Re: [PATCH V2 25/37] perf script: Add synthesized Intel PT power and ptwrite events

[Adrian Hunter <adrian.hunter@intel.com>]

On 06/28/2017 04:04 PM, Arnaldo Carvalho de Melo wrote:
> Em Fri, May 26, 2017 at 11:17:26AM +0300, Adrian Hunter escreveu:
>> Add definitions for synthesized Intel PT events for power and ptwrite.
>  
>> +++ b/tools/perf/util/event.h
>> +/*
>> + * Raw data formats for synthesized events. Note that raw data plus the raw data
>> + * size (4 bytes) must align to 8-bytes.
>> + */
>> +
>> +struct perf_synth_intel_ptwrite {
>> +	union {
>> +		struct {
>> +			u32	ip		:  1,
>> +				reserved	: 31;
>> +		};
>> +		u32	flags;
>> +	};
>> +	u64	payload;
>> +} __packed;
> 
> 
> some versions of clang and gcc dislike this __packed here:
> 
> In file included from builtin-script.c:5:
> In file included from /git/linux/tools/perf/util/debug.h:8:
> /git/linux/tools/perf/util/event.h:274:2: error: packed attribute is unnecessary for (null) [-Werror,-Wpacked]
>         union {
>         ^
> /git/linux/tools/perf/util/event.h:285:6: error: packed attribute is unnecessary for 'reserved' [-Werror,-Wpacked]
>         u32 reserved;
>             ^
> /git/linux/tools/perf/util/event.h:298:6: error: packed attribute is unnecessary for 'reserved' [-Werror,-Wpacked]
>         u32 reserved;
>             ^
> /git/linux/tools/perf/util/event.h:322:6: error: packed attribute is unnecessary for 'reserved' [-Werror,-Wpacked]
>         u32 reserved;
>             ^
> 4 errors generated.
> mv: can't rename '/tmp/build/perf/.builtin-script.o.tmp': No such file or directory
> 
> /git/linux/tools/build/Makefile.build:101: recipe for target '/tmp/build/perf/builtin-script.o' failed
> 
> Failing in various distros:
> 
> [root@jouet ~]# waitp 3940 ; time dm
>    1 92.3684147260 alpine:3.4: FAIL
>    2 95.9136365930 alpine:3.5: FAIL
>    3 104.8328303770 alpine:3.6: FAIL
>    4 121.6584964930 alpine:edge: FAIL
>    5 37.2536373490 android-ndk:r12b-arm: Ok
>    6 83.9077612370 archlinux:latest: Ok
>    7 14.7094639200 centos:5: FAIL
>    8 16.6371634320 centos:6: FAIL
> 
> Investigating...

Re-reading the documentation for __packed, it seems like the following
might be better:

diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index c283603f59c7..a7547cb3b760 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -278,8 +278,8 @@ struct perf_synth_intel_ptwrite {
 		};
 		u32	flags;
 	};
-	u64	payload;
-} __packed;
+	u64	payload __packed;
+};
 
 struct perf_synth_intel_mwait {
 	u32 reserved;
@@ -291,8 +291,8 @@ struct perf_synth_intel_mwait {
 				reserved2	: 30;
 		};
 		u64	payload;
-	};
-} __packed;
+	} __packed;
+};
 
 struct perf_synth_intel_pwre {
 	u32 reserved;
@@ -305,8 +305,8 @@ struct perf_synth_intel_pwre {
 				reserved2	: 48;
 		};
 		u64	payload;
-	};
-} __packed;
+	} __packed;
+};
 
 struct perf_synth_intel_exstop {
 	union {
@@ -328,8 +328,8 @@ struct perf_synth_intel_pwrx {
 				reserved1	: 52;
 		};
 		u64	payload;
-	};
-} __packed;
+	} __packed;
+};
 
 struct perf_synth_intel_cbr {
 	union {