From patchwork Tue Dec 19 14:32:34 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 181019 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a05:7300:24d3:b0:fb:cd0c:d3e with SMTP id r19csp1982427dyi; Tue, 19 Dec 2023 06:38:38 -0800 (PST) X-Google-Smtp-Source: AGHT+IHGI1rrSBf6QLpRl6FRyOQtI5OIP2N8m/MlGZ8fCG7mf39M/mCsuE1+FarA5WTf0FP4ceoS X-Received: by 2002:a05:6a20:4f97:b0:18c:328b:61db with SMTP id gh23-20020a056a204f9700b0018c328b61dbmr7674014pzb.1.1702996718591; Tue, 19 Dec 2023 06:38:38 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1702996718; cv=none; d=google.com; s=arc-20160816; b=yuyJ95dS96E29kfdztAUsalK0c71HuFtSB0trifbnjUsBYkFJ3CklcgYPlAQKZ8G6D iBVuc61WPdc2Km0F6A4e9jgQmgUfShkzo7T+f2GVc+tvhdNbsHeQpE8F3RTMg08ZS65s YZY/nY1mBOoOki3j8TlWNjndBExSwlSZ6DaR16acTUwJGhyRdN4Gg5Oa0HJfjhK1mxWo MNxcMbGywBgFzqIpAiMpN3RVj2HXyTpt/0FIRImJ1F+wcfFhs9/3PrR9mXa7V271UtQ3 5Gye531Y7dduYytsOzPDhdUxWc8LzhFeyUaBTI7CHtGpg3c/dROhZpXKX1AluZHbf2Am 6BtA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:list-unsubscribe:list-subscribe:list-id:precedence :references:subject:cc:to:from:date:user-agent:message-id; bh=P7avDLj+gWiWqQSqVzz8gVNMbdecm31D8+HRpt1YMK4=; fh=oBUriZ5QvWuRogSS7DOkWRwC7Cys61uAHVoBLBDlcB4=; b=X/bPPj9t9Nnlaec9FOtE2T+N3w4jN9jU2Fn7k2j5OjO2+sL0K185qdHBbcy8yEAM6k 2comAxR/d2g5BtfaLwk5c737MVPIzrFc+uRPLczUntg+i/1uHVnAU9AWdIucrqoJypSi JsJ1BykoM/q5b1HA/rWkgl3kE3cZMb/Spbt1rQh9WT3ugsKJddvfzK5QUijRTsrvH2sS lyFXPPRNtMOFuVkKN4lqDk4Mc50HrFtXvhGlu6a6zzrVc5nIutZV7jjkxrDTpxg2DT32 TMEFW+MlIT7xd+htLqRSNRHMkDejdZjTAOH8vKz6oec3ZUA+JcwnsrMSwmXw4LNigXaI 4BDw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel+bounces-5377-ouuuleilei=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) smtp.mailfrom="linux-kernel+bounces-5377-ouuuleilei=gmail.com@vger.kernel.org" Received: from sy.mirrors.kernel.org (sy.mirrors.kernel.org. [2604:1380:40f1:3f00::1]) by mx.google.com with ESMTPS id p20-20020a63fe14000000b0059d48c43152si19907688pgh.40.2023.12.19.06.38.38 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 19 Dec 2023 06:38:38 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel+bounces-5377-ouuuleilei=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) client-ip=2604:1380:40f1:3f00::1; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel+bounces-5377-ouuuleilei=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) smtp.mailfrom="linux-kernel+bounces-5377-ouuuleilei=gmail.com@vger.kernel.org" Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sy.mirrors.kernel.org (Postfix) with ESMTPS id 3361EB223A8 for ; Tue, 19 Dec 2023 14:35:41 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 42B1136B19; Tue, 19 Dec 2023 14:32:05 +0000 (UTC) X-Original-To: linux-kernel@vger.kernel.org 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 BB752208BC for ; Tue, 19 Dec 2023 14:32:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 24EF2C433C7; Tue, 19 Dec 2023 14:32:00 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.97) (envelope-from ) id 1rFb9X-00000003MDx-130V; Tue, 19 Dec 2023 09:32:59 -0500 Message-ID: <20231219143259.032310636@goodmis.org> User-Agent: quilt/0.67 Date: Tue, 19 Dec 2023 09:32:34 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Sean Paul , Arun Easi , Daniel Wagner , Dmytro Maluka Subject: [for-next][PATCH 01/10] tracing: Allow creating instances with specified system events References: <20231219143233.204534014@goodmis.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1785721486733798632 X-GMAIL-MSGID: 1785721486733798632 From: "Steven Rostedt (Google)" A trace instance may only need to enable specific events. As the eventfs directory of an instance currently creates all events which adds overhead, allow internal instances to be created with just the events in systems that they care about. This currently only deals with systems and not individual events, but this should bring down the overhead of creating instances for specific use cases quite bit. The trace_array_get_by_name() now has another parameter "systems". This parameter is a const string pointer of a comma/space separated list of event systems that should be created by the trace_array. (Note if the trace_array already exists, this parameter is ignored). The list of systems is saved and if a module is loaded, its events will not be added unless the system for those events also match the systems string. Link: https://lore.kernel.org/linux-trace-kernel/20231213093701.03fddec0@gandalf.local.home Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Sean Paul Cc: Arun Easi Cc: Daniel Wagner Tested-by: Dmytro Maluka Signed-off-by: Steven Rostedt (Google) --- drivers/scsi/qla2xxx/qla_os.c | 2 +- include/linux/trace.h | 4 +-- kernel/trace/trace.c | 23 +++++++++++--- kernel/trace/trace.h | 1 + kernel/trace/trace_boot.c | 2 +- kernel/trace/trace_events.c | 48 +++++++++++++++++++++++++++-- samples/ftrace/sample-trace-array.c | 2 +- 7 files changed, 70 insertions(+), 12 deletions(-) diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c index 03348f605c2e..dd674378f2f3 100644 --- a/drivers/scsi/qla2xxx/qla_os.c +++ b/drivers/scsi/qla2xxx/qla_os.c @@ -2889,7 +2889,7 @@ static void qla2x00_iocb_work_fn(struct work_struct *work) static void qla_trace_init(void) { - qla_trc_array = trace_array_get_by_name("qla2xxx"); + qla_trc_array = trace_array_get_by_name("qla2xxx", NULL); if (!qla_trc_array) { ql_log(ql_log_fatal, NULL, 0x0001, "Unable to create qla2xxx trace instance, instance logging will be disabled.\n"); diff --git a/include/linux/trace.h b/include/linux/trace.h index 2a70a447184c..fdcd76b7be83 100644 --- a/include/linux/trace.h +++ b/include/linux/trace.h @@ -51,7 +51,7 @@ int trace_array_printk(struct trace_array *tr, unsigned long ip, const char *fmt, ...); int trace_array_init_printk(struct trace_array *tr); void trace_array_put(struct trace_array *tr); -struct trace_array *trace_array_get_by_name(const char *name); +struct trace_array *trace_array_get_by_name(const char *name, const char *systems); int trace_array_destroy(struct trace_array *tr); /* For osnoise tracer */ @@ -84,7 +84,7 @@ static inline int trace_array_init_printk(struct trace_array *tr) static inline void trace_array_put(struct trace_array *tr) { } -static inline struct trace_array *trace_array_get_by_name(const char *name) +static inline struct trace_array *trace_array_get_by_name(const char *name, const char *systems) { return NULL; } diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 199df497db07..59e39b652afb 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9490,7 +9490,8 @@ static int trace_array_create_dir(struct trace_array *tr) return ret; } -static struct trace_array *trace_array_create(const char *name) +static struct trace_array * +trace_array_create_systems(const char *name, const char *systems) { struct trace_array *tr; int ret; @@ -9510,6 +9511,12 @@ static struct trace_array *trace_array_create(const char *name) if (!zalloc_cpumask_var(&tr->pipe_cpumask, GFP_KERNEL)) goto out_free_tr; + if (systems) { + tr->system_names = kstrdup_const(systems, GFP_KERNEL); + if (!tr->system_names) + goto out_free_tr; + } + tr->trace_flags = global_trace.trace_flags & ~ZEROED_TRACE_FLAGS; cpumask_copy(tr->tracing_cpumask, cpu_all_mask); @@ -9556,12 +9563,18 @@ static struct trace_array *trace_array_create(const char *name) free_trace_buffers(tr); free_cpumask_var(tr->pipe_cpumask); free_cpumask_var(tr->tracing_cpumask); + kfree_const(tr->system_names); kfree(tr->name); kfree(tr); return ERR_PTR(ret); } +static struct trace_array *trace_array_create(const char *name) +{ + return trace_array_create_systems(name, NULL); +} + static int instance_mkdir(const char *name) { struct trace_array *tr; @@ -9587,6 +9600,7 @@ static int instance_mkdir(const char *name) /** * trace_array_get_by_name - Create/Lookup a trace array, given its name. * @name: The name of the trace array to be looked up/created. + * @systems: A list of systems to create event directories for (NULL for all) * * Returns pointer to trace array with given name. * NULL, if it cannot be created. @@ -9600,7 +9614,7 @@ static int instance_mkdir(const char *name) * trace_array_put() is called, user space can not delete it. * */ -struct trace_array *trace_array_get_by_name(const char *name) +struct trace_array *trace_array_get_by_name(const char *name, const char *systems) { struct trace_array *tr; @@ -9612,7 +9626,7 @@ struct trace_array *trace_array_get_by_name(const char *name) goto out_unlock; } - tr = trace_array_create(name); + tr = trace_array_create_systems(name, systems); if (IS_ERR(tr)) tr = NULL; @@ -9659,6 +9673,7 @@ static int __remove_instance(struct trace_array *tr) free_cpumask_var(tr->pipe_cpumask); free_cpumask_var(tr->tracing_cpumask); + kfree_const(tr->system_names); kfree(tr->name); kfree(tr); @@ -10377,7 +10392,7 @@ __init static void enable_instances(void) if (IS_ENABLED(CONFIG_TRACER_MAX_TRACE)) do_allocate_snapshot(tok); - tr = trace_array_get_by_name(tok); + tr = trace_array_get_by_name(tok, NULL); if (!tr) { pr_warn("Failed to create instance buffer %s\n", curr_str); continue; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 0489e72c8169..79180aed13ee 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -377,6 +377,7 @@ struct trace_array { unsigned char trace_flags_index[TRACE_FLAGS_MAX_SIZE]; unsigned int flags; raw_spinlock_t start_lock; + const char *system_names; struct list_head err_log; struct dentry *dir; struct dentry *options; diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index 7ccc7a8e155b..dbe29b4c6a7a 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -633,7 +633,7 @@ trace_boot_init_instances(struct xbc_node *node) if (!p || *p == '\0') continue; - tr = trace_array_get_by_name(p); + tr = trace_array_get_by_name(p, NULL); if (!tr) { pr_err("Failed to get trace instance %s\n", p); continue; diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index f29e815ca5b2..b70d03818038 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -2896,6 +2896,27 @@ void trace_event_eval_update(struct trace_eval_map **map, int len) up_write(&trace_event_sem); } +static bool event_in_systems(struct trace_event_call *call, + const char *systems) +{ + const char *system; + const char *p; + + if (!systems) + return true; + + system = call->class->system; + p = strstr(systems, system); + if (!p) + return false; + + if (p != systems && !isspace(*(p - 1)) && *(p - 1) != ',') + return false; + + p += strlen(system); + return !*p || isspace(*p) || *p == ','; +} + static struct trace_event_file * trace_create_new_event(struct trace_event_call *call, struct trace_array *tr) @@ -2905,9 +2926,12 @@ trace_create_new_event(struct trace_event_call *call, struct trace_event_file *file; unsigned int first; + if (!event_in_systems(call, tr->system_names)) + return NULL; + file = kmem_cache_alloc(file_cachep, GFP_TRACE); if (!file) - return NULL; + return ERR_PTR(-ENOMEM); pid_list = rcu_dereference_protected(tr->filtered_pids, lockdep_is_held(&event_mutex)); @@ -2972,8 +2996,17 @@ __trace_add_new_event(struct trace_event_call *call, struct trace_array *tr) struct trace_event_file *file; file = trace_create_new_event(call, tr); + /* + * trace_create_new_event() returns ERR_PTR(-ENOMEM) if failed + * allocation, or NULL if the event is not part of the tr->system_names. + * When the event is not part of the tr->system_names, return zero, not + * an error. + */ if (!file) - return -ENOMEM; + return 0; + + if (IS_ERR(file)) + return PTR_ERR(file); if (eventdir_initialized) return event_create_dir(tr->event_dir, file); @@ -3012,8 +3045,17 @@ __trace_early_add_new_event(struct trace_event_call *call, int ret; file = trace_create_new_event(call, tr); + /* + * trace_create_new_event() returns ERR_PTR(-ENOMEM) if failed + * allocation, or NULL if the event is not part of the tr->system_names. + * When the event is not part of the tr->system_names, return zero, not + * an error. + */ if (!file) - return -ENOMEM; + return 0; + + if (IS_ERR(file)) + return PTR_ERR(file); ret = event_define_fields(call); if (ret) diff --git a/samples/ftrace/sample-trace-array.c b/samples/ftrace/sample-trace-array.c index 6aba02a31c96..d0ee9001c7b3 100644 --- a/samples/ftrace/sample-trace-array.c +++ b/samples/ftrace/sample-trace-array.c @@ -105,7 +105,7 @@ static int __init sample_trace_array_init(void) * NOTE: This function increments the reference counter * associated with the trace array - "tr". */ - tr = trace_array_get_by_name("sample-instance"); + tr = trace_array_get_by_name("sample-instance", "sched,timer,kprobes"); if (!tr) return -1;