perf mem/c2c: Set PERF_SAMPLE_WEIGHT for LOAD_STORE events

Currently perf sets PERF_SAMPLE_WEIGHT flag only for mem load events.
Set it for combined load-store event as well which will enable recording
of load latency by default on arch that does not support independent
mem load event.

Also document missing -W in perf-record man page.

Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ali Saidi <alisaidi@amazon.com>
Cc: Ananth Narayan <ananth.narayan@amd.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kim Phillips <kim.phillips@amd.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Santosh Shukla <santosh.shukla@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Link: https://lore.kernel.org/r/20221006153946.7816-5-ravi.bangoria@amd.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Author: Ravi Bangoria

tools/perf/Documentation/perf-record.txt

@@ -411,6 +411,7 @@ is enabled for all the sampling events. The sampled branch type is the same for
 The various filters must be specified as a comma separated list: --branch-filter any_ret,u,k
 Note that this feature may not be available on all processors.
 
+-W::
 --weight::
 Enable weightened sampling. An additional weight is recorded per sample and can be
 displayed with the weight and local_weight sort keys.  This currently works for TSX

tools/perf/builtin-c2c.c

@@ -3281,6 +3281,7 @@ static int perf_c2c__record(int argc, const char **argv)
 		 */
 		if (e->tag) {
 			e->record = true;
+			rec_argv[i++] = "-W";
 		} else {
 			e = perf_mem_events__ptr(PERF_MEM_EVENTS__LOAD);
 			e->record = true;

tools/perf/builtin-mem.c

@@ -122,6 +122,7 @@ static int __cmd_record(int argc, const char **argv, struct perf_mem *mem)
 	    (mem->operation & MEM_OPERATION_LOAD) &&
 	    (mem->operation & MEM_OPERATION_STORE)) {
 		e->record = true;
+		rec_argv[i++] = "-W";
 	} else {
 		if (mem->operation & MEM_OPERATION_LOAD) {
 			e = perf_mem_events__ptr(PERF_MEM_EVENTS__LOAD);