From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ABB18C48BDF for ; Tue, 22 Jun 2021 14:44:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 93D8661374 for ; Tue, 22 Jun 2021 14:44:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231890AbhFVOqQ (ORCPT ); Tue, 22 Jun 2021 10:46:16 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:20260 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232022AbhFVOqL (ORCPT ); Tue, 22 Jun 2021 10:46:11 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1624373035; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=wPQDo8D079dUGMyCxyfQNoqPlDR92XvC7RUcDbbW3hs=; b=X6aTAog6iVPMrValB+zutp2WL9tTrjNHxf++aajyvWG+m/0iUp2l5mXAhQ1bWSudxIskNK 1psCA4PZLzL+XvWMiOADzdtQDARLWm3Y6fBbUNu3kGFS2YDmEuwb8558K3gxjIjpdX4hiQ CdaYCRtne+Dcqdyn7Rzsz+pJ8Go1OTw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-201-8G5RJG0yP2i8vrDuQo9_Qg-1; Tue, 22 Jun 2021 10:43:53 -0400 X-MC-Unique: 8G5RJG0yP2i8vrDuQo9_Qg-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9473119251A1; Tue, 22 Jun 2021 14:43:51 +0000 (UTC) Received: from x1.bristot.me.homenet.telecomitalia.it (unknown [10.10.115.243]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5334A5D9F0; Tue, 22 Jun 2021 14:43:41 +0000 (UTC) From: Daniel Bristot de Oliveira To: Steven Rostedt Cc: Phil Auld , Sebastian Andrzej Siewior , Kate Carcia , Daniel Bristot de Oliveira , Jonathan Corbet , Ingo Molnar , Peter Zijlstra , Thomas Gleixner , Alexandre Chartre , Clark Willaims , John Kacur , Juri Lelli , Borislav Petkov , "H. Peter Anvin" , x86@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH V5 06/14] trace/hwlat: Use trace_min_max_param for width and window params Date: Tue, 22 Jun 2021 16:42:24 +0200 Message-Id: In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Use the trace_min_max_param to reduce code duplication. No functional change. Cc: Jonathan Corbet Cc: Steven Rostedt Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Alexandre Chartre Cc: Clark Willaims Cc: John Kacur Cc: Juri Lelli Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: x86@kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira --- kernel/trace/trace_hwlat.c | 145 ++++++------------------------------- 1 file changed, 24 insertions(+), 121 deletions(-) diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c index 5a85d696a167..c3a41ba61052 100644 --- a/kernel/trace/trace_hwlat.c +++ b/kernel/trace/trace_hwlat.c @@ -527,115 +527,6 @@ static int start_per_cpu_kthreads(struct trace_array *tr) return retval; } -/* - * hwlat_read - Wrapper read function for reading both window and width - * @filp: The active open file structure - * @ubuf: The userspace provided buffer to read value into - * @cnt: The maximum number of bytes to read - * @ppos: The current "file" position - * - * This function provides a generic read implementation for the global state - * "hwlat_data" structure filesystem entries. - */ -static ssize_t hwlat_read(struct file *filp, char __user *ubuf, - size_t cnt, loff_t *ppos) -{ - char buf[U64STR_SIZE]; - u64 *entry = filp->private_data; - u64 val; - int len; - - if (!entry) - return -EFAULT; - - if (cnt > sizeof(buf)) - cnt = sizeof(buf); - - val = *entry; - - len = snprintf(buf, sizeof(buf), "%llu\n", val); - - return simple_read_from_buffer(ubuf, cnt, ppos, buf, len); -} - -/** - * hwlat_width_write - Write function for "width" entry - * @filp: The active open file structure - * @ubuf: The user buffer that contains the value to write - * @cnt: The maximum number of bytes to write to "file" - * @ppos: The current position in @file - * - * This function provides a write implementation for the "width" interface - * to the hardware latency detector. It can be used to configure - * for how many us of the total window us we will actively sample for any - * hardware-induced latency periods. Obviously, it is not possible to - * sample constantly and have the system respond to a sample reader, or, - * worse, without having the system appear to have gone out to lunch. It - * is enforced that width is less that the total window size. - */ -static ssize_t -hwlat_width_write(struct file *filp, const char __user *ubuf, - size_t cnt, loff_t *ppos) -{ - u64 val; - int err; - - err = kstrtoull_from_user(ubuf, cnt, 10, &val); - if (err) - return err; - - mutex_lock(&hwlat_data.lock); - if (val < hwlat_data.sample_window) - hwlat_data.sample_width = val; - else - err = -EINVAL; - mutex_unlock(&hwlat_data.lock); - - if (err) - return err; - - return cnt; -} - -/** - * hwlat_window_write - Write function for "window" entry - * @filp: The active open file structure - * @ubuf: The user buffer that contains the value to write - * @cnt: The maximum number of bytes to write to "file" - * @ppos: The current position in @file - * - * This function provides a write implementation for the "window" interface - * to the hardware latency detector. The window is the total time - * in us that will be considered one sample period. Conceptually, windows - * occur back-to-back and contain a sample width period during which - * actual sampling occurs. Can be used to write a new total window size. It - * is enforced that any value written must be greater than the sample width - * size, or an error results. - */ -static ssize_t -hwlat_window_write(struct file *filp, const char __user *ubuf, - size_t cnt, loff_t *ppos) -{ - u64 val; - int err; - - err = kstrtoull_from_user(ubuf, cnt, 10, &val); - if (err) - return err; - - mutex_lock(&hwlat_data.lock); - if (hwlat_data.sample_width < val) - hwlat_data.sample_window = val; - else - err = -EINVAL; - mutex_unlock(&hwlat_data.lock); - - if (err) - return err; - - return cnt; -} - static void *s_mode_start(struct seq_file *s, loff_t *pos) { int mode = *pos; @@ -760,16 +651,28 @@ static ssize_t hwlat_mode_write(struct file *filp, const char __user *ubuf, return ret; } -static const struct file_operations width_fops = { - .open = tracing_open_generic, - .read = hwlat_read, - .write = hwlat_width_write, +/* + * The width parameter is read/write using the generic trace_min_max_param + * method. The *val is protected by the hwlat_data lock and is upper + * bounded by the window parameter. + */ +static struct trace_min_max_param hwlat_width = { + .lock = &hwlat_data.lock, + .val = &hwlat_data.sample_width, + .max = &hwlat_data.sample_window, + .min = NULL, }; -static const struct file_operations window_fops = { - .open = tracing_open_generic, - .read = hwlat_read, - .write = hwlat_window_write, +/* + * The window parameter is read/write using the generic trace_min_max_param + * method. The *val is protected by the hwlat_data lock and is lower + * bounded by the width parameter. + */ +static struct trace_min_max_param hwlat_window = { + .lock = &hwlat_data.lock, + .val = &hwlat_data.sample_window, + .max = NULL, + .min = &hwlat_data.sample_width, }; static const struct file_operations thread_mode_fops = { @@ -802,15 +705,15 @@ static int init_tracefs(void) hwlat_sample_window = tracefs_create_file("window", 0640, top_dir, - &hwlat_data.sample_window, - &window_fops); + &hwlat_window, + &trace_min_max_fops); if (!hwlat_sample_window) goto err; hwlat_sample_width = tracefs_create_file("width", 0644, top_dir, - &hwlat_data.sample_width, - &width_fops); + &hwlat_width, + &trace_min_max_fops); if (!hwlat_sample_width) goto err; -- 2.31.1