From: Stefan Metzmacher <metze@samba.org>
Date: Thu, 30 Jun 2022 10:39:18 +0000 (+0000)
Subject: s3:dbwrap_watch: call dbwrap_watched_trigger_wakeup() outside of the low level record... 
X-Git-Tag: ldb-2.6.1~14
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d5c7e2e27385a4730ff8674650700bd25b77f975;p=thirdparty%2Fsamba.git

s3:dbwrap_watch: call dbwrap_watched_trigger_wakeup() outside of the low level record lock

This gives a nice speed up, as it's unlikely for the waiters to hit
contention.

The following test with 256 commections all looping with open/close
on the same inode (share root) is improved drastically:

  smbtorture //127.0.0.1/m -Uroot%test smb2.create.bench-path-contention-shared \
     --option='torture:bench_path=' \
     --option="torture:timelimit=60" \
     --option="torture:nprocs=256"

From some like this:

   open[num/s=8800,avslat=0.021445,minlat=0.000095,maxlat=0.179786]
   close[num/s=8800,avslat=0.021658,minlat=0.000044,maxlat=0.179819]

to:

   open[num/s=10223,avslat=0.017922,minlat=0.000083,maxlat=0.106759]
   close[num/s=10223,avslat=0.017694,minlat=0.000040,maxlat=0.107345]

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15125

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>

Autobuild-User(master): Ralph Böhme <slow@samba.org>
Autobuild-Date(master): Tue Jul 26 14:32:35 UTC 2022 on sn-devel-184
---

diff --git a/source3/lib/dbwrap/dbwrap_watch.c b/source3/lib/dbwrap/dbwrap_watch.c
index 96eaefc1a41..e5b11aa124e 100644
--- a/source3/lib/dbwrap/dbwrap_watch.c
+++ b/source3/lib/dbwrap/dbwrap_watch.c
@@ -143,7 +143,6 @@ struct db_watched_ctx {
 struct db_watched_record {
 	struct db_record *rec;
 	struct server_id self;
-	struct messaging_context *msg_ctx;
 	struct {
 		struct db_record *rec;
 		TDB_DATA initial_value;
@@ -211,6 +210,8 @@ static NTSTATUS dbwrap_watched_storev(struct db_record *rec,
 				      const TDB_DATA *dbufs, int num_dbufs,
 				      int flags);
 static NTSTATUS dbwrap_watched_delete(struct db_record *rec);
+static void dbwrap_watched_trigger_wakeup(struct messaging_context *msg_ctx,
+					  struct dbwrap_watcher *watcher);
 static int db_watched_record_destructor(struct db_watched_record *wrec);
 
 static void db_watched_record_init(struct db_context *db,
@@ -233,7 +234,6 @@ static void db_watched_record_init(struct db_context *db,
 	*wrec = (struct db_watched_record) {
 		.rec = rec,
 		.self = messaging_server_id(msg_ctx),
-		.msg_ctx = msg_ctx,
 		.backend = {
 			.rec = backend_rec,
 			.initial_value = backend_value,
@@ -422,7 +422,13 @@ static void db_watched_record_fini(struct db_watched_record *wrec)
 
 static int db_watched_record_destructor(struct db_watched_record *wrec)
 {
+	struct db_record *rec = wrec->rec;
+	struct db_watched_ctx *ctx = talloc_get_type_abort(
+		rec->db->private_data, struct db_watched_ctx);
+
 	db_watched_record_fini(wrec);
+	TALLOC_FREE(wrec->backend.rec);
+	dbwrap_watched_trigger_wakeup(ctx->msg, &wrec->wakeup.watcher);
 	return 0;
 }
 
@@ -480,6 +486,8 @@ static NTSTATUS dbwrap_watched_do_locked(struct db_context *db, TDB_DATA key,
 
 	DBG_DEBUG("dbwrap_watched_do_locked_fn returned\n");
 
+	dbwrap_watched_trigger_wakeup(state.msg_ctx, &wrec.wakeup.watcher);
+
 	return NT_STATUS_OK;
 }
 
@@ -562,13 +570,6 @@ static void dbwrap_watched_trigger_wakeup(struct messaging_context *msg_ctx,
 	}
 }
 
-static void dbwrap_watched_record_wakeup(
-	struct db_watched_record *wrec)
-{
-	dbwrap_watched_record_prepare_wakeup(wrec);
-	dbwrap_watched_trigger_wakeup(wrec->msg_ctx, &wrec->wakeup.watcher);
-}
-
 static NTSTATUS dbwrap_watched_record_storev(
 	struct db_watched_record *wrec,
 	const TDB_DATA *dbufs, int num_dbufs, int flags)
@@ -581,7 +582,7 @@ static NTSTATUS dbwrap_watched_record_storev(
 	NTSTATUS status;
 	size_t add_count = 0;
 
-	dbwrap_watched_record_wakeup(wrec);
+	dbwrap_watched_record_prepare_wakeup(wrec);
 
 	wrec->backend.initial_valid = false;
 	wrec->force_fini_store = false;