

[root@five ~]# perf record -F 10000 -a sleep 2
[ perf record: Woken up 1 times to write data ]
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
lzma: fopen failed on vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory' [ perf record: Captured and wrote 1.024 MB perf.data (1366 samples) ]
[root@five ~]#

This happens when collecting the buildid, when we find samples for kernel modules, fix it by checking if the looked up DSO is a kernel module by other means.

Fixes 02213cec64bb ("perf maps: Mark module DSOs with kernel type")
Cc Alexander Shishkin <[email protected]>
Cc Kim Phillips <[email protected]>
Cc Michael Petlan <[email protected]>
Cc Namhyung Kim <[email protected]>
Cc Ravi Bangoria <[email protected]>
---
 tools/perf/util/symbol.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)
tools/perf/util/symbol.c +6 -7
index 1077013..26bc6a0 100644
@@ -1622,7 +1622,12 @@ int dso__load(struct dso *dso, struct map *map)
 		goto out;
 	}
 
-	if (dso->kernel) {
+	kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
+		dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
+		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
+		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
+
+	if (dso->kernel && !kmod) {
 		if (dso->kernel == DSO_TYPE_KERNEL)
 			ret = dso__load_kernel_sym(dso, map);
 		else if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
@@ -1650,12 +1655,6 @@ int dso__load(struct dso *dso, struct map *map)
 	if (!name)
 		goto out;
 
-	kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
-		dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
-		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
-		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
-
-
 	/*
 	 * Read the build id if possible. This is required for
 	 * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work