* [PATCH v2] interconnect: Add interconnect_graph file to debugfs
@ 2019-11-18 22:34 Leonard Crestez
2019-12-16 8:20 ` Georgi Djakov
0 siblings, 1 reply; 2+ messages in thread
From: Leonard Crestez @ 2019-11-18 22:34 UTC (permalink / raw)
To: Georgi Djakov
Cc: Bjorn Andersson, Evan Green, David Dai, Jordan Crouse,
Rafael J. Wysocki, Greg Kroah-Hartman, Jonathan Corbet, linux-pm,
linux-doc
The interconnect graphs can be difficult to understand and the current
"interconnect_summary" file doesn't even display links in any way.
Add a new "interconnect_graph" file to debugfs in the graphviz "dot"
format which describes interconnect providers, nodes and links.
The file is human-readable and can be visualized by piping through
graphviz. Example:
ssh $TARGET cat /sys/kernel/debug/interconnect/interconnect_graph \
| dot -Tsvg > interconnect_graph.svg
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
Documentation/driver-api/interconnect.rst | 23 ++++++++
drivers/interconnect/core.c | 66 +++++++++++++++++++++++
2 files changed, 89 insertions(+)
Example output as a github gist:
https://gist.github.com/cdleonard/2f74a7efe74587e3d4b57cf7983b46a8
The qcs404 driver was hacked to probe on imx, the links to "0" seem to
from incorrect trailing 0s on DEFINE_QNODE. Possibly fallout from
switching to ARRAY_SIZE(__VA_ARGS__)?
This makes it easier to understand the interconnect graph than just
staring at registration code.
Changes since RFC v1:
* Document under driver-api/interconnect.rst
* Collect reviews
Link to v1: https://patchwork.kernel.org/patch/11242921/
diff --git a/Documentation/driver-api/interconnect.rst b/Documentation/driver-api/interconnect.rst
index cdeb5825f314..77a85aad8d2f 100644
--- a/Documentation/driver-api/interconnect.rst
+++ b/Documentation/driver-api/interconnect.rst
@@ -89,5 +89,28 @@ Interconnect consumers
Interconnect consumers are the clients which use the interconnect APIs to
get paths between endpoints and set their bandwidth/latency/QoS requirements
for these interconnect paths. These interfaces are not currently
documented.
+
+Interconnect debugfs interfaces
+-------------------------------
+
+Like several other subsystems interconnect will create some files for debugging
+and introspection. Files in debugfs are not considered ABI so application
+software shouldn't rely on format details
+change between kernel versions.
+
+``/sys/kernel/debug/interconnect/interconnect_summary``:
+
+Show all interconnect nodes in the system with their aggregated bandwith
+request. Indented under each node show bandwith requests from each device.
+
+``/sys/kernel/debug/interconnect/interconnect_graph``:
+
+Show the interconnect graph in the graphviz dot format. It shows all
+interconnect nodes and links in the system and groups together nodes from the
+same provider as subgraphs. The format is human-readable and can also be piped
+through dot to generate diagrams in many graphical formats::
+
+ $ cat /sys/kernel/debug/interconnect/interconnect_graph | \
+ dot -Tsvg > interconnect_graph.svg
diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index c498796adc07..07e91288c7f4 100644
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -92,10 +92,74 @@ static int icc_summary_show(struct seq_file *s, void *data)
return 0;
}
DEFINE_SHOW_ATTRIBUTE(icc_summary);
+static void icc_graph_show_link(struct seq_file *s, int level,
+ struct icc_node *n, struct icc_node *m)
+{
+ seq_printf(s, "%s\"%d:%s\" -> \"%d:%s\"\n",
+ level == 2 ? "\t\t" : "\t",
+ n->id, n->name, m->id, m->name);
+}
+
+static void icc_graph_show_node(struct seq_file *s, struct icc_node *n)
+{
+ seq_printf(s, "\t\t\"%d:%s\" [label=\"%d:%s",
+ n->id, n->name, n->id, n->name);
+ seq_printf(s, "\n\t\t\t|avg_bw=%ukBps", n->avg_bw);
+ seq_printf(s, "\n\t\t\t|peak_bw=%ukBps", n->peak_bw);
+ seq_puts(s, "\"]\n");
+}
+
+static int icc_graph_show(struct seq_file *s, void *data)
+{
+ struct icc_provider *provider;
+ struct icc_node *n;
+ int cluster_index = 0;
+ int i;
+
+ seq_puts(s, "digraph {\n\trankdir = LR\n\tnode [shape = record]\n");
+ mutex_lock(&icc_lock);
+
+ /* draw providers as cluster subgraphs */
+ cluster_index = 0;
+ list_for_each_entry(provider, &icc_providers, provider_list) {
+ seq_printf(s, "\tsubgraph cluster_%d {\n", ++cluster_index);
+ if (provider->dev)
+ seq_printf(s, "\t\tlabel = \"%s\"\n",
+ dev_name(provider->dev));
+
+ /* draw nodes */
+ list_for_each_entry(n, &provider->nodes, node_list)
+ icc_graph_show_node(s, n);
+
+ /* draw internal links */
+ list_for_each_entry(n, &provider->nodes, node_list)
+ for (i = 0; i < n->num_links; ++i)
+ if (n->provider == n->links[i]->provider)
+ icc_graph_show_link(s, 2, n,
+ n->links[i]);
+
+ seq_puts(s, "\t}\n");
+ }
+
+ /* draw external links */
+ list_for_each_entry(provider, &icc_providers, provider_list)
+ list_for_each_entry(n, &provider->nodes, node_list)
+ for (i = 0; i < n->num_links; ++i)
+ if (n->provider != n->links[i]->provider)
+ icc_graph_show_link(s, 1, n,
+ n->links[i]);
+
+ mutex_unlock(&icc_lock);
+ seq_puts(s, "}");
+
+ return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(icc_graph);
+
static struct icc_node *node_find(const int id)
{
return idr_find(&icc_idr, id);
}
@@ -800,10 +864,12 @@ EXPORT_SYMBOL_GPL(icc_provider_del);
static int __init icc_init(void)
{
icc_debugfs_dir = debugfs_create_dir("interconnect", NULL);
debugfs_create_file("interconnect_summary", 0444,
icc_debugfs_dir, NULL, &icc_summary_fops);
+ debugfs_create_file("interconnect_graph", 0444,
+ icc_debugfs_dir, NULL, &icc_graph_fops);
return 0;
}
static void __exit icc_exit(void)
{
--
2.17.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2] interconnect: Add interconnect_graph file to debugfs
2019-11-18 22:34 [PATCH v2] interconnect: Add interconnect_graph file to debugfs Leonard Crestez
@ 2019-12-16 8:20 ` Georgi Djakov
0 siblings, 0 replies; 2+ messages in thread
From: Georgi Djakov @ 2019-12-16 8:20 UTC (permalink / raw)
To: Leonard Crestez
Cc: Bjorn Andersson, Evan Green, David Dai, Jordan Crouse,
Rafael J. Wysocki, Greg Kroah-Hartman, Jonathan Corbet, linux-pm,
linux-doc
Hi Leonard,
On 19.11.19 г. 0:34 ч., Leonard Crestez wrote:
> The interconnect graphs can be difficult to understand and the current
> "interconnect_summary" file doesn't even display links in any way.
>
> Add a new "interconnect_graph" file to debugfs in the graphviz "dot"
> format which describes interconnect providers, nodes and links.
>
> The file is human-readable and can be visualized by piping through
> graphviz. Example:
>
> ssh $TARGET cat /sys/kernel/debug/interconnect/interconnect_graph \
> | dot -Tsvg > interconnect_graph.svg
>
> Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
> Documentation/driver-api/interconnect.rst | 23 ++++++++
> drivers/interconnect/core.c | 66 +++++++++++++++++++++++
> 2 files changed, 89 insertions(+)
>
> Example output as a github gist:
> https://gist.github.com/cdleonard/2f74a7efe74587e3d4b57cf7983b46a8
>
> The qcs404 driver was hacked to probe on imx, the links to "0" seem to
> from incorrect trailing 0s on DEFINE_QNODE. Possibly fallout from
> switching to ARRAY_SIZE(__VA_ARGS__)?
>
> This makes it easier to understand the interconnect graph than just
> staring at registration code.
>
> Changes since RFC v1:
> * Document under driver-api/interconnect.rst
> * Collect reviews
> Link to v1: https://patchwork.kernel.org/patch/11242921/
>
> diff --git a/Documentation/driver-api/interconnect.rst b/Documentation/driver-api/interconnect.rst
> index cdeb5825f314..77a85aad8d2f 100644
> --- a/Documentation/driver-api/interconnect.rst
> +++ b/Documentation/driver-api/interconnect.rst
> @@ -89,5 +89,28 @@ Interconnect consumers
>
> Interconnect consumers are the clients which use the interconnect APIs to
> get paths between endpoints and set their bandwidth/latency/QoS requirements
> for these interconnect paths. These interfaces are not currently
> documented.
> +
> +Interconnect debugfs interfaces
> +-------------------------------
> +
> +Like several other subsystems interconnect will create some files for debugging
> +and introspection. Files in debugfs are not considered ABI so application
> +software shouldn't rely on format details
> +change between kernel versions.
> +
> +``/sys/kernel/debug/interconnect/interconnect_summary``:
> +
> +Show all interconnect nodes in the system with their aggregated bandwith
s/bandwith/bandwidth/
> +request. Indented under each node show bandwith requests from each device.
s/bandwith/bandwidth/
> +
> +``/sys/kernel/debug/interconnect/interconnect_graph``:
> +
> +Show the interconnect graph in the graphviz dot format. It shows all
> +interconnect nodes and links in the system and groups together nodes from the
> +same provider as subgraphs. The format is human-readable and can also be piped
> +through dot to generate diagrams in many graphical formats::
> +
> + $ cat /sys/kernel/debug/interconnect/interconnect_graph | \
> + dot -Tsvg > interconnect_graph.svg
> diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
> index c498796adc07..07e91288c7f4 100644
> --- a/drivers/interconnect/core.c
> +++ b/drivers/interconnect/core.c
> @@ -92,10 +92,74 @@ static int icc_summary_show(struct seq_file *s, void *data)
>
> return 0;
> }
> DEFINE_SHOW_ATTRIBUTE(icc_summary);
>
> +static void icc_graph_show_link(struct seq_file *s, int level,
> + struct icc_node *n, struct icc_node *m)
> +{
> + seq_printf(s, "%s\"%d:%s\" -> \"%d:%s\"\n",
> + level == 2 ? "\t\t" : "\t",
> + n->id, n->name, m->id, m->name);
Nit: Should be aligned to the open parenthesis.
> +}
> +
> +static void icc_graph_show_node(struct seq_file *s, struct icc_node *n)
> +{
> + seq_printf(s, "\t\t\"%d:%s\" [label=\"%d:%s",
> + n->id, n->name, n->id, n->name);
> + seq_printf(s, "\n\t\t\t|avg_bw=%ukBps", n->avg_bw);
> + seq_printf(s, "\n\t\t\t|peak_bw=%ukBps", n->peak_bw);
> + seq_puts(s, "\"]\n");
> +}
> +
> +static int icc_graph_show(struct seq_file *s, void *data)
> +{
> + struct icc_provider *provider;
> + struct icc_node *n;
> + int cluster_index = 0;
> + int i;
> +
> + seq_puts(s, "digraph {\n\trankdir = LR\n\tnode [shape = record]\n");
> + mutex_lock(&icc_lock);
> +
> + /* draw providers as cluster subgraphs */
> + cluster_index = 0;
> + list_for_each_entry(provider, &icc_providers, provider_list) {
> + seq_printf(s, "\tsubgraph cluster_%d {\n", ++cluster_index);
> + if (provider->dev)
> + seq_printf(s, "\t\tlabel = \"%s\"\n",
> + dev_name(provider->dev));
> +
> + /* draw nodes */
> + list_for_each_entry(n, &provider->nodes, node_list)
> + icc_graph_show_node(s, n);
> +
> + /* draw internal links */
> + list_for_each_entry(n, &provider->nodes, node_list)
> + for (i = 0; i < n->num_links; ++i)
> + if (n->provider == n->links[i]->provider)
> + icc_graph_show_link(s, 2, n,
> + n->links[i]);
> +
> + seq_puts(s, "\t}\n");
> + }
> +
> + /* draw external links */
> + list_for_each_entry(provider, &icc_providers, provider_list)
> + list_for_each_entry(n, &provider->nodes, node_list)
> + for (i = 0; i < n->num_links; ++i)
> + if (n->provider != n->links[i]->provider)
> + icc_graph_show_link(s, 1, n,
> + n->links[i]);
> +
> + mutex_unlock(&icc_lock);
> + seq_puts(s, "}");
> +
> + return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(icc_graph);
> +
> static struct icc_node *node_find(const int id)
> {
> return idr_find(&icc_idr, id);
> }
>
> @@ -800,10 +864,12 @@ EXPORT_SYMBOL_GPL(icc_provider_del);
> static int __init icc_init(void)
> {
> icc_debugfs_dir = debugfs_create_dir("interconnect", NULL);
> debugfs_create_file("interconnect_summary", 0444,
> icc_debugfs_dir, NULL, &icc_summary_fops);
> + debugfs_create_file("interconnect_graph", 0444,
> + icc_debugfs_dir, NULL, &icc_graph_fops);
> return 0;
> }
>
> static void __exit icc_exit(void)
> {
This is good stuff! Thank you! I will fix up the typos while applying,
no need to resend it.
BR,
Georgi
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