on synchronous garbage collection running in background.
Default value for this option is on. So garbage
collection is on by default.
+gc_merge When background_gc is on, this option can be enabled to
+ let background GC thread to handle foreground GC requests,
+ it can eliminate the sluggish issue caused by slow foreground
+ GC operation when GC is triggered from a process with limited
+ I/O and CPU resources.
+nogc_merge Disable GC merge feature.
disable_roll_forward Disable the roll-forward recovery routine
norecovery Disable the roll-forward recovery routine, mounted read-
only (i.e., -o ro,disable_roll_forward)
#define F2FS_MOUNT_NORECOVERY 0x04000000
#define F2FS_MOUNT_ATGC 0x08000000
#define F2FS_MOUNT_MERGE_CHECKPOINT 0x10000000
+#define F2FS_MOUNT_GC_MERGE 0x20000000
#define F2FS_OPTION(sbi) ((sbi)->mount_opt)
#define clear_opt(sbi, option) (F2FS_OPTION(sbi).opt &= ~F2FS_MOUNT_##option)
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;
+ wait_queue_head_t *fggc_wq = &sbi->gc_thread->fggc_wq;
unsigned int wait_ms;
wait_ms = gc_th->min_sleep_time;
set_freezable();
do {
- bool sync_mode;
+ bool sync_mode, foreground = false;
wait_event_interruptible_timeout(*wq,
kthread_should_stop() || freezing(current) ||
+ waitqueue_active(fggc_wq) ||
gc_th->gc_wake,
msecs_to_jiffies(wait_ms));
+ if (test_opt(sbi, GC_MERGE) && waitqueue_active(fggc_wq))
+ foreground = true;
+
/* give it a try one time */
if (gc_th->gc_wake)
gc_th->gc_wake = 0;
goto do_gc;
}
- if (!down_write_trylock(&sbi->gc_lock)) {
+ if (foreground) {
+ down_write(&sbi->gc_lock);
+ goto do_gc;
+ } else if (!down_write_trylock(&sbi->gc_lock)) {
stat_other_skip_bggc_count(sbi);
goto next;
}
else
increase_sleep_time(gc_th, &wait_ms);
do_gc:
- stat_inc_bggc_count(sbi->stat_info);
+ if (!foreground)
+ stat_inc_bggc_count(sbi->stat_info);
sync_mode = F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_SYNC;
+ /* foreground GC was been triggered via f2fs_balance_fs() */
+ if (foreground)
+ sync_mode = false;
+
/* if return value is not zero, no victim was selected */
- if (f2fs_gc(sbi, sync_mode, true, false, NULL_SEGNO))
+ if (f2fs_gc(sbi, sync_mode, !foreground, false, NULL_SEGNO))
wait_ms = gc_th->no_gc_sleep_time;
+ if (foreground)
+ wake_up_all(&gc_th->fggc_wq);
+
trace_f2fs_background_gc(sbi->sb, wait_ms,
prefree_segments(sbi), free_segments(sbi));
sbi->gc_thread = gc_th;
init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
+ init_waitqueue_head(&sbi->gc_thread->fggc_wq);
sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
"f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
if (IS_ERR(gc_th->f2fs_gc_task)) {
if (!gc_th)
return;
kthread_stop(gc_th->f2fs_gc_task);
+ wake_up_all(&gc_th->fggc_wq);
kfree(gc_th);
sbi->gc_thread = NULL;
}
/* for changing gc mode */
unsigned int gc_wake;
+
+ /* for GC_MERGE mount option */
+ wait_queue_head_t fggc_wq; /*
+ * caller of f2fs_balance_fs()
+ * will wait on this wait queue.
+ */
};
struct gc_inode_list {
* dir/node pages without enough free segments.
*/
if (has_not_enough_free_secs(sbi, 0, 0)) {
- down_write(&sbi->gc_lock);
- f2fs_gc(sbi, false, false, false, NULL_SEGNO);
+ if (test_opt(sbi, GC_MERGE) && sbi->gc_thread &&
+ sbi->gc_thread->f2fs_gc_task) {
+ DEFINE_WAIT(wait);
+
+ prepare_to_wait(&sbi->gc_thread->fggc_wq, &wait,
+ TASK_UNINTERRUPTIBLE);
+ wake_up(&sbi->gc_thread->gc_wait_queue_head);
+ io_schedule();
+ finish_wait(&sbi->gc_thread->fggc_wq, &wait);
+ } else {
+ down_write(&sbi->gc_lock);
+ f2fs_gc(sbi, false, false, false, NULL_SEGNO);
+ }
}
}
Opt_compress_chksum,
Opt_compress_mode,
Opt_atgc,
+ Opt_gc_merge,
+ Opt_nogc_merge,
Opt_err,
};
{Opt_compress_chksum, "compress_chksum"},
{Opt_compress_mode, "compress_mode=%s"},
{Opt_atgc, "atgc"},
+ {Opt_gc_merge, "gc_merge"},
+ {Opt_nogc_merge, "nogc_merge"},
{Opt_err, NULL},
};
case Opt_atgc:
set_opt(sbi, ATGC);
break;
+ case Opt_gc_merge:
+ set_opt(sbi, GC_MERGE);
+ break;
+ case Opt_nogc_merge:
+ clear_opt(sbi, GC_MERGE);
+ break;
default:
f2fs_err(sbi, "Unrecognized mount option \"%s\" or missing value",
p);
else if (F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_OFF)
seq_printf(seq, ",background_gc=%s", "off");
+ if (test_opt(sbi, GC_MERGE))
+ seq_puts(seq, ",gc_merge");
+
if (test_opt(sbi, DISABLE_ROLL_FORWARD))
seq_puts(seq, ",disable_roll_forward");
if (test_opt(sbi, NORECOVERY))
* option. Also sync the filesystem.
*/
if ((*flags & SB_RDONLY) ||
- F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_OFF) {
+ (F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_OFF &&
+ !test_opt(sbi, GC_MERGE))) {
if (sbi->gc_thread) {
f2fs_stop_gc_thread(sbi);
need_restart_gc = true;
* If filesystem is not mounted as read-only then
* do start the gc_thread.
*/
- if (F2FS_OPTION(sbi).bggc_mode != BGGC_MODE_OFF && !f2fs_readonly(sb)) {
+ if ((F2FS_OPTION(sbi).bggc_mode != BGGC_MODE_OFF ||
+ test_opt(sbi, GC_MERGE)) && !f2fs_readonly(sb)) {
/* After POR, we can run background GC thread.*/
err = f2fs_start_gc_thread(sbi);
if (err)