linux-kernel - [PATCH v2 12/35] x86/resctrl: Move max_{name,data}

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Date: Fri, 26 Apr 2024 16:08:41 +0100
From: Dave Martin <Dave.Martin@....com>
To: x86@...nel.org,
	linux-kernel@...r.kernel.org
Cc: James Morse <james.morse@....com>,
	Fenghua Yu <fenghua.yu@...el.com>,
	Reinette Chatre <reinette.chatre@...el.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	Borislav Petkov <bp@...en8.de>,
	H Peter Anvin <hpa@...or.com>,
	Babu Moger <Babu.Moger@....com>,
	shameerali.kolothum.thodi@...wei.com,
	D Scott Phillips OS <scott@...amperecomputing.com>,
	carl@...amperecomputing.com,
	lcherian@...vell.com,
	bobo.shaobowang@...wei.com,
	"Shaopeng Tan (Fujitsu)" <tan.shaopeng@...itsu.com>,
	baolin.wang@...ux.alibaba.com,
	Jamie Iles <quic_jiles@...cinc.com>,
	Xin Hao <xhao@...ux.alibaba.com>,
	Peter Newman <peternewman@...gle.com>,
	dfustini@...libre.com,
	amitsinght@...vell.com,
	David Hildenbrand <david@...hat.com>,
	Rex Nie <rex.nie@...uarmicro.com>
Subject: [PATCH v2 12/35] x86/resctrl: Move max_{name,data}_width into resctrl code

From: James Morse <james.morse@....com>

max_name_width and max_data_width are used to pad the strings in the
resctrl schemata file.

This should be part of the fs code as it influences the user-space
interface, but currently max_data_width is generated by the arch init code.
max_name_width is already managed by schemata_list_add().

Move the variables and max_data_width's initialisation code to rdtgroup.c.
There is no need for an extra rdt_init_padding() helper as the length
of the name can be considered when schemata_list_add() creates each
schema entry.

Signed-off-by: James Morse <james.morse@....com>
Signed-off-by: Dave Martin <Dave.Martin@....com>

---

Changes in v2:

 * Up-case "CBM" in the comment retained from rdt_init_padding(), for
   consistency with usage in comments elsewhere in the resctrl code.

   No functional change.
---
 arch/x86/kernel/cpu/resctrl/core.c     | 22 ----------------------
 arch/x86/kernel/cpu/resctrl/rdtgroup.c | 12 ++++++++++++
 2 files changed, 12 insertions(+), 22 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 9a09a64bbb7f..9551ca4a6480 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -44,12 +44,6 @@ static DEFINE_MUTEX(domain_list_lock);
  */
 DEFINE_PER_CPU(struct resctrl_pqr_state, pqr_state);
 
-/*
- * Used to store the max resource name width and max resource data width
- * to display the schemata in a tabular format
- */
-int max_name_width, max_data_width;
-
 /*
  * Global boolean for rdt_alloc which is true if any
  * resource allocation is enabled.
@@ -648,20 +642,6 @@ static int resctrl_arch_offline_cpu(unsigned int cpu)
 	return 0;
 }
 
-/*
- * Choose a width for the resource name and resource data based on the
- * resource that has widest name and cbm.
- */
-static __init void rdt_init_padding(void)
-{
-	struct rdt_resource *r;
-
-	for_each_alloc_capable_rdt_resource(r) {
-		if (r->data_width > max_data_width)
-			max_data_width = r->data_width;
-	}
-}
-
 enum {
 	RDT_FLAG_CMT,
 	RDT_FLAG_MBM_TOTAL,
@@ -959,8 +939,6 @@ static int __init resctrl_arch_late_init(void)
 	if (!get_rdt_resources())
 		return -ENODEV;
 
-	rdt_init_padding();
-
 	state = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
 				  "x86/resctrl/cat:online:",
 				  resctrl_arch_online_cpu,
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 58b59b102986..9d4c8d641615 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -58,6 +58,12 @@ static struct kernfs_node *kn_mongrp;
 /* Kernel fs node for "mon_data" directory under root */
 static struct kernfs_node *kn_mondata;
 
+/*
+ * Used to store the max resource name width and max resource data width
+ * to display the schemata in a tabular format
+ */
+int max_name_width, max_data_width;
+
 static struct seq_buf last_cmd_status;
 static char last_cmd_status_buf[512];
 
@@ -2593,6 +2599,12 @@ static int schemata_list_add(struct rdt_resource *r, enum resctrl_conf_type type
 	if (cl > max_name_width)
 		max_name_width = cl;
 
+	/*
+	 * Choose a width for the resource data based on the resource that has
+	 * widest name and CBM.
+	 */
+	max_data_width = max(max_data_width, r->data_width);
+
 	INIT_LIST_HEAD(&s->list);
 	list_add(&s->list, &resctrl_schema_all);
 
-- 
2.34.1