Commit cb07d71f authored by Babu Moger's avatar Babu Moger Committed by Borislav Petkov (AMD)
Browse files

x86/resctrl: Introduce "-o debug" mount option 



Add "-o debug" option to mount resctrl filesystem in debug mode.  When
in debug mode resctrl displays files that have the new RFTYPE_DEBUG flag
to help resctrl debugging.

Signed-off-by: default avatarBabu Moger <babu.moger@amd.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarPeter Newman <peternewman@google.com>
Reviewed-by: default avatarTan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: default avatarFenghua Yu <fenghua.yu@intel.com>
Reviewed-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Reviewed-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: default avatarPeter Newman <peternewman@google.com>
Tested-by: default avatarTan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Link: https://lore.kernel.org/r/20231017002308.134480-7-babu.moger@amd.com
parent d27567a0

Documentation/arch/x86/resctrl.rst

+4 −1
Original line number Diff line number Diff line
@@ -35,7 +35,7 @@ about the feature from resctrl's info directory. 


To use the feature mount the file system::



 # mount -t resctrl resctrl [-o cdp[,cdpl2][,mba_MBps]] /sys/fs/resctrl

 # mount -t resctrl resctrl [-o cdp[,cdpl2][,mba_MBps][,debug]] /sys/fs/resctrl



mount options are:
@@ -46,6 +46,9 @@ mount options are: 
"mba_MBps":

	Enable the MBA Software Controller(mba_sc) to specify MBA

	bandwidth in MBps

"debug":

	Make debug files accessible. Available debug files are annotated with

	"Available only with debug option".



L2 and L3 CDP are controlled separately.

arch/x86/kernel/cpu/resctrl/internal.h

+2 −0
Original line number Diff line number Diff line
@@ -59,6 +59,7 @@ struct rdt_fs_context { 
	bool				enable_cdpl2;

	bool				enable_cdpl3;

	bool				enable_mba_mbps;

	bool				enable_debug;

};



static inline struct rdt_fs_context *rdt_fc2context(struct fs_context *fc)
@@ -248,6 +249,7 @@ struct rdtgroup { 
#define RFTYPE_TOP			BIT(6)

#define RFTYPE_RES_CACHE		BIT(8)

#define RFTYPE_RES_MB			BIT(9)

#define RFTYPE_DEBUG			BIT(10)

#define RFTYPE_CTRL_INFO		(RFTYPE_INFO | RFTYPE_CTRL)

#define RFTYPE_MON_INFO			(RFTYPE_INFO | RFTYPE_MON)

#define RFTYPE_TOP_INFO			(RFTYPE_INFO | RFTYPE_TOP)

arch/x86/kernel/cpu/resctrl/rdtgroup.c

+18 −0
Original line number Diff line number Diff line
@@ -59,6 +59,8 @@ static void rdtgroup_destroy_root(void); 


struct dentry *debugfs_resctrl;



static bool resctrl_debug;



void rdt_last_cmd_clear(void)

{

	lockdep_assert_held(&rdtgroup_mutex);
@@ -1892,6 +1894,9 @@ static int rdtgroup_add_files(struct kernfs_node *kn, unsigned long fflags) 


	lockdep_assert_held(&rdtgroup_mutex);



	if (resctrl_debug)

		fflags |= RFTYPE_DEBUG;



	for (rft = rfts; rft < rfts + len; rft++) {

		if (rft->fflags && ((fflags & rft->fflags) == rft->fflags)) {

			ret = rdtgroup_add_file(kn, rft);
@@ -2395,6 +2400,8 @@ static void rdt_disable_ctx(void) 
	resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false);

	resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false);

	set_mba_sc(false);



	resctrl_debug = false;

}



static int rdt_enable_ctx(struct rdt_fs_context *ctx)
@@ -2419,6 +2426,9 @@ static int rdt_enable_ctx(struct rdt_fs_context *ctx) 
			goto out_cdpl3;

	}



	if (ctx->enable_debug)

		resctrl_debug = true;



	return 0;



out_cdpl3:
@@ -2623,6 +2633,7 @@ enum rdt_param { 
	Opt_cdp,

	Opt_cdpl2,

	Opt_mba_mbps,

	Opt_debug,

	nr__rdt_params

};
@@ -2630,6 +2641,7 @@ static const struct fs_parameter_spec rdt_fs_parameters[] = { 
	fsparam_flag("cdp",		Opt_cdp),

	fsparam_flag("cdpl2",		Opt_cdpl2),

	fsparam_flag("mba_MBps",	Opt_mba_mbps),

	fsparam_flag("debug",		Opt_debug),

	{}

};
@@ -2655,6 +2667,9 @@ static int rdt_parse_param(struct fs_context *fc, struct fs_parameter *param) 
			return -EINVAL;

		ctx->enable_mba_mbps = true;

		return 0;

	case Opt_debug:

		ctx->enable_debug = true;

		return 0;

	}



	return -EINVAL;
@@ -3723,6 +3738,9 @@ static int rdtgroup_show_options(struct seq_file *seq, struct kernfs_root *kf) 
	if (is_mba_sc(&rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl))

		seq_puts(seq, ",mba_MBps");



	if (resctrl_debug)

		seq_puts(seq, ",debug");



	return 0;

}