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authorTheodore Ts'o <tytso@mit.edu>2009-09-30 08:32:42 +0400
committerTheodore Ts'o <tytso@mit.edu>2009-09-30 08:32:42 +0400
commit296c355cd6443d89fa251885a8d78778fe111dc4 (patch)
tree5cf7c8b115617dc3829a16a5969894d37b73173c /fs
parent90576c0b9a0b5323fc4bd7f23f49be0d234f36d1 (diff)
downloadlinux-296c355cd6443d89fa251885a8d78778fe111dc4.tar.xz
ext4: Use tracepoints for mb_history trace file
The /proc/fs/ext4/<dev>/mb_history was maintained manually, and had a number of problems: it required a largish amount of memory to be allocated for each ext4 filesystem, and the s_mb_history_lock introduced a CPU contention problem. By ripping out the mb_history code and replacing it with ftrace tracepoints, and we get more functionality: timestamps, event filtering, the ability to correlate mballoc history with other ext4 tracepoints, etc. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs')
-rw-r--r--fs/ext4/ext4.h14
-rw-r--r--fs/ext4/mballoc.c301
-rw-r--r--fs/ext4/mballoc.h33
-rw-r--r--fs/ext4/super.c18
4 files changed, 19 insertions, 347 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index b491576e11c3..c508cf7be75c 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -65,6 +65,12 @@ typedef __u32 ext4_lblk_t;
/* data type for block group number */
typedef unsigned int ext4_group_t;
+/*
+ * Flags used in mballoc's allocation_context flags field.
+ *
+ * Also used to show what's going on for debugging purposes when the
+ * flag field is exported via the traceport interface
+ */
/* prefer goal again. length */
#define EXT4_MB_HINT_MERGE 0x0001
@@ -971,14 +977,6 @@ struct ext4_sb_info {
unsigned long s_mb_last_group;
unsigned long s_mb_last_start;
- /* history to debug policy */
- struct ext4_mb_history *s_mb_history;
- int s_mb_history_cur;
- int s_mb_history_max;
- int s_mb_history_num;
- spinlock_t s_mb_history_lock;
- int s_mb_history_filter;
-
/* stats for buddy allocator */
spinlock_t s_mb_pa_lock;
atomic_t s_bal_reqs; /* number of reqs with len > 1 */
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 3e2320e66721..bba12824defa 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2096,207 +2096,6 @@ out:
return err;
}
-#ifdef EXT4_MB_HISTORY
-struct ext4_mb_proc_session {
- struct ext4_mb_history *history;
- struct super_block *sb;
- int start;
- int max;
-};
-
-static void *ext4_mb_history_skip_empty(struct ext4_mb_proc_session *s,
- struct ext4_mb_history *hs,
- int first)
-{
- if (hs == s->history + s->max)
- hs = s->history;
- if (!first && hs == s->history + s->start)
- return NULL;
- while (hs->orig.fe_len == 0) {
- hs++;
- if (hs == s->history + s->max)
- hs = s->history;
- if (hs == s->history + s->start)
- return NULL;
- }
- return hs;
-}
-
-static void *ext4_mb_seq_history_start(struct seq_file *seq, loff_t *pos)
-{
- struct ext4_mb_proc_session *s = seq->private;
- struct ext4_mb_history *hs;
- int l = *pos;
-
- if (l == 0)
- return SEQ_START_TOKEN;
- hs = ext4_mb_history_skip_empty(s, s->history + s->start, 1);
- if (!hs)
- return NULL;
- while (--l && (hs = ext4_mb_history_skip_empty(s, ++hs, 0)) != NULL);
- return hs;
-}
-
-static void *ext4_mb_seq_history_next(struct seq_file *seq, void *v,
- loff_t *pos)
-{
- struct ext4_mb_proc_session *s = seq->private;
- struct ext4_mb_history *hs = v;
-
- ++*pos;
- if (v == SEQ_START_TOKEN)
- return ext4_mb_history_skip_empty(s, s->history + s->start, 1);
- else
- return ext4_mb_history_skip_empty(s, ++hs, 0);
-}
-
-static int ext4_mb_seq_history_show(struct seq_file *seq, void *v)
-{
- char buf[25], buf2[25], buf3[25], *fmt;
- struct ext4_mb_history *hs = v;
-
- if (v == SEQ_START_TOKEN) {
- seq_printf(seq, "%-5s %-8s %-23s %-23s %-23s %-5s "
- "%-5s %-2s %-6s %-5s %-5s %-6s\n",
- "pid", "inode", "original", "goal", "result", "found",
- "grps", "cr", "flags", "merge", "tail", "broken");
- return 0;
- }
-
- if (hs->op == EXT4_MB_HISTORY_ALLOC) {
- fmt = "%-5u %-8u %-23s %-23s %-23s %-5u %-5u %-2u "
- "0x%04x %-5s %-5u %-6u\n";
- sprintf(buf2, "%u/%d/%u@%u", hs->result.fe_group,
- hs->result.fe_start, hs->result.fe_len,
- hs->result.fe_logical);
- sprintf(buf, "%u/%d/%u@%u", hs->orig.fe_group,
- hs->orig.fe_start, hs->orig.fe_len,
- hs->orig.fe_logical);
- sprintf(buf3, "%u/%d/%u@%u", hs->goal.fe_group,
- hs->goal.fe_start, hs->goal.fe_len,
- hs->goal.fe_logical);
- seq_printf(seq, fmt, hs->pid, hs->ino, buf, buf3, buf2,
- hs->found, hs->groups, hs->cr, hs->flags,
- hs->merged ? "M" : "", hs->tail,
- hs->buddy ? 1 << hs->buddy : 0);
- } else if (hs->op == EXT4_MB_HISTORY_PREALLOC) {
- fmt = "%-5u %-8u %-23s %-23s %-23s\n";
- sprintf(buf2, "%u/%d/%u@%u", hs->result.fe_group,
- hs->result.fe_start, hs->result.fe_len,
- hs->result.fe_logical);
- sprintf(buf, "%u/%d/%u@%u", hs->orig.fe_group,
- hs->orig.fe_start, hs->orig.fe_len,
- hs->orig.fe_logical);
- seq_printf(seq, fmt, hs->pid, hs->ino, buf, "", buf2);
- } else if (hs->op == EXT4_MB_HISTORY_DISCARD) {
- sprintf(buf2, "%u/%d/%u", hs->result.fe_group,
- hs->result.fe_start, hs->result.fe_len);
- seq_printf(seq, "%-5u %-8u %-23s discard\n",
- hs->pid, hs->ino, buf2);
- } else if (hs->op == EXT4_MB_HISTORY_FREE) {
- sprintf(buf2, "%u/%d/%u", hs->result.fe_group,
- hs->result.fe_start, hs->result.fe_len);
- seq_printf(seq, "%-5u %-8u %-23s free\n",
- hs->pid, hs->ino, buf2);
- }
- return 0;
-}
-
-static void ext4_mb_seq_history_stop(struct seq_file *seq, void *v)
-{
-}
-
-static const struct seq_operations ext4_mb_seq_history_ops = {
- .start = ext4_mb_seq_history_start,
- .next = ext4_mb_seq_history_next,
- .stop = ext4_mb_seq_history_stop,
- .show = ext4_mb_seq_history_show,
-};
-
-static int ext4_mb_seq_history_open(struct inode *inode, struct file *file)
-{
- struct super_block *sb = PDE(inode)->data;
- struct ext4_sb_info *sbi = EXT4_SB(sb);
- struct ext4_mb_proc_session *s;
- int rc;
- int size;
-
- if (unlikely(sbi->s_mb_history == NULL))
- return -ENOMEM;
- s = kmalloc(sizeof(*s), GFP_KERNEL);
- if (s == NULL)
- return -ENOMEM;
- s->sb = sb;
- size = sizeof(struct ext4_mb_history) * sbi->s_mb_history_max;
- s->history = kmalloc(size, GFP_KERNEL);
- if (s->history == NULL) {
- kfree(s);
- return -ENOMEM;
- }
-
- spin_lock(&sbi->s_mb_history_lock);
- memcpy(s->history, sbi->s_mb_history, size);
- s->max = sbi->s_mb_history_max;
- s->start = sbi->s_mb_history_cur % s->max;
- spin_unlock(&sbi->s_mb_history_lock);
-
- rc = seq_open(file, &ext4_mb_seq_history_ops);
- if (rc == 0) {
- struct seq_file *m = (struct seq_file *)file->private_data;
- m->private = s;
- } else {
- kfree(s->history);
- kfree(s);
- }
- return rc;
-
-}
-
-static int ext4_mb_seq_history_release(struct inode *inode, struct file *file)
-{
- struct seq_file *seq = (struct seq_file *)file->private_data;
- struct ext4_mb_proc_session *s = seq->private;
- kfree(s->history);
- kfree(s);
- return seq_release(inode, file);
-}
-
-static ssize_t ext4_mb_seq_history_write(struct file *file,
- const char __user *buffer,
- size_t count, loff_t *ppos)
-{
- struct seq_file *seq = (struct seq_file *)file->private_data;
- struct ext4_mb_proc_session *s = seq->private;
- struct super_block *sb = s->sb;
- char str[32];
- int value;
-
- if (count >= sizeof(str)) {
- printk(KERN_ERR "EXT4-fs: %s string too long, max %u bytes\n",
- "mb_history", (int)sizeof(str));
- return -EOVERFLOW;
- }
-
- if (copy_from_user(str, buffer, count))
- return -EFAULT;
-
- value = simple_strtol(str, NULL, 0);
- if (value < 0)
- return -ERANGE;
- EXT4_SB(sb)->s_mb_history_filter = value;
-
- return count;
-}
-
-static const struct file_operations ext4_mb_seq_history_fops = {
- .owner = THIS_MODULE,
- .open = ext4_mb_seq_history_open,
- .read = seq_read,
- .write = ext4_mb_seq_history_write,
- .llseek = seq_lseek,
- .release = ext4_mb_seq_history_release,
-};
-
static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos)
{
struct super_block *sb = seq->private;
@@ -2396,82 +2195,6 @@ static const struct file_operations ext4_mb_seq_groups_fops = {
.release = seq_release,
};
-static void ext4_mb_history_release(struct super_block *sb)
-{
- struct ext4_sb_info *sbi = EXT4_SB(sb);
-
- if (sbi->s_proc != NULL) {
- remove_proc_entry("mb_groups", sbi->s_proc);
- if (sbi->s_mb_history_max)
- remove_proc_entry("mb_history", sbi->s_proc);
- }
- kfree(sbi->s_mb_history);
-}
-
-static void ext4_mb_history_init(struct super_block *sb)
-{
- struct ext4_sb_info *sbi = EXT4_SB(sb);
- int i;
-
- if (sbi->s_proc != NULL) {
- if (sbi->s_mb_history_max)
- proc_create_data("mb_history", S_IRUGO, sbi->s_proc,
- &ext4_mb_seq_history_fops, sb);
- proc_create_data("mb_groups", S_IRUGO, sbi->s_proc,
- &ext4_mb_seq_groups_fops, sb);
- }
-
- sbi->s_mb_history_cur = 0;
- spin_lock_init(&sbi->s_mb_history_lock);
- i = sbi->s_mb_history_max * sizeof(struct ext4_mb_history);
- sbi->s_mb_history = i ? kzalloc(i, GFP_KERNEL) : NULL;
- /* if we can't allocate history, then we simple won't use it */
-}
-
-static noinline_for_stack void
-ext4_mb_store_history(struct ext4_allocation_context *ac)
-{
- struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
- struct ext4_mb_history h;
-
- if (sbi->s_mb_history == NULL)
- return;
-
- if (!(ac->ac_op & sbi->s_mb_history_filter))
- return;
-
- h.op = ac->ac_op;
- h.pid = current->pid;
- h.ino = ac->ac_inode ? ac->ac_inode->i_ino : 0;
- h.orig = ac->ac_o_ex;
- h.result = ac->ac_b_ex;
- h.flags = ac->ac_flags;
- h.found = ac->ac_found;
- h.groups = ac->ac_groups_scanned;
- h.cr = ac->ac_criteria;
- h.tail = ac->ac_tail;
- h.buddy = ac->ac_buddy;
- h.merged = 0;
- if (ac->ac_op == EXT4_MB_HISTORY_ALLOC) {
- if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
- ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
- h.merged = 1;
- h.goal = ac->ac_g_ex;
- h.result = ac->ac_f_ex;
- }
-
- spin_lock(&sbi->s_mb_history_lock);
- memcpy(sbi->s_mb_history + sbi->s_mb_history_cur, &h, sizeof(h));
- if (++sbi->s_mb_history_cur >= sbi->s_mb_history_max)
- sbi->s_mb_history_cur = 0;
- spin_unlock(&sbi->s_mb_history_lock);
-}
-
-#else
-#define ext4_mb_history_release(sb)
-#define ext4_mb_history_init(sb)
-#endif
-
/* Create and initialize ext4_group_info data for the given group. */
int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
@@ -2690,7 +2413,6 @@ int ext4_mb_init(struct super_block *sb, int needs_recovery)
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_history_filter = EXT4_MB_HISTORY_DEFAULT;
sbi->s_mb_group_prealloc = MB_DEFAULT_GROUP_PREALLOC;
sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group);
@@ -2708,7 +2430,9 @@ int ext4_mb_init(struct super_block *sb, int needs_recovery)
spin_lock_init(&lg->lg_prealloc_lock);
}
- ext4_mb_history_init(sb);
+ if (sbi->s_proc)
+ proc_create_data("mb_groups", S_IRUGO, sbi->s_proc,
+ &ext4_mb_seq_groups_fops, sb);
if (sbi->s_journal)
sbi->s_journal->j_commit_callback = release_blocks_on_commit;
@@ -2788,7 +2512,8 @@ int ext4_mb_release(struct super_block *sb)
}
free_percpu(sbi->s_locality_groups);
- ext4_mb_history_release(sb);
+ if (sbi->s_proc)
+ remove_proc_entry("mb_groups", sbi->s_proc);
return 0;
}
@@ -3274,7 +2999,10 @@ static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
atomic_inc(&sbi->s_bal_breaks);
}
- ext4_mb_store_history(ac);
+ if (ac->ac_op == EXT4_MB_HISTORY_ALLOC)
+ trace_ext4_mballoc_alloc(ac);
+ else
+ trace_ext4_mballoc_prealloc(ac);
}
/*
@@ -3774,7 +3502,6 @@ ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,
if (ac) {
ac->ac_sb = sb;
ac->ac_inode = pa->pa_inode;
- ac->ac_op = EXT4_MB_HISTORY_DISCARD;
}
while (bit < end) {
@@ -3794,7 +3521,7 @@ ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,
ac->ac_b_ex.fe_start = bit;
ac->ac_b_ex.fe_len = next - bit;
ac->ac_b_ex.fe_logical = 0;
- ext4_mb_store_history(ac);
+ trace_ext4_mballoc_discard(ac);
}
trace_ext4_mb_release_inode_pa(ac, pa, grp_blk_start + bit,
@@ -3829,9 +3556,6 @@ ext4_mb_release_group_pa(struct ext4_buddy *e4b,
ext4_group_t group;
ext4_grpblk_t bit;
- if (ac)
- ac->ac_op = EXT4_MB_HISTORY_DISCARD;
-
trace_ext4_mb_release_group_pa(ac, pa);
BUG_ON(pa->pa_deleted == 0);
ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
@@ -3846,7 +3570,7 @@ ext4_mb_release_group_pa(struct ext4_buddy *e4b,
ac->ac_b_ex.fe_start = bit;
ac->ac_b_ex.fe_len = pa->pa_len;
ac->ac_b_ex.fe_logical = 0;
- ext4_mb_store_history(ac);
+ trace_ext4_mballoc_discard(ac);
}
return 0;
@@ -4737,7 +4461,6 @@ void ext4_mb_free_blocks(handle_t *handle, struct inode *inode,
ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
if (ac) {
- ac->ac_op = EXT4_MB_HISTORY_FREE;
ac->ac_inode = inode;
ac->ac_sb = sb;
}
@@ -4804,7 +4527,7 @@ do_more:
ac->ac_b_ex.fe_group = block_group;
ac->ac_b_ex.fe_start = bit;
ac->ac_b_ex.fe_len = count;
- ext4_mb_store_history(ac);
+ trace_ext4_mballoc_free(ac);
}
err = ext4_mb_load_buddy(sb, block_group, &e4b);
diff --git a/fs/ext4/mballoc.h b/fs/ext4/mballoc.h
index 14f25f253112..0ca811061bc7 100644
--- a/fs/ext4/mballoc.h
+++ b/fs/ext4/mballoc.h
@@ -52,18 +52,8 @@ extern u8 mb_enable_debug;
#define mb_debug(n, fmt, a...)
#endif
-/*
- * with EXT4_MB_HISTORY mballoc stores last N allocations in memory
- * and you can monitor it in /proc/fs/ext4/<dev>/mb_history
- */
-#define EXT4_MB_HISTORY
#define EXT4_MB_HISTORY_ALLOC 1 /* allocation */
#define EXT4_MB_HISTORY_PREALLOC 2 /* preallocated blocks used */
-#define EXT4_MB_HISTORY_DISCARD 4 /* preallocation discarded */
-#define EXT4_MB_HISTORY_FREE 8 /* free */
-
-#define EXT4_MB_HISTORY_DEFAULT (EXT4_MB_HISTORY_ALLOC | \
- EXT4_MB_HISTORY_PREALLOC)
/*
* How long mballoc can look for a best extent (in found extents)
@@ -217,22 +207,6 @@ struct ext4_allocation_context {
#define AC_STATUS_FOUND 2
#define AC_STATUS_BREAK 3
-struct ext4_mb_history {
- struct ext4_free_extent orig; /* orig allocation */
- struct ext4_free_extent goal; /* goal allocation */
- struct ext4_free_extent result; /* result allocation */
- unsigned pid;
- unsigned ino;
- __u16 found; /* how many extents have been found */
- __u16 groups; /* how many groups have been scanned */
- __u16 tail; /* what tail broke some buddy */
- __u16 buddy; /* buddy the tail ^^^ broke */
- __u16 flags;
- __u8 cr:3; /* which phase the result extent was found at */
- __u8 op:4;
- __u8 merged:1;
-};
-
struct ext4_buddy {
struct page *bd_buddy_page;
void *bd_buddy;
@@ -247,13 +221,6 @@ struct ext4_buddy {
#define EXT4_MB_BITMAP(e4b) ((e4b)->bd_bitmap)
#define EXT4_MB_BUDDY(e4b) ((e4b)->bd_buddy)
-#ifndef EXT4_MB_HISTORY
-static inline void ext4_mb_store_history(struct ext4_allocation_context *ac)
-{
- return;
-}
-#endif
-
#define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
static inline ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb,
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index e5b206a043a5..12e726a7073f 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -50,13 +50,6 @@
#define CREATE_TRACE_POINTS
#include <trace/events/ext4.h>
-static int default_mb_history_length = 1000;
-
-module_param_named(default_mb_history_length, default_mb_history_length,
- int, 0644);
-MODULE_PARM_DESC(default_mb_history_length,
- "Default number of entries saved for mb_history");
-
struct proc_dir_entry *ext4_proc_root;
static struct kset *ext4_kset;
@@ -1079,7 +1072,7 @@ enum {
Opt_journal_update, Opt_journal_dev,
Opt_journal_checksum, Opt_journal_async_commit,
Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
- Opt_data_err_abort, Opt_data_err_ignore, Opt_mb_history_length,
+ Opt_data_err_abort, Opt_data_err_ignore,
Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err, Opt_resize,
@@ -1126,7 +1119,6 @@ static const match_table_t tokens = {
{Opt_data_writeback, "data=writeback"},
{Opt_data_err_abort, "data_err=abort"},
{Opt_data_err_ignore, "data_err=ignore"},
- {Opt_mb_history_length, "mb_history_length=%u"},
{Opt_offusrjquota, "usrjquota="},
{Opt_usrjquota, "usrjquota=%s"},
{Opt_offgrpjquota, "grpjquota="},
@@ -1367,13 +1359,6 @@ static int parse_options(char *options, struct super_block *sb,
case Opt_data_err_ignore:
clear_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
break;
- case Opt_mb_history_length:
- if (match_int(&args[0], &option))
- return 0;
- if (option < 0)
- return 0;
- sbi->s_mb_history_max = option;
- break;
#ifdef CONFIG_QUOTA
case Opt_usrjquota:
qtype = USRQUOTA;
@@ -2435,7 +2420,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
- sbi->s_mb_history_max = default_mb_history_length;
set_opt(sbi->s_mount_opt, BARRIER);