Currently, we dynamicly alloc sit_entry_set from slab, and link all the
sit_entry_set
by sit_entry_set->set_list.
It is inefficient, since in add_sit_entry, we may need to travel all the list
to find
the target sit_entry_set.
This patch fixes this by introducing a static array:
f2fs_sm_info->sit_sets
(struct sit_entry_set *sit_sets)
when we can find the target sit_entry_set in O(1) time, and then to update the
sit_entry_set
info.
What's more there is no need to alloc/free slab memory.
footprint:(64bit machine)
1T : sizeof(struct sit_entry_set) * 1T/(2M*55) = 0.87M
128G : sizeof(struct sit_entry_set) * 128G/(2M*55) = 1.16k
64G : 0.55k
32G : 0.27k
Signed-off-by: Hou Pengyang <houpengy...@huawei.com>
---
fs/f2fs/f2fs.h | 2 +-
fs/f2fs/segment.c | 75 +++++++++++++++++++------------------------------------
fs/f2fs/segment.h | 1 -
3 files changed, 26 insertions(+), 52 deletions(-)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 198da30..429d33b 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -732,7 +732,7 @@ struct f2fs_sm_info {
/* for batched trimming */
unsigned int trim_sections; /* # of sections to trim */
- struct list_head sit_entry_set; /* sit entry set list */
+ struct sit_entry_set *sit_sets; /* # of dirty segment in this
sit_entry_set */
struct list_head dirty_set[SIT_ENTRY_PER_BLOCK + 1];
unsigned int ipu_policy; /* in-place-update policy */
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index af470d3..04d6329 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -28,7 +28,6 @@
static struct kmem_cache *discard_entry_slab;
static struct kmem_cache *discard_cmd_slab;
-static struct kmem_cache *sit_entry_set_slab;
static struct kmem_cache *inmem_entry_slab;
static unsigned long __reverse_ulong(unsigned char *str)
@@ -2641,56 +2640,30 @@ static struct page *get_next_sit_page(struct
f2fs_sb_info *sbi,
return dst_page;
}
-static struct sit_entry_set *grab_sit_entry_set(void)
-{
- struct sit_entry_set *ses =
- f2fs_kmem_cache_alloc(sit_entry_set_slab, GFP_NOFS);
-
- ses->entry_cnt = 0;
- INIT_LIST_HEAD(&ses->set_list);
- INIT_LIST_HEAD(&ses->cnt_list);
- return ses;
-}
-
static void release_sit_entry_set(struct sit_entry_set *ses)
{
- list_del(&ses->set_list);
list_del(&ses->cnt_list);
- kmem_cache_free(sit_entry_set_slab, ses);
+ INIT_LIST_HEAD(&ses->cnt_list);
}
static void add_sit_entry(struct f2fs_sb_info *sbi,
- unsigned int segno, struct list_head
*head)
+ unsigned int segno)
{
- struct sit_entry_set *ses;
struct f2fs_sm_info *sm_i = SM_I(sbi);
- unsigned int start_segno = START_SEGNO(segno);
+ unsigned int set = SIT_BLOCK_OFFSET(segno);
+ struct sit_entry_set *ses= &sm_i->sit_sets[set];
- list_for_each_entry(ses, head, set_list) {
- if (ses->start_segno == start_segno) {
- ses->entry_cnt++;
- list_move_tail(&ses->cnt_list,
&sm_i->dirty_set[ses->entry_cnt]);
- return;
- }
- }
-
- ses = grab_sit_entry_set();
-
- ses->start_segno = start_segno;
ses->entry_cnt++;
list_move_tail(&ses->cnt_list, &sm_i->dirty_set[ses->entry_cnt]);
- list_add(&ses->set_list, head);
}
static void add_sits_in_set(struct f2fs_sb_info *sbi)
{
- struct f2fs_sm_info *sm_info = SM_I(sbi);
- struct list_head *set_list = &sm_info->sit_entry_set;
unsigned long *bitmap = SIT_I(sbi)->dirty_sentries_bitmap;
unsigned int segno;
for_each_set_bit(segno, bitmap, MAIN_SEGS(sbi))
- add_sit_entry(sbi, segno, set_list);
+ add_sit_entry(sbi, segno);
}
static void remove_sits_in_journal(struct f2fs_sb_info *sbi)
@@ -2708,7 +2681,7 @@ static void remove_sits_in_journal(struct f2fs_sb_info
*sbi)
dirtied = __mark_sit_entry_dirty(sbi, segno);
if (!dirtied)
- add_sit_entry(sbi, segno, &SM_I(sbi)->sit_entry_set);
+ add_sit_entry(sbi, segno);
}
update_sits_in_cursum(journal, -i);
up_write(&curseg->journal_rwsem);
@@ -2788,7 +2761,6 @@ void flush_sit_entries(struct f2fs_sb_info *sbi, struct
cp_control *cpc)
struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
struct f2fs_journal *journal = curseg->journal;
struct sit_entry_set *ses, *tmp;
- struct list_head *head = &SM_I(sbi)->sit_entry_set;
bool to_journal = true;
int i;
@@ -2826,7 +2798,6 @@ void flush_sit_entries(struct f2fs_sb_info *sbi, struct
cp_control *cpc)
f2fs_bug_on(sbi, !list_empty(&sm_i->dirty_set[i]));
}
- f2fs_bug_on(sbi, !list_empty(head));
f2fs_bug_on(sbi, sit_i->dirty_sentries);
out:
if (cpc->reason & CP_DISCARD) {
@@ -3191,13 +3162,26 @@ static void init_min_max_mtime(struct f2fs_sb_info *sbi)
mutex_unlock(&sit_i->sentry_lock);
}
-static void init_sit_dirty_set_list(struct f2fs_sb_info *sbi)
+static int init_sit_dirty_set_list(struct f2fs_sb_info *sbi)
{
struct f2fs_sm_info *sm_i = SM_I(sbi);
- int i;
+ int i, entries;
+
+ entries = (MAIN_SEGS(sbi) + SIT_ENTRY_PER_BLOCK - 1) /
SIT_ENTRY_PER_BLOCK;
+ sm_i->sit_sets = f2fs_kvzalloc(entries *
+ sizeof(struct
sit_entry_set), GFP_KERNEL);
+ if (!sm_i->sit_sets)
+ return -ENOMEM;
+
+ /* kvzalloc, so no need to init sit_entry_set->entry-cnt */
+ for (i = 0; i < entries; i++) {
+ INIT_LIST_HEAD(&sm_i->sit_sets[i].cnt_list);
+ sm_i->sit_sets[i].start_segno = i * SIT_ENTRY_PER_BLOCK;
+ }
for (i = 0; i <= SIT_ENTRY_PER_BLOCK; i++)
INIT_LIST_HEAD(&sm_i->dirty_set[i]);
+ return 0;
}
int build_segment_manager(struct f2fs_sb_info *sbi)
@@ -3233,8 +3217,6 @@ int build_segment_manager(struct f2fs_sb_info *sbi)
sm_info->trim_sections = DEF_BATCHED_TRIM_SECTIONS;
- INIT_LIST_HEAD(&sm_info->sit_entry_set);
-
if (test_opt(sbi, FLUSH_MERGE) && !f2fs_readonly(sbi->sb)) {
err = create_flush_cmd_control(sbi);
if (err)
@@ -3264,8 +3246,8 @@ int build_segment_manager(struct f2fs_sb_info *sbi)
return err;
init_min_max_mtime(sbi);
- init_sit_dirty_set_list(sbi);
- return 0;
+ err = init_sit_dirty_set_list(sbi);
+ return err;
}
static void discard_dirty_segmap(struct f2fs_sb_info *sbi,
@@ -3372,6 +3354,7 @@ void destroy_segment_manager(struct f2fs_sb_info *sbi)
destroy_curseg(sbi);
destroy_free_segmap(sbi);
destroy_sit_info(sbi);
+ kfree(sm_info->sit_sets);
sbi->sm_info = NULL;
kfree(sm_info);
}
@@ -3388,19 +3371,12 @@ int __init create_segment_manager_caches(void)
if (!discard_cmd_slab)
goto destroy_discard_entry;
- sit_entry_set_slab = f2fs_kmem_cache_create("sit_entry_set",
- sizeof(struct sit_entry_set));
- if (!sit_entry_set_slab)
- goto destroy_discard_cmd;
-
inmem_entry_slab = f2fs_kmem_cache_create("inmem_page_entry",
sizeof(struct inmem_pages));
if (!inmem_entry_slab)
- goto destroy_sit_entry_set;
+ goto destroy_discard_cmd;
return 0;
-destroy_sit_entry_set:
- kmem_cache_destroy(sit_entry_set_slab);
destroy_discard_cmd:
kmem_cache_destroy(discard_cmd_slab);
destroy_discard_entry:
@@ -3411,7 +3387,6 @@ int __init create_segment_manager_caches(void)
void destroy_segment_manager_caches(void)
{
- kmem_cache_destroy(sit_entry_set_slab);
kmem_cache_destroy(discard_cmd_slab);
kmem_cache_destroy(discard_entry_slab);
kmem_cache_destroy(inmem_entry_slab);
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index 3fca58e..dfb6ed5 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -294,7 +294,6 @@ struct curseg_info {
};
struct sit_entry_set {
- struct list_head set_list; /* link with all sit sets globally */
struct list_head cnt_list; /* link to sets with same # of dirty sit
entries */
unsigned int start_segno; /* start segno of sits in set */
unsigned int entry_cnt; /* the # of sit entries in set */
--
2.10.1
------------------------------------------------------------------------------
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