From patchwork Wed Jul 3 05:32:41 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: 13721409 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 D24F61DA302; Wed, 3 Jul 2024 05:32:45 +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=1719984765; cv=none; b=fMI4RfKcH6j3lPp86FH+y5+d/UeryCkI7UljvADFYRFVnLELPVKfJyqbAxeqd+BMg9juWctbGRMDVPcZ0iWofvkjnasAu/1ToFHfx8Bo1sVQve+bBLXhAQPtHs06WQY64V2gqP+bM1Yun0rzCvLU20sfD0hU+SGlI0hESernLTM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719984765; c=relaxed/simple; bh=yASA+Rf1zDX+0KCFPs6HM3eJ73+5gsj+bg/LWKkH1AQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=u42kvG2e7q76fXtoDtoQmbfTDhfx6UCy2Q8504EyV8U+2Gqt5RNMWnHME7JbkCj6+T/1N3oOcdWT7Ws1Ag1DMm04MoalaZGLXa1i4RyYGwCw2h1lIoybcwOnAQX9WlpmzyU7sjKdBq4Z5IisGbaF2dq3LFcsoScDiDV2hH3jkRg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pjp9PwXZ; 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="pjp9PwXZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B222EC32781; Wed, 3 Jul 2024 05:32:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719984765; bh=yASA+Rf1zDX+0KCFPs6HM3eJ73+5gsj+bg/LWKkH1AQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pjp9PwXZcwj2+yDUO1WjeWkzf1QQFH3Hf/tUbLjxAMHwBBFK1iwWgxa/lUe4X0j5d gTrKmS42L3f2+KUCpFTJXaHNjcNnRzUUNkFuLn8gGW2evWKBJlBRJPOM++FFO38Rsu H5UFjIsRhGT562mnUx0AK1+QzJdFdZV1uSNH4cBeJdWLJ7Q73PiZq/bscNXzbvoY+O 4SSUQ81f40/wLIcHHtpuvodCPQaZIdMAOoeHejkXVY21sUCoFMErpjbhl/R5/34ucX HoNmXxDKObQb5vsGMdjaEyADjZDRp3C4yzFhY9uQwSKjoN+ngRZgI+BoG7JKtEGfwH t05oWWZWoxUpA== 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 v2 1/3] tracing/hist: Add poll(POLLIN) support on hist file Date: Wed, 3 Jul 2024 14:32:41 +0900 Message-Id: <171998476131.54594.7301141358736133273.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <171998475175.54594.7244942110355338359.stgit@devnote2> References: <171998475175.54594.7244942110355338359.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 that is not good idea to peek the `trace` for the event randomely happens. And `trace_pipe` is not coming back until a page is filled with events. This allows user to wait for a specific events on `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 you do read() on 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 --- include/linux/trace_events.h | 5 +++ kernel/trace/trace_events.c | 18 +++++++++ kernel/trace/trace_events_hist.c | 76 +++++++++++++++++++++++++++++++++++++- 3 files changed, 96 insertions(+), 3 deletions(-) diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 9df3e2973626..0d496e2d1064 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -663,6 +663,11 @@ struct trace_event_file { struct trace_subsystem_dir *system; struct list_head triggers; +#ifdef CONFIG_HIST_TRIGGERS + struct irq_work hist_work; + wait_queue_head_t hist_wq; +#endif + /* * 32 bit flags: * bit 0: enabled diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 6ef29eba90ce..07ce5b024dd9 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -2965,6 +2965,20 @@ 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_wq from irq_work because the hist trigger + * may happen in any context. + */ +static void hist_event_irq_work(struct irq_work *work) +{ + struct trace_event_file *event_file; + + event_file = container_of(work, struct trace_event_file, hist_work); + wake_up_all(&event_file->hist_wq); +} +#endif + static struct trace_event_file * trace_create_new_event(struct trace_event_call *call, struct trace_array *tr) @@ -2996,6 +3010,10 @@ trace_create_new_event(struct trace_event_call *call, atomic_set(&file->tm_ref, 0); INIT_LIST_HEAD(&file->triggers); list_add(&file->list, &tr->events); +#ifdef CONFIG_HIST_TRIGGERS + init_irq_work(&file->hist_work, hist_event_irq_work); + init_waitqueue_head(&file->hist_wq); +#endif event_file_get(file); return file; diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 6ece1308d36a..136d91139949 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -5314,6 +5314,9 @@ 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); + + if (hist_data->event_file && wq_has_sleeper(&hist_data->event_file->hist_wq)) + irq_work_queue(&hist_data->event_file->hist_work); } static void hist_trigger_stacktrace_print(struct seq_file *m, @@ -5593,15 +5596,36 @@ 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_data(m->private); + event_file = event_file_data(hist_file->file); if (unlikely(!event_file)) { ret = -ENODEV; goto out_unlock; @@ -5611,6 +5635,7 @@ 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); @@ -5618,24 +5643,69 @@ 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; + __poll_t ret = 0; + + mutex_lock(&event_mutex); + + event_file = event_file_data(file); + if (!event_file) { + ret = EPOLLERR; + goto out_unlock; + } + + poll_wait(file, &event_file->hist_wq, wait); + + if (hist_file->last_read != get_hist_hit_count(event_file)) + ret = EPOLLIN | EPOLLRDNORM; + +out_unlock: + mutex_unlock(&event_mutex); + + return ret; +} + +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 Wed Jul 3 05:32:50 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: 13721410 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 3EE16383B1; Wed, 3 Jul 2024 05:32:54 +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=1719984775; cv=none; b=VDscg7ntUonNNwaQ0BuO7sAsZRQJ7X2hny2ln8z+5uCgy4XcIUW+ZJ1dTxrkMpKlny5YHYgKUFCG6nMpC8c/9bMrsjBKFdMVkPvizrVOYOP/Apur2hnhfNkrV+on8d3lA3hqEhWhWsF7G5NGRgwn5dhgb2Qw1h+PxWdV1MGDdf0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719984775; c=relaxed/simple; bh=WULNwgwERPKbPxbI+UaCGX2Ay60pymtdMlPiYvx3DeU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=F6tahv5nYKzAFA1r1/on/u3nJ7wEEn8AoEV+tzqVvoZ4o2+FmlLpYFv9T/jEEaY4Laqmt0KAmxMQkXfhDeQ2lUnOol3T9361v8bAI31Q3VXM7NbRS+s/RM7D0hQNqmp9FnHlnEmeWRPjvWhpEuqLjY+J29u/JWkYA+w2YIeyb30= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KgBCHXuj; 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="KgBCHXuj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E6A7EC32781; Wed, 3 Jul 2024 05:32:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719984774; bh=WULNwgwERPKbPxbI+UaCGX2Ay60pymtdMlPiYvx3DeU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KgBCHXujA8Q/s4vtuumqlicoQBkopCAtrz5CpZ0yBW24UnSaDLxOShYhHtzRqOxuD sMrcY4VgIFXLbaKsYbtDsYiADzEARwwJ078znf8hetQmk/hndmmc6Jfaa/Qmpx6kTd YLYlG3Aj63SB7h7gKbIqiPAL5kZj+G++I4MHzN6Mc/eId4BaMea1OoNFBnhA8lDdsg allkCMwqOv4J6ZVb98vjoyKVXCcCDPEjH4cSU+5fIQwzGHPj2t80gAP6XB2zQNNcGG H7QXZO8tnCKRpPx/vwdoUjArow/OocsUQP2Pl2EzZs3bnVWLRBhYZB4LoLFFRK7pd2 3zLZj8+RqLr1w== 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 v2 2/3] tracing/hist: Support POLLPRI event for poll on histogram Date: Wed, 3 Jul 2024 14:32:50 +0900 Message-Id: <171998477066.54594.13188592197265452865.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <171998475175.54594.7244942110355338359.stgit@devnote2> References: <171998475175.54594.7244942110355338359.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 flashed until read the hist file, user needs to repeat read() and poll() on hist for monitoring the event continuously. But the read() is somewhat redundant only for monitoring events. This add POLLPRI poll event on hist, this event returns when a histogram is updated after open(), poll() or read(). Thus it is possible to wait next event without read(). Signed-off-by: Masami Hiramatsu (Google) Reviewed-by: Tom Zanussi --- kernel/trace/trace_events_hist.c | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 136d91139949..a22454ad36d8 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -5599,6 +5599,7 @@ 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) @@ -5636,6 +5637,11 @@ 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); @@ -5649,6 +5655,7 @@ static __poll_t event_hist_poll(struct file *file, struct poll_table_struct *wai struct seq_file *m = file->private_data; struct hist_file_data *hist_file = m->private; __poll_t ret = 0; + u64 cnt; mutex_lock(&event_mutex); @@ -5660,8 +5667,13 @@ static __poll_t event_hist_poll(struct file *file, struct poll_table_struct *wai poll_wait(file, &event_file->hist_wq, wait); - if (hist_file->last_read != get_hist_hit_count(event_file)) - ret = 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; + } out_unlock: mutex_unlock(&event_mutex); @@ -5680,6 +5692,7 @@ 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; @@ -5690,13 +5703,25 @@ static int event_hist_open(struct inode *inode, struct file *file) hist_file = kzalloc(sizeof(*hist_file), GFP_KERNEL); if (!hist_file) return -ENOMEM; + + mutex_lock(&event_mutex); + event_file = event_file_data(file); + if (!event_file) { + ret = -ENODEV; + goto out_unlock; + } + 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); + +out_unlock: if (ret) kfree(hist_file); + mutex_unlock(&event_mutex); return ret; } From patchwork Wed Jul 3 05:33:00 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: 13721411 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 1E8B561FD4; Wed, 3 Jul 2024 05:33:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; 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Wed, 3 Jul 2024 05:33:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719984783; bh=qMUrvkxecOx/v3yAVcd4bfohhjch6A/wjtM7rqSvV/g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PmN8nv6GXyGbXfjwXwc48AHyl38EgSsWzC9dgCS9wYpXax6U4pS5QDd6lUd22jRTV hJgOaGyrvV2f9AZFzd2reezTb00n5gEdwSx+8zwRJeEeQu+bkDDZtH/j0WMEM3udzN k7ojdCv4DQPEzb7Pk3utvYNPmvCDLyn1zPDbaI+NF/AJoVvT51WNTK3BKF4brWdZg+ cEEOvKfQPDxWCYNbTwxaWMZ2/lY5kaErdr0Pav2ECGIkYChEvLw1aZbzYmV7zCKtna 4/0u8XFLoaRLUUafh/3liWYctMoE773XA4t3bEKq9Hdl/e4wQemBUJiXAOYdXpp7kv kGqVH/Tbnk2Mw== 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 v2 3/3] selftests/tracing: Add hist poll() support test Date: Wed, 3 Jul 2024 14:33:00 +0900 Message-Id: <171998477999.54594.16011632695593086016.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <171998475175.54594.7244942110355338359.stgit@devnote2> References: <171998475175.54594.7244942110355338359.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) --- Changes in v2: - Update poll command to support both of POLLIN and POLLPRI, and timeout. - Identify unsupported stable kernel if poll-in returns soon. - Test both of POLLIN and POLLPRI. --- tools/testing/selftests/ftrace/Makefile | 2 + tools/testing/selftests/ftrace/poll.c | 62 +++++++++++++++++ .../ftrace/test.d/trigger/trigger-hist-poll.tc | 74 ++++++++++++++++++++ 3 files changed, 138 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 := $(OUTPUT)/logs/* +TEST_GEN_PROGS = poll + include ../lib.mk diff --git a/tools/testing/selftests/ftrace/poll.c b/tools/testing/selftests/ftrace/poll.c new file mode 100644 index 000000000000..8003a59fe042 --- /dev/null +++ b/tools/testing/selftests/ftrace/poll.c @@ -0,0 +1,62 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Simple poll on a file. + * + * Copyright (c) 2024 Google LLC. + */ + +#include +#include +#include +#include +#include +#include +#include + +#define BUFSIZE 4096 + +/* + * Usage: + * poll [timeout] + */ +int main(int argc, char *argv[]) +{ + struct pollfd pfd; + char buf[BUFSIZE]; + int timeout = -1; + int ret; + + if (argc < 3) + return -1; + + if (!strcmp(argv[1], "in")) + pfd.events = POLLIN; + else if (!strcmp(argv[1], "pri")) + pfd.events = POLLPRI; + + pfd.fd = open(argv[2], O_RDONLY); + if (pfd.fd < 0) { + perror("open"); + return -1; + } + + if (argc == 4) + timeout = atoi(argv[3]); + + /* Reset poll by read if POLLIN is specified. */ + if (pfd.events & POLLIN) + do {} while (read(pfd.fd, buf, BUFSIZE) == BUFSIZE); + + ret = poll(&pfd, 1, timeout); + if (ret < 0 && errno != EINTR) { + perror("poll"); + return -1; + } + close(pfd.fd); + + /* If timeout happned, return code is 0 */ + if (ret == 0) + return 1; + + return 0; +} diff --git a/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-poll.tc b/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-poll.tc new file mode 100644 index 000000000000..53bea74e2234 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-poll.tc @@ -0,0 +1,74 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: event trigger - test poll wait on histogram +# requires: set_event events/sched/sched_process_free/trigger events/sched/sched_process_free/hist +# flags: instance + +POLL=${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} in ${EVENT}/hist 1000 +ret=$? +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} in ${EVENT}/hist 4000 +echo 0 > tracing_on + +if [ -d /proc/${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} pri ${EVENT}/hist 4000 +echo 0 > tracing_on + +if [ -d /proc/${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