pgsql/ oc/src/sgml/wal.sgml rc/backend/access/ ...

CVSROOT:    /cvsroot
Module name:    pgsql
Changes by:    tgl@postgresql.org    01/09/29 00:02:27

Modified files:
    doc/src/sgml   : wal.sgml
    src/backend/access/transam: clog.c varsup.c xact.c xlog.c
    src/backend/bootstrap: bootparse.y bootstrap.c
    src/backend/commands: vacuumlazy.c
    src/backend/storage/buffer: README buf_init.c buf_table.c
                                bufmgr.c freelist.c
    src/backend/storage/freespace: freespace.c
    src/backend/storage/ipc: ipc.c ipci.c shmem.c sinval.c
                             sinvaladt.c
    src/backend/storage/lmgr: Makefile README deadlock.c lock.c
                              proc.c s_lock.c spin.c
    src/backend/storage/smgr: mm.c smgr.c
    src/backend/utils/init: postinit.c
    src/backend/utils/misc: guc.c postgresql.conf.sample
    src/include/access: clog.h transam.h
    src/include    : miscadmin.h
    src/include/storage: buf_internals.h freespace.h ipc.h lock.h
                         proc.h s_lock.h shmem.h sinval.h smgr.h
                         spin.h
Added files:
    src/backend/storage/lmgr: lwlock.c
    src/include/storage: lwlock.h

Log message:
    Implement new 'lightweight lock manager' that's intermediate between
    existing lock manager and spinlocks: it understands exclusive vs shared
    lock but has few other fancy features.  Replace most uses of spinlocks
    with lightweight locks.  All remaining uses of spinlocks have very short
    lock hold times (a few dozen instructions), so tweak spinlock backoff
    code to work efficiently given this assumption.  All per my proposal on
    pghackers 26-Sep-01.