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Divide the lock manager's shared state into 'partitions', so as to

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reduce contention for the former single LockMgrLock.  Per my recent
proposal.  I set it up for 16 partitions, but on a pgbench test this
gives only a marginal further improvement over 4 partitions --- we need
to test more scenarios to choose the number of partitions.
This commit is contained in:
Tom Lane
2005-12-11 21:02:18 +00:00
parent be8100d64e
commit ec0baf949e
10 changed files with 643 additions and 415 deletions
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20
src/backend/storage/lmgr/deadlock.c
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@@ -12,7 +12,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/storage/lmgr/deadlock.c,v 1.37 2005/12/09 01:22:04 tgl Exp $
* $PostgreSQL: pgsql/src/backend/storage/lmgr/deadlock.c,v 1.38 2005/12/11 21:02:18 tgl Exp $
*
* Interface:
*
@@ -53,9 +53,9 @@ typedef struct
* Information saved about each edge in a detected deadlock cycle. This
* is used to print a diagnostic message upon failure.
*
* Note: because we want to examine this info after releasing the LockMgrLock,
* we can't just store LOCK and PGPROC pointers; we must extract out all the
* info we want to be able to print.
* Note: because we want to examine this info after releasing the lock
* manager's partition locks, we can't just store LOCK and PGPROC pointers;
* we must extract out all the info we want to be able to print.
*/
typedef struct
{
@@ -188,19 +188,11 @@ InitDeadLockChecking(void)
* deadlock. If resolution is impossible, return TRUE --- the caller
* is then expected to abort the given proc's transaction.
*
* We can't block on user locks, so no sense testing for deadlock
* because there is no blocking, and no timer for the block. So,
* only look at regular locks.
*
* We must have already locked the master lock before being called.
* NOTE: although the lockmethod structure appears to allow each lock
* table to have a different masterLock, all locks that can block had
* better use the same LWLock, else this code will not be adequately
* interlocked!
* Caller must already have locked all partitions of the lock tables.
*
* On failure, deadlock details are recorded in deadlockDetails[] for
* subsequent printing by DeadLockReport(). That activity is separate
* because we don't want to do it while holding the master lock.
* because we don't want to do it while holding all those LWLocks.
*/
bool
DeadLockCheck(PGPROC *proc)