[PATCH 2/6] f2fs: move out f2fs_balance_fs from gc_thread_func

[PATCH 2/6] f2fs: move out f2fs_balance_fs from gc_thread_func

[Namjae Jeon]

From: Namjae Jeon <namjae.jeon@samsung.com>

When GC thread is running continously there is no need to call
f2fs_balance_fs unconditinally for garbage collection, instead
the garbage collection will be taken via. calling f2fs_gc in the
thread. So, we can move out the balance out of thread loop and
make it run initially when the thread is started.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
---
 fs/f2fs/gc.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 375e69e..66ac6ad 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -34,6 +34,8 @@ static int gc_thread_func(void *data)
 
 	wait_ms = GC_THREAD_MIN_SLEEP_TIME;
 
+	f2fs_balance_fs(sbi);
+
 	do {
 		if (try_to_freeze())
 			continue;
@@ -49,7 +51,6 @@ static int gc_thread_func(void *data)
 			continue;
 		}
 
-		f2fs_balance_fs(sbi);
 
 		if (!test_opt(sbi, BG_GC))
 			continue;
-- 
1.7.9.5

Re: [PATCH 2/6] f2fs: move out f2fs_balance_fs from gc_thread_func

[Changman Lee]

As you know, f2fs_balance_fs conducts gc if f2fs has not enough free
sections. But, the purpose of background gc is to conduct gc during idle
time without checking free sections so that f2fs can solve defragment
condition.

Could you review this?

--> 8 --

>From fbda3262dac81c4f0d7ae8b9b757c820da593120 Mon Sep 17 00:00:00 2001
From: Changman Lee <cm224.lee@samsung.com>
Date: Mon, 4 Feb 2013 10:05:09 +0900
Subject: [PATCH] f2fs: remove unnecessary gc option check and balance_fs

 1. If f2fs is mounted with background_gc_off option, checking
    BG_GC is not redundant.
 2. f2fs_balance_fs is checked in f2fs_gc, so this is also redundant.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
---
 fs/f2fs/gc.c |    7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 8fe43f3..e5c47f6 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -49,11 +49,6 @@ static int gc_thread_func(void *data)
 			continue;
 		}
 
-		f2fs_balance_fs(sbi);
-
-		if (!test_opt(sbi, BG_GC))
-			continue;
-
 		/*
 		 * [GC triggering condition]
 		 * 0. GC is not conducted currently.
@@ -96,6 +91,8 @@ int start_gc_thread(struct f2fs_sb_info *sbi)
 {
 	struct f2fs_gc_kthread *gc_th;
 
+	if (!test_opt(sbi, BG_GC))
+		return 0;
 	gc_th = kmalloc(sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
 	if (!gc_th)
 		return -ENOMEM;
-- 
1.7.10.4

Re: [PATCH 2/6] f2fs: move out f2fs_balance_fs from gc_thread_func

[Namjae Jeon]

2013/2/4, Changman Lee <cm224.lee@samsung.com>:
> As you know, f2fs_balance_fs conducts gc if f2fs has not enough free
> sections. But, the purpose of background gc is to conduct gc during idle
> time without checking free sections so that f2fs can solve defragment
> condition.
>
> Could you review this?
Yes, right. make sense.
This patch also looks good to me.
Thanks a lot !
>
> --> 8 --
>
> From fbda3262dac81c4f0d7ae8b9b757c820da593120 Mon Sep 17 00:00:00 2001
> From: Changman Lee <cm224.lee@samsung.com>
> Date: Mon, 4 Feb 2013 10:05:09 +0900
> Subject: [PATCH] f2fs: remove unnecessary gc option check and balance_fs
>
>  1. If f2fs is mounted with background_gc_off option, checking
>     BG_GC is not redundant.
>  2. f2fs_balance_fs is checked in f2fs_gc, so this is also redundant.
>
> Signed-off-by: Changman Lee <cm224.lee@samsung.com>
> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
> ---
>  fs/f2fs/gc.c |    7 ++-----
>  1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> index 8fe43f3..e5c47f6 100644
> --- a/fs/f2fs/gc.c
> +++ b/fs/f2fs/gc.c
> @@ -49,11 +49,6 @@ static int gc_thread_func(void *data)
>  			continue;
>  		}
>
> -		f2fs_balance_fs(sbi);
> -
> -		if (!test_opt(sbi, BG_GC))
> -			continue;
> -
>  		/*
>  		 * [GC triggering condition]
>  		 * 0. GC is not conducted currently.
> @@ -96,6 +91,8 @@ int start_gc_thread(struct f2fs_sb_info *sbi)
>  {
>  	struct f2fs_gc_kthread *gc_th;
>
> +	if (!test_opt(sbi, BG_GC))
> +		return 0;
>  	gc_th = kmalloc(sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
>  	if (!gc_th)
>  		return -ENOMEM;
> --
> 1.7.10.4
>
>
>
>