caching on files module. If this is set, the debugging output may be
enabled by setting bits in /sys/modules/cachefiles/parameter/debug or
by including a debugging specifier in /etc/cachefilesd.conf.
-
-config CACHEFILES_HISTOGRAM
- bool "Gather latency information on CacheFiles"
- depends on CACHEFILES && PROC_FS
- help
-
- This option causes latency information to be gathered on CacheFiles
- operation and exported through file:
-
- /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.rst for more
- information.
security.o \
xattr.o
-cachefiles-$(CONFIG_CACHEFILES_HISTOGRAM) += proc.o
-
obj-$(CONFIG_CACHEFILES) := cachefiles.o
extern int cachefiles_check_in_use(struct cachefiles_cache *cache,
struct dentry *dir, char *filename);
-/*
- * proc.c
- */
-#ifdef CONFIG_CACHEFILES_HISTOGRAM
-extern atomic_t cachefiles_lookup_histogram[HZ];
-extern atomic_t cachefiles_mkdir_histogram[HZ];
-extern atomic_t cachefiles_create_histogram[HZ];
-
-extern int __init cachefiles_proc_init(void);
-extern void cachefiles_proc_cleanup(void);
-static inline
-void cachefiles_hist(atomic_t histogram[], unsigned long start_jif)
-{
- unsigned long jif = jiffies - start_jif;
- if (jif >= HZ)
- jif = HZ - 1;
- atomic_inc(&histogram[jif]);
-}
-
-#else
-#define cachefiles_proc_init() (0)
-#define cachefiles_proc_cleanup() do {} while (0)
-#define cachefiles_hist(hist, start_jif) do {} while (0)
-#endif
-
/*
* rdwr.c
*/
goto error_object_jar;
}
- ret = cachefiles_proc_init();
- if (ret < 0)
- goto error_proc;
-
pr_info("Loaded\n");
return 0;
-error_proc:
- kmem_cache_destroy(cachefiles_object_jar);
error_object_jar:
misc_deregister(&cachefiles_dev);
error_dev:
{
pr_info("Unloading\n");
- cachefiles_proc_cleanup();
kmem_cache_destroy(cachefiles_object_jar);
misc_deregister(&cachefiles_dev);
}
struct dentry *dir, *next = NULL;
struct inode *inode;
struct path path;
- unsigned long start;
const char *name;
int ret, nlen;
inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
- start = jiffies;
next = lookup_one_len(name, dir, nlen);
- cachefiles_hist(cachefiles_lookup_histogram, start);
if (IS_ERR(next)) {
trace_cachefiles_lookup(object, next, NULL);
goto lookup_error;
ret = security_path_mkdir(&path, next, 0);
if (ret < 0)
goto create_error;
- start = jiffies;
ret = vfs_mkdir(&init_user_ns, d_inode(dir), next, 0);
- cachefiles_hist(cachefiles_mkdir_histogram, start);
if (!key)
trace_cachefiles_mkdir(object, next, ret);
if (ret < 0)
ret = security_path_mknod(&path, next, S_IFREG, 0);
if (ret < 0)
goto create_error;
- start = jiffies;
ret = vfs_create(&init_user_ns, d_inode(dir), next,
S_IFREG, true);
- cachefiles_hist(cachefiles_create_histogram, start);
trace_cachefiles_create(object, next, ret);
if (ret < 0)
goto create_error;
const char *dirname)
{
struct dentry *subdir;
- unsigned long start;
struct path path;
int ret;
inode_lock(d_inode(dir));
retry:
- start = jiffies;
subdir = lookup_one_len(dirname, dir, strlen(dirname));
- cachefiles_hist(cachefiles_lookup_histogram, start);
if (IS_ERR(subdir)) {
if (PTR_ERR(subdir) == -ENOMEM)
goto nomem_d_alloc;
struct cachefiles_object *object;
struct rb_node *_n;
struct dentry *victim;
- unsigned long start;
int ret;
//_enter(",%pd/,%s",
/* look up the victim */
inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
- start = jiffies;
victim = lookup_one_len(filename, dir, strlen(filename));
- cachefiles_hist(cachefiles_lookup_histogram, start);
if (IS_ERR(victim))
goto lookup_error;
+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-or-later
-/* CacheFiles statistics
- *
- * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@redhat.com)
- */
-
-#include <linux/module.h>
-#include <linux/proc_fs.h>
-#include <linux/seq_file.h>
-#include "internal.h"
-
-atomic_t cachefiles_lookup_histogram[HZ];
-atomic_t cachefiles_mkdir_histogram[HZ];
-atomic_t cachefiles_create_histogram[HZ];
-
-/*
- * display the latency histogram
- */
-static int cachefiles_histogram_show(struct seq_file *m, void *v)
-{
- unsigned long index;
- unsigned x, y, z, t;
-
- 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;
-
- t = (index * 1000) / HZ;
-
- seq_printf(m, "%4lu 0.%03u %9u %9u %9u\n", index, t, x, y, z);
- return 0;
- }
-}
-
-/*
- * set up the iterator to start reading from the first line
- */
-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;
-}
-
-/*
- * move to the next line
- */
-static void *cachefiles_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 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,
-};
-
-/*
- * initialise the /proc/fs/cachefiles/ directory
- */
-int __init cachefiles_proc_init(void)
-{
- _enter("");
-
- if (!proc_mkdir("fs/cachefiles", NULL))
- goto error_dir;
-
- if (!proc_create_seq("fs/cachefiles/histogram", S_IFREG | 0444, NULL,
- &cachefiles_histogram_ops))
- 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);
-}
See Documentation/filesystems/caching/fscache.rst for more information.
-config FSCACHE_HISTOGRAM
- bool "Gather latency information on local caching"
- 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.rst for more information.
-
config FSCACHE_DEBUG
bool "Debug FS-Cache"
depends on FSCACHE
fscache-$(CONFIG_PROC_FS) += proc.o
fscache-$(CONFIG_FSCACHE_STATS) += stats.o
-fscache-$(CONFIG_FSCACHE_HISTOGRAM) += histogram.o
fscache-$(CONFIG_FSCACHE_OBJECT_LIST) += object-list.o
obj-$(CONFIG_FSCACHE) := fscache.o
+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-or-later
-/* FS-Cache latency histogram
- *
- * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@redhat.com)
- */
-
-#define FSCACHE_DEBUG_LEVEL THREAD
-#include <linux/module.h>
-#include <linux/proc_fs.h>
-#include <linux/seq_file.h>
-#include "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)
-{
-}
-
-const struct seq_operations fscache_histogram_ops = {
- .start = fscache_histogram_start,
- .stop = fscache_histogram_stop,
- .next = fscache_histogram_next,
- .show = fscache_histogram_show,
-};
extern struct fscache_cookie fscache_fsdef_index;
extern struct fscache_cookie_def fscache_fsdef_netfs_def;
-/*
- * 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 seq_operations fscache_histogram_ops;
-
-#else
-#define fscache_hist(hist, start_jif) do {} while (0)
-#endif
-
/*
* main.c
*/
{
struct fscache_object *object =
container_of(work, struct fscache_object, work);
- unsigned long start;
_enter("{OBJ%x}", object->debug_id);
- start = jiffies;
fscache_object_sm_dispatcher(object);
- fscache_hist(fscache_objs_histogram, start);
fscache_put_object(object, fscache_obj_put_work);
}
spin_lock(&parent->lock);
parent->n_ops++;
parent->n_obj_ops++;
- object->lookup_jif = jiffies;
spin_unlock(&parent->lock);
_leave("");
object->cache->ops->lookup_complete(object);
fscache_stat_d(&fscache_n_cop_lookup_complete);
- fscache_hist(fscache_obj_instantiate_histogram, object->lookup_jif);
fscache_stat(&fscache_n_object_avail);
_leave("");
{
struct fscache_operation *op =
container_of(work, struct fscache_operation, work);
- unsigned long start;
_enter("{OBJ%x OP%x,%d}",
op->object->debug_id, op->debug_id, atomic_read(&op->usage));
trace_fscache_op(op->object->cookie, op, fscache_op_work);
ASSERT(op->processor != NULL);
- start = jiffies;
op->processor(op);
- fscache_hist(fscache_ops_histogram, start);
fscache_put_operation(op);
_leave("");
ASSERTIFCMP(op->op.state != FSCACHE_OP_ST_INITIALISED,
atomic_read(&op->n_pages), ==, 0);
- fscache_hist(fscache_retrieval_histogram, op->start_time);
if (op->context)
fscache_put_context(op->cookie, op->context);
op->mapping = mapping;
op->end_io_func = end_io_func;
op->context = context;
- op->start_time = jiffies;
INIT_LIST_HEAD(&op->to_do);
/* Pin the netfs read context in case we need to do the actual netfs
*/
int fscache_wait_for_deferred_lookup(struct fscache_cookie *cookie)
{
- unsigned long jif;
-
_enter("");
if (!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags)) {
fscache_stat(&fscache_n_retrievals_wait);
- jif = jiffies;
if (wait_on_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP,
TASK_INTERRUPTIBLE) != 0) {
fscache_stat(&fscache_n_retrievals_intr);
ASSERT(!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags));
smp_rmb();
- fscache_hist(fscache_retrieval_delay_histogram, jif);
_leave(" = 0 [dly]");
return 0;
}
goto error_stats;
#endif
-#ifdef CONFIG_FSCACHE_HISTOGRAM
- if (!proc_create_seq("fs/fscache/histogram", S_IFREG | 0444, NULL,
- &fscache_histogram_ops))
- goto error_histogram;
-#endif
-
#ifdef CONFIG_FSCACHE_OBJECT_LIST
if (!proc_create("fs/fscache/objects", S_IFREG | 0444, NULL,
&fscache_objlist_proc_ops))
#ifdef CONFIG_FSCACHE_OBJECT_LIST
error_objects:
#endif
-#ifdef CONFIG_FSCACHE_HISTOGRAM
- remove_proc_entry("fs/fscache/histogram", NULL);
-error_histogram:
-#endif
#ifdef CONFIG_FSCACHE_STATS
remove_proc_entry("fs/fscache/stats", NULL);
error_stats:
#ifdef CONFIG_FSCACHE_OBJECT_LIST
remove_proc_entry("fs/fscache/objects", NULL);
#endif
-#ifdef CONFIG_FSCACHE_HISTOGRAM
- remove_proc_entry("fs/fscache/histogram", NULL);
-#endif
#ifdef CONFIG_FSCACHE_STATS
remove_proc_entry("fs/fscache/stats", NULL);
#endif
fscache_rw_complete_t end_io_func; /* function to call on I/O completion */
void *context; /* netfs read context (pinned) */
struct list_head to_do; /* list of things to be done by the backend */
- unsigned long start_time; /* time at which retrieval started */
atomic_t n_pages; /* number of pages to be retrieved */
};
projects / linux-block.git / commitdiff