From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f73.google.com (mail-wm1-f73.google.com [209.85.128.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C6E3E288C3F for ; Tue, 6 May 2025 16:48:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746550126; cv=none; b=FY7ovzIxK6JuoakxAswqfR2ngrgE71TiLsyFZogf/FByzZxUaAvtHll+qpcwsSUkAX7zDOLcdoXPVjZLbzq2LAzIK3E1Q1wMpZSUQV47DsRloY08yf8359ChijSmqjVS8RgubBldcFqhqEYWfObFh57qt+3mMJrbpQ2Cj8IfSCQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746550126; c=relaxed/simple; bh=wQBFYyELFNvHLzXQ+9NDItNJua1krR5kq62o/pGyp00=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=lMJOrqNv8X1AJ6qndE7Y1BISo5Q71P0jQsCX9snxnbNfXo3KywkczRNPRILlQHvSZgfZSKNqX6i1iwN6neIgfbioC2wpP2HNI9ei8vcDFtYDCAQCw4hX2/I2aSoIgiJ8kSZMRVnM1shHTJrvC/bHLpniQ6XsXmQqu6fTwKyJAHw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--vdonnefort.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=bR9JYyrv; arc=none smtp.client-ip=209.85.128.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--vdonnefort.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="bR9JYyrv" Received: by mail-wm1-f73.google.com with SMTP id 5b1f17b1804b1-43cf44b66f7so33713185e9.1 for ; Tue, 06 May 2025 09:48:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1746550123; x=1747154923; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=BsA8D4HjHlecCQdG9p+xY7qsrnVwx8gbv9XN30ZeOP4=; b=bR9JYyrvUSRjjHakZMmh4XDVWz2izyU7VdR5W3vueye2bDCYALbv2nw0QYjuu8OpJT qjgWNs5PLPntopdZhqh1UqRLj38h4IcI77ELmS31x89IUrFfmXqwVUm6sPXgK2/Q/iO0 5zj9zLDCTKdhF+4zQg9q+r+rJuP5+kpn2KJigVkIa0Bl3g0ngNdVkWEZ2Claaxu+NS6v LPR/LnX9OCqVPB+ve/CvYvwwe07rPQ0Z9mwDgRLhyPHeDyKW5IGDChuVDZSS27AujT7C 0fjUbWpXKFtgJOFYahEDkbuWtTJN1SBZxIt0IbgKxwDoC/mF5U02Ns/HeHH4BXBzRCIR /LCQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1746550123; x=1747154923; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=BsA8D4HjHlecCQdG9p+xY7qsrnVwx8gbv9XN30ZeOP4=; b=AYXj/pIBj0bySkYbW7BotyThUMoNjkt3NYI1RcIC3sZiyYMURxjQ2wzVaIsmFrZL1L bmxi0bzrlAfZfMcpTS6DjYFL52uvXTD4dknJwgca+EpfeAlVushJZUq2PQfirx56Oj6m faJ5FcbucQ7vwTSGBYzSKp+YAZ23jxwmA/EzxRqJ6FPpZswOT3tCJmNuwqbxq7yNn+fp qlW/hFkdjZ89GxvD0f4Gg+hU5kV9FINR/7MqKSCRPF4OjfBo/R49ep09s/xP1kZCWvmk 4abguiHwVjp8yi4wsfNFXNOby93bCHKJOXs3YoWQXTYtqM/Dlr31LlferAsHMyMOepKY nhWQ== X-Forwarded-Encrypted: i=1; AJvYcCVLAXYVK7RSux+4KdM0cuIMHH+lEer2gFTI7uXbbyFslYThfLH+1002s9aWnupxBAhNDst25yDmooOsBORh2my8DqA=@vger.kernel.org X-Gm-Message-State: AOJu0Yz4K1AXk69KcqXLib5uRJQg9VtUQaBWdbE70BO/c1AaqKEXaHmF ehzm5K/HhGlpo3UAsygEPg1resWgmFt9riyl//4cIrN4Acb4UYhstYrys4JXfMFTtCI7XbkC8bK 2WeCeT+hLtDgo9iKnfQ== X-Google-Smtp-Source: AGHT+IF5PMMWTS3cwH1oB8k42s2Xq6vSAGn672jUyunHJnJQKljjoLiBSvKPyhszSFei8WE+2z41aT3Hv72Lx/Nf X-Received: from wmbay23.prod.google.com ([2002:a05:600c:1e17:b0:43d:522a:45e8]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:5105:b0:43d:1840:a13f with SMTP id 5b1f17b1804b1-441d100a9edmr34417665e9.25.1746550123251; Tue, 06 May 2025 09:48:43 -0700 (PDT) Date: Tue, 6 May 2025 17:47:59 +0100 In-Reply-To: <20250506164820.515876-1-vdonnefort@google.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250506164820.515876-1-vdonnefort@google.com> X-Mailer: git-send-email 2.49.0.967.g6a0df3ecc3-goog Message-ID: <20250506164820.515876-4-vdonnefort@google.com> Subject: [PATCH v4 03/24] tracing: Add reset to trace remotes From: Vincent Donnefort To: rostedt@goodmis.org, mhiramat@kernel.org, mathieu.desnoyers@efficios.com, linux-trace-kernel@vger.kernel.org, maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com Cc: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, jstultz@google.com, qperret@google.com, will@kernel.org, kernel-team@android.com, linux-kernel@vger.kernel.org, Vincent Donnefort Content-Type: text/plain; charset="UTF-8" For standard trace instance, "trace" files allow to do non-consuming read of the ring-buffers. This is however not applicable to ring-buffer remotes due to the lack of support in the meta-page. Nonetheless this file is still useful to reset a ring-buffer so let's add a write-only version. Signed-off-by: Vincent Donnefort diff --git a/include/linux/trace_remote.h b/include/linux/trace_remote.h index de043a6f2fe0..1aa99da3c96a 100644 --- a/include/linux/trace_remote.h +++ b/include/linux/trace_remote.h @@ -11,6 +11,7 @@ struct trace_remote_callbacks { void (*unload_trace_buffer)(struct trace_buffer_desc *desc, void *priv); int (*enable_tracing)(bool enable, void *priv); int (*swap_reader_page)(unsigned int cpu, void *priv); + int (*reset)(unsigned int cpu, void *priv); }; int trace_remote_register(const char *name, struct trace_remote_callbacks *cbs, void *priv); diff --git a/kernel/trace/trace_remote.c b/kernel/trace/trace_remote.c index 462c2d085a08..2221705f65f4 100644 --- a/kernel/trace/trace_remote.c +++ b/kernel/trace/trace_remote.c @@ -70,6 +70,7 @@ static int trace_remote_load(struct trace_remote *remote) rb_remote->desc = remote->trace_buffer_desc; rb_remote->swap_reader_page = remote->cbs->swap_reader_page; rb_remote->priv = remote->priv; + rb_remote->reset = remote->cbs->reset; remote->trace_buffer = ring_buffer_remote(rb_remote); if (!remote->trace_buffer) { remote->cbs->unload_trace_buffer(remote->trace_buffer_desc, remote->priv); @@ -135,6 +136,19 @@ static int trace_remote_stop(struct trace_remote *remote) return 0; } +static void trace_remote_reset(struct trace_remote *remote, int cpu) +{ + lockdep_assert_held(&remote->lock); + + if (!trace_remote_loaded(remote)) + return; + + if (cpu == RING_BUFFER_ALL_CPUS) + ring_buffer_reset(remote->trace_buffer); + else + ring_buffer_reset_cpu(remote->trace_buffer, cpu); +} + static ssize_t tracing_on_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { @@ -369,6 +383,26 @@ static const struct file_operations trace_pipe_fops = { .release = trace_pipe_release, }; +static ssize_t trace_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) +{ + struct inode *inode = file_inode(filp); + struct trace_remote *remote = inode->i_private; + int cpu = RING_BUFFER_ALL_CPUS; + + if (inode->i_cdev) + cpu = (long)inode->i_cdev - 1; + + guard(mutex)(&remote->lock); + + trace_remote_reset(remote, cpu); + + return cnt; +} + +static const struct file_operations trace_fops = { + .write = trace_write, +}; + static int trace_remote_init_tracefs(const char *name, struct trace_remote *remote) { struct dentry *remote_d, *percpu_d; @@ -399,7 +433,9 @@ static int trace_remote_init_tracefs(const char *name, struct trace_remote *remo !trace_create_file("buffer_size_kb", TRACEFS_MODE_WRITE, remote_d, remote, &buffer_size_kb_fops) || !trace_create_file("trace_pipe", TRACEFS_MODE_READ, remote_d, remote, - &trace_pipe_fops)) + &trace_pipe_fops) || + !trace_create_file("trace", 0200, remote_d, remote, + &trace_fops)) goto err; percpu_d = tracefs_create_dir("per_cpu", remote_d); @@ -421,7 +457,9 @@ static int trace_remote_init_tracefs(const char *name, struct trace_remote *remo } if (!trace_create_cpu_file("trace_pipe", TRACEFS_MODE_READ, cpu_d, remote, cpu, - &trace_pipe_fops)) + &trace_pipe_fops) || + !trace_create_cpu_file("trace", 0200, cpu_d, remote, cpu, + &trace_fops)) goto err; } -- 2.49.0.967.g6a0df3ecc3-goog