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=-13.8 required=3.0 tests=BAYES_00, 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 40DE9C49EAF for ; Sat, 26 Jun 2021 13:06:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B8E461C35 for ; Sat, 26 Jun 2021 13:06:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231139AbhFZNId (ORCPT ); Sat, 26 Jun 2021 09:08:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:33894 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230094AbhFZNIA (ORCPT ); Sat, 26 Jun 2021 09:08:00 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8EAD761C44; Sat, 26 Jun 2021 13:05:38 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.94.2) (envelope-from ) id 1lx809-000Emh-JV; Sat, 26 Jun 2021 09:05:37 -0400 Message-ID: <20210626130537.449914328@goodmis.org> User-Agent: quilt/0.66 Date: Sat, 26 Jun 2021 09:04:20 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Phil Auld , Sebastian Andrzej Siewior , Kate Carcia , 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, Daniel Bristot de Oliveira Subject: [for-next][PATCH 16/24] trace/hwlat: Use trace_min_max_param for width and window params References: <20210626130404.033700863@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Daniel Bristot de Oliveira Use the trace_min_max_param to reduce code duplication. No functional change. Link: https://lkml.kernel.org/r/b91accd5a7c6c14ea02d3379aae974ba22b47dd6.1624372313.git.bristot@redhat.com Cc: Phil Auld Cc: Sebastian Andrzej Siewior Cc: Kate Carcia Cc: Jonathan Corbet 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 Signed-off-by: Steven Rostedt (VMware) --- 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 3957b36826e2..44f46bc1140f 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; -- 2.30.2