Tue Jul 14 19:56:31 PDT 2009

commit ae8e83e6e95ab527d7528e1f38a1f95aa251908e
Author: Matthew Dillon <dillon at apollo.backplane.com>
Date:   Tue Jul 14 19:31:18 2009 -0700

    MPSAFE - tsleep_interlock, BUF/BIO, cluster, swap_pager.
    
    * tsleep_interlock()/tsleep() could miss wakeups during periods of
      heavy cpu activity.  What would happen is code inbetween the two
      calls would try to send an IPI (say, issue a wakeup()), but while
      sending the IPI the kernel would be forced to process incoming IPIs
      synchronous to avoid a deadlock.
    
      The new tsleep_interlock()/tsleep() code adds another TAILQ_ENTRY to
      the thread structure allowing tsleep_interlock() to formally place
      the thread on the appropriate sleep queue without having to deschedule
      the thread.  Any wakeup which occurs between the interlock and the
      real tsleep() call will remove the thread from the queue and the
      later tsleep() call will recognize this and simply return without sleeping.
    
      The new tsleep() call requires PINTERLOCKED to be passed to tsleep
      so tsleep() knows that the thread has already been placed on a sleep
      queue.
    
    * Continue making BUF/BIO MPSAFE.  Remove B_ASYNC and B_WANT from buf->b_flag
      and add a new bio->bio_flags field to the bio.  Add BIO_SYNC, BIO_WANT,
      and BIO_DONE.  Use atomic_cmpset_int() (aka cmpxchg) to interlock
      biodone() against biowait().
    
      vn_strategy() and dev_dstrategy() call semantics now require that
      synchronous BIO's install a bio_done function and set BIO_SYNC in
      the bio.
    
    * Clean up the cluster code a bit.
    
    * Redo the swap_pager code.  Instead of issuing I/O during the collection,
      which depended on critical sections to avoid races in the cluster append,
      we now build the entire collection first and then dispatch the I/O.
      This allows us to use only async completion for the BIOs, instead of
      a hybrid sync-or-async completion.

Summary of changes:
 sys/bus/cam/cam_sim.c               |    4 +-
 sys/bus/cam/cam_xpt.c               |    4 +-
 sys/dev/disk/ahci/ahci_dragonfly.c  |    4 +-
 sys/dev/disk/aic7xxx/aic_osm_lib.c  |    8 +-
 sys/dev/disk/ata/ata-raid.c         |   25 +--
 sys/dev/disk/fd/fd.c                |   19 +--
 sys/dev/disk/nata/ata-raid.c        |    4 +-
 sys/dev/disk/sili/sili_dragonfly.c  |    4 +-
 sys/dev/disk/vn/vn.c                |    2 -
 sys/dev/drm/drmP.h                  |    4 +-
 sys/dev/drm/drm_drv.c               |    6 +-
 sys/dev/drm/drm_lock.c              |    4 +-
 sys/dev/drm/radeon_cp.c             |   10 +-
 sys/dev/netif/iwi/if_iwi.c          |   20 +--
 sys/dev/raid/aac/aac.c              |   12 +-
 sys/dev/raid/vinum/vinuminterrupt.c |    1 +
 sys/dev/raid/vinum/vinumio.c        |    4 +-
 sys/dev/raid/vinum/vinumrequest.c   |    3 +-
 sys/dev/raid/vinum/vinumrevive.c    |   14 +-
 sys/dev/sound/pcm/sound.c           |    4 +-
 sys/kern/kern_device.c              |    5 +-
 sys/kern/kern_lock.c                |    6 +-
 sys/kern/kern_physio.c              |   15 +-
 sys/kern/kern_synch.c               |  252 ++++++++++++---------
 sys/kern/kern_umtx.c                |    2 +-
 sys/kern/lwkt_ipiq.c                |    4 +-
 sys/kern/lwkt_serialize.c           |    9 +-
 sys/kern/lwkt_thread.c              |   11 +
 sys/kern/subr_bus.c                 |    4 +-
 sys/kern/subr_diskgpt.c             |    8 +-
 sys/kern/subr_disklabel32.c         |   16 +-
 sys/kern/subr_disklabel64.c         |   12 +-
 sys/kern/subr_diskmbr.c             |    8 +-
 sys/kern/sys_pipe.c                 |    4 +-
 sys/kern/vfs_aio.c                  |   22 +-
 sys/kern/vfs_bio.c                  |  420 ++++++++++++++++++++++-------------
 sys/kern/vfs_cluster.c              |   96 +++++----
 sys/kern/vfs_subr.c                 |   16 +-
 sys/kern/vfs_vnops.c                |    4 +-
 sys/net/tap/if_tap.c                |    4 +-
 sys/netproto/smb/smb_subr.c         |    4 +-
 sys/sys/bio.h                       |    8 +
 sys/sys/buf.h                       |   26 +--
 sys/sys/buf2.h                      |   14 ++
 sys/sys/systm.h                     |    3 +-
 sys/sys/thread.h                    |    3 +-
 sys/vfs/gnu/ext2fs/ext2_bmap.c      |    9 +-
 sys/vfs/gnu/ext2fs/ext2_inode.c     |    4 +-
 sys/vfs/hammer/hammer_io.c          |   41 +---
 sys/vfs/hammer/hammer_subs.c        |    8 +-
 sys/vfs/mfs/mfs_vnops.c             |    1 -
 sys/vfs/nfs/nfs_bio.c               |   32 +++-
 sys/vfs/nfs/nfs_serv.c              |   13 +-
 sys/vfs/nfs/nfs_syscalls.c          |    1 +
 sys/vfs/nfs/nfs_vnops.c             |    9 +-
 sys/vfs/nwfs/nwfs_io.c              |    7 +-
 sys/vfs/nwfs/nwfs_vnops.c           |    5 +-
 sys/vfs/smbfs/smbfs_io.c            |    7 +-
 sys/vfs/smbfs/smbfs_vnops.c         |    5 +-
 sys/vfs/specfs/spec_vnops.c         |   33 +--
 sys/vfs/ufs/ffs_balloc.c            |    1 -
 sys/vfs/ufs/ffs_inode.c             |    8 +-
 sys/vfs/ufs/ffs_rawread.c           |   28 +--
 sys/vfs/ufs/ufs_bmap.c              |    9 +-
 sys/vm/swap_pager.c                 |  178 +++++-----------
 65 files changed, 784 insertions(+), 747 deletions(-)

http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff/ae8e83e6e95ab527d7528e1f38a1f95aa251908e


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