From: Namjae Jeon <[email protected]> Add sysfs entry gc_idle to control the gc policy. Where gc_idle = 1 corresponds to selecting a cost benefit approach, while gc_idle = 2 corresponds to selecting a greedy approach to garbage collection. The selection is mutually exclusive one approach will work at any point. If gc_idle = 0, then this option is disabled.
Cc: Gu Zheng <[email protected]> Signed-off-by: Namjae Jeon <[email protected]> Signed-off-by: Pankaj Kumar <[email protected]> --- Documentation/ABI/testing/sysfs-fs-f2fs | 6 +++++- Documentation/filesystems/f2fs.txt | 6 ++++++ fs/f2fs/gc.c | 24 +++++++++++++++++++++--- fs/f2fs/gc.h | 3 +++ fs/f2fs/super.c | 2 ++ 5 files changed, 37 insertions(+), 4 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs index 5f44095..31942ef 100644 --- a/Documentation/ABI/testing/sysfs-fs-f2fs +++ b/Documentation/ABI/testing/sysfs-fs-f2fs @@ -19,4 +19,8 @@ Description: Controls the default sleep time for gc_thread. Time is in milliseconds. - +What: /sys/fs/f2fs/<disk>/gc_idle +Date: July 2013 +Contact: "Namjae Jeon" <[email protected]> +Description: + Controls the victim selection policy for garbage collection. diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt index 5daf3bb..3cd27be 100644 --- a/Documentation/filesystems/f2fs.txt +++ b/Documentation/filesystems/f2fs.txt @@ -158,6 +158,12 @@ Files in /sys/fs/f2fs/<devname> time for the garbage collection thread. Time is in milliseconds. + gc_idle This parameter controls the selection of victim + policy for garbage collection. Setting gc_idle = 0 + (default) will disable this option. Setting + gc_idle = 1 will select the Cost Benefit approach + & setting gc_idle = 2 will select the greedy aproach. + ================================================================================ USAGE ================================================================================ diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c index 60d4f67..2c0c8ad 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -106,6 +106,8 @@ int start_gc_thread(struct f2fs_sb_info *sbi) gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME; gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME; + gc_th->gc_idle = 0; + 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, @@ -130,9 +132,25 @@ void stop_gc_thread(struct f2fs_sb_info *sbi) sbi->gc_thread = NULL; } -static int select_gc_type(int gc_type) +static int select_gc_type(struct f2fs_gc_kthread *gc_th, int gc_type) { - return (gc_type == BG_GC) ? GC_CB : GC_GREEDY; + int gc_mode; + + if (gc_th && gc_th->gc_idle) { + /* Cost Benefit Policy */ + if (gc_th->gc_idle == 1) { + gc_mode = GC_CB; + goto out; + } else if (gc_th->gc_idle == 2) { + /* Greedy Policy */ + gc_mode = GC_GREEDY; + goto out; + } + } + + gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY; +out: + return gc_mode; } static void select_policy(struct f2fs_sb_info *sbi, int gc_type, @@ -145,7 +163,7 @@ static void select_policy(struct f2fs_sb_info *sbi, int gc_type, p->dirty_segmap = dirty_i->dirty_segmap[type]; p->ofs_unit = 1; } else { - p->gc_mode = select_gc_type(gc_type); + p->gc_mode = select_gc_type(sbi->gc_thread, gc_type); p->dirty_segmap = dirty_i->dirty_segmap[DIRTY]; p->ofs_unit = sbi->segs_per_sec; } diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h index f4bf44c..c22dee9 100644 --- a/fs/f2fs/gc.h +++ b/fs/f2fs/gc.h @@ -30,6 +30,9 @@ struct f2fs_gc_kthread { unsigned int min_sleep_time; unsigned int max_sleep_time; unsigned int no_gc_sleep_time; + + /* for changing gc mode */ + unsigned int gc_idle; }; struct inode_entry { diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 0a3e88f..f9c6c0b 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -148,12 +148,14 @@ static struct f2fs_attr f2fs_attr_##_name = { \ 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); +F2FS_RW_ATTR(gc_idle, gc_idle); #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), + ATTR_LIST(gc_idle), NULL, }; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
