[PATCH] Update two optimisations that check for oplocks to the lease area

Ralph Böhme slow at samba.org
Thu May 4 10:26:48 UTC 2017


Hi!

This is the one I talked about in my talk.

I took another look and found another plase where we need this.

Both combined eat 12%CPU in perf, not including syscalls.

Please review carefully and push if ok. Thanks!

-slow
-------------- next part --------------
From 56f1da66edd62ffb7192a462664227fe9c0ae3f2 Mon Sep 17 00:00:00 2001
From: Ralph Boehme <slow at samba.org>
Date: Thu, 4 May 2017 11:50:01 +0200
Subject: [PATCH 1/4] s3/locking: add const to fsp_lease_type

Bug: https://bugzilla.samba.org/show_bug.cgi?id=12766

Signed-off-by: Ralph Boehme <slow at samba.org>
---
 source3/locking/leases_util.c | 2 +-
 source3/locking/proto.h       | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/source3/locking/leases_util.c b/source3/locking/leases_util.c
index cb307c8..5d07ff9 100644
--- a/source3/locking/leases_util.c
+++ b/source3/locking/leases_util.c
@@ -46,7 +46,7 @@ uint32_t map_oplock_to_lease_type(uint16_t op_type)
 	return ret;
 }
 
-uint32_t fsp_lease_type(struct files_struct *fsp)
+uint32_t fsp_lease_type(const struct files_struct *fsp)
 {
 	if (fsp->oplock_type == LEASE_OPLOCK) {
 		return fsp->lease->lease.lease_state;
diff --git a/source3/locking/proto.h b/source3/locking/proto.h
index 967af02..44ab315 100644
--- a/source3/locking/proto.h
+++ b/source3/locking/proto.h
@@ -257,6 +257,6 @@ bool release_posix_lock_posix_flavour(files_struct *fsp,
 
 /* The following definitions come from locking/leases_util.c */
 uint32_t map_oplock_to_lease_type(uint16_t op_type);
-uint32_t fsp_lease_type(struct files_struct *fsp);
+uint32_t fsp_lease_type(const struct files_struct *fsp);
 
 #endif /* _LOCKING_PROTO_H_ */
-- 
2.9.3


From 4c224ecd9f91fb89298ee91161e866643d494902 Mon Sep 17 00:00:00 2001
From: Ralph Boehme <slow at samba.org>
Date: Thu, 4 May 2017 11:50:56 +0200
Subject: [PATCH 2/4] s3/locking: helper functions for lease types

Add some helper functions that will be used to update a bunch of checks
for exclusive oplocks to the lease area.

Bug: https://bugzilla.samba.org/show_bug.cgi?id=12766

Signed-off-by: Ralph Boehme <slow at samba.org>
---
 source3/locking/leases_util.c | 17 +++++++++++++++++
 source3/locking/proto.h       |  2 ++
 2 files changed, 19 insertions(+)

diff --git a/source3/locking/leases_util.c b/source3/locking/leases_util.c
index 5d07ff9..af1e837 100644
--- a/source3/locking/leases_util.c
+++ b/source3/locking/leases_util.c
@@ -53,3 +53,20 @@ uint32_t fsp_lease_type(const struct files_struct *fsp)
 	}
 	return map_oplock_to_lease_type(fsp->oplock_type);
 }
+
+uint32_t lease_type_is_exclusive(uint32_t lease_type)
+{
+	if ((lease_type & (SMB2_LEASE_READ | SMB2_LEASE_WRITE)) ==
+	    (SMB2_LEASE_READ | SMB2_LEASE_WRITE)) {
+		return true;
+	}
+
+	return false;
+}
+
+bool fsp_lease_type_is_exclusive(const struct files_struct *fsp)
+{
+	uint32_t lease_type = fsp_lease_type(fsp);
+
+	return lease_type_is_exclusive(lease_type);
+}
diff --git a/source3/locking/proto.h b/source3/locking/proto.h
index 44ab315..5d2326a 100644
--- a/source3/locking/proto.h
+++ b/source3/locking/proto.h
@@ -258,5 +258,7 @@ bool release_posix_lock_posix_flavour(files_struct *fsp,
 /* The following definitions come from locking/leases_util.c */
 uint32_t map_oplock_to_lease_type(uint16_t op_type);
 uint32_t fsp_lease_type(const struct files_struct *fsp);
+uint32_t lease_type_is_exclusive(uint32_t lease_type);
+bool fsp_lease_type_is_exclusive(const struct files_struct *fsp);
 
 #endif /* _LOCKING_PROTO_H_ */
-- 
2.9.3


From b704c881885498cf308cd867106a4a33b530fd28 Mon Sep 17 00:00:00 2001
From: Ralph Boehme <slow at samba.org>
Date: Thu, 20 Apr 2017 21:37:37 +0200
Subject: [PATCH 3/4] s3/smbd: update exclusive oplock optimisation to the
 lease area

This is similar to 9533a55ee5ffe430589dcea845851b84876ef656 but this
time in the contend_level2_oplocks_begin_default() function.

The idea of the optimisation is to avoid expensive db queries in
locking.tdb if we *know* we're the only open.

Bug: https://bugzilla.samba.org/show_bug.cgi?id=12766

Signed-off-by: Ralph Boehme <slow at samba.org>
---
 source3/smbd/oplock.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/source3/smbd/oplock.c b/source3/smbd/oplock.c
index 417eda5..cd92c83 100644
--- a/source3/smbd/oplock.c
+++ b/source3/smbd/oplock.c
@@ -1044,7 +1044,7 @@ static void contend_level2_oplocks_begin_default(files_struct *fsp,
 	 * the shared memory area whilst doing this.
 	 */
 
-	if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
+	if (fsp_lease_type_is_exclusive(fsp)) {
 		/*
 		 * There can't be any level2 oplocks, we're alone.
 		 */
-- 
2.9.3


From 2b47711a7a93a7a92f04d5083de6939b8b4685d6 Mon Sep 17 00:00:00 2001
From: Ralph Boehme <slow at samba.org>
Date: Thu, 4 May 2017 11:52:16 +0200
Subject: [PATCH 4/4] s3/smbd: update exclusive oplock optimisation to the
 lease area

Update an optimisation in update_num_read_oplocks() that checks for
exclusive oplocks to the lease area.

The idea of the optimisation is to avoid expensive db queries in
brlock.tdb if we *know* we're the only open.

Bug: https://bugzilla.samba.org/show_bug.cgi?id=12766

Signed-off-by: Ralph Boehme <slow at samba.org>
---
 source3/smbd/oplock.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/source3/smbd/oplock.c b/source3/smbd/oplock.c
index cd92c83..87ca53c 100644
--- a/source3/smbd/oplock.c
+++ b/source3/smbd/oplock.c
@@ -166,13 +166,17 @@ bool update_num_read_oplocks(files_struct *fsp, struct share_mode_lock *lck)
 	uint32_t num_read_oplocks = 0;
 	uint32_t i;
 
-	if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
+	if (fsp_lease_type_is_exclusive(fsp)) {
+		uint32_t lease_type;
+
 		/*
 		 * If we're the only one, we don't need a brlock entry
 		 */
 		remove_stale_share_mode_entries(d);
 		SMB_ASSERT(d->num_share_modes == 1);
-		SMB_ASSERT(EXCLUSIVE_OPLOCK_TYPE(d->share_modes[0].op_type));
+
+		lease_type = get_lease_type(d, 0);
+		SMB_ASSERT(lease_type_is_exclusive(lease_type));
 		return true;
 	}
 
-- 
2.9.3



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