From patchwork Sun Jan 12 05:26:35 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 13936220 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 42BDF632; Sun, 12 Jan 2025 05:26:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736659602; cv=none; b=ujP2o+yi+C/troUlX7fmlj6MF+bBay7a1JV7qbiXrEwcM61h7LbsCwm8yY0ZJwsZZ4B2I0NUCI6ORxBnwW2jW/xpi58KQRx7O+WaG1/LjaUdod4ZoP5olxd+O236RjwZuSzYTmDLpCsEkblMPRUwTpjEuzQpT2bCy51QxJQZeTA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736659602; c=relaxed/simple; bh=WEuTKqsqdUyEs81BC4WOvmVz9HYQKyyQ9xf+QyvZH1s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=qv6fgDRct6r9EteVsfxKD3CDzfwAJ1F9Zuh43MeygK4mcAaW5DHtJ2oZbDQvPOJCFDkC7MSz5qIN3fXQrlabuFFEmXmEeSR6AF1ZnVKh1vY6+VqrZoPbqBZX5LLLrCLOSRhAVFjgLZJdcWAaAIPZuxOIM1DKvol1Uy49RUllksU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FVz9rd+H; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FVz9rd+H" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0CE9BC4CEE0; Sun, 12 Jan 2025 05:26:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1736659600; bh=WEuTKqsqdUyEs81BC4WOvmVz9HYQKyyQ9xf+QyvZH1s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FVz9rd+HP/ZfGeJ7amyLZFnacEoymLHIxjT7g5Ns16yCMb5niLWPWaLxzB3t4/qpB 9kcpbfEkWO5JOfgdbfjSiTxxrF3thsmvxQLIYiKbKLKUpEpCHCso/fM4QdBHp7BIkB T1QYfOmnhYUupubPrlA1zoY+jJOVs2bBNHSrCQ7F0YHZUKbxjO5cokcjtA5gHZ8oHE tJzbN3qnvHK/a9TXyXiKfif2w8Qqq2Tdy1CSUh3F7Pf+omyWsDqKVsz5C0er9owYhq RJfMMC7/H8uSiYKUSJdBB1eVT1Q4zxA1WhYAB+Jtke4JwQzq2RN2gFFPC2R0fXyMrp fmyLN9NKEm1Zg== From: "Masami Hiramatsu (Google)" To: Steven Rostedt , Jiri Olsa Cc: Alexei Starovoitov , Florent Revest , linux-trace-kernel@vger.kernel.org, LKML , Martin KaFai Lau , bpf , Alexei Starovoitov , Alan Maguire , Mark Rutland , Masami Hiramatsu Subject: [PATCH] fgraph: Move trace_clock_local() for return time to function_graph tracer Date: Sun, 12 Jan 2025 14:26:35 +0900 Message-ID: <173665959558.1629214.16724136597211810729.stgit@devnote2> X-Mailer: git-send-email 2.43.0 In-Reply-To: References: User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Masami Hiramatsu (Google) Since the ftrace_graph_ret::rettime is only referred in the function_graph tracer, the trace_clock_local() call in fgraph is just an overhead for other fgraph users. Move the trace_clock_local() for recording return time to function_graph tracer and the rettime field is just zeroed in the fgraph side. That rettime field is updated by one of the function_graph tracer and cached for other function_graph tracer instances. According to Jiri's report[1], removing this function will gain fprobe performance ~27%. [1] https://lore.kernel.org/all/Z3aSuql3fnXMVMoM@krava/ Reported-by: Jiri Olsa Signed-off-by: Masami Hiramatsu (Google) Reviewed-by: Masami Hiramatsu (Google) --- include/linux/ftrace.h | 11 +++++++++++ kernel/trace/fgraph.c | 2 +- kernel/trace/trace_functions_graph.c | 2 ++ 3 files changed, 14 insertions(+), 1 deletion(-) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 07092dfb21a4..a2fb7360d6e2 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -1155,6 +1155,17 @@ struct ftrace_graph_ret { unsigned long long rettime; } __packed; +static inline void ftrace_graph_ret_record_time(struct ftrace_graph_ret *trace) +{ + if (!trace->rettime) + trace->rettime = trace_clock_local(); +} + +static inline void ftrace_graph_ret_init_time(struct ftrace_graph_ret *trace) +{ + trace->rettime = 0; +} + struct fgraph_ops; /* Type of the callback handlers for tracing function graph*/ diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index c928527251e3..bc1e5f0493b6 100644 --- a/kernel/trace/fgraph.c +++ b/kernel/trace/fgraph.c @@ -826,7 +826,7 @@ __ftrace_return_to_handler(struct ftrace_regs *fregs, unsigned long frame_pointe return (unsigned long)panic; } - trace.rettime = trace_clock_local(); + ftrace_graph_ret_init_time(&trace); if (fregs) ftrace_regs_set_instruction_pointer(fregs, ret); diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index d0e4f412c298..7e4d91d42d8e 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -327,6 +327,7 @@ void trace_graph_return(struct ftrace_graph_ret *trace, int size; int cpu; + ftrace_graph_ret_record_time(trace); ftrace_graph_addr_finish(gops, trace); if (*task_var & TRACE_GRAPH_NOTRACE) { @@ -361,6 +362,7 @@ static void trace_graph_thresh_return(struct ftrace_graph_ret *trace, struct fgraph_times *ftimes; int size; + ftrace_graph_ret_record_time(trace); ftrace_graph_addr_finish(gops, trace); if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT)) {