From patchwork Mon Oct 28 19:09:25 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mathieu Desnoyers X-Patchwork-Id: 13853921 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 81F391E00BD; Mon, 28 Oct 2024 19:11:15 +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=1730142678; cv=none; b=CNGuB5u275fbAf08Ml6z8ycNBNNh7Mh2q9VsNHLl6cJ+9Xto4KQ8IIwHganTfZsF/H5oRPgX9eShPfCQBP+gKFFXjuEIDMJ4upec73OS7419tq4+cEPjVIJq0USRHr0/Xyp9NIi01nT77FdPIKlrs2W6soPXedwQw453gYy+nyU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730142678; c=relaxed/simple; bh=adS58VZKpMyBhjeczUuBLAUJ2Kusr9Rs3Sub45oP7p0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=tU+sGw9sYRuFVcvGMvL35DjNj9tjkjxShDX4bJYoUUFp8o+67jWNVRO8Tp31ZUt61hesO+2n3h5xIM4IaHtEeqlrIZS2H1lL9PGl/S7SeQKixSTJtMzvGz0d3/TGN2ezPk8QcgF/foIwgWPiAmngZEvNT5Va18ygbUHrTDrNJTM= 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=g6sZFsC5; 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="g6sZFsC5" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=efficios.com; s=smtpout1; t=1730142674; bh=adS58VZKpMyBhjeczUuBLAUJ2Kusr9Rs3Sub45oP7p0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=g6sZFsC5pT/r2fXHG4MVsLNwZy9pXSuIgzAAh6KE4Mmg+5Q1rLSncWAsBRFO74KsW fwimsUmtBreOT5gT1wofFXBxKMuSdaujOk9vVQZVZdmkkVfdNhxl0EbVImEtlUdAC+ Phtp2By4nqqApBjG/PrPBELmbRkALQA4WZg6ylMuwiJ3JgEJ0Kxu6SlDCSAfCPof5d UEb5fFazfPQcLu3nCcfqcjwTieREyhUjc4GMhmxaYBjT0/lz0MyTiKuXxjwiXGOBwN itb+PjP0g+JhJ6SwFzGIUmSJACA/LNMn3eXmDjZts6GYCMg8v3it1DLuqQSnzxuvhI ClLGUi9b1PAjA== 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 4XcjfT3R62zsN5; Mon, 28 Oct 2024 15:11:13 -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 2/4] tracing: Introduce tracepoint_is_faultable() Date: Mon, 28 Oct 2024 15:09:25 -0400 Message-Id: <20241028190927.648953-3-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: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-State: RFC Introduce a "faultable" flag within the extended structure to know whether a tracepoint needs rcu tasks trace grace period before reclaim. This can be queried using tracepoint_is_faultable(). 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 Acked-by: Andrii Nakryiko --- include/linux/tracepoint-defs.h | 2 ++ include/linux/tracepoint.h | 24 ++++++++++++++++++++++++ include/trace/define_trace.h | 2 +- 3 files changed, 27 insertions(+), 1 deletion(-) diff --git a/include/linux/tracepoint-defs.h b/include/linux/tracepoint-defs.h index 967c08d9da84..aebf0571c736 100644 --- a/include/linux/tracepoint-defs.h +++ b/include/linux/tracepoint-defs.h @@ -32,6 +32,8 @@ struct tracepoint_func { struct tracepoint_ext { int (*regfunc)(void); void (*unregfunc)(void); + /* Flags. */ + unsigned int faultable:1; }; struct tracepoint { diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index 83dc24ee8b13..259f0ab4ece6 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -104,6 +104,12 @@ void for_each_tracepoint_in_module(struct module *mod, * tracepoint_synchronize_unregister must be called between the last tracepoint * probe unregistration and the end of module exit to make sure there is no * caller executing a probe when it is freed. + * + * An alternative is to use the following for batch reclaim associated + * with a given tracepoint: + * + * - tracepoint_is_faultable() == false: call_rcu() + * - tracepoint_is_faultable() == true: call_rcu_tasks_trace() */ #ifdef CONFIG_TRACEPOINTS static inline void tracepoint_synchronize_unregister(void) @@ -111,9 +117,17 @@ static inline void tracepoint_synchronize_unregister(void) synchronize_rcu_tasks_trace(); synchronize_rcu(); } +static inline bool tracepoint_is_faultable(struct tracepoint *tp) +{ + return tp->ext && tp->ext->faultable; +} #else static inline void tracepoint_synchronize_unregister(void) { } +static inline bool tracepoint_is_faultable(struct tracepoint *tp) +{ + return false; +} #endif #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS @@ -345,6 +359,15 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) struct tracepoint_ext __tracepoint_ext_##_name = { \ .regfunc = _reg, \ .unregfunc = _unreg, \ + .faultable = false, \ + }; \ + __DEFINE_TRACE_EXT(_name, &__tracepoint_ext_##_name, PARAMS(_proto), PARAMS(_args)); + +#define DEFINE_TRACE_SYSCALL(_name, _reg, _unreg, _proto, _args) \ + struct tracepoint_ext __tracepoint_ext_##_name = { \ + .regfunc = _reg, \ + .unregfunc = _unreg, \ + .faultable = true, \ }; \ __DEFINE_TRACE_EXT(_name, &__tracepoint_ext_##_name, PARAMS(_proto), PARAMS(_args)); @@ -389,6 +412,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) #define __DECLARE_TRACE_SYSCALL __DECLARE_TRACE #define DEFINE_TRACE_FN(name, reg, unreg, proto, args) +#define DEFINE_TRACE_SYSCALL(name, reg, unreg, proto, args) #define DEFINE_TRACE(name, proto, args) #define EXPORT_TRACEPOINT_SYMBOL_GPL(name) #define EXPORT_TRACEPOINT_SYMBOL(name) diff --git a/include/trace/define_trace.h b/include/trace/define_trace.h index ff5fa17a6259..63fea2218afa 100644 --- a/include/trace/define_trace.h +++ b/include/trace/define_trace.h @@ -48,7 +48,7 @@ #undef TRACE_EVENT_SYSCALL #define TRACE_EVENT_SYSCALL(name, proto, args, struct, assign, print, reg, unreg) \ - DEFINE_TRACE_FN(name, reg, unreg, PARAMS(proto), PARAMS(args)) + DEFINE_TRACE_SYSCALL(name, reg, unreg, PARAMS(proto), PARAMS(args)) #undef TRACE_EVENT_NOP #define TRACE_EVENT_NOP(name, proto, args, struct, assign, print)