[GIT PULL 0/2] perf/urgent fixes

[GIT PULL 0/2] perf/urgent fixes

[Arnaldo Carvalho de Melo]

Hi Ingo,

	Please consider pulling,

- Arnaldo

The following changes since commit 65ea03e31e5ab47f784b1a701419264af97d3205:

  Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent (2015-07-15 13:31:21 +0200)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git tags/perf-urgent-for-mingo

for you to fetch changes up to 3c71ba3f80bbd476bbfb2a008da9b676031cbd32:

  perf tools: Really allow to specify custom CC, AR or LD (2015-07-15 11:57:28 -0300)

----------------------------------------------------------------
perf/urgent fixes:

User visible:

- Fix misplaced check for HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT in
  the auxtrace code, which made 'perf record' fail straight away
  in some architectures, even when auxtrace wasn't involved. (Adrian Hunter)

Developer stuff:

- Really allow to specify custom CC, AR or LD (Alexey Brodkin)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

----------------------------------------------------------------
Adrian Hunter (1):
      perf auxtrace: Fix misplaced check for HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT

Alexey Brodkin (1):
      perf tools: Really allow to specify custom CC, AR or LD

 tools/perf/Makefile.perf   | 19 ++++++++++++++++---
 tools/perf/util/auxtrace.c | 10 +++++-----
 2 files changed, 21 insertions(+), 8 deletions(-)

[PATCH 1/2] perf auxtrace: Fix misplaced check for HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT

[Arnaldo Carvalho de Melo]

From: Adrian Hunter <adrian.hunter@intel.com>

Move the checking for HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT for AUX area mmaps
until after checking if such mmaps are used anyway.

Reported-by: Alexey Brodkin <Alexey.Brodkin@synopsys.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Alexey Brodkin <Alexey.Brodkin@synopsys.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Cc: linux-arch@vger.kernel.org
Link: http://lkml.kernel.org/r/55A5023C.7020907@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/auxtrace.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c
index 7e7405c9b936..83d9dd96fe08 100644
--- a/tools/perf/util/auxtrace.c
+++ b/tools/perf/util/auxtrace.c
@@ -53,11 +53,6 @@ int auxtrace_mmap__mmap(struct auxtrace_mmap *mm,
 {
 	struct perf_event_mmap_page *pc = userpg;
 
-#if BITS_PER_LONG != 64 && !defined(HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT)
-	pr_err("Cannot use AUX area tracing mmaps\n");
-	return -1;
-#endif
-
 	WARN_ONCE(mm->base, "Uninitialized auxtrace_mmap\n");
 
 	mm->userpg = userpg;
@@ -73,6 +68,11 @@ int auxtrace_mmap__mmap(struct auxtrace_mmap *mm,
 		return 0;
 	}
 
+#if BITS_PER_LONG != 64 && !defined(HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT)
+	pr_err("Cannot use AUX area tracing mmaps\n");
+	return -1;
+#endif
+
 	pc->aux_offset = mp->offset;
 	pc->aux_size = mp->len;
 
-- 
2.1.0

[PATCH 2/2] perf tools: Really allow to specify custom CC, AR or LD

[Arnaldo Carvalho de Melo]

From: Alexey Brodkin <Alexey.Brodkin@synopsys.com>

Commit 5ef7bbb09f7b ("perf tools: Allow to specify custom linker
command") was meant to enable usage non $(CROSS_COMPILE)ld linker during
perf building.

But implementation didn't take into account the fact that LD is a
pre-defined variable in GNU Make. I.e. it is always defined.

Which means there's no point to check "LD ?= ..." because it will never
succeed.

And so LD will be either that explicitly passed to make like this:

 ------->8-------
 make LD=path_to_my_ld ...
 ------->8-------
 or default value, which is host's "ld".

Latter leads to failure of cross-linkage because instead of cross linker
"$(CROSS_COMPILE)ld" host's "ld" is used.

Fortunately there's a way to do correct substitution of $(CROSS_COMPILE)ld
with user defined LD on command-line.

As a reference was used implementation in "tools/lib/traceevent/Makefile".

Build tested for x86_64 and ARC.

Thanks Jiri for this hint.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Fixes: 5ef7bbb09f7b ("perf tools: Allow to specify custom linker command")
Cc: Aaro Koskinen <aaro.koskinen@nokia.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: linux-arch@vger.kernel.org
Link: http://lkml.kernel.org/r/1436864720-26316-1-git-send-email-abrodkin@synopsys.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/Makefile.perf | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 7a4b549214e3..bba34636b733 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -109,9 +109,22 @@ $(OUTPUT)PERF-VERSION-FILE: ../../.git/HEAD
 	$(Q)$(SHELL_PATH) util/PERF-VERSION-GEN $(OUTPUT)
 	$(Q)touch $(OUTPUT)PERF-VERSION-FILE
 
-CC = $(CROSS_COMPILE)gcc
-LD ?= $(CROSS_COMPILE)ld
-AR = $(CROSS_COMPILE)ar
+# Makefiles suck: This macro sets a default value of $(2) for the
+# variable named by $(1), unless the variable has been set by
+# environment or command line. This is necessary for CC and AR
+# because make sets default values, so the simpler ?= approach
+# won't work as expected.
+define allow-override
+  $(if $(or $(findstring environment,$(origin $(1))),\
+            $(findstring command line,$(origin $(1)))),,\
+    $(eval $(1) = $(2)))
+endef
+
+# Allow setting CC and AR and LD, or setting CROSS_COMPILE as a prefix.
+$(call allow-override,CC,$(CROSS_COMPILE)gcc)
+$(call allow-override,AR,$(CROSS_COMPILE)ar)
+$(call allow-override,LD,$(CROSS_COMPILE)ld)
+
 PKG_CONFIG = $(CROSS_COMPILE)pkg-config
 
 RM      = rm -f
-- 
2.1.0

Re: [GIT PULL 0/2] perf/urgent fixes

[Ingo Molnar]

* Arnaldo Carvalho de Melo <acme@kernel.org> wrote:

> Hi Ingo,
> 
> 	Please consider pulling,
> 
> - Arnaldo
> 
> The following changes since commit 65ea03e31e5ab47f784b1a701419264af97d3205:
> 
>   Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent (2015-07-15 13:31:21 +0200)
> 
> are available in the git repository at:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git tags/perf-urgent-for-mingo
> 
> for you to fetch changes up to 3c71ba3f80bbd476bbfb2a008da9b676031cbd32:
> 
>   perf tools: Really allow to specify custom CC, AR or LD (2015-07-15 11:57:28 -0300)
> 
> ----------------------------------------------------------------
> perf/urgent fixes:
> 
> User visible:
> 
> - Fix misplaced check for HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT in
>   the auxtrace code, which made 'perf record' fail straight away
>   in some architectures, even when auxtrace wasn't involved. (Adrian Hunter)
> 
> Developer stuff:
> 
> - Really allow to specify custom CC, AR or LD (Alexey Brodkin)
> 
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> 
> ----------------------------------------------------------------
> Adrian Hunter (1):
>       perf auxtrace: Fix misplaced check for HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT
> 
> Alexey Brodkin (1):
>       perf tools: Really allow to specify custom CC, AR or LD
> 
>  tools/perf/Makefile.perf   | 19 ++++++++++++++++---
>  tools/perf/util/auxtrace.c | 10 +++++-----
>  2 files changed, 21 insertions(+), 8 deletions(-)

Pulled, thanks Arnaldo!

	Ingo