Commit c4f43922 authored by Ian Rogers's avatar Ian Rogers Committed by Arnaldo Carvalho de Melo
Browse files

perf header: Add e_machine/e_flags to the header 



Add 64-bits of feature data to record the ELF machine and flags.

This allows readers to initialize based on the data.

For example, `perf kvm stat` wants to initialize based on the kind of
data to be read, but at initialization time there are no threads to base
this data upon and using the host means cross platform support won't
work.

The values in the perf_env also act as a cache for these within the
session.

Signed-off-by: default avatarIan Rogers <irogers@google.com>
Cc: Aditya Bodkhe <aditya.b1@linux.ibm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrew Jones <ajones@ventanamicro.com>
Cc: Anubhav Shelat <ashelat@redhat.com>
Cc: Anup Patel <anup@brainfault.org>
Cc: Athira Rajeev <atrajeev@linux.ibm.com>
Cc: Blake Jones <blakejones@google.com>
Cc: Chun-Tse Shao <ctshao@google.com>
Cc: Dapeng Mi <dapeng1.mi@linux.intel.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <pjw@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quan Zhou <zhouquan@iscas.ac.cn>
Cc: Shimin Guo <shimin.guo@skydio.com>
Cc: Swapnil Sapkal <swapnil.sapkal@amd.com>
Cc: Thomas Falcon <thomas.falcon@intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yunseong Kim <ysk@kzalloc.com>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 07ad6f31

tools/perf/util/env.h

+3 −0
Original line number Diff line number Diff line
@@ -74,6 +74,9 @@ struct perf_env { 
	char			*os_release;

	char			*version;

	char			*arch;

	/* e_machine expanded from 16 to 32-bits for alignment. */

	u32			e_machine;

	u32			e_flags;

	int			nr_cpus_online;

	int			nr_cpus_avail;

	char			*cpu_desc;

tools/perf/util/header.c

+33 −0
Original line number Diff line number Diff line
@@ -379,6 +379,21 @@ static int write_arch(struct feat_fd *ff, 
	return do_write_string(ff, uts.machine);

}



static int write_e_machine(struct feat_fd *ff,

			   struct evlist *evlist __maybe_unused)

{

	/* e_machine expanded from 16 to 32-bits for alignment. */

	uint32_t e_flags;

	uint32_t e_machine = perf_session__e_machine(evlist->session, &e_flags);

	int ret;



	ret = do_write(ff, &e_machine, sizeof(e_machine));

	if (ret)

		return ret;



	return do_write(ff, &e_flags, sizeof(e_flags));

}



static int write_version(struct feat_fd *ff,

			 struct evlist *evlist __maybe_unused)

{
@@ -1785,6 +1800,12 @@ static void print_arch(struct feat_fd *ff, FILE *fp) 
	fprintf(fp, "# arch : %s\n", ff->ph->env.arch);

}



static void print_e_machine(struct feat_fd *ff, FILE *fp)

{

	fprintf(fp, "# e_machine : %u\n", ff->ph->env.e_machine);

	fprintf(fp, "#   e_flags : %u\n", ff->ph->env.e_flags);

}



static void print_cpudesc(struct feat_fd *ff, FILE *fp)

{

	fprintf(fp, "# cpudesc : %s\n", ff->ph->env.cpu_desc);
@@ -2612,6 +2633,17 @@ FEAT_PROCESS_STR_FUN(arch, arch); 
FEAT_PROCESS_STR_FUN(cpudesc, cpu_desc);

FEAT_PROCESS_STR_FUN(cpuid, cpuid);



static int process_e_machine(struct feat_fd *ff, void *data __maybe_unused)

{

	int ret;



	ret = do_read_u32(ff, &ff->ph->env.e_machine);

	if (ret)

		return ret;



	return do_read_u32(ff, &ff->ph->env.e_flags);

}



#ifdef HAVE_LIBTRACEEVENT

static int process_tracing_data(struct feat_fd *ff, void *data)

{
@@ -3730,6 +3762,7 @@ const struct perf_header_feature_ops feat_ops[HEADER_LAST_FEATURE] = { 
	FEAT_OPN(HYBRID_TOPOLOGY,	hybrid_topology,	true),

	FEAT_OPR(PMU_CAPS,	pmu_caps,	false),

	FEAT_OPR(CPU_DOMAIN_INFO,	cpu_domain_info,	true),

	FEAT_OPR(E_MACHINE,	e_machine,	false),

};



struct header_print_data {

tools/perf/util/header.h

+1 −0
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ enum { 
	HEADER_HYBRID_TOPOLOGY,

	HEADER_PMU_CAPS,

	HEADER_CPU_DOMAIN_INFO,

	HEADER_E_MACHINE,

	HEADER_LAST_FEATURE,

	HEADER_FEAT_BITS	= 256,

};

tools/perf/util/session.c

+27 −6
Original line number Diff line number Diff line
@@ -2967,7 +2967,6 @@ struct perf_env *perf_session__env(struct perf_session *session) 
struct perf_session__e_machine_cb_args {

	uint32_t e_flags;

	uint16_t e_machine;

	bool need_e_flags;

};



static int perf_session__e_machine_cb(struct thread *thread, void *_args)
@@ -2975,8 +2974,7 @@ static int perf_session__e_machine_cb(struct thread *thread, void *_args) 
	struct perf_session__e_machine_cb_args *args = _args;

	struct machine *machine = maps__machine(thread__maps(thread));



	args->e_machine = thread__e_machine(thread, machine,

					    args->need_e_flags ? &args->e_flags : NULL);

	args->e_machine = thread__e_machine(thread, machine, &args->e_flags);

	return args->e_machine != EM_NONE ? 1 : 0;

}
@@ -2988,8 +2986,8 @@ uint16_t perf_session__e_machine(struct perf_session *session, uint32_t *e_flags 
{

	struct perf_session__e_machine_cb_args args = {

		.e_machine = EM_NONE,

		.need_e_flags = e_flags != NULL,

	};

	struct perf_env *env;



	if (!session) {

		/* Default to assuming a host machine. */
@@ -2999,12 +2997,35 @@ uint16_t perf_session__e_machine(struct perf_session *session, uint32_t *e_flags 
		return EM_HOST;

	}



	env = perf_session__env(session);

	if (env && env->e_machine != EM_NONE) {

		if (e_flags)

			*e_flags = env->e_flags;



		return env->e_machine;

	}



	machines__for_each_thread(&session->machines,

				  perf_session__e_machine_cb,

				  &args);



	if (args.e_machine != EM_NONE) {

		if (env) {

			env->e_machine = args.e_machine;

			env->e_flags = args.e_flags;

		}

		if (e_flags)

			*e_flags = args.e_flags;



	return args.e_machine == EM_NONE ? EM_HOST : args.e_machine;

		return args.e_machine;

	}



	/*

	 * Couldn't determine from the perf_env or current set of

	 * threads. Default to the host.

	 */

	if (e_flags)

		*e_flags = EF_HOST;



	return EM_HOST;

}