1 commit d8d8fd9192a54c7b8caef8cca9b7a1eb5e5e3298
2 Author: Alex Zhuravlev <alex.zhuravlev@sun.com>
3 AuthorDate: Thu Oct 23 10:02:19 2008 +0000
5 Subject: ext4: support for tunable preallocation window
6 Add support for tunable preallocation window and new tunables
7 for large/small requests.
10 Signed-off-by: Alex Zhuravlev <alex.zhuravlev@sun.com>
11 Reviewed-by: Kalpak Shah <kalpak@clusterfs.com>
12 Reviewed-by: Andreas Dilger <andreas.dilger@sun.com>
16 fs/ext4/mballoc.c | 215 +++++++++++++++++++++++++++++++++++++++++-------------
17 fs/ext4/sysfs.c | 8 +-
18 4 files changed, 180 insertions(+), 53 deletions(-)
22 @@ -1241,6 +1241,8 @@ extern void ext4_set_bits(void *bm, int
23 /* Metadata checksum algorithm codes */
24 #define EXT4_CRC32C_CHKSUM 1
26 +#define EXT4_MAX_PREALLOC_TABLE 64
29 * Structure of the super block
31 @@ -1497,11 +1499,13 @@ struct ext4_sb_info {
34 unsigned long s_stripe;
35 - unsigned int s_mb_stream_request;
36 + unsigned long s_mb_small_req;
37 + unsigned long s_mb_large_req;
38 unsigned int s_mb_max_to_scan;
39 unsigned int s_mb_min_to_scan;
40 unsigned int s_mb_stats;
41 unsigned int s_mb_order2_reqs;
42 + unsigned long *s_mb_prealloc_table;
43 unsigned int s_mb_group_prealloc;
44 unsigned int s_max_dir_size_kb;
45 /* where last allocation was done - for stream allocation */
46 @@ -2645,6 +2649,7 @@ extern int ext4_init_inode_table(struct
47 extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
50 +extern const struct proc_ops ext4_seq_prealloc_table_fops;
51 extern const struct seq_operations ext4_mb_seq_groups_ops;
52 extern long ext4_mb_stats;
53 extern long ext4_mb_max_to_scan;
56 @@ -2698,6 +2698,9 @@ static int ext4_writepages(struct addres
57 PAGE_SIZE >> inode->i_blkbits);
60 + if (wbc->nr_to_write < sbi->s_mb_small_req)
61 + wbc->nr_to_write = sbi->s_mb_small_req;
63 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
66 --- a/fs/ext4/mballoc.c
67 +++ b/fs/ext4/mballoc.c
68 @@ -2455,6 +2455,99 @@ const struct seq_operations ext4_mb_seq_
69 .show = ext4_mb_seq_groups_show,
72 +static int ext4_mb_check_and_update_prealloc(struct ext4_sb_info *sbi,
73 + char *str, size_t cnt,
76 + unsigned long value;
77 + unsigned long prev = 0;
86 + while ((cur < end) && (*cur == ' ')) cur++;
87 + value = simple_strtol(cur, &next, 0);
95 + if (value > (sbi->s_blocks_per_group - 1 - 1 - sbi->s_itb_per_group))
98 + /* they should add values in order */
103 + sbi->s_mb_prealloc_table[num] = value;
109 + if (num > EXT4_MAX_PREALLOC_TABLE - 1)
113 + sbi->s_mb_prealloc_table[num] = 0;
118 +static ssize_t ext4_mb_prealloc_table_proc_write(struct file *file,
119 + const char __user *buf,
120 + size_t cnt, loff_t *pos)
122 + struct ext4_sb_info *sbi = EXT4_SB(PDE_DATA(file_inode(file)));
126 + if (cnt >= sizeof(str))
128 + if (copy_from_user(str, buf, cnt))
131 + rc = ext4_mb_check_and_update_prealloc(sbi, str, cnt, 0);
135 + rc = ext4_mb_check_and_update_prealloc(sbi, str, cnt, 1);
136 + return rc ? rc : cnt;
139 +static int mb_prealloc_table_seq_show(struct seq_file *m, void *v)
141 + struct ext4_sb_info *sbi = EXT4_SB(m->private);
144 + for (i = 0; i < EXT4_MAX_PREALLOC_TABLE &&
145 + sbi->s_mb_prealloc_table[i] != 0; i++)
146 + seq_printf(m, "%ld ", sbi->s_mb_prealloc_table[i]);
147 + seq_printf(m, "\n");
152 +static int mb_prealloc_table_seq_open(struct inode *inode, struct file *file)
154 + return single_open(file, mb_prealloc_table_seq_show, PDE_DATA(inode));
157 +const struct proc_ops ext4_seq_prealloc_table_fops = {
158 + .proc_open = mb_prealloc_table_seq_open,
159 + .proc_read = seq_read,
160 + .proc_lseek = seq_lseek,
161 + .proc_release = single_release,
162 + .proc_write = ext4_mb_prealloc_table_proc_write,
165 static struct kmem_cache *get_groupinfo_cache(int blocksize_bits)
167 int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
168 @@ -2685,7 +2778,7 @@ static int ext4_groupinfo_create_slab(si
169 int ext4_mb_init(struct super_block *sb)
171 struct ext4_sb_info *sbi = EXT4_SB(sb);
173 + unsigned i, j, k, l;
174 unsigned offset, offset_incr;
177 @@ -2734,7 +2827,6 @@ int ext4_mb_init(struct super_block *sb)
178 sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN;
179 sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN;
180 sbi->s_mb_stats = MB_DEFAULT_STATS;
181 - sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD;
182 sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS;
184 * The default group preallocation is 512, which for 4k block
185 @@ -2758,9 +2850,29 @@ int ext4_mb_init(struct super_block *sb)
186 * RAID stripe size so that preallocations don't fragment
189 - if (sbi->s_stripe > 1) {
190 - sbi->s_mb_group_prealloc = roundup(
191 - sbi->s_mb_group_prealloc, sbi->s_stripe);
193 + /* Allocate table once */
194 + sbi->s_mb_prealloc_table = kzalloc(
195 + EXT4_MAX_PREALLOC_TABLE * sizeof(unsigned long), GFP_NOFS);
196 + if (sbi->s_mb_prealloc_table == NULL) {
201 + if (sbi->s_stripe == 0) {
202 + for (k = 0, l = 4; k <= 9; ++k, l *= 2)
203 + sbi->s_mb_prealloc_table[k] = l;
205 + sbi->s_mb_small_req = 256;
206 + sbi->s_mb_large_req = 1024;
207 + sbi->s_mb_group_prealloc = 512;
209 + for (k = 0, l = sbi->s_stripe; k <= 2; ++k, l *= 2)
210 + sbi->s_mb_prealloc_table[k] = l;
212 + sbi->s_mb_small_req = sbi->s_stripe;
213 + sbi->s_mb_large_req = sbi->s_stripe * 8;
214 + sbi->s_mb_group_prealloc = sbi->s_stripe * 4;
217 sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group);
218 @@ -2788,6 +2900,7 @@ out_free_locality_groups:
219 free_percpu(sbi->s_locality_groups);
220 sbi->s_locality_groups = NULL;
222 + kfree(sbi->s_mb_prealloc_table);
223 kfree(sbi->s_mb_offsets);
224 sbi->s_mb_offsets = NULL;
225 kfree(sbi->s_mb_maxs);
226 @@ -2800,6 +2840,7 @@ int ext4_mb_release(struct super_block *sb)
230 + kfree(sbi->s_mb_prealloc_table);
231 kfree(sbi->s_mb_offsets);
232 kfree(sbi->s_mb_maxs);
233 iput(sbi->s_buddy_cache);
234 @@ -3057,7 +3170,6 @@ ext4_mb_mark_diskspace_used(struct ext4_
237 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
238 - BUG_ON(ac->ac_b_ex.fe_len <= 0);
242 @@ -3187,13 +3299,14 @@ ext4_mb_normalize_request(struct ext4_al
243 struct ext4_allocation_request *ar)
245 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
247 + int bsbits, i, wind;
249 - loff_t size, start_off;
251 loff_t orig_size __maybe_unused;
253 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
254 struct ext4_prealloc_space *pa;
255 + unsigned long value, last_non_zero;
257 /* do normalize only data requests, metadata requests
258 do not need preallocation */
259 @@ -3222,51 +3335,46 @@ ext4_mb_normalize_request(struct ext4_al
260 size = size << bsbits;
261 if (size < i_size_read(ac->ac_inode))
262 size = i_size_read(ac->ac_inode);
264 + size = (size + ac->ac_sb->s_blocksize - 1) >> bsbits;
267 + value = last_non_zero = 0;
269 - /* max size of free chunks */
271 + /* let's choose preallocation window depending on file size */
272 + for (i = 0; i < EXT4_MAX_PREALLOC_TABLE; i++) {
273 + value = sbi->s_mb_prealloc_table[i];
277 + last_non_zero = value;
279 -#define NRL_CHECK_SIZE(req, size, max, chunk_size) \
280 - (req <= (size) || max <= (chunk_size))
281 + if (size <= value) {
287 - /* first, try to predict filesize */
288 - /* XXX: should this table be tunable? */
290 - if (size <= 16 * 1024) {
292 - } else if (size <= 32 * 1024) {
294 - } else if (size <= 64 * 1024) {
296 - } else if (size <= 128 * 1024) {
298 - } else if (size <= 256 * 1024) {
300 - } else if (size <= 512 * 1024) {
302 - } else if (size <= 1024 * 1024) {
303 - size = 1024 * 1024;
304 - } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) {
305 - start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
306 - (21 - bsbits)) << 21;
307 - size = 2 * 1024 * 1024;
308 - } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) {
309 - start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
310 - (22 - bsbits)) << 22;
311 - size = 4 * 1024 * 1024;
312 - } else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len,
313 - (8<<20)>>bsbits, max, 8 * 1024)) {
314 - start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
315 - (23 - bsbits)) << 23;
316 - size = 8 * 1024 * 1024;
318 + if (last_non_zero != 0) {
319 + __u64 tstart, tend;
320 + /* file is quite large, we now preallocate with
321 + * the biggest configured window with regart to
322 + * logical offset */
323 + wind = last_non_zero;
324 + tstart = ac->ac_o_ex.fe_logical;
325 + do_div(tstart, wind);
326 + start = tstart * wind;
327 + tend = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len - 1;
328 + do_div(tend, wind);
329 + tend = tend * wind + wind;
330 + size = tend - start;
333 - start_off = (loff_t) ac->ac_o_ex.fe_logical << bsbits;
334 - size = (loff_t) EXT4_C2B(EXT4_SB(ac->ac_sb),
335 - ac->ac_o_ex.fe_len) << bsbits;
338 - size = size >> bsbits;
339 - start = start_off >> bsbits;
344 /* don't cover already allocated blocks in selected range */
345 if (ar->pleft && start <= ar->lleft) {
346 @@ -3348,7 +3456,6 @@ ext4_mb_normalize_request(struct ext4_al
347 (unsigned long) ac->ac_o_ex.fe_logical);
350 - BUG_ON(size <= 0 || size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
352 /* now prepare goal request */
354 @@ -4341,11 +4448,19 @@ static void ext4_mb_group_or_file(struct
356 /* don't use group allocation for large files */
357 size = max(size, isize);
358 - if (size > sbi->s_mb_stream_request) {
359 + if ((ac->ac_o_ex.fe_len >= sbi->s_mb_small_req) ||
360 + (size >= sbi->s_mb_large_req)) {
361 ac->ac_flags |= EXT4_MB_STREAM_ALLOC;
366 + * request is so large that we don't care about
367 + * streaming - it overweights any possible seek
369 + if (ac->ac_o_ex.fe_len >= sbi->s_mb_large_req)
372 BUG_ON(ac->ac_lg != NULL);
374 * locality group prealloc space are per cpu. The reason for having
375 --- a/fs/ext4/sysfs.c
376 +++ b/fs/ext4/sysfs.c
377 @@ -213,7 +213,8 @@ EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats
378 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
379 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
380 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
381 -EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
382 +EXT4_RW_ATTR_SBI_UI(mb_small_req, s_mb_small_req);
383 +EXT4_RW_ATTR_SBI_UI(mb_large_req, s_mb_large_req);
384 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
385 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
386 EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error);
387 @@ -255,7 +256,8 @@ static struct attribute *ext4_attrs[] =
388 ATTR_LIST(mb_max_to_scan),
389 ATTR_LIST(mb_min_to_scan),
390 ATTR_LIST(mb_order2_req),
391 - ATTR_LIST(mb_stream_req),
392 + ATTR_LIST(mb_small_req),
393 + ATTR_LIST(mb_large_req),
394 ATTR_LIST(mb_group_prealloc),
395 ATTR_LIST(max_writeback_mb_bump),
396 ATTR_LIST(extent_max_zeroout_kb),
397 @@ -510,6 +512,8 @@ int ext4_register_sysfs(struct super_blo
399 proc_create_seq_data("mb_groups", S_IRUGO, sbi->s_proc,
400 &ext4_mb_seq_groups_ops, sb);
401 + proc_create_data("prealloc_table", S_IRUGO, sbi->s_proc,
402 + &ext4_seq_prealloc_table_fops, sb);