From patchwork Fri Dec 27 04:07:57 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu \(Google\)" X-Patchwork-Id: 853949 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 CC9CC524B4; Fri, 27 Dec 2024 04:08:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735272482; cv=none; b=WE01zbhQuP8wAzPu9KD+r4HmJ1INfB/CaYLm/Nt5jI/jKaUXPYHbEyuk+A0WJnwDSVLMa7JZyRm97dkJifvxZKc+gaZD9hLU7Qz3ZlQTcZYT+L6xcUMhfzKSXlTb6w0eJ1gbLAx8ix1w1+quOAj7yB+y2MBwmgAfb+HxkNRO0jI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735272482; c=relaxed/simple; bh=TchTdNcfedUw/CH++HJkkUKA69Xgwj9N7+N9n9Ihqtg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=tSqqWIbmrfey6lZSly2jmA1+ws5WlF77Lpx/zukVOYHtUniK4qMYY7O/0iNyFOYNNvrPoxhKflVYhZf/Cj9RcF3AkNz/+m60GLbHo9OiOA9MYDWSnQl703dW0hTblQKF0OMf7219iJg8TUtjKJL1RqVYA/ivNsKjyVR/QwTuvVU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QYoAEBwB; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="QYoAEBwB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6BB35C4CED0; Fri, 27 Dec 2024 04:08:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1735272482; bh=TchTdNcfedUw/CH++HJkkUKA69Xgwj9N7+N9n9Ihqtg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QYoAEBwBsFc8nij8kIefT6ii85vYHWc27S3RYMDVIAmVuJGYi3vK2HLWqSP5yGobV mfkY0xDm4GBP5PpDBHKefHnK9EJ+Dn8ki8TSfBNFnVeuzXlMU6TTIJ12ztNsKndcgd mOu9BC/Zqz12Q6hKmJp9HfqXUeIMpT8C1mOD8jsSsTVoKvmiRQqXHbKpCIBpW50zSl jvFUIF+sQqG2Fv4agtYfhyqYnIPmmL3jagxompeHP+0Foc7rE/vWgFD0G4dhvrDI4b dMetRqNuMWPnRsPVATdACnyYWaMqWPA/RAhpy/JDXKx+2k/OmU1AurMs8EPiU5nU7S 48CdYEeiKqkzg== From: "Masami Hiramatsu (Google)" To: Steven Rostedt , Shuah Khan Cc: Masami Hiramatsu , Tom Zanussi , Mathieu Desnoyers , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH v7 1/3] tracing/hist: Add poll(POLLIN) support on hist file Date: Fri, 27 Dec 2024 13:07:57 +0900 Message-ID: <173527247756.464571.14236296701625509931.stgit@devnote2> X-Mailer: git-send-email 2.43.0 In-Reply-To: <173527246726.464571.11533527581374142406.stgit@devnote2> References: <173527246726.464571.11533527581374142406.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Masami Hiramatsu (Google) Add poll syscall support on the `hist` file. The Waiter will be waken up when the histogram is updated with POLLIN. Currently, there is no way to wait for a specific event in userspace. So user needs to peek the `trace` periodicaly, or wait on `trace_pipe`. But it is not a good idea to peek at the `trace` for an event that randomly happens. And `trace_pipe` is not coming back until a page is filled with events. This allows a user to wait for a specific event on the `hist` file. User can set a histogram trigger on the event which they want to monitor and poll() on its `hist` file. Since this poll() returns POLLIN, the next poll() will return soon unless a read() happens on that hist file. NOTE: To read the hist file again, you must set the file offset to 0, but just for monitoring the event, you may not need to read the histogram. Signed-off-by: Masami Hiramatsu (Google) Reviewed-by: Tom Zanussi --- Changes in v7: - Reword description according to Steve's comment. - Use guard() for mutex. --- include/linux/trace_events.h | 14 ++++++++ kernel/trace/trace_events.c | 14 ++++++++ kernel/trace/trace_events_hist.c | 69 ++++++++++++++++++++++++++++++++++++-- 3 files changed, 94 insertions(+), 3 deletions(-) diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 2a5df5b62cfc..47caca4e7ff4 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -669,6 +669,20 @@ struct trace_event_file { atomic_t tm_ref; /* trigger-mode reference counter */ }; +#ifdef CONFIG_HIST_TRIGGERS +extern struct irq_work hist_poll_work; +extern wait_queue_head_t hist_poll_wq; + +static inline void hist_poll_wakeup(void) +{ + if (wq_has_sleeper(&hist_poll_wq)) + irq_work_queue(&hist_poll_work); +} + +#define hist_poll_wait(file, wait) \ + poll_wait(file, &hist_poll_wq, wait) +#endif + #define __TRACE_EVENT_FLAGS(name, value) \ static int __init trace_init_flags_##name(void) \ { \ diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 77e68efbd43e..e34b4a88d8ec 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -2972,6 +2972,20 @@ static bool event_in_systems(struct trace_event_call *call, return !*p || isspace(*p) || *p == ','; } +#ifdef CONFIG_HIST_TRIGGERS +/* + * Wake up waiter on the hist_poll_wq from irq_work because the hist trigger + * may happen in any context. + */ +static void hist_poll_event_irq_work(struct irq_work *work) +{ + wake_up_all(&hist_poll_wq); +} + +DEFINE_IRQ_WORK(hist_poll_work, hist_poll_event_irq_work); +DECLARE_WAIT_QUEUE_HEAD(hist_poll_wq); +#endif + static struct trace_event_file * trace_create_new_event(struct trace_event_call *call, struct trace_array *tr) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 9c058aa8baf3..e169f67c6088 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -5311,6 +5311,8 @@ static void event_hist_trigger(struct event_trigger_data *data, if (resolve_var_refs(hist_data, key, var_ref_vals, true)) hist_trigger_actions(hist_data, elt, buffer, rec, rbe, key, var_ref_vals); + + hist_poll_wakeup(); } static void hist_trigger_stacktrace_print(struct seq_file *m, @@ -5590,15 +5592,36 @@ static void hist_trigger_show(struct seq_file *m, n_entries, (u64)atomic64_read(&hist_data->map->drops)); } +struct hist_file_data { + struct file *file; + u64 last_read; +}; + +static u64 get_hist_hit_count(struct trace_event_file *event_file) +{ + struct hist_trigger_data *hist_data; + struct event_trigger_data *data; + u64 ret = 0; + + list_for_each_entry(data, &event_file->triggers, list) { + if (data->cmd_ops->trigger_type == ETT_EVENT_HIST) { + hist_data = data->private_data; + ret += atomic64_read(&hist_data->map->hits); + } + } + return ret; +} + static int hist_show(struct seq_file *m, void *v) { + struct hist_file_data *hist_file = m->private; struct event_trigger_data *data; struct trace_event_file *event_file; int n = 0, ret = 0; mutex_lock(&event_mutex); - event_file = event_file_file(m->private); + event_file = event_file_file(hist_file->file); if (unlikely(!event_file)) { ret = -ENODEV; goto out_unlock; @@ -5608,6 +5631,7 @@ static int hist_show(struct seq_file *m, void *v) if (data->cmd_ops->trigger_type == ETT_EVENT_HIST) hist_trigger_show(m, data, n++); } + hist_file->last_read = get_hist_hit_count(event_file); out_unlock: mutex_unlock(&event_mutex); @@ -5615,24 +5639,63 @@ static int hist_show(struct seq_file *m, void *v) return ret; } +static __poll_t event_hist_poll(struct file *file, struct poll_table_struct *wait) +{ + struct trace_event_file *event_file; + struct seq_file *m = file->private_data; + struct hist_file_data *hist_file = m->private; + + guard(mutex)(&event_mutex); + + event_file = event_file_data(file); + if (!event_file) + return EPOLLERR; + + hist_poll_wait(file, wait); + + if (hist_file->last_read != get_hist_hit_count(event_file)) + return EPOLLIN | EPOLLRDNORM; + + return 0; +} + +static int event_hist_release(struct inode *inode, struct file *file) +{ + struct seq_file *m = file->private_data; + struct hist_file_data *hist_file = m->private; + + kfree(hist_file); + return tracing_single_release_file_tr(inode, file); +} + static int event_hist_open(struct inode *inode, struct file *file) { + struct hist_file_data *hist_file; int ret; ret = tracing_open_file_tr(inode, file); if (ret) return ret; + hist_file = kzalloc(sizeof(*hist_file), GFP_KERNEL); + if (!hist_file) + return -ENOMEM; + hist_file->file = file; + /* Clear private_data to avoid warning in single_open() */ file->private_data = NULL; - return single_open(file, hist_show, file); + ret = single_open(file, hist_show, hist_file); + if (ret) + kfree(hist_file); + return ret; } const struct file_operations event_hist_fops = { .open = event_hist_open, .read = seq_read, .llseek = seq_lseek, - .release = tracing_single_release_file_tr, + .release = event_hist_release, + .poll = event_hist_poll, }; #ifdef CONFIG_HIST_TRIGGERS_DEBUG From patchwork Fri Dec 27 04:08:07 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu \(Google\)" X-Patchwork-Id: 854081 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 E30D4524B4; 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dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="T3kG7Btm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 74817C4CED0; Fri, 27 Dec 2024 04:08:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1735272492; bh=1o3QZz/u4OLqgGCv2X2q5J2aE3A5JYecgIy0yAal9S0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=T3kG7BtmBrhHQLumSMXptCf+wceq3uyQdD15RT5nkKVVBXjUobhUzaZtjwBkOlY/O GDZ6NDwYHGRb9fjpXsgPAryFPyAOaWQw5NYLdENDdAEpnzA+ptHJvB46PhshXEB4fl xnSWRHVAscNjEZwCVEQyNtDT16YTtLx23Hfa2fFbDA3adPAmew/Lh9akcIW+CZ2tOs 1if0CuiGNiuFyf986n00Hbp6AzEnFhP03P/TLg+c8dymHWaKHhrqAOwRPusroSuDce nax8il+gaTRyxxzM0DmUj3NF8oZyJTHRjmrRhUHKPhIUf/keubZuwZR2U6YRn2Dek+ T5WPboYtE6r8A== From: "Masami Hiramatsu (Google)" To: Steven Rostedt , Shuah Khan Cc: Masami Hiramatsu , Tom Zanussi , Mathieu Desnoyers , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH v7 2/3] tracing/hist: Support POLLPRI event for poll on histogram Date: Fri, 27 Dec 2024 13:08:07 +0900 Message-ID: <173527248770.464571.2536902137325258133.stgit@devnote2> X-Mailer: git-send-email 2.43.0 In-Reply-To: <173527246726.464571.11533527581374142406.stgit@devnote2> References: <173527246726.464571.11533527581374142406.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Masami Hiramatsu (Google) Since POLLIN will not be flushed until the hist file is read, the user needs to repeatedly read() and poll() on the hist file for monitoring the event continuously. But the read() is somewhat redundant when the user is only monitoring for event updates. Add POLLPRI poll event on the hist file so the event returns when a histogram is updated after open(), poll() or read(). Thus it is possible to wait for the next event without having to issue a read(). Signed-off-by: Masami Hiramatsu (Google) Reviewed-by: Tom Zanussi --- Changes in v7: - Reword description according to Steve's comment. - Use guard() in hist_poll_open(). --- kernel/trace/trace_events_hist.c | 29 ++++++++++++++++++++++++++--- 1 file changed, 26 insertions(+), 3 deletions(-) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index e169f67c6088..15f76c681c6c 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -5595,6 +5595,7 @@ static void hist_trigger_show(struct seq_file *m, struct hist_file_data { struct file *file; u64 last_read; + u64 last_act; }; static u64 get_hist_hit_count(struct trace_event_file *event_file) @@ -5632,6 +5633,11 @@ static int hist_show(struct seq_file *m, void *v) hist_trigger_show(m, data, n++); } hist_file->last_read = get_hist_hit_count(event_file); + /* + * Update last_act too so that poll()/POLLPRI can wait for the next + * event after any syscall on hist file. + */ + hist_file->last_act = hist_file->last_read; out_unlock: mutex_unlock(&event_mutex); @@ -5644,6 +5650,8 @@ static __poll_t event_hist_poll(struct file *file, struct poll_table_struct *wai struct trace_event_file *event_file; struct seq_file *m = file->private_data; struct hist_file_data *hist_file = m->private; + __poll_t ret = 0; + u64 cnt; guard(mutex)(&event_mutex); @@ -5653,10 +5661,15 @@ static __poll_t event_hist_poll(struct file *file, struct poll_table_struct *wai hist_poll_wait(file, wait); - if (hist_file->last_read != get_hist_hit_count(event_file)) - return EPOLLIN | EPOLLRDNORM; + cnt = get_hist_hit_count(event_file); + if (hist_file->last_read != cnt) + ret |= EPOLLIN | EPOLLRDNORM; + if (hist_file->last_act != cnt) { + hist_file->last_act = cnt; + ret |= EPOLLPRI; + } - return 0; + return ret; } static int event_hist_release(struct inode *inode, struct file *file) @@ -5670,6 +5683,7 @@ static int event_hist_release(struct inode *inode, struct file *file) static int event_hist_open(struct inode *inode, struct file *file) { + struct trace_event_file *event_file; struct hist_file_data *hist_file; int ret; @@ -5677,16 +5691,25 @@ static int event_hist_open(struct inode *inode, struct file *file) if (ret) return ret; + guard(mutex)(&event_mutex); + + event_file = event_file_data(file); + if (!event_file) + return -ENODEV; + hist_file = kzalloc(sizeof(*hist_file), GFP_KERNEL); if (!hist_file) return -ENOMEM; + hist_file->file = file; + hist_file->last_act = get_hist_hit_count(event_file); /* Clear private_data to avoid warning in single_open() */ file->private_data = NULL; ret = single_open(file, hist_show, hist_file); if (ret) kfree(hist_file); + return ret; } From patchwork Fri Dec 27 04:08:18 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu \(Google\)" X-Patchwork-Id: 853948 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 4963912BF24; 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dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="SlR/Vp6u" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 63E89C4CED0; Fri, 27 Dec 2024 04:08:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1735272502; bh=TLRRJpSlyRF7o1BYWCZ2PSNtTMR3NYJ6wwaKz5Sm11U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SlR/Vp6uFIdGZOQMAAxMqvIgDR47DO1tJ6UXASnBzeFDqqmzgCtYPbjn1TJf0QvcD GLu0EYOTDUi8vUo3AUGpM550NWcRWZZf4atsQ+tqiqqf5nlJf3K2j/xB0MxsTNnfoq ya2u3qKsAenbNYKixMDZQ/XD5dndeJGjjqgPOkJrPu/PVJsqhrymaOZF+NJwOTWOtY /9RCcF+x4UfXo4D48zQkOsW2cvoWn2EJOpWdn26BjWX+zq80yC8HOf4ZvtdWj83oAc iwD908fQqW2N4S/6JukseFPL8feeK1eaxWsYhz3TMn9E6hga9YZUcPWod0iTLTBDpo FHECiZaRWsgPQ== From: "Masami Hiramatsu (Google)" To: Steven Rostedt , Shuah Khan Cc: Masami Hiramatsu , Tom Zanussi , Mathieu Desnoyers , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH v7 3/3] selftests/tracing: Add hist poll() support test Date: Fri, 27 Dec 2024 13:08:18 +0900 Message-ID: <173527249794.464571.10924229554900263368.stgit@devnote2> X-Mailer: git-send-email 2.43.0 In-Reply-To: <173527246726.464571.11533527581374142406.stgit@devnote2> References: <173527246726.464571.11533527581374142406.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Masami Hiramatsu (Google) Add a testcase for poll() on hist file. This introduces a helper binary to the ftracetest, because there is no good way to reliably execute poll() on hist file. Signed-off-by: Masami Hiramatsu (Google) Reviewed-by: Shuah Khan --- Changes in v7: - Add comm histogram filter for specifying test sleep command. --- tools/testing/selftests/ftrace/Makefile | 2 + tools/testing/selftests/ftrace/poll.c | 74 ++++++++++++++++++++ .../ftrace/test.d/trigger/trigger-hist-poll.tc | 74 ++++++++++++++++++++ 3 files changed, 150 insertions(+) create mode 100644 tools/testing/selftests/ftrace/poll.c create mode 100644 tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-poll.tc diff --git a/tools/testing/selftests/ftrace/Makefile b/tools/testing/selftests/ftrace/Makefile index a1e955d2de4c..49d96bb16355 100644 --- a/tools/testing/selftests/ftrace/Makefile +++ b/tools/testing/selftests/ftrace/Makefile @@ -6,4 +6,6 @@ TEST_PROGS := ftracetest-ktap TEST_FILES := test.d settings EXTRA_CLEAN := $(OUTPUT)/logs/* +TEST_GEN_PROGS = poll + include ../lib.mk diff --git a/tools/testing/selftests/ftrace/poll.c b/tools/testing/selftests/ftrace/poll.c new file mode 100644 index 000000000000..53258f7515e7 --- /dev/null +++ b/tools/testing/selftests/ftrace/poll.c @@ -0,0 +1,74 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Simple poll on a file. + * + * Copyright (c) 2024 Google LLC. + */ + +#include +#include +#include +#include +#include +#include +#include + +#define BUFSIZE 4096 + +/* + * Usage: + * poll [-I|-P] [-t timeout] FILE + */ +int main(int argc, char *argv[]) +{ + struct pollfd pfd = {.events = POLLIN}; + char buf[BUFSIZE]; + int timeout = -1; + int ret, opt; + + while ((opt = getopt(argc, argv, "IPt:")) != -1) { + switch (opt) { + case 'I': + pfd.events = POLLIN; + break; + case 'P': + pfd.events = POLLPRI; + break; + case 't': + timeout = atoi(optarg); + break; + default: + fprintf(stderr, "Usage: %s [-I|-P] [-t timeout] FILE\n", + argv[0]); + return -1; + } + } + if (optind >= argc) { + fprintf(stderr, "Error: Polling file is not specified\n"); + return -1; + } + + pfd.fd = open(argv[optind], O_RDONLY); + if (pfd.fd < 0) { + fprintf(stderr, "failed to open %s", argv[optind]); + perror("open"); + return -1; + } + + /* Reset poll by read if POLLIN is specified. */ + if (pfd.events & POLLIN) + do {} while (read(pfd.fd, buf, BUFSIZE) == BUFSIZE); + + ret = poll(&pfd, 1, timeout); + if (ret < 0 && errno != EINTR) { + perror("poll"); + return -1; + } + close(pfd.fd); + + /* If timeout happned (ret == 0), exit code is 1 */ + if (ret == 0) + return 1; + + return 0; +} diff --git a/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-poll.tc b/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-poll.tc new file mode 100644 index 000000000000..cbd01a71ecad --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-poll.tc @@ -0,0 +1,74 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: event trigger - test poll wait on histogram +# requires: set_event events/sched/sched_process_free/trigger events/sched/sched_process_free/hist +# flags: instance + +POLL=${FTRACETEST_ROOT}/poll + +if [ ! -x ${POLL} ]; then + echo "poll program is not compiled!" + exit_unresolved +fi + +EVENT=events/sched/sched_process_free/ + +# Check poll ops is supported. Before implementing poll on hist file, it +# returns soon with POLLIN | POLLOUT, but not POLLPRI. + +# This must wait >1 sec and return 1 (timeout). +set +e +${POLL} -I -t 1000 ${EVENT}/hist +ret=$? +set -e +if [ ${ret} != 1 ]; then + echo "poll on hist file is not supported" + exit_unsupported +fi + +# Test POLLIN +echo > trace +echo "hist:key=comm" > ${EVENT}/trigger +echo 1 > ${EVENT}/enable + +# This sleep command will exit after 2 seconds. +sleep 2 & +BGPID=$! +# if timeout happens, poll returns 1. +${POLL} -I -t 4000 ${EVENT}/hist +echo 0 > tracing_on + +if [ -d /proc/${BGPID} ]; then + echo "poll exits too soon" + kill -KILL ${BGPID} ||: + exit_fail +fi + +if ! grep -qw "sleep" trace; then + echo "poll exits before event happens" + exit_fail +fi + +# Test POLLPRI +echo > trace +echo 1 > tracing_on + +# This sleep command will exit after 2 seconds. +sleep 2 & +BGPID=$! +# if timeout happens, poll returns 1. +${POLL} -P -t 4000 ${EVENT}/hist +echo 0 > tracing_on + +if [ -d /proc/${BGPID} ]; then + echo "poll exits too soon" + kill -KILL ${BGPID} ||: + exit_fail +fi + +if ! grep -qw "sleep" trace; then + echo "poll exits before event happens" + exit_fail +fi + +exit_pass