Re: [PATCH 11/45] FS-Cache: Add use of /proc and presentation of statistics [ver #41]

From: David Howells
Date: Fri Nov 21 2008 - 10:32:45 EST

Alexey Dobriyan <adobriyan@xxxxxxxxx> wrote:

> This is overly complex for unclear need. Just set_printf() all these lines
> and drop iterator business. Use single_open()! Ditto for histo stuff.

I disagree with respect to the histogram stuff. The whole point of having
iterators is to iterate over a lot of things, and the histogram code may
generate several pages worth of data.

Anyway, I've sorted the stats and histogram code and documentation out for both
FS-Cache and CacheFiles and attached it here in one delta patch. Could you
look it over and see what you think? I'll merge it into the various patches
later.

David
---
diff --git a/Documentation/filesystems/caching/cachefiles.txt b/Documentation/filesystems/caching/cachefiles.txt
index ed5bb0c..c78a49b 100644
--- a/Documentation/filesystems/caching/cachefiles.txt
+++ b/Documentation/filesystems/caching/cachefiles.txt
@@ -22,6 +22,10 @@ Contents:

(*) A note on security.

+ (*) Statistical information.
+
+ (*) Debugging.
+

========
OVERVIEW
@@ -439,3 +443,59 @@ file.
LSM hooks exist that allow SELinux (or Smack or whatever) to reject a request
for CacheFiles to run in a context of a specific security label, or to create
files and directories with another security label.
+
+
+=======================
+STATISTICAL INFORMATION
+=======================
+
+If FS-Cache is compiled with the following option enabled:
+
+ CONFIG_CACHEFILES_HISTOGRAM=y
+
+then it will gather certain statistics and display them through a proc file.
+
+ (*) /proc/fs/cachefiles/histogram
+
+ cat /proc/fs/cachefiles/histogram
+ JIFS SECS LOOKUPS MKDIRS CREATES
+ ===== ===== ========= ========= =========
+
+ This shows the breakdown of the number of times each amount of time
+ between 0 jiffies and HZ-1 jiffies a variety of tasks took to run. The
+ columns are as follows:
+
+ COLUMN TIME MEASUREMENT
+ ======= =======================================================
+ LOOKUPS Length of time to perform a lookup on the backing fs
+ MKDIRS Length of time to perform a mkdir on the backing fs
+ CREATES Length of time to perform a create on the backing fs
+
+ Each row shows the number of events that took a particular range of times.
+ Each step is 1 jiffy in size. The JIFS column indicates the particular
+ jiffy range covered, and the SECS field the equivalent number of seconds.
+
+
+=========
+DEBUGGING
+=========
+
+If CONFIG_CACHEFILES_DEBUG is enabled, the CacheFiles facility can have runtime
+debugging enabled by adjusting the value in:
+
+ /sys/module/cachefiles/parameters/debug
+
+This is a bitmask of debugging streams to enable:
+
+ BIT VALUE STREAM POINT
+ ======= ======= =============================== =======================
+ 0 1 General Function entry trace
+ 1 2 Function exit trace
+ 2 4 General
+
+The appropriate set of values should be OR'd together and the result written to
+the control file. For example:
+
+ echo $((1|4|8)) >/sys/module/cachefiles/parameters/debug
+
+will turn on all function entry debugging.
diff --git a/Documentation/filesystems/caching/fscache.txt b/Documentation/filesystems/caching/fscache.txt
index 8ff2caa..9e94b94 100644
--- a/Documentation/filesystems/caching/fscache.txt
+++ b/Documentation/filesystems/caching/fscache.txt
@@ -200,7 +200,6 @@ STATISTICAL INFORMATION

If FS-Cache is compiled with the following options enabled:

- CONFIG_FSCACHE_PROC=y (implied by the following two)
CONFIG_FSCACHE_STATS=y
CONFIG_FSCACHE_HISTOGRAM=y

@@ -280,7 +279,7 @@ proc files.
(*) /proc/fs/fscache/histogram

cat /proc/fs/fscache/histogram
- +HZ +TIME OBJ INST OP RUNS OBJ RUNS RETRV DLY RETRIEVLS
+ JIFS SECS OBJ INST OP RUNS OBJ RUNS RETRV DLY RETRIEVLS
===== ===== ========= ========= ========= ========= =========

This shows the breakdown of the number of times each amount of time
@@ -296,16 +295,16 @@ proc files.
RETRIEVLS Time between beginning and end of a retrieval

Each row shows the number of events that took a particular range of times.
- Each step is 1 jiffy in size. The +HZ column indicates the particular
- jiffy range covered, and the +TIME field the equivalent number of seconds.
+ Each step is 1 jiffy in size. The JIFS column indicates the particular
+ jiffy range covered, and the SECS field the equivalent number of seconds.


=========
DEBUGGING
=========

-The FS-Cache facility can have runtime debugging enabled by adjusting the value
-in:
+If CONFIG_FSCACHE_DEBUG is enabled, the FS-Cache facility can have runtime
+debugging enabled by adjusting the value in:

/sys/module/fscache/parameters/debug

@@ -332,4 +331,3 @@ the control file. For example:
echo $((1|8|64)) >/sys/module/fscache/parameters/debug

will turn on all function entry debugging.
-
diff --git a/fs/cachefiles/Kconfig b/fs/cachefiles/Kconfig
index ddbdd85..11f54c3 100644
--- a/fs/cachefiles/Kconfig
+++ b/fs/cachefiles/Kconfig
@@ -21,13 +21,19 @@ config CACHEFILES_DEBUG

config CACHEFILES_HISTOGRAM
bool "Gather latency information on CacheFiles"
- depends on CACHEFILES && FSCACHE_PROC
+ depends on CACHEFILES && PROC_FS
help

This option causes latency information to be gathered on CacheFiles
operation and exported through file:

- /proc/fs/fscache/cachefiles/histogram
+ /proc/fs/cachefiles/histogram
+
+ The generation of this histogram adds a certain amount of overhead to
+ execution as there are a number of points at which data is gathered,
+ and on a multi-CPU system these may be on cachelines that keep
+ bouncing between CPUs. On the other hand, the histogram may be
+ useful for debugging purposes. Saying 'N' here is recommended.

See Documentation/filesystems/caching/cachefiles.txt for more
information.
diff --git a/fs/cachefiles/cf-proc.c b/fs/cachefiles/cf-proc.c
index c0d5444..d09beb5 100644
--- a/fs/cachefiles/cf-proc.c
+++ b/fs/cachefiles/cf-proc.c
@@ -14,104 +14,47 @@
#include <linux/seq_file.h>
#include "cf-internal.h"

-struct cachefiles_proc {
- unsigned nlines;
- const struct seq_operations *ops;
-};
-
atomic_t cachefiles_lookup_histogram[HZ];
atomic_t cachefiles_mkdir_histogram[HZ];
atomic_t cachefiles_create_histogram[HZ];

-static struct proc_dir_entry *proc_cachefiles;
-
-static int cachefiles_proc_open(struct inode *inode, struct file *file);
-static void *cachefiles_proc_start(struct seq_file *m, loff_t *pos);
-static void cachefiles_proc_stop(struct seq_file *m, void *v);
-static void *cachefiles_proc_next(struct seq_file *m, void *v, loff_t *pos);
-static int cachefiles_histogram_show(struct seq_file *m, void *v);
-
-static const struct file_operations cachefiles_proc_fops = {
- .open = cachefiles_proc_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = seq_release,
-};
-
-static const struct seq_operations cachefiles_histogram_ops = {
- .start = cachefiles_proc_start,
- .stop = cachefiles_proc_stop,
- .next = cachefiles_proc_next,
- .show = cachefiles_histogram_show,
-};
-
-static const struct cachefiles_proc cachefiles_histogram = {
- .nlines = HZ + 1,
- .ops = &cachefiles_histogram_ops,
-};
-
/*
- * initialise the /proc/fs/fscache/cachefiles/ directory
+ * display the latency histogram
*/
-int __init cachefiles_proc_init(void)
+static int cachefiles_histogram_show(struct seq_file *m, void *v)
{
- struct proc_dir_entry *p;
-
- _enter("");
-
- proc_cachefiles = proc_mkdir("cachefiles", proc_fscache);
- if (!proc_cachefiles)
- goto error_dir;
- proc_cachefiles->owner = THIS_MODULE;
-
- p = create_proc_entry("histogram", 0, proc_cachefiles);
- if (!p)
- goto error_histogram;
- p->proc_fops = &cachefiles_proc_fops;
- p->owner = THIS_MODULE;
- p->data = (void *) &cachefiles_histogram;
-
- _leave(" = 0");
- return 0;
+ unsigned long index;
+ unsigned x, y, z, t;

-error_histogram:
- remove_proc_entry("fs/cachefiles", NULL);
-error_dir:
- _leave(" = -ENOMEM");
- return -ENOMEM;
-}
+ switch ((unsigned long) v) {
+ case 1:
+ seq_puts(m, "JIFS SECS LOOKUPS MKDIRS CREATES\n");
+ return 0;
+ case 2:
+ seq_puts(m, "===== ===== ========= ========= =========\n");
+ return 0;
+ default:
+ index = (unsigned long) v - 3;
+ x = atomic_read(&cachefiles_lookup_histogram[index]);
+ y = atomic_read(&cachefiles_mkdir_histogram[index]);
+ z = atomic_read(&cachefiles_create_histogram[index]);
+ if (x == 0 && y == 0 && z == 0)
+ return 0;

-/*
- * clean up the /proc/fs/fscache/cachefiles/ directory
- */
-void cachefiles_proc_cleanup(void)
-{
- remove_proc_entry("histogram", proc_cachefiles);
- remove_proc_entry("cachefiles", proc_fscache);
-}
+ t = (index * 1000) / HZ;

-/*
- * open "/proc/fs/fscache/cachefiles/XXX" which provide statistics summaries
- */
-static int cachefiles_proc_open(struct inode *inode, struct file *file)
-{
- const struct cachefiles_proc *proc = PDE(inode)->data;
- struct seq_file *m;
- int ret;
-
- ret = seq_open(file, proc->ops);
- if (ret == 0) {
- m = file->private_data;
- m->private = (void *) proc;
+ seq_printf(m, "%4lu 0.%03u %9u %9u %9u\n", index, t, x, y, z);
+ return 0;
}
- return ret;
}

/*
* set up the iterator to start reading from the first line
*/
-static void *cachefiles_proc_start(struct seq_file *m, loff_t *_pos)
+static void *cachefiles_histogram_start(struct seq_file *m, loff_t *_pos)
{
+ if ((unsigned long long)*_pos >= HZ + 2)
+ return NULL;
if (*_pos == 0)
*_pos = 1;
return (void *)(unsigned long) *_pos;
@@ -120,47 +63,72 @@ static void *cachefiles_proc_start(struct seq_file *m, loff_t *_pos)
/*
* move to the next line
*/
-static void *cachefiles_proc_next(struct seq_file *m, void *v, loff_t *pos)
+static void *cachefiles_histogram_next(struct seq_file *m, void *v, loff_t *pos)
{
- const struct cachefiles_proc *proc = m->private;
-
(*pos)++;
- return *pos > proc->nlines ? NULL : (void *)(unsigned long) *pos;
+ return (unsigned long long)*pos > HZ + 2 ?
+ NULL : (void *)(unsigned long) *pos;
}

/*
* clean up after reading
*/
-static void cachefiles_proc_stop(struct seq_file *m, void *v)
+static void cachefiles_histogram_stop(struct seq_file *m, void *v)
{
}

+static const struct seq_operations cachefiles_histogram_ops = {
+ .start = cachefiles_histogram_start,
+ .stop = cachefiles_histogram_stop,
+ .next = cachefiles_histogram_next,
+ .show = cachefiles_histogram_show,
+};
+
/*
- * display the time-taken histogram
+ * open "/proc/fs/cachefiles/XXX" which provide statistics summaries
*/
-static int cachefiles_histogram_show(struct seq_file *m, void *v)
+static int cachefiles_histogram_open(struct inode *inode, struct file *file)
{
- unsigned long index;
- unsigned x, y, z, t;
+ return seq_open(file, &cachefiles_histogram_ops);
+}

- switch ((unsigned long) v) {
- case 1:
- seq_puts(m, "JIFS SECS LOOKUPS MKDIRS CREATES\n");
- return 0;
- case 2:
- seq_puts(m, "===== ===== ========= ========= =========\n");
- return 0;
- default:
- index = (unsigned long) v - 3;
- x = atomic_read(&cachefiles_lookup_histogram[index]);
- y = atomic_read(&cachefiles_mkdir_histogram[index]);
- z = atomic_read(&cachefiles_create_histogram[index]);
- if (x == 0 && y == 0 && z == 0)
- return 0;
+static const struct file_operations cachefiles_histogram_fops = {
+ .owner = THIS_MODULE,
+ .open = cachefiles_histogram_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};

- t = (index * 1000) / HZ;
+/*
+ * initialise the /proc/fs/cachefiles/ directory
+ */
+int __init cachefiles_proc_init(void)
+{
+ _enter("");

- seq_printf(m, "%4lu 0.%03u %9u %9u %9u\n", index, t, x, y, z);
- return 0;
- }
+ if (!proc_mkdir("fs/cachefiles", NULL))
+ goto error_dir;
+
+ if (!proc_create("fs/cachefiles/histogram", S_IFREG | 0444, NULL,
+ &cachefiles_histogram_fops))
+ goto error_histogram;
+
+ _leave(" = 0");
+ return 0;
+
+error_histogram:
+ remove_proc_entry("fs/cachefiles", NULL);
+error_dir:
+ _leave(" = -ENOMEM");
+ return -ENOMEM;
+}
+
+/*
+ * clean up the /proc/fs/cachefiles/ directory
+ */
+void cachefiles_proc_cleanup(void)
+{
+ remove_proc_entry("fs/cachefiles/histogram", NULL);
+ remove_proc_entry("fs/cachefiles", NULL);
}
diff --git a/fs/fscache/Kconfig b/fs/fscache/Kconfig
index b9ff04a..9bbb8ce 100644
--- a/fs/fscache/Kconfig
+++ b/fs/fscache/Kconfig
@@ -11,31 +11,38 @@ config FSCACHE

See Documentation/filesystems/caching/fscache.txt for more information.

-config FSCACHE_PROC
- bool "Provide /proc interface for local caching statistics"
- depends on FSCACHE && PROC_FS
-
config FSCACHE_STATS
bool "Gather statistical information on local caching"
- depends on FSCACHE_PROC
+ depends on FSCACHE && PROC_FS
help
This option causes statistical information to be gathered on local
caching and exported through file:

/proc/fs/fscache/stats

+ The gathering of statistics adds a certain amount of overhead to
+ execution as there are a quite a few stats gathered, and on a
+ multi-CPU system these may be on cachelines that keep bouncing
+ between CPUs. On the other hand, the stats are very useful for
+ debugging purposes. Saying 'Y' here is recommended.
+
See Documentation/filesystems/caching/fscache.txt for more information.

config FSCACHE_HISTOGRAM
bool "Gather latency information on local caching"
- depends on FSCACHE_PROC
+ depends on FSCACHE && PROC_FS
help
-
This option causes latency information to be gathered on local
caching and exported through file:

/proc/fs/fscache/histogram

+ The generation of this histogram adds a certain amount of overhead to
+ execution as there are a number of points at which data is gathered,
+ and on a multi-CPU system these may be on cachelines that keep
+ bouncing between CPUs. On the other hand, the histogram may be
+ useful for debugging purposes. Saying 'N' here is recommended.
+
See Documentation/filesystems/caching/fscache.txt for more information.

config FSCACHE_DEBUG
diff --git a/fs/fscache/Makefile b/fs/fscache/Makefile
index 572b012..3f6a198 100644
--- a/fs/fscache/Makefile
+++ b/fs/fscache/Makefile
@@ -10,8 +10,10 @@ fscache-y := \
fsc-netfs.o \
fsc-object.o \
fsc-operation.o \
- fsc-page.o \
- fsc-proc.o \
- fsc-stats.o
+ fsc-page.o
+
+fscache-$(CONFIG_PROC_FS) += fsc-proc.o
+fscache-$(CONFIG_FSCACHE_STATS) += fsc-stats.o
+fscache-$(CONFIG_FSCACHE_HISTOGRAM) += fsc-histogram.o

obj-$(CONFIG_FSCACHE) := fscache.o
diff --git a/fs/fscache/fsc-histogram.c b/fs/fscache/fsc-histogram.c
new file mode 100644
index 0000000..d1cbbc3
--- /dev/null
+++ b/fs/fscache/fsc-histogram.c
@@ -0,0 +1,109 @@
+/* FS-Cache latency histogram
+ *
+ * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@xxxxxxxxxx)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#define FSCACHE_DEBUG_LEVEL THREAD
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include "fsc-internal.h"
+
+atomic_t fscache_obj_instantiate_histogram[HZ];
+atomic_t fscache_objs_histogram[HZ];
+atomic_t fscache_ops_histogram[HZ];
+atomic_t fscache_retrieval_delay_histogram[HZ];
+atomic_t fscache_retrieval_histogram[HZ];
+
+/*
+ * display the time-taken histogram
+ */
+static int fscache_histogram_show(struct seq_file *m, void *v)
+{
+ unsigned long index;
+ unsigned n[5], t;
+
+ switch ((unsigned long) v) {
+ case 1:
+ seq_puts(m, "JIFS SECS OBJ INST OP RUNS OBJ RUNS "
+ " RETRV DLY RETRIEVLS\n");
+ return 0;
+ case 2:
+ seq_puts(m, "===== ===== ========= ========= ========="
+ " ========= =========\n");
+ return 0;
+ default:
+ index = (unsigned long) v - 3;
+ n[0] = atomic_read(&fscache_obj_instantiate_histogram[index]);
+ n[1] = atomic_read(&fscache_ops_histogram[index]);
+ n[2] = atomic_read(&fscache_objs_histogram[index]);
+ n[3] = atomic_read(&fscache_retrieval_delay_histogram[index]);
+ n[4] = atomic_read(&fscache_retrieval_histogram[index]);
+ if (!(n[0] | n[1] | n[2] | n[3] | n[4]))
+ return 0;
+
+ t = (index * 1000) / HZ;
+
+ seq_printf(m, "%4lu 0.%03u %9u %9u %9u %9u %9u\n",
+ index, t, n[0], n[1], n[2], n[3], n[4]);
+ return 0;
+ }
+}
+
+/*
+ * set up the iterator to start reading from the first line
+ */
+static void *fscache_histogram_start(struct seq_file *m, loff_t *_pos)
+{
+ if ((unsigned long long)*_pos >= HZ + 2)
+ return NULL;
+ if (*_pos == 0)
+ *_pos = 1;
+ return (void *)(unsigned long) *_pos;
+}
+
+/*
+ * move to the next line
+ */
+static void *fscache_histogram_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ (*pos)++;
+ return (unsigned long long)*pos > HZ + 2 ?
+ NULL : (void *)(unsigned long) *pos;
+}
+
+/*
+ * clean up after reading
+ */
+static void fscache_histogram_stop(struct seq_file *m, void *v)
+{
+}
+
+static const struct seq_operations fscache_histogram_ops = {
+ .start = fscache_histogram_start,
+ .stop = fscache_histogram_stop,
+ .next = fscache_histogram_next,
+ .show = fscache_histogram_show,
+};
+
+/*
+ * open "/proc/fs/fscache/histogram" to provide latency data
+ */
+static int fscache_histogram_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &fscache_histogram_ops);
+}
+
+const struct file_operations fscache_histogram_fops = {
+ .owner = THIS_MODULE,
+ .open = fscache_histogram_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
diff --git a/fs/fscache/fsc-internal.h b/fs/fscache/fsc-internal.h
index f2ff86b..e5eb297 100644
--- a/fs/fscache/fsc-internal.h
+++ b/fs/fscache/fsc-internal.h
@@ -51,6 +51,30 @@ extern struct fscache_cookie fscache_fsdef_index;
extern struct fscache_cookie_def fscache_fsdef_netfs_def;

/*
+ * fsc-histogram.c
+ */
+#ifdef CONFIG_FSCACHE_HISTOGRAM
+extern atomic_t fscache_obj_instantiate_histogram[HZ];
+extern atomic_t fscache_objs_histogram[HZ];
+extern atomic_t fscache_ops_histogram[HZ];
+extern atomic_t fscache_retrieval_delay_histogram[HZ];
+extern atomic_t fscache_retrieval_histogram[HZ];
+
+static inline void fscache_hist(atomic_t histogram[], unsigned long start_jif)
+{
+ unsigned long jif = jiffies - start_jif;
+ if (jif >= HZ)
+ jif = HZ - 1;
+ atomic_inc(&histogram[jif]);
+}
+
+extern const struct file_operations fscache_histogram_fops;
+
+#else
+#define fscache_hist(hist, start_jif) do {} while (0)
+#endif
+
+/*
* fsc-main.c
*/
extern unsigned fscache_defer_lookup;
@@ -80,6 +104,17 @@ extern void fscache_start_operations(struct fscache_object *);
extern void fscache_operation_gc(struct work_struct *);

/*
+ * fsc-proc.c
+ */
+#ifdef CONFIG_PROC_FS
+extern int __init fscache_proc_init(void);
+extern void fscache_proc_cleanup(void);
+#else
+#define fscache_proc_init() (0)
+#define fscache_proc_cleanup() do {} while (0)
+#endif
+
+/*
* fsc-stats.c
*/
#ifdef CONFIG_FSCACHE_STATS
@@ -164,36 +199,11 @@ static inline void fscache_stat(atomic_t *stat)
{
atomic_inc(stat);
}
-#else
-
-#define fscache_stat(stat) do {} while (0)
-#endif
-
-#ifdef CONFIG_FSCACHE_HISTOGRAM
-extern atomic_t fscache_obj_instantiate_histogram[HZ];
-extern atomic_t fscache_objs_histogram[HZ];
-extern atomic_t fscache_ops_histogram[HZ];
-extern atomic_t fscache_retrieval_delay_histogram[HZ];
-extern atomic_t fscache_retrieval_histogram[HZ];
-
-static inline void fscache_hist(atomic_t histogram[], unsigned long start_jif)
-{
- unsigned long jif = jiffies - start_jif;
- if (jif >= HZ)
- jif = HZ - 1;
- atomic_inc(&histogram[jif]);
-}

+extern const struct file_operations fscache_stats_fops;
#else
-#define fscache_hist(hist, start_jif) do {} while (0)
-#endif

-#ifdef CONFIG_FSCACHE_PROC
-extern int __init fscache_proc_init(void);
-extern void fscache_proc_cleanup(void);
-#else
-#define fscache_proc_init() (0)
-#define fscache_proc_cleanup() do {} while (0)
+#define fscache_stat(stat) do {} while (0)
#endif

/*
diff --git a/fs/fscache/fsc-proc.c b/fs/fscache/fsc-proc.c
index dd6daa5..2f549f3 100644
--- a/fs/fscache/fsc-proc.c
+++ b/fs/fscache/fsc-proc.c
@@ -15,94 +15,26 @@
#include <linux/seq_file.h>
#include "fsc-internal.h"

-struct fscache_proc {
- unsigned nlines;
- const struct seq_operations *ops;
-};
-
-struct proc_dir_entry *proc_fscache;
-EXPORT_SYMBOL(proc_fscache);
-
-#if defined(CONFIG_FSCACHE_STATS) || defined(CONFIG_FSCACHE_HISTOGRAM)
-static int fscache_proc_open(struct inode *inode, struct file *file);
-static void *fscache_proc_start(struct seq_file *m, loff_t *pos);
-static void fscache_proc_stop(struct seq_file *m, void *v);
-static void *fscache_proc_next(struct seq_file *m, void *v, loff_t *pos);
-
-static const struct file_operations fscache_proc_fops = {
- .open = fscache_proc_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = seq_release,
-};
-#endif
-
-#ifdef CONFIG_FSCACHE_STATS
-static int fscache_stats_show(struct seq_file *m, void *v);
-
-static const struct seq_operations fscache_stats_ops = {
- .start = fscache_proc_start,
- .stop = fscache_proc_stop,
- .next = fscache_proc_next,
- .show = fscache_stats_show,
-};
-
-static const struct fscache_proc fscache_stats = {
- .nlines = 17,
- .ops = &fscache_stats_ops,
-};
-#endif
-
-#ifdef CONFIG_FSCACHE_HISTOGRAM
-static int fscache_histogram_show(struct seq_file *m, void *v);
-
-static const struct seq_operations fscache_histogram_ops = {
- .start = fscache_proc_start,
- .stop = fscache_proc_stop,
- .next = fscache_proc_next,
- .show = fscache_histogram_show,
-};
-
-static const struct fscache_proc fscache_histogram = {
- .nlines = HZ + 1,
- .ops = &fscache_histogram_ops,
-};
-#endif
-
-#define FSC_DESC(SELECT, N) ((void *) (unsigned long) (((SELECT) << 16) | (N)))
-
/*
* initialise the /proc/fs/fscache/ directory
*/
int __init fscache_proc_init(void)
{
-#if defined(CONFIG_FSCACHE_STATS) || defined(CONFIG_FSCACHE_HISTOGRAM)
- struct proc_dir_entry *p;
-#endif
-
_enter("");

- proc_fscache = proc_mkdir("fs/fscache", NULL);
- if (!proc_fscache)
+ if (!proc_mkdir("fs/fscache", NULL))
goto error_dir;
- proc_fscache->owner = THIS_MODULE;

#ifdef CONFIG_FSCACHE_STATS
- p = create_proc_entry("stats", 0, proc_fscache);
- if (!p)
+ if (!proc_create("fs/fscache/stats", S_IFREG | 0444, NULL,
+ &fscache_stats_fops))
goto error_stats;
- p->proc_fops = &fscache_proc_fops;
- p->owner = THIS_MODULE;
- p->data = (void *) &fscache_stats;
#endif

#ifdef CONFIG_FSCACHE_HISTOGRAM
- p = create_proc_entry("histogram", 0, proc_fscache);
- if (!p)
+ if (!proc_create("fs/fscache/histogram", S_IFREG | 0444, NULL,
+ &fscache_histogram_fops))
goto error_histogram;
- p->proc_fops = &fscache_proc_fops;
- p->owner = THIS_MODULE;
- p->data = (void *) &fscache_histogram;
#endif

_leave(" = 0");
@@ -112,7 +44,7 @@ int __init fscache_proc_init(void)
error_histogram:
#endif
#ifdef CONFIG_FSCACHE_STATS
- remove_proc_entry("stats", proc_fscache);
+ remove_proc_entry("fs/fscache/stats", NULL);
error_stats:
#endif
remove_proc_entry("fs/fscache", NULL);
@@ -127,244 +59,10 @@ error_dir:
void fscache_proc_cleanup(void)
{
#ifdef CONFIG_FSCACHE_HISTOGRAM
- remove_proc_entry("histogram", proc_fscache);
+ remove_proc_entry("fs/fscache/histogram", NULL);
#endif
#ifdef CONFIG_FSCACHE_STATS
- remove_proc_entry("stats", proc_fscache);
+ remove_proc_entry("fs/fscache/stats", NULL);
#endif
remove_proc_entry("fs/fscache", NULL);
}
-
-#if defined(CONFIG_FSCACHE_STATS) || defined(CONFIG_FSCACHE_HISTOGRAM)
-/*
- * open "/proc/fs/fscache/XXX" which provide statistics summaries
- */
-static int fscache_proc_open(struct inode *inode, struct file *file)
-{
- const struct fscache_proc *proc = PDE(inode)->data;
- struct seq_file *m;
- int ret;
-
- ret = seq_open(file, proc->ops);
- if (ret == 0) {
- m = file->private_data;
- m->private = (void *) proc;
- }
- return ret;
-}
-
-/*
- * set up the iterator to start reading from the first line
- */
-static void *fscache_proc_start(struct seq_file *m, loff_t *_pos)
-{
- if (*_pos == 0)
- *_pos = 1;
- return (void *)(unsigned long) *_pos;
-}
-
-/*
- * move to the next line
- */
-static void *fscache_proc_next(struct seq_file *m, void *v, loff_t *pos)
-{
- const struct fscache_proc *proc = m->private;
-
- (*pos)++;
- return *pos > proc->nlines ? NULL : (void *)(unsigned long) *pos;
-}
-
-/*
- * clean up after reading
- */
-static void fscache_proc_stop(struct seq_file *m, void *v)
-{
-}
-#endif
-
-#ifdef CONFIG_FSCACHE_STATS
-/*
- * display the general statistics
- */
-static int fscache_stats_show(struct seq_file *m, void *v)
-{
- unsigned long line = (unsigned long) v;
-
- switch (line) {
- case 1:
- seq_puts(m, "FS-Cache statistics\n");
- break;
-
- case 2:
- seq_printf(m, "Cookies: idx=%u dat=%u spc=%u\n",
- atomic_read(&fscache_n_cookie_index),
- atomic_read(&fscache_n_cookie_data),
- atomic_read(&fscache_n_cookie_special));
- break;
-
- case 3:
- seq_printf(m, "Objects: alc=%u nal=%u avl=%u ded=%u\n",
- atomic_read(&fscache_n_object_alloc),
- atomic_read(&fscache_n_object_no_alloc),
- atomic_read(&fscache_n_object_avail),
- atomic_read(&fscache_n_object_dead));
- break;
-
- case 4:
- seq_printf(m, "ChkAux : non=%u ok=%u upd=%u obs=%u\n",
- atomic_read(&fscache_n_checkaux_none),
- atomic_read(&fscache_n_checkaux_okay),
- atomic_read(&fscache_n_checkaux_update),
- atomic_read(&fscache_n_checkaux_obsolete));
- break;
-
- case 5:
- seq_printf(m, "Pages : mrk=%u unc=%u\n",
- atomic_read(&fscache_n_marks),
- atomic_read(&fscache_n_uncaches));
- break;
-
- case 6:
- seq_printf(m, "Acquire: n=%u nul=%u noc=%u ok=%u nbf=%u"
- " oom=%u\n",
- atomic_read(&fscache_n_acquires),
- atomic_read(&fscache_n_acquires_null),
- atomic_read(&fscache_n_acquires_no_cache),
- atomic_read(&fscache_n_acquires_ok),
- atomic_read(&fscache_n_acquires_nobufs),
- atomic_read(&fscache_n_acquires_oom));
- break;
-
- case 7:
- seq_printf(m, "Lookups: n=%u neg=%u pos=%u crt=%u\n",
- atomic_read(&fscache_n_object_lookups),
- atomic_read(&fscache_n_object_lookups_negative),
- atomic_read(&fscache_n_object_lookups_positive),
- atomic_read(&fscache_n_object_created));
- break;
-
- case 8:
- seq_printf(m, "Updates: n=%u nul=%u run=%u\n",
- atomic_read(&fscache_n_updates),
- atomic_read(&fscache_n_updates_null),
- atomic_read(&fscache_n_updates_run));
- break;
-
- case 9:
- seq_printf(m, "Relinqs: n=%u nul=%u wcr=%u\n",
- atomic_read(&fscache_n_relinquishes),
- atomic_read(&fscache_n_relinquishes_null),
- atomic_read(&fscache_n_relinquishes_waitcrt));
- break;
-
- case 10:
- seq_printf(m, "AttrChg: n=%u ok=%u nbf=%u oom=%u run=%u\n",
- atomic_read(&fscache_n_attr_changed),
- atomic_read(&fscache_n_attr_changed_ok),
- atomic_read(&fscache_n_attr_changed_nobufs),
- atomic_read(&fscache_n_attr_changed_nomem),
- atomic_read(&fscache_n_attr_changed_calls));
- break;
-
- case 11:
- seq_printf(m, "Allocs : n=%u ok=%u wt=%u nbf=%u\n",
- atomic_read(&fscache_n_allocs),
- atomic_read(&fscache_n_allocs_ok),
- atomic_read(&fscache_n_allocs_wait),
- atomic_read(&fscache_n_allocs_nobufs));
- break;
- case 12:
- seq_printf(m, "Allocs : ops=%u owt=%u\n",
- atomic_read(&fscache_n_alloc_ops),
- atomic_read(&fscache_n_alloc_op_waits));
- break;
-
- case 13:
- seq_printf(m, "Retrvls: n=%u ok=%u wt=%u nod=%u nbf=%u"
- " int=%u oom=%u\n",
- atomic_read(&fscache_n_retrievals),
- atomic_read(&fscache_n_retrievals_ok),
- atomic_read(&fscache_n_retrievals_wait),
- atomic_read(&fscache_n_retrievals_nodata),
- atomic_read(&fscache_n_retrievals_nobufs),
- atomic_read(&fscache_n_retrievals_intr),
- atomic_read(&fscache_n_retrievals_nomem));
- break;
- case 14:
- seq_printf(m, "Retrvls: ops=%u owt=%u\n",
- atomic_read(&fscache_n_retrieval_ops),
- atomic_read(&fscache_n_retrieval_op_waits));
- break;
-
- case 15:
- seq_printf(m, "Stores : n=%u ok=%u agn=%u nbf=%u oom=%u\n",
- atomic_read(&fscache_n_stores),
- atomic_read(&fscache_n_stores_ok),
- atomic_read(&fscache_n_stores_again),
- atomic_read(&fscache_n_stores_nobufs),
- atomic_read(&fscache_n_stores_oom));
- break;
- case 16:
- seq_printf(m, "Stores : ops=%u run=%u\n",
- atomic_read(&fscache_n_store_ops),
- atomic_read(&fscache_n_store_calls));
- break;
-
- case 17:
- seq_printf(m, "Ops : pend=%u run=%u enq=%u\n",
- atomic_read(&fscache_n_op_pend),
- atomic_read(&fscache_n_op_run),
- atomic_read(&fscache_n_op_enqueue));
- break;
-
- case 18:
- seq_printf(m, "Ops : dfr=%u rel=%u gc=%u\n",
- atomic_read(&fscache_n_op_deferred_release),
- atomic_read(&fscache_n_op_release),
- atomic_read(&fscache_n_op_gc));
- break;
-
- default:
- break;
- }
- return 0;
-}
-
-#endif /* end CONFIG_FSCACHE_STATS */
-
-#ifdef CONFIG_FSCACHE_HISTOGRAM
-/*
- * display the time-taken histogram
- */
-static int fscache_histogram_show(struct seq_file *m, void *v)
-{
- unsigned long index;
- unsigned n[5], t;
-
- switch ((unsigned long) v) {
- case 1:
- seq_puts(m, "JIFS SECS OBJ INST OP RUNS OBJ RUNS "
- " RETRV DLY RETRIEVLS\n");
- return 0;
- case 2:
- seq_puts(m, "===== ===== ========= ========= ========="
- " ========= =========\n");
- return 0;
- default:
- index = (unsigned long) v - 3;
- n[0] = atomic_read(&fscache_obj_instantiate_histogram[index]);
- n[1] = atomic_read(&fscache_ops_histogram[index]);
- n[2] = atomic_read(&fscache_objs_histogram[index]);
- n[3] = atomic_read(&fscache_retrieval_delay_histogram[index]);
- n[4] = atomic_read(&fscache_retrieval_histogram[index]);
- if (!(n[0] | n[1] | n[2] | n[3] | n[4]))
- return 0;
-
- t = (index * 1000) / HZ;
-
- seq_printf(m, "%4lu 0.%03u %9u %9u %9u %9u %9u\n",
- index, t, n[0], n[1], n[2], n[3], n[4]);
- return 0;
- }
-}
-#endif /* end CONFIG_FSCACHE_HISTOGRAM */
diff --git a/fs/fscache/fsc-stats.c b/fs/fscache/fsc-stats.c
index 8762d43..93ffc8f 100644
--- a/fs/fscache/fsc-stats.c
+++ b/fs/fscache/fsc-stats.c
@@ -18,7 +18,6 @@
/*
* operation counters
*/
-#ifdef CONFIG_FSCACHE_STATS
atomic_t fscache_n_op_pend;
atomic_t fscache_n_op_run;
atomic_t fscache_n_op_enqueue;
@@ -93,12 +92,121 @@ atomic_t fscache_n_checkaux_none;
atomic_t fscache_n_checkaux_okay;
atomic_t fscache_n_checkaux_update;
atomic_t fscache_n_checkaux_obsolete;
-#endif
-
-#ifdef CONFIG_FSCACHE_HISTOGRAM
-atomic_t fscache_obj_instantiate_histogram[HZ];
-atomic_t fscache_objs_histogram[HZ];
-atomic_t fscache_ops_histogram[HZ];
-atomic_t fscache_retrieval_delay_histogram[HZ];
-atomic_t fscache_retrieval_histogram[HZ];
-#endif
+
+/*
+ * display the general statistics
+ */
+static int fscache_stats_show(struct seq_file *m, void *v)
+{
+ seq_puts(m, "FS-Cache statistics\n");
+
+ seq_printf(m, "Cookies: idx=%u dat=%u spc=%u\n",
+ atomic_read(&fscache_n_cookie_index),
+ atomic_read(&fscache_n_cookie_data),
+ atomic_read(&fscache_n_cookie_special));
+
+ seq_printf(m, "Objects: alc=%u nal=%u avl=%u ded=%u\n",
+ atomic_read(&fscache_n_object_alloc),
+ atomic_read(&fscache_n_object_no_alloc),
+ atomic_read(&fscache_n_object_avail),
+ atomic_read(&fscache_n_object_dead));
+ seq_printf(m, "ChkAux : non=%u ok=%u upd=%u obs=%u\n",
+ atomic_read(&fscache_n_checkaux_none),
+ atomic_read(&fscache_n_checkaux_okay),
+ atomic_read(&fscache_n_checkaux_update),
+ atomic_read(&fscache_n_checkaux_obsolete));
+
+ seq_printf(m, "Pages : mrk=%u unc=%u\n",
+ atomic_read(&fscache_n_marks),
+ atomic_read(&fscache_n_uncaches));
+
+ seq_printf(m, "Acquire: n=%u nul=%u noc=%u ok=%u nbf=%u"
+ " oom=%u\n",
+ atomic_read(&fscache_n_acquires),
+ atomic_read(&fscache_n_acquires_null),
+ atomic_read(&fscache_n_acquires_no_cache),
+ atomic_read(&fscache_n_acquires_ok),
+ atomic_read(&fscache_n_acquires_nobufs),
+ atomic_read(&fscache_n_acquires_oom));
+
+ seq_printf(m, "Lookups: n=%u neg=%u pos=%u crt=%u\n",
+ atomic_read(&fscache_n_object_lookups),
+ atomic_read(&fscache_n_object_lookups_negative),
+ atomic_read(&fscache_n_object_lookups_positive),
+ atomic_read(&fscache_n_object_created));
+
+ seq_printf(m, "Updates: n=%u nul=%u run=%u\n",
+ atomic_read(&fscache_n_updates),
+ atomic_read(&fscache_n_updates_null),
+ atomic_read(&fscache_n_updates_run));
+
+ seq_printf(m, "Relinqs: n=%u nul=%u wcr=%u\n",
+ atomic_read(&fscache_n_relinquishes),
+ atomic_read(&fscache_n_relinquishes_null),
+ atomic_read(&fscache_n_relinquishes_waitcrt));
+
+ seq_printf(m, "AttrChg: n=%u ok=%u nbf=%u oom=%u run=%u\n",
+ atomic_read(&fscache_n_attr_changed),
+ atomic_read(&fscache_n_attr_changed_ok),
+ atomic_read(&fscache_n_attr_changed_nobufs),
+ atomic_read(&fscache_n_attr_changed_nomem),
+ atomic_read(&fscache_n_attr_changed_calls));
+
+ seq_printf(m, "Allocs : n=%u ok=%u wt=%u nbf=%u\n",
+ atomic_read(&fscache_n_allocs),
+ atomic_read(&fscache_n_allocs_ok),
+ atomic_read(&fscache_n_allocs_wait),
+ atomic_read(&fscache_n_allocs_nobufs));
+ seq_printf(m, "Allocs : ops=%u owt=%u\n",
+ atomic_read(&fscache_n_alloc_ops),
+ atomic_read(&fscache_n_alloc_op_waits));
+
+ seq_printf(m, "Retrvls: n=%u ok=%u wt=%u nod=%u nbf=%u"
+ " int=%u oom=%u\n",
+ atomic_read(&fscache_n_retrievals),
+ atomic_read(&fscache_n_retrievals_ok),
+ atomic_read(&fscache_n_retrievals_wait),
+ atomic_read(&fscache_n_retrievals_nodata),
+ atomic_read(&fscache_n_retrievals_nobufs),
+ atomic_read(&fscache_n_retrievals_intr),
+ atomic_read(&fscache_n_retrievals_nomem));
+ seq_printf(m, "Retrvls: ops=%u owt=%u\n",
+ atomic_read(&fscache_n_retrieval_ops),
+ atomic_read(&fscache_n_retrieval_op_waits));
+
+ seq_printf(m, "Stores : n=%u ok=%u agn=%u nbf=%u oom=%u\n",
+ atomic_read(&fscache_n_stores),
+ atomic_read(&fscache_n_stores_ok),
+ atomic_read(&fscache_n_stores_again),
+ atomic_read(&fscache_n_stores_nobufs),
+ atomic_read(&fscache_n_stores_oom));
+ seq_printf(m, "Stores : ops=%u run=%u\n",
+ atomic_read(&fscache_n_store_ops),
+ atomic_read(&fscache_n_store_calls));
+
+ seq_printf(m, "Ops : pend=%u run=%u enq=%u\n",
+ atomic_read(&fscache_n_op_pend),
+ atomic_read(&fscache_n_op_run),
+ atomic_read(&fscache_n_op_enqueue));
+ seq_printf(m, "Ops : dfr=%u rel=%u gc=%u\n",
+ atomic_read(&fscache_n_op_deferred_release),
+ atomic_read(&fscache_n_op_release),
+ atomic_read(&fscache_n_op_gc));
+ return 0;
+}
+
+/*
+ * open "/proc/fs/fscache/stats" allowing provision of a statistical summary
+ */
+static int fscache_stats_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, fscache_stats_show, NULL);
+}
+
+const struct file_operations fscache_stats_fops = {
+ .owner = THIS_MODULE,
+ .open = fscache_stats_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
diff --git a/include/linux/fscache-cache.h b/include/linux/fscache-cache.h
index a31f4c1..0410bd9 100644
--- a/include/linux/fscache-cache.h
+++ b/include/linux/fscache-cache.h
@@ -29,10 +29,6 @@ struct fscache_cache_ops;
struct fscache_object;
struct fscache_operation;

-#ifdef CONFIG_FSCACHE_PROC
-extern struct proc_dir_entry *proc_fscache;
-#endif
-
/*
* cache tag definition
*/

--
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