Viewing: ext4-prealloc.patch
commit d8d8fd9192a54c7b8caef8cca9b7a1eb5e5e3298
Author: Alex Zhuravlev <alex.zhuravlev@sun.com>
AuthorDate: Thu Oct 23 10:02:19 2008 +0000
Subject: ext4: support for tunable preallocation window
Add support for tunable preallocation window and new tunables
for large/small requests.
Bugzilla-ID: b=12800
Signed-off-by: Alex Zhuravlev <alex.zhuravlev@sun.com>
Reviewed-by: Kalpak Shah <kalpak@clusterfs.com>
Reviewed-by: Andreas Dilger <andreas.dilger@sun.com>
---
fs/ext4/ext4.h | 7 +-
fs/ext4/inode.c | 3 +
fs/ext4/mballoc.c | 220 +++++++++++++++++++++++++++++++++++-----------
fs/ext4/sysfs.c | 8 +-
4 files changed, 183 insertions(+), 55 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 2947e215..c57686b4 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1297,6 +1297,8 @@ extern void ext4_set_bits(void *bm, int cur, int len);
/* Metadata checksum algorithm codes */
#define EXT4_CRC32C_CHKSUM 1
+#define EXT4_MAX_PREALLOC_TABLE 64
+
/*
* Structure of the super block
*/
@@ -1555,11 +1557,13 @@ struct ext4_sb_info {
/* tunables */
unsigned long s_stripe;
unsigned int s_mb_max_linear_groups;
- unsigned int s_mb_stream_request;
+ unsigned long s_mb_small_req;
+ unsigned long s_mb_large_req;
unsigned int s_mb_max_to_scan;
unsigned int s_mb_min_to_scan;
unsigned int s_mb_stats;
unsigned int s_mb_order2_reqs;
+ unsigned long *s_mb_prealloc_table;
unsigned int s_mb_group_prealloc;
unsigned int s_mb_max_inode_prealloc;
unsigned int s_max_dir_size_kb;
@@ -2917,6 +2921,7 @@ int ext4_fc_record_regions(struct super_block *sb, int ino,
int len, int replay);
/* mballoc.c */
+extern const struct proc_ops ext4_seq_prealloc_table_fops;
extern const struct seq_operations ext4_mb_seq_groups_ops;
extern const struct seq_operations ext4_mb_seq_structs_summary_ops;
extern long ext4_mb_stats;
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index e84b7181..f309de76 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2757,6 +2757,9 @@ static int ext4_writepages(struct address_space *mapping,
PAGE_SIZE >> inode->i_blkbits);
}
+ if (wbc->nr_to_write < sbi->s_mb_small_req)
+ wbc->nr_to_write = sbi->s_mb_small_req;
+
if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
range_whole = 1;
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index b014aa93..e1074fdb 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -3074,6 +3074,99 @@ const struct seq_operations ext4_mb_seq_structs_summary_ops = {
.show = ext4_mb_seq_structs_summary_show,
};
+static int ext4_mb_check_and_update_prealloc(struct ext4_sb_info *sbi,
+ char *str, size_t cnt,
+ int update)
+{
+ unsigned long value;
+ unsigned long prev = 0;
+ char *cur;
+ char *next;
+ char *end;
+ int num = 0;
+
+ cur = str;
+ end = str + cnt;
+ while (cur < end) {
+ while ((cur < end) && (*cur == ' ')) cur++;
+ value = simple_strtol(cur, &next, 0);
+ if (value == 0)
+ break;
+ if (cur == next)
+ return -EINVAL;
+
+ cur = next;
+
+ if (value > (sbi->s_blocks_per_group - 1 - 1 - sbi->s_itb_per_group))
+ return -EINVAL;
+
+ /* they should add values in order */
+ if (value <= prev)
+ return -EINVAL;
+
+ if (update)
+ sbi->s_mb_prealloc_table[num] = value;
+
+ prev = value;
+ num++;
+ }
+
+ if (num > EXT4_MAX_PREALLOC_TABLE - 1)
+ return -EOVERFLOW;
+
+ if (update)
+ sbi->s_mb_prealloc_table[num] = 0;
+
+ return 0;
+}
+
+static ssize_t ext4_mb_prealloc_table_proc_write(struct file *file,
+ const char __user *buf,
+ size_t cnt, loff_t *pos)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(PDE_DATA(file_inode(file)));
+ char str[128];
+ int rc;
+
+ if (cnt >= sizeof(str))
+ return -EINVAL;
+ if (copy_from_user(str, buf, cnt))
+ return -EFAULT;
+
+ rc = ext4_mb_check_and_update_prealloc(sbi, str, cnt, 0);
+ if (rc)
+ return rc;
+
+ rc = ext4_mb_check_and_update_prealloc(sbi, str, cnt, 1);
+ return rc ? rc : cnt;
+}
+
+static int mb_prealloc_table_seq_show(struct seq_file *m, void *v)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(m->private);
+ int i;
+
+ for (i = 0; i < EXT4_MAX_PREALLOC_TABLE &&
+ sbi->s_mb_prealloc_table[i] != 0; i++)
+ seq_printf(m, "%ld ", sbi->s_mb_prealloc_table[i]);
+ seq_printf(m, "\n");
+
+ return 0;
+}
+
+static int mb_prealloc_table_seq_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, mb_prealloc_table_seq_show, PDE_DATA(inode));
+}
+
+const struct proc_ops ext4_seq_prealloc_table_fops = {
+ .proc_open = mb_prealloc_table_seq_open,
+ .proc_read = seq_read,
+ .proc_lseek = seq_lseek,
+ .proc_release = single_release,
+ .proc_write = ext4_mb_prealloc_table_proc_write,
+};
+
static struct kmem_cache *get_groupinfo_cache(int blocksize_bits)
{
int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
@@ -3335,7 +3428,7 @@ static int ext4_groupinfo_create_slab(size_t size)
int ext4_mb_init(struct super_block *sb)
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
- unsigned i, j;
+ unsigned i, j, k, l;
unsigned offset, offset_incr;
unsigned max;
int ret;
@@ -3404,7 +3497,6 @@ int ext4_mb_init(struct super_block *sb)
sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN;
sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN;
sbi->s_mb_stats = MB_DEFAULT_STATS;
- sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD;
sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS;
sbi->s_mb_max_inode_prealloc = MB_DEFAULT_MAX_INODE_PREALLOC;
/*
@@ -3429,9 +3521,29 @@ int ext4_mb_init(struct super_block *sb)
* RAID stripe size so that preallocations don't fragment
* the stripes.
*/
- if (sbi->s_stripe > 1) {
- sbi->s_mb_group_prealloc = roundup(
- sbi->s_mb_group_prealloc, sbi->s_stripe);
+
+ /* Allocate table once */
+ sbi->s_mb_prealloc_table = kzalloc(
+ EXT4_MAX_PREALLOC_TABLE * sizeof(unsigned long), GFP_NOFS);
+ if (sbi->s_mb_prealloc_table == NULL) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if (sbi->s_stripe == 0) {
+ for (k = 0, l = 4; k <= 9; ++k, l *= 2)
+ sbi->s_mb_prealloc_table[k] = l;
+
+ sbi->s_mb_small_req = 256;
+ sbi->s_mb_large_req = 1024;
+ sbi->s_mb_group_prealloc = 512;
+ } else {
+ for (k = 0, l = sbi->s_stripe; k <= 2; ++k, l *= 2)
+ sbi->s_mb_prealloc_table[k] = l;
+
+ sbi->s_mb_small_req = sbi->s_stripe;
+ sbi->s_mb_large_req = sbi->s_stripe * 8;
+ sbi->s_mb_group_prealloc = sbi->s_stripe * 4;
}
sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group);
@@ -3465,6 +3577,7 @@ out_free_locality_groups:
out:
kfree(sbi->s_mb_largest_free_orders);
kfree(sbi->s_mb_largest_free_orders_locks);
+ kfree(sbi->s_mb_prealloc_table);
kfree(sbi->s_mb_offsets);
sbi->s_mb_offsets = NULL;
kfree(sbi->s_mb_maxs);
@@ -3523,6 +3636,7 @@ int ext4_mb_release(struct super_block *sb)
}
kfree(sbi->s_mb_largest_free_orders);
kfree(sbi->s_mb_largest_free_orders_locks);
+ kfree(sbi->s_mb_prealloc_table);
kfree(sbi->s_mb_offsets);
kfree(sbi->s_mb_maxs);
iput(sbi->s_buddy_cache);
@@ -3737,7 +3851,6 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
int err, len;
BUG_ON(ac->ac_status != AC_STATUS_FOUND);
- BUG_ON(ac->ac_b_ex.fe_len <= 0);
sb = ac->ac_sb;
sbi = EXT4_SB(sb);
@@ -3973,13 +4086,14 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac,
{
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
struct ext4_super_block *es = sbi->s_es;
- int bsbits, max;
+ int bsbits, i, wind;
ext4_lblk_t end;
- loff_t size, start_off;
+ loff_t size;
loff_t orig_size __maybe_unused;
ext4_lblk_t start;
struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
struct ext4_prealloc_space *pa;
+ unsigned long value, last_non_zero;
/* do normalize only data requests, metadata requests
do not need preallocation */
@@ -4008,51 +4122,46 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac,
size = size << bsbits;
if (size < i_size_read(ac->ac_inode))
size = i_size_read(ac->ac_inode);
- orig_size = size;
+ size = (size + ac->ac_sb->s_blocksize - 1) >> bsbits;
+
+ start = wind = 0;
+ value = last_non_zero = 0;
+
+ /* let's choose preallocation window depending on file size */
+ for (i = 0; i < EXT4_MAX_PREALLOC_TABLE; i++) {
+ value = sbi->s_mb_prealloc_table[i];
+ if (value == 0)
+ break;
+ else
+ last_non_zero = value;
- /* max size of free chunks */
- max = 2 << bsbits;
-
-#define NRL_CHECK_SIZE(req, size, max, chunk_size) \
- (req <= (size) || max <= (chunk_size))
-
- /* first, try to predict filesize */
- /* XXX: should this table be tunable? */
- start_off = 0;
- if (size <= 16 * 1024) {
- size = 16 * 1024;
- } else if (size <= 32 * 1024) {
- size = 32 * 1024;
- } else if (size <= 64 * 1024) {
- size = 64 * 1024;
- } else if (size <= 128 * 1024) {
- size = 128 * 1024;
- } else if (size <= 256 * 1024) {
- size = 256 * 1024;
- } else if (size <= 512 * 1024) {
- size = 512 * 1024;
- } else if (size <= 1024 * 1024) {
- size = 1024 * 1024;
- } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) {
- start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
- (21 - bsbits)) << 21;
- size = 2 * 1024 * 1024;
- } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) {
- start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
- (22 - bsbits)) << 22;
- size = 4 * 1024 * 1024;
- } else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len,
- (8<<20)>>bsbits, max, 8 * 1024)) {
- start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
- (23 - bsbits)) << 23;
- size = 8 * 1024 * 1024;
+ if (size <= value) {
+ wind = value;
+ break;
+ }
+ }
+
+ if (wind == 0) {
+ if (last_non_zero != 0) {
+ __u64 tstart, tend;
+ /* file is quite large, we now preallocate with
+ * the biggest configured window with regart to
+ * logical offset */
+ wind = last_non_zero;
+ tstart = ac->ac_o_ex.fe_logical;
+ do_div(tstart, wind);
+ start = tstart * wind;
+ tend = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len - 1;
+ do_div(tend, wind);
+ tend = tend * wind + wind;
+ size = tend - start;
+ }
} else {
- start_off = (loff_t) ac->ac_o_ex.fe_logical << bsbits;
- size = (loff_t) EXT4_C2B(EXT4_SB(ac->ac_sb),
- ac->ac_o_ex.fe_len) << bsbits;
+ size = wind;
}
- size = size >> bsbits;
- start = start_off >> bsbits;
+
+
+ orig_size = size;
/*
* For tiny groups (smaller than 8MB) the chosen allocation
@@ -4143,7 +4252,6 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac,
(unsigned long) ac->ac_o_ex.fe_logical);
BUG();
}
- BUG_ON(size <= 0 || size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
/* now prepare goal request */
@@ -5149,11 +5257,19 @@ static void ext4_mb_group_or_file(struct ext4_allocation_context *ac)
/* don't use group allocation for large files */
size = max(size, isize);
- if (size > sbi->s_mb_stream_request) {
+ if ((ac->ac_o_ex.fe_len >= sbi->s_mb_small_req) ||
+ (size >= sbi->s_mb_large_req)) {
ac->ac_flags |= EXT4_MB_STREAM_ALLOC;
return;
}
+ /*
+ * request is so large that we don't care about
+ * streaming - it overweights any possible seek
+ */
+ if (ac->ac_o_ex.fe_len >= sbi->s_mb_large_req)
+ return;
+
BUG_ON(ac->ac_lg != NULL);
/*
* locality group prealloc space are per cpu. The reason for having
diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c
index 2314f744..5fc52fc1 100644
--- a/fs/ext4/sysfs.c
+++ b/fs/ext4/sysfs.c
@@ -212,7 +212,8 @@ EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
-EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
+EXT4_RW_ATTR_SBI_UI(mb_small_req, s_mb_small_req);
+EXT4_RW_ATTR_SBI_UI(mb_large_req, s_mb_large_req);
EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
EXT4_RW_ATTR_SBI_UI(mb_max_inode_prealloc, s_mb_max_inode_prealloc);
EXT4_RW_ATTR_SBI_UI(mb_max_linear_groups, s_mb_max_linear_groups);
@@ -261,7 +262,8 @@ static struct attribute *ext4_attrs[] = {
ATTR_LIST(mb_max_to_scan),
ATTR_LIST(mb_min_to_scan),
ATTR_LIST(mb_order2_req),
- ATTR_LIST(mb_stream_req),
+ ATTR_LIST(mb_small_req),
+ ATTR_LIST(mb_large_req),
ATTR_LIST(mb_group_prealloc),
ATTR_LIST(mb_max_inode_prealloc),
ATTR_LIST(mb_max_linear_groups),
@@ -541,6 +543,8 @@ int ext4_register_sysfs(struct super_block *sb)
ext4_fc_info_show, sb);
proc_create_seq_data("mb_groups", S_IRUGO, sbi->s_proc,
&ext4_mb_seq_groups_ops, sb);
+ proc_create_data("prealloc_table", S_IRUGO, sbi->s_proc,
+ &ext4_seq_prealloc_table_fops, sb);
proc_create_single_data("mb_stats", 0444, sbi->s_proc,
ext4_seq_mb_stats_show, sb);
proc_create_seq_data("mb_structs_summary", 0444, sbi->s_proc,
--
2.34.1
