From d2dc095f4280ad5fdea33769e8e119fd16648426 Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Sun, 4 Aug 2013 23:10:15 +0900 Subject: [PATCH] f2fs: add sysfs entries to select the gc policy 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 Signed-off-by: Namjae Jeon Signed-off-by: Pankaj Kumar Reviewed-by: Gu Zheng [Jaegeuk Kim: change the select_gc_type() flow slightly] Signed-off-by: Jaegeuk Kim --- Documentation/ABI/testing/sysfs-fs-f2fs | 6 ++++++ Documentation/filesystems/f2fs.txt | 6 ++++++ fs/f2fs/gc.c | 16 +++++++++++++--- fs/f2fs/gc.h | 3 +++ fs/f2fs/super.c | 2 ++ 5 files changed, 30 insertions(+), 3 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs index 98e53a09530a..31942efcaf0e 100644 --- a/Documentation/ABI/testing/sysfs-fs-f2fs +++ b/Documentation/ABI/testing/sysfs-fs-f2fs @@ -18,3 +18,9 @@ Contact: "Namjae Jeon" Description: Controls the default sleep time for gc_thread. Time is in milliseconds. + +What: /sys/fs/f2fs//gc_idle +Date: July 2013 +Contact: "Namjae Jeon" +Description: + Controls the victim selection policy for garbage collection. diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt index 5daf3bb2eef9..3cd27bed6349 100644 --- a/Documentation/filesystems/f2fs.txt +++ b/Documentation/filesystems/f2fs.txt @@ -158,6 +158,12 @@ Files in /sys/fs/f2fs/ 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 60d4f674efa7..d286d8be8e68 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 +132,17 @@ 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 = (gc_type == BG_GC) ? GC_CB : GC_GREEDY; + + if (gc_th && gc_th->gc_idle) { + if (gc_th->gc_idle == 1) + gc_mode = GC_CB; + else if (gc_th->gc_idle == 2) + gc_mode = GC_GREEDY; + } + return gc_mode; } static void select_policy(struct f2fs_sb_info *sbi, int gc_type, @@ -145,7 +155,7 @@ 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 f4bf44c9deda..c22dee9f1422 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 e161a24fbf39..94c0e2049546 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, };