From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Heikki Krogerus <heikki.krogerus@linux.intel.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Bartosz Golaszewski <bgolaszewski@baylibre.com>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
linux-kernel@vger.kernel.org
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Subject: [PATCH v2 1/1] devres: Enable trace events
Date: Tue, 13 Apr 2021 14:38:01 +0300 [thread overview]
Message-ID: <20210413113801.18245-1-andriy.shevchenko@linux.intel.com> (raw)
In some cases the printf() mechanism is too heavy and can't be used.
For example, when debugging a race condition involving devres API.
When CONFIG_DEBUG_DEVRES is enabled I can't reproduce an issue, and
otherwise it's quite visible with a useful information being collected.
Enable trace events for devres part of the driver core.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
v2: fixed compilation error (lkp), elaborate commit message (Greg)
drivers/base/Makefile | 3 +++
drivers/base/devres.c | 23 +++++++++++-------
drivers/base/trace.c | 10 ++++++++
drivers/base/trace.h | 56 +++++++++++++++++++++++++++++++++++++++++++
4 files changed, 83 insertions(+), 9 deletions(-)
create mode 100644 drivers/base/trace.c
create mode 100644 drivers/base/trace.h
diff --git a/drivers/base/Makefile b/drivers/base/Makefile
index 8b93a7f291ec..ef8e44a7d288 100644
--- a/drivers/base/Makefile
+++ b/drivers/base/Makefile
@@ -30,3 +30,6 @@ obj-y += test/
ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG
+# define_trace.h needs to know how to find our header
+CFLAGS_trace.o := -I$(src)
+obj-$(CONFIG_TRACING) += trace.o
diff --git a/drivers/base/devres.c b/drivers/base/devres.c
index db1f3137fc81..a0850bd1eab7 100644
--- a/drivers/base/devres.c
+++ b/drivers/base/devres.c
@@ -14,14 +14,13 @@
#include <asm/sections.h>
#include "base.h"
+#include "trace.h"
struct devres_node {
struct list_head entry;
dr_release_t release;
-#ifdef CONFIG_DEBUG_DEVRES
const char *name;
size_t size;
-#endif
};
struct devres {
@@ -43,10 +42,6 @@ struct devres_group {
/* -- 8 pointers */
};
-#ifdef CONFIG_DEBUG_DEVRES
-static int log_devres = 0;
-module_param_named(log, log_devres, int, S_IRUGO | S_IWUSR);
-
static void set_node_dbginfo(struct devres_node *node, const char *name,
size_t size)
{
@@ -54,7 +49,11 @@ static void set_node_dbginfo(struct devres_node *node, const char *name,
node->size = size;
}
-static void devres_log(struct device *dev, struct devres_node *node,
+#ifdef CONFIG_DEBUG_DEVRES
+static int log_devres = 0;
+module_param_named(log, log_devres, int, S_IRUGO | S_IWUSR);
+
+static void devres_dbg(struct device *dev, struct devres_node *node,
const char *op)
{
if (unlikely(log_devres))
@@ -62,10 +61,16 @@ static void devres_log(struct device *dev, struct devres_node *node,
op, node, node->name, node->size);
}
#else /* CONFIG_DEBUG_DEVRES */
-#define set_node_dbginfo(node, n, s) do {} while (0)
-#define devres_log(dev, node, op) do {} while (0)
+#define devres_dbg(dev, node, op) do {} while (0)
#endif /* CONFIG_DEBUG_DEVRES */
+static void devres_log(struct device *dev, struct devres_node *node,
+ const char *op)
+{
+ trace_devres_log(dev, op, node, node->name, node->size);
+ devres_dbg(dev, node, op);
+}
+
/*
* Release functions for devres group. These callbacks are used only
* for identification.
diff --git a/drivers/base/trace.c b/drivers/base/trace.c
new file mode 100644
index 000000000000..b24b0a309c4a
--- /dev/null
+++ b/drivers/base/trace.c
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Device core Trace Support
+ * Copyright (C) 2021, Intel Corporation
+ *
+ * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+ */
+
+#define CREATE_TRACE_POINTS
+#include "trace.h"
diff --git a/drivers/base/trace.h b/drivers/base/trace.h
new file mode 100644
index 000000000000..3192e18f877e
--- /dev/null
+++ b/drivers/base/trace.h
@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Device core Trace Support
+ * Copyright (C) 2021, Intel Corporation
+ *
+ * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM dev
+
+#if !defined(__DEV_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define __DEV_TRACE_H
+
+#include <linux/device.h>
+#include <linux/tracepoint.h>
+#include <linux/types.h>
+
+DECLARE_EVENT_CLASS(devres,
+ TP_PROTO(struct device *dev, const char *op, void *node, const char *name, size_t size),
+ TP_ARGS(dev, op, node, name, size),
+ TP_STRUCT__entry(
+ __string(devname, dev_name(dev))
+ __field(struct device *, dev)
+ __field(const char *, op)
+ __field(void *, node)
+ __field(const char *, name)
+ __field(size_t, size)
+ ),
+ TP_fast_assign(
+ __assign_str(devname, dev_name(dev));
+ __entry->op = op;
+ __entry->node = node;
+ __entry->name = name;
+ __entry->size = size;
+ ),
+ TP_printk("%s %3s %p %s (%zu bytes)", __get_str(devname),
+ __entry->op, __entry->node, __entry->name, __entry->size)
+);
+
+DEFINE_EVENT(devres, devres_log,
+ TP_PROTO(struct device *dev, const char *op, void *node, const char *name, size_t size),
+ TP_ARGS(dev, op, node, name, size)
+);
+
+#endif /* __DEV_TRACE_H */
+
+/* this part has to be here */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE trace
+
+#include <trace/define_trace.h>
--
2.30.2
next reply other threads:[~2021-04-13 11:37 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-13 11:38 Andy Shevchenko [this message]
2021-04-13 12:00 ` [PATCH v2 1/1] devres: Enable trace events Heikki Krogerus
2021-04-13 12:25 ` Andy Shevchenko
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210413113801.18245-1-andriy.shevchenko@linux.intel.com \
--to=andriy.shevchenko@linux.intel.com \
--cc=bgolaszewski@baylibre.com \
--cc=gregkh@linuxfoundation.org \
--cc=heikki.krogerus@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=rafael@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).