[Ocfs2-devel] [PATCH 1/1] OCFS2: fasten dlm_lock_resource hash_table lookups
wengang wang
wen.gang.wang at oracle.com
Tue Apr 21 23:04:07 PDT 2009
#backporting the 3 patches at http://kernel.us.oracle.com/~smushran/srini/ to 1.2.
enlarge hash_table capacity to fasten hash_table lookups.
Signed-off-by: Wengang wang <wen.gang.wang at oracle.com>
--
diff -up ./svnocfs2-1.2/fs/ocfs2/dlm/dlmdebug.c.orig ./svnocfs2-1.2/fs/ocfs2/dlm/dlmdebug.c
--- ./svnocfs2-1.2/fs/ocfs2/dlm/dlmdebug.c.orig 2009-04-22 11:00:37.000000000 +0800
+++ ./svnocfs2-1.2/fs/ocfs2/dlm/dlmdebug.c 2009-04-22 11:08:27.000000000 +0800
@@ -547,7 +547,7 @@ void dlm_dump_lock_resources(struct dlm_
spin_lock(&dlm->spinlock);
for (i=0; i<DLM_HASH_BUCKETS; i++) {
- bucket = &(dlm->lockres_hash[i]);
+ bucket = dlm_lockres_hash(dlm, i);
hlist_for_each_entry(res, iter, bucket, hash_node)
dlm_print_one_lock_resource(res);
}
diff -up ./svnocfs2-1.2/fs/ocfs2/dlm/dlmrecovery.c.orig ./svnocfs2-1.2/fs/ocfs2/dlm/dlmrecovery.c
--- ./svnocfs2-1.2/fs/ocfs2/dlm/dlmrecovery.c.orig 2009-04-22 11:01:18.000000000 +0800
+++ ./svnocfs2-1.2/fs/ocfs2/dlm/dlmrecovery.c 2009-04-22 11:21:12.000000000 +0800
@@ -2064,7 +2064,7 @@ static void dlm_finish_local_lockres_rec
* the RECOVERING state and set the owner
* if necessary */
for (i = 0; i < DLM_HASH_BUCKETS; i++) {
- bucket = &(dlm->lockres_hash[i]);
+ bucket = dlm_lockres_hash(dlm, i);
hlist_for_each_entry(res, hash_iter, bucket, hash_node) {
if (res->state & DLM_LOCK_RES_RECOVERING) {
if (res->owner == dead_node) {
@@ -2259,7 +2259,7 @@ static void dlm_do_local_recovery_cleanu
* need to be fired as a result.
*/
for (i = 0; i < DLM_HASH_BUCKETS; i++) {
- bucket = &(dlm->lockres_hash[i]);
+ bucket = dlm_lockres_hash(dlm, i);
hlist_for_each_entry(res, iter, bucket, hash_node) {
/* always prune any $RECOVERY entries for dead nodes,
* otherwise hangs can occur during later recovery */
diff -up ./svnocfs2-1.2/fs/ocfs2/dlm/dlmdomain.c.orig ./svnocfs2-1.2/fs/ocfs2/dlm/dlmdomain.c
--- ./svnocfs2-1.2/fs/ocfs2/dlm/dlmdomain.c.orig 2009-04-22 11:00:47.000000000 +0800
+++ ./svnocfs2-1.2/fs/ocfs2/dlm/dlmdomain.c 2009-04-22 11:33:26.000000000 +0800
@@ -49,6 +49,34 @@
#define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_DOMAIN)
#include "cluster/masklog.h"
+static void dlm_free_pagevec(void **vec, int pages)
+{
+ while (pages--)
+ free_page((unsigned long)vec[pages]);
+ kfree(vec);
+}
+
+static void **dlm_alloc_pagevec(int pages)
+{
+ void **vec = kmalloc(pages * sizeof(void *), GFP_KERNEL);
+ int i;
+
+ if (!vec)
+ return NULL;
+
+ for (i = 0; i < pages; i++) {
+ vec[i] = (void *)__get_free_page(GFP_KERNEL);
+ if (!vec[i])
+ goto out_free;
+ }
+ mlog(0, "Allocated DLM hash pagevec; %d pages (%lu expected), %Zd "
+ "buckets per page\n", pages, DLM_HASH_PAGES, DLM_BUCKETS_PER_PAGE);
+ return vec;
+out_free:
+ dlm_free_pagevec(vec, i);
+ return NULL;
+}
+
/*
* ocfs2 node maps are array of long int, which limits to send them freely
* across the wire due to endianness issues. To workaround this, we convert
@@ -127,7 +155,7 @@ void __dlm_insert_lockres(struct dlm_ctx
q = &res->lockname;
q->hash = full_name_hash(q->name, q->len);
- bucket = &(dlm->lockres_hash[q->hash % DLM_HASH_BUCKETS]);
+ bucket = dlm_lockres_hash(dlm, q->hash);
/* get a reference for our hashtable */
dlm_lockres_get(res);
@@ -151,7 +179,7 @@ struct dlm_lock_resource * __dlm_lookup_
hash = full_name_hash(name, len);
- bucket = &(dlm->lockres_hash[hash % DLM_HASH_BUCKETS]);
+ bucket = dlm_lockres_hash(dlm, hash);
/* check for pre-existing lock */
hlist_for_each(iter, bucket) {
@@ -394,7 +422,7 @@ static int dlm_migrate_all_locks(struct
for (i = 0; i < DLM_HASH_BUCKETS; i++) {
redo_bucket:
n = 0;
- bucket = &dlm->lockres_hash[i];
+ bucket = dlm_lockres_hash(dlm, i);
iter = bucket->first;
while (iter) {
n++;
@@ -1356,7 +1384,8 @@ static struct dlm_ctxt *dlm_alloc_ctxt(c
goto leave;
}
- dlm->lockres_hash = (struct hlist_head *) __get_free_page(GFP_KERNEL);
+ dlm->lockres_hash = (struct hlist_head **)
+ dlm_alloc_pagevec(DLM_HASH_PAGES);
if (!dlm->lockres_hash) {
mlog_errno(-ENOMEM);
kfree(dlm->name);
@@ -1366,7 +1395,7 @@ static struct dlm_ctxt *dlm_alloc_ctxt(c
}
for (i=0; i<DLM_HASH_BUCKETS; i++)
- INIT_HLIST_HEAD(&dlm->lockres_hash[i]);
+ INIT_HLIST_HEAD(dlm_lockres_hash(dlm, i));
strcpy(dlm->name, domain);
dlm->key = key;
diff -up ./svnocfs2-1.2/fs/ocfs2/dlm/dlmcommon.h.orig ./svnocfs2-1.2/fs/ocfs2/dlm/dlmcommon.h
--- ./svnocfs2-1.2/fs/ocfs2/dlm/dlmcommon.h.orig 2009-04-22 10:59:51.000000000 +0800
+++ ./svnocfs2-1.2/fs/ocfs2/dlm/dlmcommon.h 2009-04-22 11:26:06.000000000 +0800
@@ -37,7 +37,14 @@
#define DLM_THREAD_SHUFFLE_INTERVAL 5 // flush everything every 5 passes
#define DLM_THREAD_MS 200 // flush at least every 200 ms
-#define DLM_HASH_BUCKETS (PAGE_SIZE / sizeof(struct hlist_head))
+#define DLM_HASH_SIZE_DEFAULT (1 << 17)
+#if DLM_HASH_SIZE_DEFAULT < PAGE_SIZE
+# define DLM_HASH_PAGES 1
+#else
+# define DLM_HASH_PAGES (DLM_HASH_SIZE_DEFAULT / PAGE_SIZE)
+#endif
+#define DLM_BUCKETS_PER_PAGE (PAGE_SIZE / sizeof(struct hlist_head))
+#define DLM_HASH_BUCKETS (DLM_HASH_PAGES * DLM_BUCKETS_PER_PAGE)
enum dlm_ast_type {
DLM_AST = 0,
@@ -86,7 +93,7 @@ enum dlm_ctxt_state {
struct dlm_ctxt
{
struct list_head list;
- struct hlist_head *lockres_hash;
+ struct hlist_head **lockres_hash;
struct list_head dirty_list;
struct list_head purge_list;
struct list_head pending_asts;
@@ -136,6 +143,13 @@ struct dlm_ctxt
struct list_head dlm_eviction_callbacks;
};
+static inline
+struct hlist_head *dlm_lockres_hash(struct dlm_ctxt *dlm, unsigned i)
+{
+ return dlm->lockres_hash[(i / DLM_BUCKETS_PER_PAGE) % DLM_HASH_PAGES]
+ + (i % DLM_BUCKETS_PER_PAGE);
+}
+
/* these keventd work queue items are for less-frequently
* called functions that cannot be directly called from the
* net message handlers for some reason, usually because
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