From nobody Mon Nov 25 10:18:37 2024 Received: from smtpout.efficios.com (smtpout.efficios.com [167.114.26.122]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 727A71DED5D; Mon, 28 Oct 2024 19:11:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=167.114.26.122 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730142677; cv=none; b=k0dF7ZiuYHAIxi6rueHh3LWxa8OKmsUdhMNjZ0KjfJzYFP/KC2GbEVOEu/4uMrhUOMLfx8eq+bJr/eesHIXlhe5neSy8nuu9lhNAoopt0iiduUXe7Q+W5HGUmFEr34wvC75iaGNWbVvzVLWwBhkP8cDeTxNud7tvENhEu15kVA0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730142677; c=relaxed/simple; bh=Vl+dJW1dLHWdx44iF4qkzr4xppHjV8IF1v86QpLfsa4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=D6CA0HFzhbXmqZQKY0jYl5n6zxV2i3+vAylzXHxfwmdLMVv0thRozfWmet38mRwTA2Ay+sHDmQ2jI14aLcjCbjHj4Dj7V/ADiK+QwDbWHRkoxHfwQltl83GElo+nE4EV8oRopG9U6spG871qQd0mwY9SBleLMWrVDvsg0ETfwhk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=efficios.com; spf=pass smtp.mailfrom=efficios.com; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b=Z35fHnfR; arc=none smtp.client-ip=167.114.26.122 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=efficios.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=efficios.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b="Z35fHnfR" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=efficios.com; s=smtpout1; t=1730142673; bh=Vl+dJW1dLHWdx44iF4qkzr4xppHjV8IF1v86QpLfsa4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Z35fHnfR6Jpwz5ma/weSFzXpLqbOyazbXw45RAlxAtyBAql1nIDl5HbNKGzKcBzP2 6S3tSo3uFolDRCNtBwkuW57mTqiA5ApfC0OUlxuAkzIlUqpD60SQpXZw1eAfmAbqIK 9aR0hOYVJrhiA6ZcHws1f4/5IR9zQ0K6kOViFu/nGV58V5Q+LV6CXEmWrYWRYDeOz4 H2Xxan9fWoqs4VcIon7GLMpPGMxTz0CbyJ6o8xWcPRL4Z49UcLMWxF6o5RoJcywoP4 gmUpIeGznWcwN6TPpkabbCVkZv+qg/8lRR0X79O8t06SC/2QXyArFYX5HbrB2IeQfK yaZlhg7v6/F9g== Received: from thinkos.internal.efficios.com (96-127-217-162.qc.cable.ebox.net [96.127.217.162]) by smtpout.efficios.com (Postfix) with ESMTPSA id 4XcjfS2p2Zzs19; Mon, 28 Oct 2024 15:11:12 -0400 (EDT) From: Mathieu Desnoyers To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, Mathieu Desnoyers , Thomas Gleixner , Michael Jeanson , Masami Hiramatsu , Peter Zijlstra , Alexei Starovoitov , Yonghong Song , "Paul E . McKenney" , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Namhyung Kim , Andrii Nakryiko , bpf@vger.kernel.org, Joel Fernandes , Jordan Rife Subject: [RFC PATCH v4 1/4] tracing: Introduce tracepoint extended structure Date: Mon, 28 Oct 2024 15:09:24 -0400 Message-Id: <20241028190927.648953-2-mathieu.desnoyers@efficios.com> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20241028190927.648953-1-mathieu.desnoyers@efficios.com> References: <20241028190927.648953-1-mathieu.desnoyers@efficios.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Shrink the struct tracepoint size from 80 bytes to 72 bytes on x86-64 by moving the (typically NULL) regfunc/unregfunc pointers to an extended structure. Signed-off-by: Mathieu Desnoyers Cc: Michael Jeanson Cc: Steven Rostedt Cc: Masami Hiramatsu Cc: Peter Zijlstra Cc: Alexei Starovoitov Cc: Yonghong Song Cc: Paul E. McKenney Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Cc: Mark Rutland Cc: Alexander Shishkin Cc: Namhyung Kim Cc: Andrii Nakryiko Cc: bpf@vger.kernel.org Cc: Joel Fernandes Cc: Jordan Rife --- include/linux/tracepoint-defs.h | 8 ++++++-- include/linux/tracepoint.h | 19 +++++++++++++------ kernel/tracepoint.c | 9 ++++----- 3 files changed, 23 insertions(+), 13 deletions(-) diff --git a/include/linux/tracepoint-defs.h b/include/linux/tracepoint-def= s.h index 60a6e8314d4c..967c08d9da84 100644 --- a/include/linux/tracepoint-defs.h +++ b/include/linux/tracepoint-defs.h @@ -29,6 +29,11 @@ struct tracepoint_func { int prio; }; =20 +struct tracepoint_ext { + int (*regfunc)(void); + void (*unregfunc)(void); +}; + struct tracepoint { const char *name; /* Tracepoint name */ struct static_key_false key; @@ -36,9 +41,8 @@ struct tracepoint { void *static_call_tramp; void *iterator; void *probestub; - int (*regfunc)(void); - void (*unregfunc)(void); struct tracepoint_func __rcu *funcs; + struct tracepoint_ext *ext; }; =20 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index 0dc67fad706c..83dc24ee8b13 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -302,7 +302,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(t= racepoint_ptr_t *p) * structures, so we create an array of pointers that will be used for ite= ration * on the tracepoints. */ -#define DEFINE_TRACE_FN(_name, _reg, _unreg, proto, args) \ +#define __DEFINE_TRACE_EXT(_name, _ext, proto, args) \ static const char __tpstrtab_##_name[] \ __section("__tracepoints_strings") =3D #_name; \ extern struct static_call_key STATIC_CALL_KEY(tp_func_##_name); \ @@ -316,9 +316,9 @@ static inline struct tracepoint *tracepoint_ptr_deref(t= racepoint_ptr_t *p) .static_call_tramp =3D STATIC_CALL_TRAMP_ADDR(tp_func_##_name), \ .iterator =3D &__traceiter_##_name, \ .probestub =3D &__probestub_##_name, \ - .regfunc =3D _reg, \ - .unregfunc =3D _unreg, \ - .funcs =3D NULL }; \ + .funcs =3D NULL, \ + .ext =3D _ext, \ + }; \ __TRACEPOINT_ENTRY(_name); \ int __traceiter_##_name(void *__data, proto) \ { \ @@ -341,8 +341,15 @@ static inline struct tracepoint *tracepoint_ptr_deref(= tracepoint_ptr_t *p) } \ DEFINE_STATIC_CALL(tp_func_##_name, __traceiter_##_name); =20 -#define DEFINE_TRACE(name, proto, args) \ - DEFINE_TRACE_FN(name, NULL, NULL, PARAMS(proto), PARAMS(args)); +#define DEFINE_TRACE_FN(_name, _reg, _unreg, _proto, _args) \ + struct tracepoint_ext __tracepoint_ext_##_name =3D { \ + .regfunc =3D _reg, \ + .unregfunc =3D _unreg, \ + }; \ + __DEFINE_TRACE_EXT(_name, &__tracepoint_ext_##_name, PARAMS(_proto), PARA= MS(_args)); + +#define DEFINE_TRACE(_name, _proto, _args) \ + __DEFINE_TRACE_EXT(_name, NULL, PARAMS(_proto), PARAMS(_args)); =20 #define EXPORT_TRACEPOINT_SYMBOL_GPL(name) \ EXPORT_SYMBOL_GPL(__tracepoint_##name); \ diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index 6474e2cf22c9..5658dc92f5b5 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -278,8 +278,8 @@ static int tracepoint_add_func(struct tracepoint *tp, struct tracepoint_func *old, *tp_funcs; int ret; =20 - if (tp->regfunc && !static_key_enabled(&tp->key)) { - ret =3D tp->regfunc(); + if (tp->ext && tp->ext->regfunc && !static_key_enabled(&tp->key)) { + ret =3D tp->ext->regfunc(); if (ret < 0) return ret; } @@ -362,9 +362,8 @@ static int tracepoint_remove_func(struct tracepoint *tp, switch (nr_func_state(tp_funcs)) { case TP_FUNC_0: /* 1->0 */ /* Removed last function */ - if (tp->unregfunc && static_key_enabled(&tp->key)) - tp->unregfunc(); - + if (tp->ext && tp->ext->unregfunc && static_key_enabled(&tp->key)) + tp->ext->unregfunc(); static_branch_disable(&tp->key); /* Set iterator static call */ tracepoint_update_call(tp, tp_funcs); --=20 2.39.5