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Date:   Tue, 20 Sep 2022 20:35:23 +0300
From:   Alexey Dobriyan <adobriyan@gmail.com>
To:     akpm@linux-foundation.org
Cc:     linux-kernel@vger.kernel.org
Subject: [PATCH] proc: mark more files as permanent
Message-ID: <Yyn527DzDMa+r0Yj@localhost.localdomain>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Precedence: bulk

Mark
	/proc/devices
	/proc/kpagecount
	/proc/kpageflags
	/proc/kpagecgroup
	/proc/loadavg
	/proc/meminfo
	/proc/softirqs
	/proc/uptime
	/proc/version

as permanent /proc entries, saving alloc/free and some
list/spinlock ops per use.

These files are never removed by the kernel so it is OK
to mark them.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---

 fs/proc/devices.c  |    6 +++++-
 fs/proc/internal.h |    5 +++++
 fs/proc/loadavg.c  |    6 +++++-
 fs/proc/meminfo.c  |    5 ++++-
 fs/proc/page.c     |    3 +++
 fs/proc/softirqs.c |    6 +++++-
 fs/proc/uptime.c   |    6 +++++-
 fs/proc/version.c  |    6 +++++-
 8 files changed, 37 insertions(+), 6 deletions(-)

--- a/fs/proc/devices.c
+++ b/fs/proc/devices.c
@@ -4,6 +4,7 @@
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <linux/blkdev.h>
+#include "internal.h"
 
 static int devinfo_show(struct seq_file *f, void *v)
 {
@@ -54,7 +55,10 @@ static const struct seq_operations devinfo_ops = {
 
 static int __init proc_devices_init(void)
 {
-	proc_create_seq("devices", 0, NULL, &devinfo_ops);
+	struct proc_dir_entry *pde;
+
+	pde = proc_create_seq("devices", 0, NULL, &devinfo_ops);
+	pde_make_permanent(pde);
 	return 0;
 }
 fs_initcall(proc_devices_init);
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -79,6 +79,11 @@ static inline bool pde_is_permanent(const struct proc_dir_entry *pde)
 	return pde->flags & PROC_ENTRY_PERMANENT;
 }
 
+static inline void pde_make_permanent(struct proc_dir_entry *pde)
+{
+	pde->flags |= PROC_ENTRY_PERMANENT;
+}
+
 extern struct kmem_cache *proc_dir_entry_cache;
 void pde_free(struct proc_dir_entry *pde);
 
--- a/fs/proc/loadavg.c
+++ b/fs/proc/loadavg.c
@@ -9,6 +9,7 @@
 #include <linux/seq_file.h>
 #include <linux/seqlock.h>
 #include <linux/time.h>
+#include "internal.h"
 
 static int loadavg_proc_show(struct seq_file *m, void *v)
 {
@@ -27,7 +28,10 @@ static int loadavg_proc_show(struct seq_file *m, void *v)
 
 static int __init proc_loadavg_init(void)
 {
-	proc_create_single("loadavg", 0, NULL, loadavg_proc_show);
+	struct proc_dir_entry *pde;
+
+	pde = proc_create_single("loadavg", 0, NULL, loadavg_proc_show);
+	pde_make_permanent(pde);
 	return 0;
 }
 fs_initcall(proc_loadavg_init);
--- a/fs/proc/meminfo.c
+++ b/fs/proc/meminfo.c
@@ -162,7 +162,10 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
 
 static int __init proc_meminfo_init(void)
 {
-	proc_create_single("meminfo", 0, NULL, meminfo_proc_show);
+	struct proc_dir_entry *pde;
+
+	pde = proc_create_single("meminfo", 0, NULL, meminfo_proc_show);
+	pde_make_permanent(pde);
 	return 0;
 }
 fs_initcall(proc_meminfo_init);
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -91,6 +91,7 @@ static ssize_t kpagecount_read(struct file *file, char __user *buf,
 }
 
 static const struct proc_ops kpagecount_proc_ops = {
+	.proc_flags	= PROC_ENTRY_PERMANENT,
 	.proc_lseek	= mem_lseek,
 	.proc_read	= kpagecount_read,
 };
@@ -268,6 +269,7 @@ static ssize_t kpageflags_read(struct file *file, char __user *buf,
 }
 
 static const struct proc_ops kpageflags_proc_ops = {
+	.proc_flags	= PROC_ENTRY_PERMANENT,
 	.proc_lseek	= mem_lseek,
 	.proc_read	= kpageflags_read,
 };
@@ -322,6 +324,7 @@ static ssize_t kpagecgroup_read(struct file *file, char __user *buf,
 }
 
 static const struct proc_ops kpagecgroup_proc_ops = {
+	.proc_flags	= PROC_ENTRY_PERMANENT,
 	.proc_lseek	= mem_lseek,
 	.proc_read	= kpagecgroup_read,
 };
--- a/fs/proc/softirqs.c
+++ b/fs/proc/softirqs.c
@@ -3,6 +3,7 @@
 #include <linux/kernel_stat.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
+#include "internal.h"
 
 /*
  * /proc/softirqs  ... display the number of softirqs
@@ -27,7 +28,10 @@ static int show_softirqs(struct seq_file *p, void *v)
 
 static int __init proc_softirqs_init(void)
 {
-	proc_create_single("softirqs", 0, NULL, show_softirqs);
+	struct proc_dir_entry *pde;
+
+	pde = proc_create_single("softirqs", 0, NULL, show_softirqs);
+	pde_make_permanent(pde);
 	return 0;
 }
 fs_initcall(proc_softirqs_init);
--- a/fs/proc/uptime.c
+++ b/fs/proc/uptime.c
@@ -7,6 +7,7 @@
 #include <linux/time.h>
 #include <linux/time_namespace.h>
 #include <linux/kernel_stat.h>
+#include "internal.h"
 
 static int uptime_proc_show(struct seq_file *m, void *v)
 {
@@ -39,7 +40,10 @@ static int uptime_proc_show(struct seq_file *m, void *v)
 
 static int __init proc_uptime_init(void)
 {
-	proc_create_single("uptime", 0, NULL, uptime_proc_show);
+	struct proc_dir_entry *pde;
+
+	pde = proc_create_single("uptime", 0, NULL, uptime_proc_show);
+	pde_make_permanent(pde);
 	return 0;
 }
 fs_initcall(proc_uptime_init);
--- a/fs/proc/version.c
+++ b/fs/proc/version.c
@@ -5,6 +5,7 @@
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <linux/utsname.h>
+#include "internal.h"
 
 static int version_proc_show(struct seq_file *m, void *v)
 {
@@ -17,7 +18,10 @@ static int version_proc_show(struct seq_file *m, void *v)
 
 static int __init proc_version_init(void)
 {
-	proc_create_single("version", 0, NULL, version_proc_show);
+	struct proc_dir_entry *pde;
+
+	pde = proc_create_single("version", 0, NULL, version_proc_show);
+	pde_make_permanent(pde);
 	return 0;
 }
 fs_initcall(proc_version_init);