[v3,05/10] cxl: add monitor function for event trace events

Message ID	166742403256.2654617.15551316837123337120.stgit@djiang5-desk3.ch.intel.com
State	Superseded
Headers	show Return-Path: <linux-cxl-owner@kernel.org> Subject: [PATCH v3 05/10] cxl: add monitor function for event trace events From: Dave Jiang <dave.jiang@intel.com> To: linux-cxl@vger.kernel.org Cc: dan.j.williams@intel.com, ira.weiny@intel.com, vishal.l.verma@intel.com, alison.schofield@intel.com, rostedt@goodmis.org Date: Wed, 02 Nov 2022 14:20:32 -0700 Message-ID: <166742403256.2654617.15551316837123337120.stgit@djiang5-desk3.ch.intel.com> In-Reply-To: <166742389426.2654617.4404053893427481848.stgit@djiang5-desk3.ch.intel.com> References: <166742389426.2654617.4404053893427481848.stgit@djiang5-desk3.ch.intel.com> User-Agent: StGit/1.4 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk
Series	cxl: add monitor support for trace events \| expand [v3,00/10] cxl: add monitor support for trace events [v3,01/10] cxl: add helper function to parse trace event to json object [v3,02/10] cxl: add helper to parse through all current events [v3,03/10] cxl: add common function to enable event trace [v3,04/10] cxl: add common function to disable event trace [v3,05/10] cxl: add monitor function for event trace events [v3,06/10] cxl: add logging functions for monitor [v3,07/10] cxl: add monitor command to cxl [v3,08/10] cxl: add an optional pid check to event parsing [v3,09/10] cxl: add systemd service for monitor [v3,10/10] cxl: add man page documentation for monitor

Message ID

166742403256.2654617.15551316837123337120.stgit@djiang5-desk3.ch.intel.com

State

Superseded

Headers

Subject: [PATCH v3 05/10] cxl: add monitor function for event trace events
From: Dave Jiang <dave.jiang@intel.com>
To: linux-cxl@vger.kernel.org
Cc: dan.j.williams@intel.com, ira.weiny@intel.com,
        vishal.l.verma@intel.com, alison.schofield@intel.com,
        rostedt@goodmis.org
Date: Wed, 02 Nov 2022 14:20:32 -0700
Message-ID: 
 <166742403256.2654617.15551316837123337120.stgit@djiang5-desk3.ch.intel.com>
In-Reply-To: 
 <166742389426.2654617.4404053893427481848.stgit@djiang5-desk3.ch.intel.com>
References: 
 <166742389426.2654617.4404053893427481848.stgit@djiang5-desk3.ch.intel.com>
User-Agent: StGit/1.4
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit
Precedence: bulk

Series

cxl: add monitor support for trace events | expand

Commit Message

Dave Jiang Nov. 2, 2022, 9:20 p.m. UTC

Add function that creates an event trace instance and utilize the cxl event
trace common functions to extract interested events from the trace buffer.
The monitoring function will pend on an epoll fd and wait for new events
to appear in the trace buffer.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 cxl/meson.build |    1 
 cxl/monitor.c   |  140 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 141 insertions(+)
 create mode 100644 cxl/monitor.c

Comments

Steven Rostedt Nov. 3, 2022, 6:06 a.m. UTC | #1

On Wed, 02 Nov 2022 14:20:32 -0700
Dave Jiang <dave.jiang@intel.com> wrote:
> ---
>  cxl/meson.build |    1 
>  cxl/monitor.c   |  140 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 141 insertions(+)
>  create mode 100644 cxl/monitor.c
> 
> diff --git a/cxl/meson.build b/cxl/meson.build
> index c59876262e76..eb8b2b1070ed 100644
> --- a/cxl/meson.build
> +++ b/cxl/meson.build
> @@ -8,6 +8,7 @@ cxl_src = [
>    'json.c',
>    'filter.c',
>    'event_trace.c',
> +  'monitor.c',
>  ]
>  
>  cxl_tool = executable('cxl',
> diff --git a/cxl/monitor.c b/cxl/monitor.c
> new file mode 100644
> index 000000000000..85559d9a4b94
> --- /dev/null
> +++ b/cxl/monitor.c
> @@ -0,0 +1,140 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (C) 2022, Intel Corp. All rights reserved.
> +/* Some bits copied from ndctl monitor code */
> +#include <stdio.h>
> +#include <unistd.h>
> +#include <errno.h>
> +#include <json-c/json.h>
> +#include <libgen.h>
> +#include <time.h>
> +#include <dirent.h>
> +#include <ccan/list/list.h>
> +#include <util/json.h>
> +#include <util/util.h>
> +#include <util/parse-options.h>
> +#include <util/parse-configs.h>
> +#include <util/strbuf.h>
> +#include <sys/epoll.h>
> +#include <sys/stat.h>
> +#include <traceevent/event-parse.h>
> +#include <tracefs/tracefs.h>
> +#include <cxl/libcxl.h>
> +
> +/* reuse the core log helpers for the monitor logger */
> +#ifndef ENABLE_LOGGING
> +#define ENABLE_LOGGING
> +#endif
> +#ifndef ENABLE_DEBUG
> +#define ENABLE_DEBUG
> +#endif
> +#include <util/log.h>
> +
> +#include "event_trace.h"
> +
> +static const char *cxl_system = "cxl";
> +
> +static struct monitor {
> +	struct log_ctx ctx;
> +	FILE *log_file;
> +	bool human;
> +} monitor;
> +
> +static int monitor_event(struct cxl_ctx *ctx)
> +{
> +	int fd, epollfd, rc = 0, timeout = -1;
> +	struct epoll_event ev, *events;
> +	struct tracefs_instance *inst;
> +	struct event_ctx ectx;
> +	int jflag;
> +
> +	events = calloc(1, sizeof(struct epoll_event));
> +	if (!events) {
> +		err(&monitor, "alloc for events error\n");
> +		return -ENOMEM;
> +	}
> +
> +	epollfd = epoll_create1(0);
> +	if (epollfd == -1) {
> +		rc = -errno;
> +		err(&monitor, "epoll_create1() error: %d\n", rc);
> +		goto epoll_err;
> +	}
> +
> +	inst = tracefs_instance_create("cxl_monitor");
> +	if (!inst) {
> +		rc = -errno;
> +		err(&monitor, "tracefs_instance_crate( failed: %d\n", rc);

 "crate"? Been coding a bit too much Rust lately?

> +		goto inst_err;
> +	}
> +
> +	fd = tracefs_instance_file_open(inst, "trace_pipe", -1);

I'm curious to why you are opening trace_pipe?

> +	if (fd < 0) {
> +		rc = fd;
> +		err(&monitor, "tracefs_instance_file_open() err: %d\n", rc);
> +		goto inst_file_err;
> +	}
> +
> +	memset(&ev, 0, sizeof(ev));
> +	ev.events = EPOLLIN;
> +	ev.data.fd = fd;

Is it a way to know if there's something to read?

-- Steve

> +
> +	if (epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &ev) != 0) {
> +		rc = -errno;
> +		err(&monitor, "epoll_ctl() error: %d\n", rc);
> +		goto epoll_ctl_err;
> +	}
> +
> +	rc = cxl_event_tracing_enable(inst, cxl_system);
> +	if (rc < 0) {
> +		err(&monitor, "cxl_trace_event_enable() failed: %d\n", rc);
> +		goto event_en_err;
> +	}
> +
> +	memset(&ectx, 0, sizeof(ectx));
> +	ectx.system = cxl_system;
> +	if (monitor.human)
> +		jflag = JSON_C_TO_STRING_PRETTY;
> +	else
> +		jflag = JSON_C_TO_STRING_PLAIN;
> +
> +	while (1) {
> +		struct jlist_node *jnode, *next;
> +
> +		rc = epoll_wait(epollfd, events, 1, timeout);
> +		if (rc < 0) {
> +			rc = -errno;
> +			if (errno != EINTR)
> +				err(&monitor, "epoll_wait error: %d\n", -errno);
> +			break;
> +		}
> +
> +		list_head_init(&ectx.jlist_head);
> +		rc = cxl_parse_events(inst, &ectx);
> +		if (rc < 0)
> +			goto parse_err;
> +
> +		if (list_empty(&ectx.jlist_head))
> +			continue;
> +
> +		list_for_each_safe(&ectx.jlist_head, jnode, next, list) {
> +			notice(&monitor, "%s\n",
> +				json_object_to_json_string_ext(jnode->jobj, jflag));
> +			list_del(&jnode->list);
> +			json_object_put(jnode->jobj);
> +			free(jnode);
> +		}
> +	}
> +
> +parse_err:
> +	rc = cxl_event_tracing_disable(inst);
> +event_en_err:
> +epoll_ctl_err:
> +	close(fd);
> +inst_file_err:
> +	tracefs_instance_free(inst);
> +inst_err:
> +	close(epollfd);
> +epoll_err:
> +	free(events);
> +	return rc;
> +}
>

Dave Jiang Nov. 3, 2022, 4:34 p.m. UTC | #2

On 11/2/2022 11:06 PM, Steven Rostedt wrote:
> On Wed, 02 Nov 2022 14:20:32 -0700
> Dave Jiang <dave.jiang@intel.com> wrote:
>> ---
>>   cxl/meson.build |    1
>>   cxl/monitor.c   |  140 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>   2 files changed, 141 insertions(+)
>>   create mode 100644 cxl/monitor.c
>>
>> diff --git a/cxl/meson.build b/cxl/meson.build
>> index c59876262e76..eb8b2b1070ed 100644
>> --- a/cxl/meson.build
>> +++ b/cxl/meson.build
>> @@ -8,6 +8,7 @@ cxl_src = [
>>     'json.c',
>>     'filter.c',
>>     'event_trace.c',
>> +  'monitor.c',
>>   ]
>>   
>>   cxl_tool = executable('cxl',
>> diff --git a/cxl/monitor.c b/cxl/monitor.c
>> new file mode 100644
>> index 000000000000..85559d9a4b94
>> --- /dev/null
>> +++ b/cxl/monitor.c
>> @@ -0,0 +1,140 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +// Copyright (C) 2022, Intel Corp. All rights reserved.
>> +/* Some bits copied from ndctl monitor code */
>> +#include <stdio.h>
>> +#include <unistd.h>
>> +#include <errno.h>
>> +#include <json-c/json.h>
>> +#include <libgen.h>
>> +#include <time.h>
>> +#include <dirent.h>
>> +#include <ccan/list/list.h>
>> +#include <util/json.h>
>> +#include <util/util.h>
>> +#include <util/parse-options.h>
>> +#include <util/parse-configs.h>
>> +#include <util/strbuf.h>
>> +#include <sys/epoll.h>
>> +#include <sys/stat.h>
>> +#include <traceevent/event-parse.h>
>> +#include <tracefs/tracefs.h>
>> +#include <cxl/libcxl.h>
>> +
>> +/* reuse the core log helpers for the monitor logger */
>> +#ifndef ENABLE_LOGGING
>> +#define ENABLE_LOGGING
>> +#endif
>> +#ifndef ENABLE_DEBUG
>> +#define ENABLE_DEBUG
>> +#endif
>> +#include <util/log.h>
>> +
>> +#include "event_trace.h"
>> +
>> +static const char *cxl_system = "cxl";
>> +
>> +static struct monitor {
>> +	struct log_ctx ctx;
>> +	FILE *log_file;
>> +	bool human;
>> +} monitor;
>> +
>> +static int monitor_event(struct cxl_ctx *ctx)
>> +{
>> +	int fd, epollfd, rc = 0, timeout = -1;
>> +	struct epoll_event ev, *events;
>> +	struct tracefs_instance *inst;
>> +	struct event_ctx ectx;
>> +	int jflag;
>> +
>> +	events = calloc(1, sizeof(struct epoll_event));
>> +	if (!events) {
>> +		err(&monitor, "alloc for events error\n");
>> +		return -ENOMEM;
>> +	}
>> +
>> +	epollfd = epoll_create1(0);
>> +	if (epollfd == -1) {
>> +		rc = -errno;
>> +		err(&monitor, "epoll_create1() error: %d\n", rc);
>> +		goto epoll_err;
>> +	}
>> +
>> +	inst = tracefs_instance_create("cxl_monitor");
>> +	if (!inst) {
>> +		rc = -errno;
>> +		err(&monitor, "tracefs_instance_crate( failed: %d\n", rc);
> 
>   "crate"? Been coding a bit too much Rust lately?

Ooops. Will fix.

> 
>> +		goto inst_err;
>> +	}
>> +
>> +	fd = tracefs_instance_file_open(inst, "trace_pipe", -1);
> 
> I'm curious to why you are opening trace_pipe?
> 
>> +	if (fd < 0) {
>> +		rc = fd;
>> +		err(&monitor, "tracefs_instance_file_open() err: %d\n", rc);
>> +		goto inst_file_err;
>> +	}
>> +
>> +	memset(&ev, 0, sizeof(ev));
>> +	ev.events = EPOLLIN;
>> +	ev.data.fd = fd;
> 
> Is it a way to know if there's something to read?

Yes. Since trace_pipe() is the read once data stream, seems like the 
right place to put the epoll on. Is that the wrong way to do this?

> 
> -- Steve
> 
>> +
>> +	if (epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &ev) != 0) {
>> +		rc = -errno;
>> +		err(&monitor, "epoll_ctl() error: %d\n", rc);
>> +		goto epoll_ctl_err;
>> +	}
>> +
>> +	rc = cxl_event_tracing_enable(inst, cxl_system);
>> +	if (rc < 0) {
>> +		err(&monitor, "cxl_trace_event_enable() failed: %d\n", rc);
>> +		goto event_en_err;
>> +	}
>> +
>> +	memset(&ectx, 0, sizeof(ectx));
>> +	ectx.system = cxl_system;
>> +	if (monitor.human)
>> +		jflag = JSON_C_TO_STRING_PRETTY;
>> +	else
>> +		jflag = JSON_C_TO_STRING_PLAIN;
>> +
>> +	while (1) {
>> +		struct jlist_node *jnode, *next;
>> +
>> +		rc = epoll_wait(epollfd, events, 1, timeout);
>> +		if (rc < 0) {
>> +			rc = -errno;
>> +			if (errno != EINTR)
>> +				err(&monitor, "epoll_wait error: %d\n", -errno);
>> +			break;
>> +		}
>> +
>> +		list_head_init(&ectx.jlist_head);
>> +		rc = cxl_parse_events(inst, &ectx);
>> +		if (rc < 0)
>> +			goto parse_err;
>> +
>> +		if (list_empty(&ectx.jlist_head))
>> +			continue;
>> +
>> +		list_for_each_safe(&ectx.jlist_head, jnode, next, list) {
>> +			notice(&monitor, "%s\n",
>> +				json_object_to_json_string_ext(jnode->jobj, jflag));
>> +			list_del(&jnode->list);
>> +			json_object_put(jnode->jobj);
>> +			free(jnode);
>> +		}
>> +	}
>> +
>> +parse_err:
>> +	rc = cxl_event_tracing_disable(inst);
>> +event_en_err:
>> +epoll_ctl_err:
>> +	close(fd);
>> +inst_file_err:
>> +	tracefs_instance_free(inst);
>> +inst_err:
>> +	close(epollfd);
>> +epoll_err:
>> +	free(events);
>> +	return rc;
>> +}
>>
>

diff --git a/cxl/meson.build b/cxl/meson.build
index c59876262e76..eb8b2b1070ed 100644
--- a/cxl/meson.build
+++ b/cxl/meson.build
@@ -8,6 +8,7 @@  cxl_src = [
   'json.c',
   'filter.c',
   'event_trace.c',
+  'monitor.c',
 ]
 
 cxl_tool = executable('cxl',
diff --git a/cxl/monitor.c b/cxl/monitor.c
new file mode 100644
index 000000000000..85559d9a4b94
--- /dev/null
+++ b/cxl/monitor.c
@@ -0,0 +1,140 @@ 
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2022, Intel Corp. All rights reserved.
+/* Some bits copied from ndctl monitor code */
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <json-c/json.h>
+#include <libgen.h>
+#include <time.h>
+#include <dirent.h>
+#include <ccan/list/list.h>
+#include <util/json.h>
+#include <util/util.h>
+#include <util/parse-options.h>
+#include <util/parse-configs.h>
+#include <util/strbuf.h>
+#include <sys/epoll.h>
+#include <sys/stat.h>
+#include <traceevent/event-parse.h>
+#include <tracefs/tracefs.h>
+#include <cxl/libcxl.h>
+
+/* reuse the core log helpers for the monitor logger */
+#ifndef ENABLE_LOGGING
+#define ENABLE_LOGGING
+#endif
+#ifndef ENABLE_DEBUG
+#define ENABLE_DEBUG
+#endif
+#include <util/log.h>
+
+#include "event_trace.h"
+
+static const char *cxl_system = "cxl";
+
+static struct monitor {
+	struct log_ctx ctx;
+	FILE *log_file;
+	bool human;
+} monitor;
+
+static int monitor_event(struct cxl_ctx *ctx)
+{
+	int fd, epollfd, rc = 0, timeout = -1;
+	struct epoll_event ev, *events;
+	struct tracefs_instance *inst;
+	struct event_ctx ectx;
+	int jflag;
+
+	events = calloc(1, sizeof(struct epoll_event));
+	if (!events) {
+		err(&monitor, "alloc for events error\n");
+		return -ENOMEM;
+	}
+
+	epollfd = epoll_create1(0);
+	if (epollfd == -1) {
+		rc = -errno;
+		err(&monitor, "epoll_create1() error: %d\n", rc);
+		goto epoll_err;
+	}
+
+	inst = tracefs_instance_create("cxl_monitor");
+	if (!inst) {
+		rc = -errno;
+		err(&monitor, "tracefs_instance_crate( failed: %d\n", rc);
+		goto inst_err;
+	}
+
+	fd = tracefs_instance_file_open(inst, "trace_pipe", -1);
+	if (fd < 0) {
+		rc = fd;
+		err(&monitor, "tracefs_instance_file_open() err: %d\n", rc);
+		goto inst_file_err;
+	}
+
+	memset(&ev, 0, sizeof(ev));
+	ev.events = EPOLLIN;
+	ev.data.fd = fd;
+
+	if (epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &ev) != 0) {
+		rc = -errno;
+		err(&monitor, "epoll_ctl() error: %d\n", rc);
+		goto epoll_ctl_err;
+	}
+
+	rc = cxl_event_tracing_enable(inst, cxl_system);
+	if (rc < 0) {
+		err(&monitor, "cxl_trace_event_enable() failed: %d\n", rc);
+		goto event_en_err;
+	}
+
+	memset(&ectx, 0, sizeof(ectx));
+	ectx.system = cxl_system;
+	if (monitor.human)
+		jflag = JSON_C_TO_STRING_PRETTY;
+	else
+		jflag = JSON_C_TO_STRING_PLAIN;
+
+	while (1) {
+		struct jlist_node *jnode, *next;
+
+		rc = epoll_wait(epollfd, events, 1, timeout);
+		if (rc < 0) {
+			rc = -errno;
+			if (errno != EINTR)
+				err(&monitor, "epoll_wait error: %d\n", -errno);
+			break;
+		}
+
+		list_head_init(&ectx.jlist_head);
+		rc = cxl_parse_events(inst, &ectx);
+		if (rc < 0)
+			goto parse_err;
+
+		if (list_empty(&ectx.jlist_head))
+			continue;
+
+		list_for_each_safe(&ectx.jlist_head, jnode, next, list) {
+			notice(&monitor, "%s\n",
+				json_object_to_json_string_ext(jnode->jobj, jflag));
+			list_del(&jnode->list);
+			json_object_put(jnode->jobj);
+			free(jnode);
+		}
+	}
+
+parse_err:
+	rc = cxl_event_tracing_disable(inst);
+event_en_err:
+epoll_ctl_err:
+	close(fd);
+inst_file_err:
+	tracefs_instance_free(inst);
+inst_err:
+	close(epollfd);
+epoll_err:
+	free(events);
+	return rc;
+}

[v3,05/10] cxl: add monitor function for event trace events

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