linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Chao Yu <yuchao0@huawei.com>
To: <jaegeuk@kernel.org>
Cc: <linux-f2fs-devel@lists.sourceforge.net>,
	<linux-kernel@vger.kernel.org>, <chao@kernel.org>,
	Chao Yu <yuchao0@huawei.com>
Subject: [PATCH 2/2] f2fs: tune discard speed with storage usage rate
Date: Fri, 10 Aug 2018 18:08:06 +0800	[thread overview]
Message-ID: <20180810100806.9298-2-yuchao0@huawei.com> (raw)
In-Reply-To: <20180810100806.9298-1-yuchao0@huawei.com>

Previously, discard speed was fixed mostly, and in high usage rate
device, we will speed up issuing discard, but it doesn't make sense
that in a non-full filesystem, we still issue discard with slow speed.

Anyway, it comes out undiscarded block makes FTL GC be lower efficient
and causing high lifetime overhead.

Let's tune discard speed as below:

a. adjust default issue interval:
		original	after
min_interval:	50ms		100ms
mid_interval:	500ms		1000ms
max_interval:	60000ms		10000ms

b. if last time we stop issuing discard due to IO interruption of user,
let's reset all {min,mid,max}_interval to default one.

c. tune {min,mid,max}_interval with below calculation method:

base_interval = default_interval / 10;
total_interval = default_interval - base_interval;
interval = base_interval + total_interval * (100 - dev_util) / 100;

For example:
min_interval (:100ms)
dev_util (%)	interval (ms)
0		100
10		91
20		82
30		73
...
80		28
90		19
100		10

Signed-off-by: Chao Yu <yuchao0@huawei.com>
---
 fs/f2fs/f2fs.h    | 11 ++++----
 fs/f2fs/segment.c | 64 +++++++++++++++++++++++++++++++++++++----------
 fs/f2fs/segment.h |  9 +++++++
 fs/f2fs/super.c   |  2 +-
 4 files changed, 67 insertions(+), 19 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 273ffdaf4891..a1dd2e1c3cb9 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -185,10 +185,9 @@ enum {
 
 #define MAX_DISCARD_BLOCKS(sbi)		BLKS_PER_SEC(sbi)
 #define DEF_MAX_DISCARD_REQUEST		8	/* issue 8 discards per round */
-#define DEF_MIN_DISCARD_ISSUE_TIME	50	/* 50 ms, if exists */
-#define DEF_MID_DISCARD_ISSUE_TIME	500	/* 500 ms, if device busy */
-#define DEF_MAX_DISCARD_ISSUE_TIME	60000	/* 60 s, if no candidates */
-#define DEF_DISCARD_URGENT_UTIL		80	/* do more discard over 80% */
+#define DEF_MIN_DISCARD_ISSUE_TIME	100	/* 100 ms, if exists */
+#define DEF_MID_DISCARD_ISSUE_TIME	1000	/* 1000 ms, if device busy */
+#define DEF_MAX_DISCARD_ISSUE_TIME	10000	/* 10000 ms, if no candidates */
 #define DEF_CP_INTERVAL			60	/* 60 secs */
 #define DEF_IDLE_INTERVAL		5	/* 5 secs */
 
@@ -248,7 +247,8 @@ struct discard_entry {
 };
 
 /* default discard granularity of inner discard thread, unit: block count */
-#define DEFAULT_DISCARD_GRANULARITY		1
+#define MID_DISCARD_GRANULARITY			16
+#define MIN_DISCARD_GRANULARITY			1
 
 /* max discard pend list number */
 #define MAX_PLIST_NUM		512
@@ -330,6 +330,7 @@ struct discard_cmd_control {
 	atomic_t discard_cmd_cnt;		/* # of cached cmd count */
 	struct rb_root root;			/* root of discard rb-tree */
 	bool rbtree_check;			/* config for consistence check */
+	bool io_interrupted;			/* last state of io interrupted */
 };
 
 /* for the list of fsync inodes, used only during recovery */
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 8b52e8dfb12f..9564aaf1f27b 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -968,6 +968,44 @@ static void __check_sit_bitmap(struct f2fs_sb_info *sbi,
 #endif
 }
 
+static void __adjust_discard_speed(unsigned int *interval,
+				unsigned int def_interval, int dev_util)
+{
+	unsigned int base_interval, total_interval;
+
+	base_interval = def_interval / 10;
+	total_interval = def_interval - base_interval;
+
+	/*
+	 * if def_interval = 100, adjusted interval should be in range of
+	 * [10, 100].
+	 */
+	*interval = base_interval + total_interval * (100 - dev_util) / 100;
+}
+
+static void __tune_discard_policy(struct f2fs_sb_info *sbi,
+					struct discard_policy *dpolicy)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	int dev_util;
+
+	if (dcc->io_interrupted) {
+		dpolicy->min_interval = DEF_MIN_DISCARD_ISSUE_TIME;
+		dpolicy->mid_interval = DEF_MID_DISCARD_ISSUE_TIME;
+		dpolicy->max_interval = DEF_MAX_DISCARD_ISSUE_TIME;
+		return;
+	}
+
+	dev_util = dev_utilization(sbi);
+
+	__adjust_discard_speed(&dpolicy->min_interval,
+				DEF_MIN_DISCARD_ISSUE_TIME, dev_util);
+	__adjust_discard_speed(&dpolicy->mid_interval,
+				DEF_MID_DISCARD_ISSUE_TIME, dev_util);
+	__adjust_discard_speed(&dpolicy->max_interval,
+				DEF_MAX_DISCARD_ISSUE_TIME, dev_util);
+}
+
 static void __init_discard_policy(struct f2fs_sb_info *sbi,
 				struct discard_policy *dpolicy,
 				int discard_type, unsigned int granularity)
@@ -982,20 +1020,11 @@ static void __init_discard_policy(struct f2fs_sb_info *sbi,
 	dpolicy->io_aware_gran = MAX_PLIST_NUM;
 
 	if (discard_type == DPOLICY_BG) {
-		dpolicy->min_interval = DEF_MIN_DISCARD_ISSUE_TIME;
-		dpolicy->mid_interval = DEF_MID_DISCARD_ISSUE_TIME;
-		dpolicy->max_interval = DEF_MAX_DISCARD_ISSUE_TIME;
 		dpolicy->io_aware = true;
 		dpolicy->sync = false;
 		dpolicy->ordered = true;
-		if (utilization(sbi) > DEF_DISCARD_URGENT_UTIL) {
-			dpolicy->granularity = 1;
-			dpolicy->max_interval = DEF_MIN_DISCARD_ISSUE_TIME;
-		}
+		__tune_discard_policy(sbi, dpolicy);
 	} else if (discard_type == DPOLICY_FORCE) {
-		dpolicy->min_interval = DEF_MIN_DISCARD_ISSUE_TIME;
-		dpolicy->mid_interval = DEF_MID_DISCARD_ISSUE_TIME;
-		dpolicy->max_interval = DEF_MAX_DISCARD_ISSUE_TIME;
 		dpolicy->io_aware = false;
 	} else if (discard_type == DPOLICY_FSTRIM) {
 		dpolicy->io_aware = false;
@@ -1353,6 +1382,8 @@ static unsigned int __issue_discard_cmd_orderly(struct f2fs_sb_info *sbi,
 	if (!issued && io_interrupted)
 		issued = -1;
 
+	dcc->io_interrupted = io_interrupted;
+
 	return issued;
 }
 
@@ -1370,7 +1401,7 @@ static int __issue_discard_cmd(struct f2fs_sb_info *sbi,
 		if (i + 1 < dpolicy->granularity)
 			break;
 
-		if (i < DEFAULT_DISCARD_GRANULARITY && dpolicy->ordered)
+		if (i < MID_DISCARD_GRANULARITY && dpolicy->ordered)
 			return __issue_discard_cmd_orderly(sbi, dpolicy);
 
 		pend_list = &dcc->pend_list[i];
@@ -1407,6 +1438,8 @@ static int __issue_discard_cmd(struct f2fs_sb_info *sbi,
 	if (!issued && io_interrupted)
 		issued = -1;
 
+	dcc->io_interrupted = io_interrupted;
+
 	return issued;
 }
 
@@ -1576,7 +1609,11 @@ static int issue_discard_thread(void *data)
 	struct f2fs_sb_info *sbi = data;
 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
 	wait_queue_head_t *q = &dcc->discard_wait_queue;
-	struct discard_policy dpolicy;
+	struct discard_policy dpolicy = {
+		.min_interval = DEF_MIN_DISCARD_ISSUE_TIME,
+		.mid_interval = DEF_MID_DISCARD_ISSUE_TIME,
+		.max_interval = DEF_MAX_DISCARD_ISSUE_TIME,
+	};
 	unsigned int wait_ms = DEF_MIN_DISCARD_ISSUE_TIME;
 	int issued;
 
@@ -1929,7 +1966,7 @@ static int create_discard_cmd_control(struct f2fs_sb_info *sbi)
 	if (!dcc)
 		return -ENOMEM;
 
-	dcc->discard_granularity = DEFAULT_DISCARD_GRANULARITY;
+	dcc->discard_granularity = MIN_DISCARD_GRANULARITY;
 	INIT_LIST_HEAD(&dcc->entry_list);
 	for (i = 0; i < MAX_PLIST_NUM; i++)
 		INIT_LIST_HEAD(&dcc->pend_list[i]);
@@ -1945,6 +1982,7 @@ static int create_discard_cmd_control(struct f2fs_sb_info *sbi)
 	dcc->next_pos = 0;
 	dcc->root = RB_ROOT;
 	dcc->rbtree_check = false;
+	dcc->io_interrupted = false;
 
 	init_waitqueue_head(&dcc->discard_wait_queue);
 	SM_I(sbi)->dcc_info = dcc;
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index 422b0ceb1eaa..63b4da72cd34 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -616,6 +616,15 @@ static inline int utilization(struct f2fs_sb_info *sbi)
 					sbi->user_block_count);
 }
 
+static inline int dev_utilization(struct f2fs_sb_info *sbi)
+{
+	unsigned int dev_blks;
+
+	dev_blks = valid_user_blocks(sbi) + SM_I(sbi)->dcc_info->undiscard_blks;
+	return div_u64((u64)dev_blks * 100,
+			MAIN_SEGS(sbi) << sbi->log_blocks_per_seg);
+}
+
 /*
  * Sometimes f2fs may be better to drop out-of-place update policy.
  * And, users can control the policy through sysfs entries.
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index b055f2ea77c5..55ed76daad23 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2862,7 +2862,7 @@ static void f2fs_tuning_parameters(struct f2fs_sb_info *sbi)
 	/* adjust parameters according to the volume size */
 	if (sm_i->main_segments <= SMALL_VOLUME_SEGMENTS) {
 		F2FS_OPTION(sbi).alloc_mode = ALLOC_MODE_REUSE;
-		sm_i->dcc_info->discard_granularity = 1;
+		sm_i->dcc_info->discard_granularity = MIN_DISCARD_GRANULARITY;
 		sm_i->ipu_policy = 1 << F2FS_IPU_FORCE;
 	}
 
-- 
2.18.0.rc1


  reply	other threads:[~2018-08-10 10:08 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-10 10:08 [PATCH 1/2] f2fs: set 4KB discard granularity by default Chao Yu
2018-08-10 10:08 ` Chao Yu [this message]
2018-08-14  4:19   ` [PATCH 2/2] f2fs: tune discard speed with storage usage rate Jaegeuk Kim
2018-08-14  7:41     ` Chao Yu
2018-08-14 17:23       ` Jaegeuk Kim
2018-08-15  1:46         ` Chao Yu
2018-08-15  2:33           ` Jaegeuk Kim
2018-08-15  2:51             ` Chao Yu
2018-08-15  2:56               ` Jaegeuk Kim
2018-08-15  3:01                 ` Chao Yu
2018-08-15  3:20                   ` Jaegeuk Kim
2018-08-15  3:30                     ` Chao Yu
     [not found]                       ` <CAD14+f1MoAjEuXwGSmL3=0ROX_f=9jZVmvNsU9gnTP=UNxsTrg@mail.gmail.com>
2018-08-16  1:23                         ` [f2fs-dev] " Jaegeuk Kim
2018-08-16 11:25                           ` Chao Yu
2018-08-17 18:30                             ` Jaegeuk Kim
2018-08-14  4:13 ` [PATCH 1/2] f2fs: set 4KB discard granularity by default Jaegeuk Kim
2018-08-14  7:08   ` Chao Yu
2018-09-04 14:36     ` [f2fs-dev] " Ju Hyung Park
2018-09-05  2:33       ` Chao Yu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180810100806.9298-2-yuchao0@huawei.com \
    --to=yuchao0@huawei.com \
    --cc=chao@kernel.org \
    --cc=jaegeuk@kernel.org \
    --cc=linux-f2fs-devel@lists.sourceforge.net \
    --cc=linux-kernel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).