All files below /sys/fs/resctrl are considered user ABI.
This leaves no place for architectures to provide additional
interfaces.
Add resctrl_debugfs_mon_info_arch_mkdir() which creates a directory in the
debugfs file system for a resource. Naming follows the layout of the
main resctrl hierarchy:
/sys/kernel/debug/resctrl/info/{resource}_MON/{arch}
The {arch} last level directory name matches the output of
the user level "uname -m" command.
Architecture code may use this directory for debug information,
or for minor tuning of features. It must not be used for basic
feature enabling as debugfs may not be configured/mounted on
production systems.
Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
---
include/linux/resctrl.h | 9 +++++++++
fs/resctrl/rdtgroup.c | 29 +++++++++++++++++++++++++++++
2 files changed, 38 insertions(+)
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index c1cfba3c8422..b6af933ca3f9 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -571,6 +571,15 @@ void resctrl_arch_reset_all_ctrls(struct rdt_resource *r);
extern unsigned int resctrl_rmid_realloc_threshold;
extern unsigned int resctrl_rmid_realloc_limit;
+/**
+ * resctrl_debugfs_mon_info_arch_mkdir() - Create a debugfs info directory.
+ * Removed by resctrl_exit().
+ * @r: Resource (must be mon_capable).
+ *
+ * Return: dentry pointer on success, or NULL on error.
+ */
+struct dentry *resctrl_debugfs_mon_info_arch_mkdir(struct rdt_resource *r);
+
int resctrl_init(void);
void resctrl_exit(void);
diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
index d1ecc5cd3089..fccac3da90cb 100644
--- a/fs/resctrl/rdtgroup.c
+++ b/fs/resctrl/rdtgroup.c
@@ -24,6 +24,7 @@
#include <linux/sched/task.h>
#include <linux/slab.h>
#include <linux/user_namespace.h>
+#include <linux/utsname.h>
#include <uapi/linux/magic.h>
@@ -75,6 +76,8 @@ static void rdtgroup_destroy_root(void);
struct dentry *debugfs_resctrl;
+static struct dentry *debugfs_resctrl_info;
+
/*
* Memory bandwidth monitoring event to use for the default CTRL_MON group
* and each new CTRL_MON group created by the user. Only relevant when
@@ -4355,6 +4358,31 @@ int resctrl_init(void)
return ret;
}
+/*
+ * Create /sys/kernel/debug/resctrl/info/{r->name}_MON/{arch} directory
+ * by request for architecture to use for debugging or minor tuning.
+ * Basic functionality of features must not be controlled by files
+ * added to this directory as debugfs may not be configured/mounted
+ * on production systems.
+ */
+struct dentry *resctrl_debugfs_mon_info_arch_mkdir(struct rdt_resource *r)
+{
+ struct dentry *moninfodir;
+ char name[32];
+
+ if (!r->mon_capable)
+ return NULL;
+
+ if (!debugfs_resctrl_info)
+ debugfs_resctrl_info = debugfs_create_dir("info", debugfs_resctrl);
+
+ sprintf(name, "%s_MON", r->name);
+
+ moninfodir = debugfs_create_dir(name, debugfs_resctrl_info);
+
+ return debugfs_create_dir(utsname()->machine, moninfodir);
+}
+
static bool resctrl_online_domains_exist(void)
{
struct rdt_resource *r;
@@ -4406,6 +4434,7 @@ void resctrl_exit(void)
debugfs_remove_recursive(debugfs_resctrl);
debugfs_resctrl = NULL;
+ debugfs_resctrl_info = NULL;
unregister_filesystem(&rdt_fs_type);
/*
--
2.50.1