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dlm: convert rsb list to rb_tree
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Change the linked lists to rb_tree's in the rsb
hash table to speed up searches.  Slow rsb searches
were having a large impact on gfs2 performance due
to the large number of dlm locks gfs2 uses.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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@AstralBob @teigland
AstralBob authored and teigland committed Nov 18, 2011
1 parent c3b92c8 commit 9beb3bf
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Showing 5 changed files with 113 additions and 55 deletions.
28 changes: 15 additions & 13 deletions fs/dlm/debug_fs.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -393,6 +393,7 @@ static const struct seq_operations format3_seq_ops;

static void *table_seq_start(struct seq_file *seq, loff_t *pos)
{
struct rb_node *node;
struct dlm_ls *ls = seq->private;
struct rsbtbl_iter *ri;
struct dlm_rsb *r;
Expand All @@ -418,9 +419,10 @@ static void *table_seq_start(struct seq_file *seq, loff_t *pos)
ri->format = 3;

spin_lock(&ls->ls_rsbtbl[bucket].lock);
if (!list_empty(&ls->ls_rsbtbl[bucket].list)) {
list_for_each_entry(r, &ls->ls_rsbtbl[bucket].list,
res_hashchain) {
if (!RB_EMPTY_ROOT(&ls->ls_rsbtbl[bucket].keep)) {
for (node = rb_first(&ls->ls_rsbtbl[bucket].keep); node;
node = rb_next(node)) {
r = rb_entry(node, struct dlm_rsb, res_hashnode);
if (!entry--) {
dlm_hold_rsb(r);
ri->rsb = r;
Expand Down Expand Up @@ -449,9 +451,9 @@ static void *table_seq_start(struct seq_file *seq, loff_t *pos)
}

spin_lock(&ls->ls_rsbtbl[bucket].lock);
if (!list_empty(&ls->ls_rsbtbl[bucket].list)) {
r = list_first_entry(&ls->ls_rsbtbl[bucket].list,
struct dlm_rsb, res_hashchain);
if (!RB_EMPTY_ROOT(&ls->ls_rsbtbl[bucket].keep)) {
node = rb_first(&ls->ls_rsbtbl[bucket].keep);
r = rb_entry(node, struct dlm_rsb, res_hashnode);
dlm_hold_rsb(r);
ri->rsb = r;
ri->bucket = bucket;
Expand All @@ -467,7 +469,7 @@ static void *table_seq_next(struct seq_file *seq, void *iter_ptr, loff_t *pos)
{
struct dlm_ls *ls = seq->private;
struct rsbtbl_iter *ri = iter_ptr;
struct list_head *next;
struct rb_node *next;
struct dlm_rsb *r, *rp;
loff_t n = *pos;
unsigned bucket;
Expand All @@ -480,10 +482,10 @@ static void *table_seq_next(struct seq_file *seq, void *iter_ptr, loff_t *pos)

spin_lock(&ls->ls_rsbtbl[bucket].lock);
rp = ri->rsb;
next = rp->res_hashchain.next;
next = rb_next(&rp->res_hashnode);

if (next != &ls->ls_rsbtbl[bucket].list) {
r = list_entry(next, struct dlm_rsb, res_hashchain);
if (next) {
r = rb_entry(next, struct dlm_rsb, res_hashnode);
dlm_hold_rsb(r);
ri->rsb = r;
spin_unlock(&ls->ls_rsbtbl[bucket].lock);
Expand Down Expand Up @@ -511,9 +513,9 @@ static void *table_seq_next(struct seq_file *seq, void *iter_ptr, loff_t *pos)
}

spin_lock(&ls->ls_rsbtbl[bucket].lock);
if (!list_empty(&ls->ls_rsbtbl[bucket].list)) {
r = list_first_entry(&ls->ls_rsbtbl[bucket].list,
struct dlm_rsb, res_hashchain);
if (!RB_EMPTY_ROOT(&ls->ls_rsbtbl[bucket].keep)) {
next = rb_first(&ls->ls_rsbtbl[bucket].keep);
r = rb_entry(next, struct dlm_rsb, res_hashnode);
dlm_hold_rsb(r);
ri->rsb = r;
ri->bucket = bucket;
Expand Down
9 changes: 6 additions & 3 deletions fs/dlm/dlm_internal.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -103,8 +103,8 @@ struct dlm_dirtable {
};

struct dlm_rsbtable {
struct list_head list;
struct list_head toss;
struct rb_root keep;
struct rb_root toss;
spinlock_t lock;
};

Expand Down Expand Up @@ -285,7 +285,10 @@ struct dlm_rsb {
unsigned long res_toss_time;
uint32_t res_first_lkid;
struct list_head res_lookup; /* lkbs waiting on first */
struct list_head res_hashchain; /* rsbtbl */
union {
struct list_head res_hashchain;
struct rb_node res_hashnode; /* rsbtbl */
};
struct list_head res_grantqueue;
struct list_head res_convertqueue;
struct list_head res_waitqueue;
Expand Down
87 changes: 70 additions & 17 deletions fs/dlm/lock.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -56,6 +56,7 @@
L: receive_xxxx_reply() <- R: send_xxxx_reply()
*/
#include <linux/types.h>
#include <linux/rbtree.h>
#include <linux/slab.h>
#include "dlm_internal.h"
#include <linux/dlm_device.h>
Expand Down Expand Up @@ -380,6 +381,8 @@ static int get_rsb_struct(struct dlm_ls *ls, char *name, int len,

r = list_first_entry(&ls->ls_new_rsb, struct dlm_rsb, res_hashchain);
list_del(&r->res_hashchain);
/* Convert the empty list_head to a NULL rb_node for tree usage: */
memset(&r->res_hashnode, 0, sizeof(struct rb_node));
ls->ls_new_rsb_count--;
spin_unlock(&ls->ls_new_rsb_spin);

Expand All @@ -388,7 +391,6 @@ static int get_rsb_struct(struct dlm_ls *ls, char *name, int len,
memcpy(r->res_name, name, len);
mutex_init(&r->res_mutex);

INIT_LIST_HEAD(&r->res_hashchain);
INIT_LIST_HEAD(&r->res_lookup);
INIT_LIST_HEAD(&r->res_grantqueue);
INIT_LIST_HEAD(&r->res_convertqueue);
Expand All @@ -400,14 +402,31 @@ static int get_rsb_struct(struct dlm_ls *ls, char *name, int len,
return 0;
}

static int search_rsb_list(struct list_head *head, char *name, int len,
static int rsb_cmp(struct dlm_rsb *r, const char *name, int nlen)
{
char maxname[DLM_RESNAME_MAXLEN];

memset(maxname, 0, DLM_RESNAME_MAXLEN);
memcpy(maxname, name, nlen);
return memcmp(r->res_name, maxname, DLM_RESNAME_MAXLEN);
}

static int search_rsb_tree(struct rb_root *tree, char *name, int len,
unsigned int flags, struct dlm_rsb **r_ret)
{
struct rb_node *node = tree->rb_node;
struct dlm_rsb *r;
int error = 0;

list_for_each_entry(r, head, res_hashchain) {
if (len == r->res_length && !memcmp(name, r->res_name, len))
int rc;

while (node) {
r = rb_entry(node, struct dlm_rsb, res_hashnode);
rc = rsb_cmp(r, name, len);
if (rc < 0)
node = node->rb_left;
else if (rc > 0)
node = node->rb_right;
else
goto found;
}
*r_ret = NULL;
Expand All @@ -420,22 +439,54 @@ static int search_rsb_list(struct list_head *head, char *name, int len,
return error;
}

static int rsb_insert(struct dlm_rsb *rsb, struct rb_root *tree)
{
struct rb_node **newn = &tree->rb_node;
struct rb_node *parent = NULL;
int rc;

while (*newn) {
struct dlm_rsb *cur = rb_entry(*newn, struct dlm_rsb,
res_hashnode);

parent = *newn;
rc = rsb_cmp(cur, rsb->res_name, rsb->res_length);
if (rc < 0)
newn = &parent->rb_left;
else if (rc > 0)
newn = &parent->rb_right;
else {
log_print("rsb_insert match");
dlm_dump_rsb(rsb);
dlm_dump_rsb(cur);
return -EEXIST;
}
}

rb_link_node(&rsb->res_hashnode, parent, newn);
rb_insert_color(&rsb->res_hashnode, tree);
return 0;
}

static int _search_rsb(struct dlm_ls *ls, char *name, int len, int b,
unsigned int flags, struct dlm_rsb **r_ret)
{
struct dlm_rsb *r;
int error;

error = search_rsb_list(&ls->ls_rsbtbl[b].list, name, len, flags, &r);
error = search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, flags, &r);
if (!error) {
kref_get(&r->res_ref);
goto out;
}
error = search_rsb_list(&ls->ls_rsbtbl[b].toss, name, len, flags, &r);
error = search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, flags, &r);
if (error)
goto out;

list_move(&r->res_hashchain, &ls->ls_rsbtbl[b].list);
rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss);
error = rsb_insert(r, &ls->ls_rsbtbl[b].keep);
if (error)
return error;

if (dlm_no_directory(ls))
goto out;
Expand Down Expand Up @@ -527,8 +578,7 @@ static int find_rsb(struct dlm_ls *ls, char *name, int namelen,
nodeid = 0;
r->res_nodeid = nodeid;
}
list_add(&r->res_hashchain, &ls->ls_rsbtbl[bucket].list);
error = 0;
error = rsb_insert(r, &ls->ls_rsbtbl[bucket].keep);
out_unlock:
spin_unlock(&ls->ls_rsbtbl[bucket].lock);
out:
Expand Down Expand Up @@ -556,7 +606,8 @@ static void toss_rsb(struct kref *kref)

DLM_ASSERT(list_empty(&r->res_root_list), dlm_print_rsb(r););
kref_init(&r->res_ref);
list_move(&r->res_hashchain, &ls->ls_rsbtbl[r->res_bucket].toss);
rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[r->res_bucket].keep);
rsb_insert(r, &ls->ls_rsbtbl[r->res_bucket].toss);
r->res_toss_time = jiffies;
if (r->res_lvbptr) {
dlm_free_lvb(r->res_lvbptr);
Expand Down Expand Up @@ -1082,19 +1133,19 @@ static void dir_remove(struct dlm_rsb *r)
r->res_name, r->res_length);
}

/* FIXME: shouldn't this be able to exit as soon as one non-due rsb is
found since they are in order of newest to oldest? */
/* FIXME: make this more efficient */

static int shrink_bucket(struct dlm_ls *ls, int b)
{
struct rb_node *n;
struct dlm_rsb *r;
int count = 0, found;

for (;;) {
found = 0;
spin_lock(&ls->ls_rsbtbl[b].lock);
list_for_each_entry_reverse(r, &ls->ls_rsbtbl[b].toss,
res_hashchain) {
for (n = rb_first(&ls->ls_rsbtbl[b].toss); n; n = rb_next(n)) {
r = rb_entry(n, struct dlm_rsb, res_hashnode);
if (!time_after_eq(jiffies, r->res_toss_time +
dlm_config.ci_toss_secs * HZ))
continue;
Expand All @@ -1108,7 +1159,7 @@ static int shrink_bucket(struct dlm_ls *ls, int b)
}

if (kref_put(&r->res_ref, kill_rsb)) {
list_del(&r->res_hashchain);
rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss);
spin_unlock(&ls->ls_rsbtbl[b].lock);

if (is_master(r))
Expand Down Expand Up @@ -4441,10 +4492,12 @@ int dlm_purge_locks(struct dlm_ls *ls)

static struct dlm_rsb *find_purged_rsb(struct dlm_ls *ls, int bucket)
{
struct rb_node *n;
struct dlm_rsb *r, *r_ret = NULL;

spin_lock(&ls->ls_rsbtbl[bucket].lock);
list_for_each_entry(r, &ls->ls_rsbtbl[bucket].list, res_hashchain) {
for (n = rb_first(&ls->ls_rsbtbl[bucket].keep); n; n = rb_next(n)) {
r = rb_entry(n, struct dlm_rsb, res_hashnode);
if (!rsb_flag(r, RSB_LOCKS_PURGED))
continue;
hold_rsb(r);
Expand Down
23 changes: 9 additions & 14 deletions fs/dlm/lockspace.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -457,8 +457,8 @@ static int new_lockspace(const char *name, int namelen, void **lockspace,
if (!ls->ls_rsbtbl)
goto out_lsfree;
for (i = 0; i < size; i++) {
INIT_LIST_HEAD(&ls->ls_rsbtbl[i].list);
INIT_LIST_HEAD(&ls->ls_rsbtbl[i].toss);
ls->ls_rsbtbl[i].keep.rb_node = NULL;
ls->ls_rsbtbl[i].toss.rb_node = NULL;
spin_lock_init(&ls->ls_rsbtbl[i].lock);
}

Expand Down Expand Up @@ -685,7 +685,7 @@ static int lockspace_busy(struct dlm_ls *ls, int force)
static int release_lockspace(struct dlm_ls *ls, int force)
{
struct dlm_rsb *rsb;
struct list_head *head;
struct rb_node *n;
int i, busy, rv;

busy = lockspace_busy(ls, force);
Expand Down Expand Up @@ -746,20 +746,15 @@ static int release_lockspace(struct dlm_ls *ls, int force)
*/

for (i = 0; i < ls->ls_rsbtbl_size; i++) {
head = &ls->ls_rsbtbl[i].list;
while (!list_empty(head)) {
rsb = list_entry(head->next, struct dlm_rsb,
res_hashchain);

list_del(&rsb->res_hashchain);
while ((n = rb_first(&ls->ls_rsbtbl[i].keep))) {
rsb = rb_entry(n, struct dlm_rsb, res_hashnode);
rb_erase(n, &ls->ls_rsbtbl[i].keep);
dlm_free_rsb(rsb);
}

head = &ls->ls_rsbtbl[i].toss;
while (!list_empty(head)) {
rsb = list_entry(head->next, struct dlm_rsb,
res_hashchain);
list_del(&rsb->res_hashchain);
while ((n = rb_first(&ls->ls_rsbtbl[i].toss))) {
rsb = rb_entry(n, struct dlm_rsb, res_hashnode);
rb_erase(n, &ls->ls_rsbtbl[i].toss);
dlm_free_rsb(rsb);
}
}
Expand Down
21 changes: 13 additions & 8 deletions fs/dlm/recover.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -715,6 +715,7 @@ void dlm_recover_rsbs(struct dlm_ls *ls)

int dlm_create_root_list(struct dlm_ls *ls)
{
struct rb_node *n;
struct dlm_rsb *r;
int i, error = 0;

Expand All @@ -727,7 +728,8 @@ int dlm_create_root_list(struct dlm_ls *ls)

for (i = 0; i < ls->ls_rsbtbl_size; i++) {
spin_lock(&ls->ls_rsbtbl[i].lock);
list_for_each_entry(r, &ls->ls_rsbtbl[i].list, res_hashchain) {
for (n = rb_first(&ls->ls_rsbtbl[i].keep); n; n = rb_next(n)) {
r = rb_entry(n, struct dlm_rsb, res_hashnode);
list_add(&r->res_root_list, &ls->ls_root_list);
dlm_hold_rsb(r);
}
Expand All @@ -741,7 +743,8 @@ int dlm_create_root_list(struct dlm_ls *ls)
continue;
}

list_for_each_entry(r, &ls->ls_rsbtbl[i].toss, res_hashchain) {
for (n = rb_first(&ls->ls_rsbtbl[i].toss); n; n = rb_next(n)) {
r = rb_entry(n, struct dlm_rsb, res_hashnode);
list_add(&r->res_root_list, &ls->ls_root_list);
dlm_hold_rsb(r);
}
Expand Down Expand Up @@ -771,16 +774,18 @@ void dlm_release_root_list(struct dlm_ls *ls)

void dlm_clear_toss_list(struct dlm_ls *ls)
{
struct dlm_rsb *r, *safe;
struct rb_node *n, *next;
struct dlm_rsb *rsb;
int i;

for (i = 0; i < ls->ls_rsbtbl_size; i++) {
spin_lock(&ls->ls_rsbtbl[i].lock);
list_for_each_entry_safe(r, safe, &ls->ls_rsbtbl[i].toss,
res_hashchain) {
if (dlm_no_directory(ls) || !is_master(r)) {
list_del(&r->res_hashchain);
dlm_free_rsb(r);
for (n = rb_first(&ls->ls_rsbtbl[i].toss); n; n = next) {
next = rb_next(n);;
rsb = rb_entry(n, struct dlm_rsb, res_hashnode);
if (dlm_no_directory(ls) || !is_master(rsb)) {
rb_erase(n, &ls->ls_rsbtbl[i].toss);
dlm_free_rsb(rsb);
}
}
spin_unlock(&ls->ls_rsbtbl[i].lock);
Expand Down

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