From patchwork Wed Feb 15 22:33:45 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ross Zwisler X-Patchwork-Id: 13142279 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1DF83C636CC for ; Wed, 15 Feb 2023 22:34:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229861AbjBOWeD (ORCPT ); Wed, 15 Feb 2023 17:34:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36830 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229824AbjBOWeB (ORCPT ); Wed, 15 Feb 2023 17:34:01 -0500 Received: from mail-il1-x12a.google.com (mail-il1-x12a.google.com [IPv6:2607:f8b0:4864:20::12a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CE7F4252B2 for ; Wed, 15 Feb 2023 14:33:59 -0800 (PST) Received: by mail-il1-x12a.google.com with SMTP id v13so172231iln.4 for ; Wed, 15 Feb 2023 14:33:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=KRiIylVtHLM7M15bsUbIunpslIeQnzNkiL62MB+UIyE=; b=XDrTWczdWtWaoFMsyxlLVwbPoQdmxEcpRJz8GQEWwI4ccFUfl2v4C8mxYu1m5tIV9N TG+TcjrZLqOfuvf95ggXwSj8/yudyG0CglTYncr55dcrtosjtDHyzohqf0vR7Yg97M1O jOsVnHpSdwpT5fJhRgPlu2bPmANuNnJKXUEjc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=KRiIylVtHLM7M15bsUbIunpslIeQnzNkiL62MB+UIyE=; b=RQ7NGKIuQ95/VIoJOJ59H8mKynEQqf1onB6SKTnT8leNP4LxRaHkenfk4RMBTEiuce CuJEOPeNw9r5a+hZ0SIV67hZbujkWePlyJ6gse936Kzl2LEzV/EUqS6/9dTBYl9po4wQ utmAFVit24LIWylL3okrPs9IgU+h9YNmIphmokgvu18cbTrtnZMxCmQV8IkCDQVjXfOg H7iVrEUKVcLKWG21lUFZ9doCGiUoa4TmjEyZ/nRrMIYrmY77AG4SUvMCL/GF2KBiEBSn zcuEn5+5Tm0eEO3PfTY2mtCA1AT5Lae97XsE8Hd4F4gp0cRgyfQeZGV20SVrCKbm7OD+ xNXw== X-Gm-Message-State: AO0yUKUHyVq2j2nEMPCZ2+SvJWEf5uUSjYb0Io0z3jx8VXC8aKWSYVTX laIO2nRz4cMSN23cI4593li6Ug== X-Google-Smtp-Source: AK7set+st368XsFs7KuhNnjJJxjSkTp+ehPsvZjpomFKZjaSs7keJycjfj1LQ7Z2YQJHHx4GupN8Hw== X-Received: by 2002:a05:6e02:1605:b0:315:2b7d:d2d8 with SMTP id t5-20020a056e02160500b003152b7dd2d8mr4248678ilu.4.1676500438753; Wed, 15 Feb 2023 14:33:58 -0800 (PST) Received: from ravnica.bld.corp.google.com ([2620:15c:183:200:6299:179b:a6e4:be59]) by smtp.gmail.com with ESMTPSA id b15-20020a92c14f000000b003141eddd283sm1131489ilh.22.2023.02.15.14.33.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 Feb 2023 14:33:58 -0800 (PST) From: Ross Zwisler X-Google-Original-From: Ross Zwisler To: linux-kernel@vger.kernel.org Cc: Ross Zwisler , Steven Rostedt , Masami Hiramatsu , linux-trace-kernel@vger.kernel.org Subject: [PATCH v2 1/6] tracing: always use canonical ftrace path Date: Wed, 15 Feb 2023 15:33:45 -0700 Message-Id: <20230215223350.2658616-2-zwisler@google.com> X-Mailer: git-send-email 2.39.1.637.g21b0678d19-goog In-Reply-To: <20230215223350.2658616-1-zwisler@google.com> References: <20230215223350.2658616-1-zwisler@google.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org The canonical location for the tracefs filesystem is at /sys/kernel/tracing. But, from Documentation/trace/ftrace.rst: Before 4.1, all ftrace tracing control files were within the debugfs file system, which is typically located at /sys/kernel/debug/tracing. For backward compatibility, when mounting the debugfs file system, the tracefs file system will be automatically mounted at: /sys/kernel/debug/tracing Many comments and Kconfig help messages in the tracing code still refer to this older debugfs path, so let's update them to avoid confusion. Signed-off-by: Ross Zwisler Acked-by: Masami Hiramatsu (Google) Reviewed-by: Mukesh Ojha --- include/linux/kernel.h | 2 +- include/linux/tracepoint.h | 4 ++-- kernel/trace/Kconfig | 20 ++++++++++---------- kernel/trace/kprobe_event_gen_test.c | 2 +- kernel/trace/ring_buffer.c | 2 +- kernel/trace/synth_event_gen_test.c | 2 +- kernel/trace/trace.c | 2 +- samples/user_events/example.c | 4 ++-- scripts/tracing/draw_functrace.py | 6 +++--- tools/lib/api/fs/tracing_path.c | 4 ++-- tools/tracing/latency/latency-collector.c | 2 +- 11 files changed, 25 insertions(+), 25 deletions(-) diff --git a/include/linux/kernel.h b/include/linux/kernel.h index fe6efb24d151..40bce7495af8 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -297,7 +297,7 @@ bool mac_pton(const char *s, u8 *mac); * * Use tracing_on/tracing_off when you want to quickly turn on or off * tracing. It simply enables or disables the recording of the trace events. - * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on + * This also corresponds to the user space /sys/kernel/tracing/tracing_on * file, which gives a means for the kernel and userspace to interact. * Place a tracing_off() in the kernel where you want tracing to end. * From user space, examine the trace, and then echo 1 > tracing_on diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index 4b33b95eb8be..fa1004fcf810 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -471,7 +471,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) * * This is how the trace record is structured and will * * be saved into the ring buffer. These are the fields * * that will be exposed to user-space in - * * /sys/kernel/debug/tracing/events/<*>/format. + * * /sys/kernel/tracing/events/<*>/format. * * * * The declared 'local variable' is called '__entry' * * @@ -531,7 +531,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) * tracepoint callback (this is used by programmatic plugins and * can also by used by generic instrumentation like SystemTap), and * it is also used to expose a structured trace record in - * /sys/kernel/debug/tracing/events/. + * /sys/kernel/tracing/events/. * * A set of (un)registration functions can be passed to the variant * TRACE_EVENT_FN to perform any (un)registration work. diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index d7043043f59c..5f5e64f9e715 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -239,7 +239,7 @@ config DYNAMIC_FTRACE enabled, and the functions not enabled will not affect performance of the system. - See the files in /sys/kernel/debug/tracing: + See the files in /sys/kernel/tracing: available_filter_functions set_ftrace_filter set_ftrace_notrace @@ -299,7 +299,7 @@ config STACK_TRACER select KALLSYMS help This special tracer records the maximum stack footprint of the - kernel and displays it in /sys/kernel/debug/tracing/stack_trace. + kernel and displays it in /sys/kernel/tracing/stack_trace. This tracer works by hooking into every function call that the kernel executes, and keeping a maximum stack depth value and @@ -339,7 +339,7 @@ config IRQSOFF_TRACER disabled by default and can be runtime (re-)started via: - echo 0 > /sys/kernel/debug/tracing/tracing_max_latency + echo 0 > /sys/kernel/tracing/tracing_max_latency (Note that kernel size and overhead increase with this option enabled. This option and the preempt-off timing option can be @@ -363,7 +363,7 @@ config PREEMPT_TRACER disabled by default and can be runtime (re-)started via: - echo 0 > /sys/kernel/debug/tracing/tracing_max_latency + echo 0 > /sys/kernel/tracing/tracing_max_latency (Note that kernel size and overhead increase with this option enabled. This option and the irqs-off timing option can be @@ -515,7 +515,7 @@ config TRACER_SNAPSHOT Allow tracing users to take snapshot of the current buffer using the ftrace interface, e.g.: - echo 1 > /sys/kernel/debug/tracing/snapshot + echo 1 > /sys/kernel/tracing/snapshot cat snapshot config TRACER_SNAPSHOT_PER_CPU_SWAP @@ -527,7 +527,7 @@ config TRACER_SNAPSHOT_PER_CPU_SWAP full swap (all buffers). If this is set, then the following is allowed: - echo 1 > /sys/kernel/debug/tracing/per_cpu/cpu2/snapshot + echo 1 > /sys/kernel/tracing/per_cpu/cpu2/snapshot After which, only the tracing buffer for CPU 2 was swapped with the main tracing buffer, and the other CPU buffers remain the same. @@ -574,7 +574,7 @@ config PROFILE_ANNOTATED_BRANCHES This tracer profiles all likely and unlikely macros in the kernel. It will display the results in: - /sys/kernel/debug/tracing/trace_stat/branch_annotated + /sys/kernel/tracing/trace_stat/branch_annotated Note: this will add a significant overhead; only turn this on if you need to profile the system's use of these macros. @@ -587,7 +587,7 @@ config PROFILE_ALL_BRANCHES taken in the kernel is recorded whether it hit or miss. The results will be displayed in: - /sys/kernel/debug/tracing/trace_stat/branch_all + /sys/kernel/tracing/trace_stat/branch_all This option also enables the likely/unlikely profiler. @@ -638,8 +638,8 @@ config BLK_DEV_IO_TRACE Tracing also is possible using the ftrace interface, e.g.: echo 1 > /sys/block/sda/sda1/trace/enable - echo blk > /sys/kernel/debug/tracing/current_tracer - cat /sys/kernel/debug/tracing/trace_pipe + echo blk > /sys/kernel/tracing/current_tracer + cat /sys/kernel/tracing/trace_pipe If unsure, say N. diff --git a/kernel/trace/kprobe_event_gen_test.c b/kernel/trace/kprobe_event_gen_test.c index c736487fc0e4..4850fdfe27f1 100644 --- a/kernel/trace/kprobe_event_gen_test.c +++ b/kernel/trace/kprobe_event_gen_test.c @@ -21,7 +21,7 @@ * Then: * * # insmod kernel/trace/kprobe_event_gen_test.ko - * # cat /sys/kernel/debug/tracing/trace + * # cat /sys/kernel/tracing/trace * * You should see many instances of the "gen_kprobe_test" and * "gen_kretprobe_test" events in the trace buffer. diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index c366a0a9ddba..4cdb2feccff3 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2886,7 +2886,7 @@ rb_check_timestamp(struct ring_buffer_per_cpu *cpu_buffer, sched_clock_stable() ? "" : "If you just came from a suspend/resume,\n" "please switch to the trace global clock:\n" - " echo global > /sys/kernel/debug/tracing/trace_clock\n" + " echo global > /sys/kernel/tracing/trace_clock\n" "or add trace_clock=global to the kernel command line\n"); } diff --git a/kernel/trace/synth_event_gen_test.c b/kernel/trace/synth_event_gen_test.c index 8d77526892f4..8dfe85499d4a 100644 --- a/kernel/trace/synth_event_gen_test.c +++ b/kernel/trace/synth_event_gen_test.c @@ -22,7 +22,7 @@ * Then: * * # insmod kernel/trace/synth_event_gen_test.ko - * # cat /sys/kernel/debug/tracing/trace + * # cat /sys/kernel/tracing/trace * * You should see several events in the trace buffer - * "create_synth_test", "empty_synth_test", and several instances of diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index c9e40f692650..1101220052b3 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1142,7 +1142,7 @@ void tracing_snapshot_instance(struct trace_array *tr) * * Note, make sure to allocate the snapshot with either * a tracing_snapshot_alloc(), or by doing it manually - * with: echo 1 > /sys/kernel/debug/tracing/snapshot + * with: echo 1 > /sys/kernel/tracing/snapshot * * If the snapshot buffer is not allocated, it will stop tracing. * Basically making a permanent snapshot. diff --git a/samples/user_events/example.c b/samples/user_events/example.c index d06dc24156ec..18e34c9d708e 100644 --- a/samples/user_events/example.c +++ b/samples/user_events/example.c @@ -23,8 +23,8 @@ #endif /* Assumes debugfs is mounted */ -const char *data_file = "/sys/kernel/debug/tracing/user_events_data"; -const char *status_file = "/sys/kernel/debug/tracing/user_events_status"; +const char *data_file = "/sys/kernel/tracing/user_events_data"; +const char *status_file = "/sys/kernel/tracing/user_events_status"; static int event_status(long **status) { diff --git a/scripts/tracing/draw_functrace.py b/scripts/tracing/draw_functrace.py index 438516bdfb3c..42fa87300941 100755 --- a/scripts/tracing/draw_functrace.py +++ b/scripts/tracing/draw_functrace.py @@ -12,9 +12,9 @@ calls. Only the functions's names and the call time are provided. Usage: Be sure that you have CONFIG_FUNCTION_TRACER - # mount -t debugfs nodev /sys/kernel/debug - # echo function > /sys/kernel/debug/tracing/current_tracer - $ cat /sys/kernel/debug/tracing/trace_pipe > ~/raw_trace_func + # mount -t tracefs nodev /sys/kernel/tracing + # echo function > /sys/kernel/tracing/current_tracer + $ cat /sys/kernel/tracing/trace_pipe > ~/raw_trace_func Wait some times but not too much, the script is a bit slow. Break the pipe (Ctrl + Z) $ scripts/tracing/draw_functrace.py < ~/raw_trace_func > draw_functrace diff --git a/tools/lib/api/fs/tracing_path.c b/tools/lib/api/fs/tracing_path.c index b8e457c841ab..7ba3e81274e8 100644 --- a/tools/lib/api/fs/tracing_path.c +++ b/tools/lib/api/fs/tracing_path.c @@ -14,8 +14,8 @@ #include "tracing_path.h" static char tracing_mnt[PATH_MAX] = "/sys/kernel/debug"; -static char tracing_path[PATH_MAX] = "/sys/kernel/debug/tracing"; -static char tracing_events_path[PATH_MAX] = "/sys/kernel/debug/tracing/events"; +static char tracing_path[PATH_MAX] = "/sys/kernel/tracing"; +static char tracing_events_path[PATH_MAX] = "/sys/kernel/tracing/events"; static void __tracing_path_set(const char *tracing, const char *mountpoint) { diff --git a/tools/tracing/latency/latency-collector.c b/tools/tracing/latency/latency-collector.c index 59a7f2346eab..0fd9c747d396 100644 --- a/tools/tracing/latency/latency-collector.c +++ b/tools/tracing/latency/latency-collector.c @@ -1584,7 +1584,7 @@ static void *do_printloop(void *arg) /* * Toss a coin to decide if we want to sleep before printing * out the backtrace. The reason for this is that opening - * /sys/kernel/debug/tracing/trace will cause a blackout of + * /sys/kernel/tracing/trace will cause a blackout of * hundreds of ms, where no latencies will be noted by the * latency tracer. Thus by randomly sleeping we try to avoid * missing traces systematically due to this. With this option