Resubmitted forgotten patches

Pickup some small fixes that have been forgotten.

David Carrillo-Cisneros (3):
perf tool cgroup: Initialize cgroup refcnt with refcount_set perf tools: Add EXCLUDE_EXTLIBS and EXTRA_PERFLIBS to makefile perf annotate: Process tracing data in pipe mode

Sudeep Holla (1):
tools: perf: Fix linker error when libelf config is disabled

 tools/perf/Makefile.perf      | 10 ++++++++--
 tools/perf/builtin-annotate.c |  1 +
 tools/perf/util/cgroup.c      |  5 ++++-
 3 files changed, 13 insertions(+), 3 deletions(-)

2.13.2.932.g7449e964c-goog

Atomic reference counters were replaced by refcount_t in
commit 79c5fe6db8c7 ("perf/core: Fix error handling in perf_event_alloc()")

In util/cgroup.c atomic_inc was replaced by refcount_inc, but the latter is not mean to initiliaze refcounts with zero value. Add a path to initialize cgrp->refcnt == 0 using refcount_set.

Before this patch:

  $ perf stat -e cycles -C 0 -G /
  perf_before: /usr/local/.../tools/include/linux/refcount.h:108: refcount_inc: Assertion `!(!refcount_inc_not_zero(r))' failed.
  Aborted (core dumped)

After this patch:

  $ perf stat -e cycles -C 0 -G /
  Performance counter stats for 'CPU(s) 0':
     17,516,664      cycles                    /

---
 tools/perf/util/cgroup.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

index 03347748f3fa..7bbc19b3caf3 100644
@@ -133,7 +133,10 @@ static int add_cgroup(struct perf_evlist *evlist, char *str)
 
 	return -1;
 found:
-	refcount_inc(&cgrp->refcnt);
+	if (refcount_read(&cgrp->refcnt) == 0)
+		refcount_set(&cgrp->refcnt, 1);
+	else
+		refcount_inc(&cgrp->refcnt);
 	counter->cgrp = cgrp;
 	return 0;
 }

2.13.2.932.g7449e964c-goog

Em Tue, Jul 18, 2017 at 06:18:36PM -0700, David Carrillo-Cisneros escreveu:

Ok, so this one was also reported by Brendan and I came up with an alternative patch, that follows the usual sequence of steps, see below.

- Arnaldo

commit b13ca9843c4ea07c5a1dbf0295986b5dfeb6ef6f

Author: Arnaldo Carvalho de Melo <[email protected]>
Date:   Tue Jul 18 20:20:19 2017 -0300

perf cgroup: Fix refcount usage

When converting from atomic_t to refcount_t we didn't follow the usual step of initializing it to one before taking any new reference, which trips over checking if taking a reference for a freed refcount_t, fix it.

Brendan's report:

---
It's 4.12-rc7, with node v4.4.1. I'm building 4.13-rc1 now, as I hit what I think is another unrelated perf bug and I'm starting to wonder what else is broken on that version:

(root) /mnt/src/linux-4.12-rc7/tools/perf # ./perf record -F 99 -a -e cpu-clock --cgroup=docker/f9e9d5df065b14646e8a11edc837a13877fd90c171137b2ba3feb67a0201cb65 -g
perf: /mnt/src/linux-4.12-rc7/tools/include/linux/refcount.h:108:
refcount_inc: Assertion `!(!refcount_inc_not_zero(r))' failed.
Aborted

that used to work...
---

Testing it:

Before:

# perf stat -e cycles -C 0 --cgroup /
perf: /home/acme/git/linux/tools/include/linux/refcount.h:108: refcount_inc: Assertion `!(!refcount_inc_not_zero(r))' failed. Aborted (core dumped)
#

After:

# perf stat -e cycles -C 0 --cgroup /
^C
Performance counter stats for 'CPU(s) 0':

132,081,393 cycles /

2.492942763 seconds time elapsed

#

index 03347748f3fa..0e77bc9e5f3c 100644
@@ -98,8 +98,10 @@ static int add_cgroup(struct perf_evlist *evlist, char *str)
 		cgrp = counter->cgrp;
 		if (!cgrp)
 			continue;
-		if (!strcmp(cgrp->name, str))
+		if (!strcmp(cgrp->name, str)) {
+			refcount_inc(&cgrp->refcnt);
 			break;
+		}
 
 		cgrp = NULL;
 	}

@@ -110,6 +112,7 @@ static int add_cgroup(struct perf_evlist *evlist, char *str)
 			return -1;
 
 		cgrp->name = str;
+		refcount_set(&cgrp->refcnt, 1);
 
 		cgrp->fd = open_cgroup(str);
 		if (cgrp->fd == -1) {

@@ -128,12 +131,11 @@ static int add_cgroup(struct perf_evlist *evlist, char *str)
 			goto found;
 		n++;
 	}
-	if (refcount_read(&cgrp->refcnt) == 0)
+	if (refcount_dec_and_test(&cgrp->refcnt))
 		free(cgrp);
 
 	return -1;
 found:
-	refcount_inc(&cgrp->refcnt);
 	counter->cgrp = cgrp;
 	return 0;
 }

The goal is to allow users to override linking of libraries that were automatically added to PERFLIBS.

EXCLUDE_EXTLIBS contains linker flags to be removed from LIBS while EXTRA_PERFLIBS contains linker flags to be added.

My use case is to force certain library to be build statically, e.g. for libelf:

EXCLUDE_EXTLIBS=-lelf EXTRA_PERFLIBS=path/libelf.a

---
 tools/perf/Makefile.perf | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

index 5008f51a08a2..100a6c1670c8 100644
@@ -33,6 +33,11 @@ include ../scripts/utilities.mak
 #
 # Define EXTRA_CFLAGS=-m64 or EXTRA_CFLAGS=-m32 as appropriate for cross-builds.
 #
+# Define EXCLUDE_EXTLIBS=-lmylib to exclude libmylib from the auto-generated
+# EXTLIBS.
+#
+# Define EXTRA_PERFLIBS to pass extra libraries to PERFLIBS.
+#
 # Define NO_DWARF if you do not want debug-info analysis feature at all.
 #
 # Define WERROR=0 to disable treating any warnings as errors.

@@ -352,7 +357,8 @@ ifdef ASCIIDOC8
   export ASCIIDOC8
 endif
 
-LIBS = -Wl,--whole-archive $(PERFLIBS) -Wl,--no-whole-archive -Wl,--start-group $(EXTLIBS) -Wl,--end-group
+EXTLIBS := $(call filter-out,$(EXCLUDE_EXTLIBS),$(EXTLIBS))
+LIBS = -Wl,--whole-archive $(PERFLIBS) $(EXTRA_PERFLIBS) -Wl,--no-whole-archive -Wl,--start-group $(EXTLIBS) -Wl,--end-group
 
 ifeq ($(USE_CLANG), 1)
   CLANGLIBS_LIST = AST Basic CodeGen Driver Frontend Lex Tooling Edit Sema Analysis Parse Serialization

2.13.2.932.g7449e964c-goog

perf annotate was missing the handler for tracing data records.

Prior to this patch we obtained "unhandled" records when piping trace events to perf annotate (using -D option to show the dump_printf messages in process_event_synth_tracing_data_stub):

  $ perf record -o - -e block:bio_free sleep 2 | perf annotate -D --stdio
  ...
  0x78 [0xc]: PERF_RECORD_TRACING_DATA: unhandled!
  ...

---
 tools/perf/builtin-annotate.c | 1 +
 1 file changed, 1 insertion(+)

index 5205408e795b..ffe28002dc4f 100644
@@ -397,6 +397,7 @@ int cmd_annotate(int argc, const char **argv)
 			.namespaces = perf_event__process_namespaces,
 			.attr	= perf_event__process_attr,
 			.build_id = perf_event__process_build_id,
+			.tracing_data   = perf_event__process_tracing_data,
 			.feature	= perf_event__process_feature,
 			.ordered_events = true,
 			.ordering_requires_timestamps = true,

2.13.2.932.g7449e964c-goog

From: Sudeep Holla <[email protected]>

When libelf is disabled in the configuration, we get the following linker error:
LINK libperf-jvmti.so
ld: cannot find -lelf
Makefile.perf:515: recipe for target 'libperf-jvmti.so' failed

Jiri pointed out that both librt and libelf are not really required. So this patch fixes the linker error by getting rid of unwanted libraries in the linker stage.

---
 tools/perf/Makefile.perf | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 100a6c1670c8..d66f90e6be5c 100644
@@ -518,7 +518,7 @@ $(LIBJVMTI_IN): FORCE
 	$(Q)$(MAKE) -f $(srctree)/tools/build/Makefile.build dir=jvmti obj=jvmti
 
 $(OUTPUT)$(LIBJVMTI): $(LIBJVMTI_IN)
-	$(QUIET_LINK)$(CC) -shared -Wl,-soname -Wl,$(LIBJVMTI) -o $@ $< -lelf -lrt
+	$(QUIET_LINK)$(CC) -shared -Wl,-soname -Wl,$(LIBJVMTI) -o $@ $<
 endif
 
 $(patsubst perf-%,%.o,$(PROGRAMS)): $(wildcard */*.h)

2.13.2.932.g7449e964c-goog

for patchset:

thanks,
jirka

Em Tue, Jul 18, 2017 at 06:18:35PM -0700, David Carrillo-Cisneros escreveu:

Thanks, applied 2-4, and sent the alternative patch for 1/4 for your information.

- Arnaldo