Re: [PATCH 1/2] f2fs: add sysfs support for controlling the gc_thread
From: Gu Zheng
Date: Wed Jul 31 2013 - 23:18:26 EST
Hi Jeon,
On 07/31/2013 10:33 PM, Namjae Jeon wrote:
> From: Namjae Jeon <namjae.jeon@xxxxxxxxxxx>
>
> Add sysfs entries to control the timing parameters for
> f2fs gc thread.
>
> Various Sysfs options introduced are:
> gc_min_sleep_time: Min Sleep time for GC in ms
> gc_max_sleep_time: Max Sleep time for GC in ms
> gc_no_gc_sleep_time: Default Sleep time for GC in ms
>
> Signed-off-by: Namjae Jeon <namjae.jeon@xxxxxxxxxxx>
> Signed-off-by: Pankaj Kumar <pankaj.km@xxxxxxxxxxx>
> ---
> Documentation/ABI/testing/sysfs-fs-f2fs | 22 ++++++
> Documentation/filesystems/f2fs.txt | 26 +++++++
> fs/f2fs/f2fs.h | 4 +
> fs/f2fs/gc.c | 17 +++--
> fs/f2fs/gc.h | 33 ++++----
> fs/f2fs/super.c | 124 +++++++++++++++++++++++++++++++
> 6 files changed, 206 insertions(+), 20 deletions(-)
> create mode 100644 Documentation/ABI/testing/sysfs-fs-f2fs
>
> diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
> new file mode 100644
> index 0000000..5f44095
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-fs-f2fs
> @@ -0,0 +1,22 @@
> +What: /sys/fs/f2fs/<disk>/gc_max_sleep_time
> +Date: July 2013
> +Contact: "Namjae Jeon" <namjae.jeon@xxxxxxxxxxx>
> +Description:
> + Controls the maximun sleep time for gc_thread. Time
> + is in milliseconds.
> +
> +What: /sys/fs/f2fs/<disk>/gc_min_sleep_time
> +Date: July 2013
> +Contact: "Namjae Jeon" <namjae.jeon@xxxxxxxxxxx>
> +Description:
> + Controls the minimum sleep time for gc_thread. Time
> + is in milliseconds.
> +
> +What: /sys/fs/f2fs/<disk>/gc_no_gc_sleep_time
> +Date: July 2013
> +Contact: "Namjae Jeon" <namjae.jeon@xxxxxxxxxxx>
> +Description:
> + Controls the default sleep time for gc_thread. Time
> + is in milliseconds.
> +
> +
> diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
> index 0500c19..2e9e873 100644
> --- a/Documentation/filesystems/f2fs.txt
> +++ b/Documentation/filesystems/f2fs.txt
> @@ -133,6 +133,32 @@ f2fs. Each file shows the whole f2fs information.
> - current memory footprint consumed by f2fs.
>
> ================================================================================
> +SYSFS ENTRIES
> +================================================================================
> +
> +Information about mounted f2fs file systems can be found in
> +/sys/fs/f2fs. Each mounted filesystem will have a directory in
> +/sys/fs/f2fs based on its device name (i.e., /sys/fs/f2fs/sda).
> +The files in each per-device directory are shown in table below.
> +
> +Files in /sys/fs/f2fs/<devname>
> +(see also Documentation/ABI/testing/sysfs-fs-f2fs)
> +..............................................................................
> + File Content
> +
> + gc_max_sleep_time This tuning parameter controls the maximum sleep
> + time for the garbage collection thread. Time is
> + in milliseconds.
> +
> + gc_min_sleep_time This tuning parameter controls the minimum sleep
> + time for the garbage collection thread. Time is
> + in milliseconds.
> +
> + gc_no_gc_sleep_time This tuning parameter controls the default sleep
> + time for the garbage collection thread. Time is
> + in milliseconds.
> +
> +================================================================================
> USAGE
> ================================================================================
>
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 78777cd..63813be 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -430,6 +430,10 @@ struct f2fs_sb_info {
> #endif
> unsigned int last_victim[2]; /* last victim segment # */
> spinlock_t stat_lock; /* lock for stat operations */
> +
> + /* For sysfs suppport */
> + struct kobject s_kobj;
> + struct completion s_kobj_unregister;
What is this completion used for? Or it's an ahead design? I do not find synchronization
routines use it. Am I missing something?
> };
>
> /*
> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> index 35f9b1a..60d4f67 100644
> --- a/fs/f2fs/gc.c
> +++ b/fs/f2fs/gc.c
> @@ -29,10 +29,11 @@ static struct kmem_cache *winode_slab;
> static int gc_thread_func(void *data)
> {
> struct f2fs_sb_info *sbi = data;
> + struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
> wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head;
> long wait_ms;
>
> - wait_ms = GC_THREAD_MIN_SLEEP_TIME;
> + wait_ms = gc_th->min_sleep_time;
>
> do {
> if (try_to_freeze())
> @@ -45,7 +46,7 @@ static int gc_thread_func(void *data)
> break;
>
> if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {
> - wait_ms = GC_THREAD_MAX_SLEEP_TIME;
> + wait_ms = increase_sleep_time(gc_th, wait_ms);
> continue;
> }
>
> @@ -66,15 +67,15 @@ static int gc_thread_func(void *data)
> continue;
>
> if (!is_idle(sbi)) {
> - wait_ms = increase_sleep_time(wait_ms);
> + wait_ms = increase_sleep_time(gc_th, wait_ms);
> mutex_unlock(&sbi->gc_mutex);
> continue;
> }
>
> if (has_enough_invalid_blocks(sbi))
> - wait_ms = decrease_sleep_time(wait_ms);
> + wait_ms = decrease_sleep_time(gc_th, wait_ms);
> else
> - wait_ms = increase_sleep_time(wait_ms);
> + wait_ms = increase_sleep_time(gc_th, wait_ms);
>
> #ifdef CONFIG_F2FS_STAT_FS
> sbi->bg_gc++;
> @@ -82,7 +83,7 @@ static int gc_thread_func(void *data)
>
> /* if return value is not zero, no victim was selected */
> if (f2fs_gc(sbi))
> - wait_ms = GC_THREAD_NOGC_SLEEP_TIME;
> + wait_ms = gc_th->no_gc_sleep_time;
> } while (!kthread_should_stop());
> return 0;
> }
> @@ -101,6 +102,10 @@ int start_gc_thread(struct f2fs_sb_info *sbi)
> goto out;
> }
>
> + gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
> + gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
> + gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
> +
> sbi->gc_thread = gc_th;
> init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
> sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
> diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h
> index 2c6a6bd..f4bf44c 100644
> --- a/fs/f2fs/gc.h
> +++ b/fs/f2fs/gc.h
> @@ -13,9 +13,9 @@
> * whether IO subsystem is idle
> * or not
> */
> -#define GC_THREAD_MIN_SLEEP_TIME 30000 /* milliseconds */
> -#define GC_THREAD_MAX_SLEEP_TIME 60000
> -#define GC_THREAD_NOGC_SLEEP_TIME 300000 /* wait 5 min */
> +#define DEF_GC_THREAD_MIN_SLEEP_TIME 30000 /* milliseconds */
> +#define DEF_GC_THREAD_MAX_SLEEP_TIME 60000
> +#define DEF_GC_THREAD_NOGC_SLEEP_TIME 300000 /* wait 5 min */
> #define LIMIT_INVALID_BLOCK 40 /* percentage over total user space */
> #define LIMIT_FREE_BLOCK 40 /* percentage over invalid + free space */
>
> @@ -25,6 +25,11 @@
> struct f2fs_gc_kthread {
> struct task_struct *f2fs_gc_task;
> wait_queue_head_t gc_wait_queue_head;
> +
> + /* for gc sleep time */
> + unsigned int min_sleep_time;
> + unsigned int max_sleep_time;
> + unsigned int no_gc_sleep_time;
Though these attributes are used for gc thread, and in current design gc_thread is always
singleton per f2fs_sb, but thare're in fact f2fs sb infos. So I think it's to attach
these to f2fs_sb_info. What's your opinion?
Thanks,
Gu
> };
>
> struct inode_entry {
> @@ -56,25 +61,25 @@ static inline block_t limit_free_user_blocks(struct f2fs_sb_info *sbi)
> return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;
> }
>
> -static inline long increase_sleep_time(long wait)
> +static inline long increase_sleep_time(struct f2fs_gc_kthread *gc_th, long wait)
> {
> - if (wait == GC_THREAD_NOGC_SLEEP_TIME)
> + if (wait == gc_th->no_gc_sleep_time)
> return wait;
>
> - wait += GC_THREAD_MIN_SLEEP_TIME;
> - if (wait > GC_THREAD_MAX_SLEEP_TIME)
> - wait = GC_THREAD_MAX_SLEEP_TIME;
> + wait += gc_th->min_sleep_time;
> + if (wait > gc_th->max_sleep_time)
> + wait = gc_th->max_sleep_time;
> return wait;
> }
>
> -static inline long decrease_sleep_time(long wait)
> +static inline long decrease_sleep_time(struct f2fs_gc_kthread *gc_th, long wait)
> {
> - if (wait == GC_THREAD_NOGC_SLEEP_TIME)
> - wait = GC_THREAD_MAX_SLEEP_TIME;
> + if (wait == gc_th->no_gc_sleep_time)
> + wait = gc_th->max_sleep_time;
>
> - wait -= GC_THREAD_MIN_SLEEP_TIME;
> - if (wait <= GC_THREAD_MIN_SLEEP_TIME)
> - wait = GC_THREAD_MIN_SLEEP_TIME;
> + wait -= gc_th->min_sleep_time;
> + if (wait <= gc_th->min_sleep_time)
> + wait = gc_th->min_sleep_time;
> return wait;
> }
>
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 70dbb31..30de280 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -23,17 +23,21 @@
> #include <linux/exportfs.h>
> #include <linux/blkdev.h>
> #include <linux/f2fs_fs.h>
> +#include <linux/kobject.h>
> +#include <linux/sysfs.h>
>
> #include "f2fs.h"
> #include "node.h"
> #include "segment.h"
> #include "xattr.h"
> +#include "gc.h"
>
> #define CREATE_TRACE_POINTS
> #include <trace/events/f2fs.h>
>
> static struct proc_dir_entry *f2fs_proc_root;
> static struct kmem_cache *f2fs_inode_cachep;
> +static struct kset *f2fs_kset;
>
> enum {
> Opt_gc_background,
> @@ -59,6 +63,114 @@ static match_table_t f2fs_tokens = {
> {Opt_err, NULL},
> };
>
> +/*Sysfs support for F2fs */
> +struct f2fs_attr {
> + struct attribute attr;
> + ssize_t (*show)(struct f2fs_attr *, struct f2fs_sb_info *, char *);
> + ssize_t (*store)(struct f2fs_attr *, struct f2fs_sb_info *,
> + const char *, size_t);
> + int offset;
> +};
> +
> +static ssize_t f2fs_sbi_show(struct f2fs_attr *a,
> + struct f2fs_sb_info *sbi, char *buf)
> +{
> + struct f2fs_gc_kthread *gc_kth = sbi->gc_thread;
> + unsigned int *ui;
> +
> + if (!gc_kth)
> + return -EFAULT;
> +
> + ui = (unsigned int *) (((char *)gc_kth) + a->offset);
> +
> + return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
> +}
> +
> +static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
> + struct f2fs_sb_info *sbi,
> + const char *buf, size_t count)
> +{
> + struct f2fs_gc_kthread *gc_kth = sbi->gc_thread;
> + unsigned long t;
> + unsigned int *ui;
> + ssize_t ret;
> +
> + if (!gc_kth)
> + return -EFAULT;
> +
> + ui = (unsigned int *) (((char *)gc_kth) + a->offset);
> +
> + ret = kstrtoul(skip_spaces(buf), 0, &t);
> + if (ret < 0)
> + return ret;
> + *ui = t;
> + return count;
> +}
> +
> +static ssize_t f2fs_attr_show(struct kobject *kobj,
> + struct attribute *attr, char *buf)
> +{
> + struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
> + s_kobj);
> + struct f2fs_attr *a = container_of(attr, struct f2fs_attr, attr);
> +
> + return a->show ? a->show(a, sbi, buf) : 0;
> +}
> +
> +static ssize_t f2fs_attr_store(struct kobject *kobj, struct attribute *attr,
> + const char *buf, size_t len)
> +{
> + struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
> + s_kobj);
> + struct f2fs_attr *a = container_of(attr, struct f2fs_attr, attr);
> +
> + return a->store ? a->store(a, sbi, buf, len) : 0;
> +}
> +
> +static void f2fs_sb_release(struct kobject *kobj)
> +{
> + struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
> + s_kobj);
> + complete(&sbi->s_kobj_unregister);
> +}
> +
> +#define F2FS_ATTR_OFFSET(_name, _mode, _show, _store, _elname) \
> +static struct f2fs_attr f2fs_attr_##_name = { \
> + .attr = {.name = __stringify(_name), .mode = _mode }, \
> + .show = _show, \
> + .store = _store, \
> + .offset = offsetof(struct f2fs_gc_kthread, _elname), \
> +}
> +
> +#define F2FS_ATTR(name, mode, show, store) \
> +static struct f2fs_attr f2fs_attr_##name = __ATTR(name, mode, show, store)
> +
> +#define F2FS_RW_ATTR(name, elname) \
> + F2FS_ATTR_OFFSET(name, 0644, f2fs_sbi_show, f2fs_sbi_store, elname)
> +
> +F2FS_RW_ATTR(gc_min_sleep_time, min_sleep_time);
> +F2FS_RW_ATTR(gc_max_sleep_time, max_sleep_time);
> +F2FS_RW_ATTR(gc_no_gc_sleep_time, no_gc_sleep_time);
> +
> +#define ATTR_LIST(name) (&f2fs_attr_##name.attr)
> +static struct attribute *f2fs_attrs[] = {
> + ATTR_LIST(gc_min_sleep_time),
> + ATTR_LIST(gc_max_sleep_time),
> + ATTR_LIST(gc_no_gc_sleep_time),
> + NULL,
> +};
> +
> +static const struct sysfs_ops f2fs_attr_ops = {
> + .show = f2fs_attr_show,
> + .store = f2fs_attr_store,
> +};
> +
> +static struct kobj_type f2fs_ktype = {
> + .default_attrs = f2fs_attrs,
> + .sysfs_ops = &f2fs_attr_ops,
> + .release = f2fs_sb_release,
> +};
> +
> void f2fs_msg(struct super_block *sb, const char *level, const char *fmt, ...)
> {
> struct va_format vaf;
> @@ -243,6 +355,7 @@ static void f2fs_put_super(struct super_block *sb)
> destroy_segment_manager(sbi);
>
> kfree(sbi->ckpt);
> + kobject_del(&sbi->s_kobj);
>
> sb->s_fs_info = NULL;
> brelse(sbi->raw_super_buf);
> @@ -818,6 +931,13 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> "the device does not support discard");
> }
>
> + sbi->s_kobj.kset = f2fs_kset;
> + init_completion(&sbi->s_kobj_unregister);
> + err = kobject_init_and_add(&sbi->s_kobj, &f2fs_ktype, NULL,
> + "%s", sb->s_id);
> + if (err)
> + goto fail;
> +
> return 0;
> fail:
> stop_gc_thread(sbi);
> @@ -892,6 +1012,9 @@ static int __init init_f2fs_fs(void)
> err = create_checkpoint_caches();
> if (err)
> goto fail;
> + f2fs_kset = kset_create_and_add("f2fs", NULL, fs_kobj);
> + if (!f2fs_kset)
> + goto fail;
> err = register_filesystem(&f2fs_fs_type);
> if (err)
> goto fail;
> @@ -910,6 +1033,7 @@ static void __exit exit_f2fs_fs(void)
> destroy_gc_caches();
> destroy_node_manager_caches();
> destroy_inodecache();
> + kset_unregister(f2fs_kset);
> }
>
> module_init(init_f2fs_fs)
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