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ocfs2/dlm: dynamically allocate lvb for dlm_lock_resource

PATCH New Wengang Wang 3 participants 5 messages Aug 26, 2010 – Sep 14, 2010 OCFS2

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Wengang Wang

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#0 lore raw

PATCH 1/5 ocfs2/dlm: dynamically allocate lvb for dlm_lock_resource

This patch tries to dynamically allocate lvb for dlm_lock_resource which needs to access lvb.

Without the patch applied,
[wwg at cool linux-2.6]$ egrep "o2dlm_lockres" /proc/slabinfo
o2dlm_lockres 42 42 256 32 2 : tunables 0 0 0 : slabdata 2 2 0

After patch applied,
[wwg at cool linux-2.6]$ egrep "o2dlm_lockres" /proc/slabinfo
o2dlm_lockres 42 42 192 21 1 : tunables 0 0 0 : slabdata 2 2 0

#the result is taken on i686

Signed-off-by Wengang Wang <[email protected]>
---
 fs/ocfs2/dlm/dlmast.c    |    2 ++
 fs/ocfs2/dlm/dlmcommon.h |    3 ++-
 fs/ocfs2/dlm/dlmdebug.c  |    6 ++++--
 fs/ocfs2/dlm/dlmlock.c   |    6 ++++++
 fs/ocfs2/dlm/dlmmaster.c |   31 ++++++++++++++++++++++++++++---
 5 files changed, 42 insertions(+), 6 deletions(-)
fs/ocfs2/dlm/dlmast.c +2 -0
index f449991..fe272b1 100644
@@ -191,6 +191,8 @@ static void dlm_update_lvb(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
 			mlog(0, "getting lvb from lockres for %s node\n",
 				  lock->ml.node == dlm->node_num ? "master" :
 				  "remote");
+			mlog_bug_on_msg(!res->lvb, "lockname : %.*s\n",
+					res->lockname.len, res->lockname.name);
 			memcpy(lksb->lvb, res->lvb, DLM_LVB_LEN);
 		}
 		/* Do nothing for lvb put requests - they should be done in
fs/ocfs2/dlm/dlmcommon.h +2 -1
index 4b6ae2c..49e6492 100644
@@ -329,7 +329,7 @@ struct dlm_lock_resource
 	wait_queue_head_t wq;
 	u8  owner;              //node which owns the lock resource, or unknown
 	u16 state;
-	char lvb[DLM_LVB_LEN];
+	char *lvb;
 	unsigned int inflight_locks;
 	unsigned long refmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
 };

@@ -1033,6 +1033,7 @@ void dlm_clean_master_list(struct dlm_ctxt *dlm,
 int dlm_lock_basts_flushed(struct dlm_ctxt *dlm, struct dlm_lock *lock);
 int __dlm_lockres_has_locks(struct dlm_lock_resource *res);
 int __dlm_lockres_unused(struct dlm_lock_resource *res);
+char *dlm_alloc_lvb(char **lvb);
 
 static inline const char * dlm_lock_mode_name(int mode)
 {
fs/ocfs2/dlm/dlmdebug.c +4 -2
index 5efdd37..15a4ca2 100644
@@ -603,9 +603,11 @@ static int dump_lockres(struct dlm_lock_resource *res, char *buf, int len)
 
 	/* lvb */
 	out += snprintf(buf + out, len - out, "LVBX:");
-	for (i = 0; i < DLM_LVB_LEN; i++)
-		out += snprintf(buf + out, len - out,
+	if (res->lvb) {
+		for (i = 0; i < DLM_LVB_LEN; i++)
+			out += snprintf(buf + out, len - out,
 					"%02x", (unsigned char)res->lvb[i]);
+	}
 	out += snprintf(buf + out, len - out, "\n");
 
 	/* granted */
fs/ocfs2/dlm/dlmlock.c +6 -0
index 69cf369..5c7ece7 100644
@@ -425,6 +425,12 @@ static void dlm_init_lock(struct dlm_lock *newlock, int type,
 	kref_init(&newlock->lock_refs);
 }
 
+char *dlm_alloc_lvb(char **lvb)
+{
+	*lvb = kzalloc(DLM_LVB_LEN, GFP_NOFS);
+	return *lvb;
+}
+
 struct dlm_lock * dlm_new_lock(int type, u8 node, u64 cookie,
 			       struct dlm_lockstatus *lksb)
 {
fs/ocfs2/dlm/dlmmaster.c +28 -3
index ffb4c68..77315a4 100644
@@ -545,6 +545,7 @@ static void dlm_lockres_release(struct kref *kref)
 
 	kmem_cache_free(dlm_lockname_cache, (void *)res->lockname.name);
 
+	kfree(res->lvb);
 	kmem_cache_free(dlm_lockres_cache, res);
 }
 

@@ -553,7 +554,20 @@ void dlm_lockres_put(struct dlm_lock_resource *res)
 	kref_put(&res->refs, dlm_lockres_release);
 }
 
-static void dlm_init_lockres(struct dlm_ctxt *dlm,
+static int dlm_lockres_uses_lvb(struct dlm_lock_resource *res)
+{
+	switch (res->lockname.name[0]) {
+	case 'M':
+	case 'Q':
+	case 'R':
+	case 'P':
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+static int dlm_init_lockres(struct dlm_ctxt *dlm,
 			     struct dlm_lock_resource *res,
 			     const char *name, unsigned int namelen)
 {

@@ -603,8 +617,16 @@ static void dlm_init_lockres(struct dlm_ctxt *dlm,
 	list_add_tail(&res->tracking, &dlm->tracking_list);
 	spin_unlock(&dlm->spinlock);
 
-	memset(res->lvb, 0, DLM_LVB_LEN);
+	if (dlm_lockres_uses_lvb(res)) {
+		if (!dlm_alloc_lvb(&res->lvb)) {
+			mlog(ML_ERROR, "no memory for lvb\n");
+			return -ENOMEM;
+		}
+	} else {
+		res->lvb = NULL;
+	}
 	memset(res->refmap, 0, sizeof(res->refmap));
+	return 0;
 }
 
 struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,

@@ -612,6 +634,7 @@ struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,
 				   unsigned int namelen)
 {
 	struct dlm_lock_resource *res = NULL;
+	int ret;
 
 	res = kmem_cache_zalloc(dlm_lockres_cache, GFP_NOFS);
 	if (!res)

@@ -621,7 +644,9 @@ struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,
 	if (!res->lockname.name)
 		goto error;
 
-	dlm_init_lockres(dlm, res, name, namelen);
+	ret = dlm_init_lockres(dlm, res, name, namelen);
+	if (ret) 
+		goto error;
 	return res;
 
 error:
Signature · 1 line
1.7.2.1
#1 lore raw

PATCH 1/5 ocfs2/dlm: dynamically allocate lvb for dlm_lock_resource

Quoted 78 lines · Wengang Wang

This patch tries to dynamically allocate lvb for dlm_lock_resource which needs to access lvb.

Without the patch applied,
[wwg at cool linux-2.6]$ egrep "o2dlm_lockres" /proc/slabinfo
o2dlm_lockres 42 42 256 32 2 : tunables 0 0 0 : slabdata 2 2 0

After patch applied,
[wwg at cool linux-2.6]$ egrep "o2dlm_lockres" /proc/slabinfo
o2dlm_lockres 42 42 192 21 1 : tunables 0 0 0 : slabdata 2 2 0

#the result is taken on i686

Signed-off-by Wengang Wang<[email protected]>
---
  fs/ocfs2/dlm/dlmast.c    |    2 ++
  fs/ocfs2/dlm/dlmcommon.h |    3 ++-
  fs/ocfs2/dlm/dlmdebug.c  |    6 ++++--
  fs/ocfs2/dlm/dlmlock.c   |    6 ++++++
  fs/ocfs2/dlm/dlmmaster.c |   31 ++++++++++++++++++++++++++++---
  5 files changed, 42 insertions(+), 6 deletions(-)
fs/ocfs2/dlm/dlmast.c +2 -0
index f449991..fe272b1 100644
@@ -191,6 +191,8 @@ static void dlm_update_lvb(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
  			mlog(0, "getting lvb from lockres for %s node\n",
  				  lock->ml.node == dlm->node_num ? "master" :
  				  "remote");
+			mlog_bug_on_msg(!res->lvb, "lockname : %.*s\n",
+					res->lockname.len, res->lockname.name);
  			memcpy(lksb->lvb, res->lvb, DLM_LVB_LEN);
  		}
  		/* Do nothing for lvb put requests - they should be done in
fs/ocfs2/dlm/dlmcommon.h +2 -1
index 4b6ae2c..49e6492 100644
@@ -329,7 +329,7 @@ struct dlm_lock_resource
  	wait_queue_head_t wq;
  	u8  owner;              //node which owns the lock resource, or unknown
  	u16 state;
-	char lvb[DLM_LVB_LEN];
+	char *lvb;
  	unsigned int inflight_locks;
  	unsigned long refmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
  };

@@ -1033,6 +1033,7 @@ void dlm_clean_master_list(struct dlm_ctxt *dlm,
  int dlm_lock_basts_flushed(struct dlm_ctxt *dlm, struct dlm_lock *lock);
  int __dlm_lockres_has_locks(struct dlm_lock_resource *res);
  int __dlm_lockres_unused(struct dlm_lock_resource *res);
+char *dlm_alloc_lvb(char **lvb);
 
  static inline const char * dlm_lock_mode_name(int mode)
  {
fs/ocfs2/dlm/dlmdebug.c +4 -2
index 5efdd37..15a4ca2 100644
@@ -603,9 +603,11 @@ static int dump_lockres(struct dlm_lock_resource *res, char *buf, int len)
 
  	/* lvb */
  	out += snprintf(buf + out, len - out, "LVBX:");
-	for (i = 0; i<  DLM_LVB_LEN; i++)
-		out += snprintf(buf + out, len - out,
+	if (res->lvb) {
+		for (i = 0; i<  DLM_LVB_LEN; i++)
+			out += snprintf(buf + out, len - out,
  					"%02x", (unsigned char)res->lvb[i]);
+	}
  	out += snprintf(buf + out, len - out, "\n");
 
  	/* granted */
fs/ocfs2/dlm/dlmlock.c +0 -0
index 69cf369..5c7ece7 100644

fs/ocfs2/dlm/dlmlock.c static void dlm_init_lock(struct dlm_lock *newlock, int type, · line 434

Quoted 10 lines
fs/ocfs2/dlm/dlmlock.c +6 -0
@@ -425,6 +425,12 @@ static void dlm_init_lock(struct dlm_lock *newlock, int type,
  	kref_init(&newlock->lock_refs);
  }
 
+char *dlm_alloc_lvb(char **lvb)
+{
+	*lvb = kzalloc(DLM_LVB_LEN, GFP_NOFS);
+	return *lvb;
+}
+

I am not sold on this still.

Quoted 23 lines
fs/ocfs2/dlm/dlmlock.c +0 -0
  struct dlm_lock * dlm_new_lock(int type, u8 node, u64 cookie,
  			       struct dlm_lockstatus *lksb)

  {
fs/ocfs2/dlm/dlmmaster.c +4 -1
index ffb4c68..77315a4 100644
@@ -545,6 +545,7 @@ static void dlm_lockres_release(struct kref *kref)
 
  	kmem_cache_free(dlm_lockname_cache, (void *)res->lockname.name);
 
+	kfree(res->lvb);
  	kmem_cache_free(dlm_lockres_cache, res);
  }
 

@@ -553,7 +554,20 @@ void dlm_lockres_put(struct dlm_lock_resource *res)
  	kref_put(&res->refs, dlm_lockres_release);
  }
 
-static void dlm_init_lockres(struct dlm_ctxt *dlm,
+static int dlm_lockres_uses_lvb(struct dlm_lock_resource *res)
+{
+	switch (res->lockname.name[0]) {

fs/ocfs2/dlm/dlmmaster.c void dlm_lockres_put(struct dlm_lock_resource *res) · line 569

Quoted 10 lines
fs/ocfs2/dlm/dlmmaster.c +9 -0
+	case 'M':
+	case 'Q':
+	case 'R':
+	case 'P':
+		return 1;
+	default:
+		return 0;
+	}
+}

How about just passing ptr to the lockname. That will make patch#2 a lot smaller.

Quoted 9 lines
fs/ocfs2/dlm/dlmmaster.c +2 -0
+
+static int dlm_init_lockres(struct dlm_ctxt *dlm,
  			     struct dlm_lock_resource *res,
  			     const char *name, unsigned int namelen)

  {
fs/ocfs2/dlm/dlmmaster.c +0 -0
@@ -603,8 +617,16 @@ static void dlm_init_lockres(struct dlm_ctxt *dlm,
  	list_add_tail(&res->tracking,&dlm->tracking_list);
  	spin_unlock(&dlm->spinlock);

fs/ocfs2/dlm/dlmmaster.c static void dlm_init_lockres(struct dlm_ctxt *dlm, · line 628

Quoted 10 lines
fs/ocfs2/dlm/dlmmaster.c +8 -1
-	memset(res->lvb, 0, DLM_LVB_LEN);
+	if (dlm_lockres_uses_lvb(res)) {
+		if (!dlm_alloc_lvb(&res->lvb)) {
+			mlog(ML_ERROR, "no memory for lvb\n");
+			return -ENOMEM;
+		}
+	} else {
+		res->lvb = NULL;
+	}

Move the allocation to the caller dlm_new_lockres. This way all allocs for the lockres are done in one place.

Quoted 25 lines
fs/ocfs2/dlm/dlmmaster.c +1 -0
  	memset(res->refmap, 0, sizeof(res->refmap));
+	return 0;
  }

struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,

fs/ocfs2/dlm/dlmmaster.c +4 -1
@@ -612,6 +634,7 @@ struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,
  				   unsigned int namelen)
  {
  	struct dlm_lock_resource *res = NULL;
+	int ret;
 
  	res = kmem_cache_zalloc(dlm_lockres_cache, GFP_NOFS);
  	if (!res)

@@ -621,7 +644,9 @@ struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,
  	if (!res->lockname.name)
  		goto error;
 
-	dlm_init_lockres(dlm, res, name, namelen);
+	ret = dlm_init_lockres(dlm, res, name, namelen);
+	if (ret)
+		goto error;
  	return res;
 
  error:
#2 lore raw

PATCH 1/5 ocfs2/dlm: dynamically allocate lvb for dlm_lock_resource

In reply to Wengang Wang
Quoted 6 lines · Wengang Wang

This patch tries to dynamically allocate lvb for dlm_lock_resource which needs to access lvb.

Without the patch applied,
[wwg at cool linux-2.6]$ egrep "o2dlm_lockres" /proc/slabinfo
o2dlm_lockres 42 42 256 32 2 : tunables 0 0 0 : slabdata 2 2 0

Quoted 6 lines

After patch applied,
[wwg at cool linux-2.6]$ egrep "o2dlm_lockres" /proc/slabinfo
o2dlm_lockres 42 42 192 21 1 : tunables 0 0 0 : slabdata 2 2 0

#the result is taken on i686

So the core logic allocates a lvb or not based on the lock name. That will not work because we support userdlm (not to be confused with userspace stack that uses fsdlm) that allows the user to specify the name.

A better solution is to make the user pass in a flag to create the lvb. That's one issue.

The other issue concerns the real savings. While the savings on a per lockres basis are impressive (will be even more on a 64-bit system), I am unsure on the overall savings.

To check that, run some workload... like a kernel build (one node should be sufficient) and gather some numbers below.

# cd /sys/kernel/debug/o2dlm/<domain>
# grep -h "^NAME:" locking_state | sort | cut -c6 | uniq -c

Marcos, Can you also gather this stat when you run metadata heavy tests.

Thanks
Sunil

#3 lore raw

PATCH 1/5 ocfs2/dlm: dynamically allocate lvb for dlm_lock_resource

Sunil,

I ran buildkernel and collect some of the stats that you requested.

You can find them at http://oss.oracle.com/~mmatsuna/ocfs2-stats/ and the files are:
ocfs2-stat-6850.log
<http://oss.oracle.com/%7Emmatsuna/ocfs2-stats/ocfs2-stat-6850.log>

ocfs2-stat-6942.log <http://oss.oracle.com/%7Emmatsuna/ocfs2-stats/ocfs2-stat-6942.log>
ocfs2-stat-10059.log <http://oss.oracle.com/%7Emmatsuna/ocfs2-stats/ocfs2-stat-10059.log>
ocfs2-stat-32460.log <http://oss.oracle.com/%7Emmatsuna/ocfs2-stats/ocfs2-stat-32460.log>

I collected samples every 30 seconds on all nodes. Each node starts two builds in parallel and the make command is "make -j2 V=1".

Quoted 33 lines · Sunil Mushran
Quoted 6 lines · Wengang Wang

This patch tries to dynamically allocate lvb for dlm_lock_resource which needs to access lvb.

Without the patch applied,
[wwg at cool linux-2.6]$ egrep "o2dlm_lockres" /proc/slabinfo
o2dlm_lockres 42 42 256 32 2 : tunables 0 0 0 : slabdata 2 2 0

Quoted 6 lines

After patch applied,
[wwg at cool linux-2.6]$ egrep "o2dlm_lockres" /proc/slabinfo
o2dlm_lockres 42 42 192 21 1 : tunables 0 0 0 : slabdata 2 2 0

#the result is taken on i686

So the core logic allocates a lvb or not based on the lock name. That will not work because we support userdlm (not to be confused with userspace stack that uses fsdlm) that allows the user to specify the name.

A better solution is to make the user pass in a flag to create the lvb. That's one issue.

The other issue concerns the real savings. While the savings on a per lockres basis are impressive (will be even more on a 64-bit system), I am unsure on the overall savings.

To check that, run some workload... like a kernel build (one node should be sufficient) and gather some numbers below.

# cd /sys/kernel/debug/o2dlm/<domain>
# grep -h "^NAME:" locking_state | sort | cut -c6 | uniq -c

Marcos, Can you also gather this stat when you run metadata heavy tests.

Quoted 7 lines

Thanks
Sunil

_______________________________________________
Ocfs2-devel mailing list
Ocfs2-devel at oss.oracle.com
http://oss.oracle.com/mailman/listinfo/ocfs2-devel

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#4 lore raw

PATCH 1/5 ocfs2/dlm: dynamically allocate lvb for dlm_lock_resource

===== 2010-09-13 : 20:25 UUID:4D5296E659E349F0997FA8997E007D8E =====
85733 M
45077 N
85714 O

       1 P
       2 Q
       1 S
    2249 W
       1 Y

I guess the feature will be useful considering the number of lockres' with lvb is less than half. Sometimes a third. So significant savings.

Having said that, it should be noted that the test itself is a bit biased as a kernel build will have more than normal number of open/dentry locks.

Still, I would vote for the savings.

Wengang,
BTW, we are already passing the lvb flag. Grep on DLM_LKF_VALBLK and LKM_VALBLK. Much better if we key on that rather than the lock name.

Sunil

Quoted 12 lines · MARCOS MATSUNAGA

Sunil,

I ran buildkernel and collect some of the stats that you requested.

You can find them at http://oss.oracle.com/~mmatsuna/ocfs2-stats/ and
the files are:
ocfs2-stat-6850.log
<http://oss.oracle.com/%7Emmatsuna/ocfs2-stats/ocfs2-stat-6850.log>
ocfs2-stat-6942.log <http://oss.oracle.com/%7Emmatsuna/ocfs2-stats/ocfs2-stat-6942.log>
ocfs2-stat-10059.log <http://oss.oracle.com/%7Emmatsuna/ocfs2-stats/ocfs2-stat-10059.log>
ocfs2-stat-32460.log <http://oss.oracle.com/%7Emmatsuna/ocfs2-stats/ocfs2-stat-32460.log>

Quoted 47 lines

I collected samples every 30 seconds on all nodes. Each node starts two builds in parallel and the make command is "make -j2 V=1".

Quoted 43 lines · Sunil Mushran
Quoted 6 lines · Wengang Wang

This patch tries to dynamically allocate lvb for dlm_lock_resource which needs to access lvb.

Without the patch applied,
[wwg at cool linux-2.6]$ egrep "o2dlm_lockres" /proc/slabinfo
o2dlm_lockres 42 42 256 32 2 : tunables 0 0 0 : slabdata 2 2 0

Quoted 7 lines

After patch applied,
[wwg at cool linux-2.6]$ egrep "o2dlm_lockres" /proc/slabinfo
o2dlm_lockres 42 42 192 21 1 : tunables 0 0 0 : slabdata 2 2 0

#the result is taken on i686

So the core logic allocates a lvb or not based on the lock name. That will not work because we support userdlm (not to be confused with userspace stack that uses fsdlm) that allows the user to specify the name.

A better solution is to make the user pass in a flag to create the lvb. That's one issue.

The other issue concerns the real savings. While the savings on a per lockres basis are impressive (will be even more on a 64-bit system), I am unsure on the overall savings.

To check that, run some workload... like a kernel build (one node should be sufficient) and gather some numbers below.

# cd /sys/kernel/debug/o2dlm/<domain>
# grep -h "^NAME:" locking_state | sort | cut -c6 | uniq -c

Marcos, Can you also gather this stat when you run metadata heavy tests.

Thanks
Sunil

_______________________________________________
Ocfs2-devel mailing list
Ocfs2-devel at oss.oracle.com
http://oss.oracle.com/mailman/listinfo/ocfs2-devel

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