1. 22 Nov, 2010 3 commits
    • Thomas Hellstrom's avatar
      kref: Add a kref_sub function · ecf7ace9
      Thomas Hellstrom authored
      Makes it possible to optimize batched multiple unrefs.
      Initial user will be drivers/gpu/ttm which accumulates unrefs to be
      processed outside of atomic code.
      Signed-off-by: default avatarThomas Hellstrom <thellstrom@vmware.com>
      Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
      ecf7ace9
    • Dave Airlie's avatar
      drm/ttm: Add a bo list reserve fastpath (v2) · d6ea8886
      Dave Airlie authored
      Makes it possible to reserve a list of buffer objects with a single
      spin lock / unlock if there is no contention.
      Should improve cpu usage on SMP kernels.
      
      v2: Initialize private list members on reserve and don't call
      ttm_bo_list_ref_sub() with zero put_count.
      Signed-off-by: default avatarThomas Hellstrom <thellstrom@vmware.com>
      Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
      d6ea8886
    • Mario Kleiner's avatar
      drm/vblank: Add support for precise vblank timestamping. · 27641c3f
      Mario Kleiner authored
      The DRI2 swap & sync implementation needs precise
      vblank counts and precise timestamps corresponding
      to those vblank counts. For conformance to the OpenML
      OML_sync_control extension specification the DRM
      timestamp associated with a vblank count should
      correspond to the start of video scanout of the first
      scanline of the video frame following the vblank
      interval for that vblank count.
      
      Therefore we need to carry around precise timestamps
      for vblanks. Currently the DRM and KMS drivers generate
      timestamps ad-hoc via do_gettimeofday() in some
      places. The resulting timestamps are sometimes not
      very precise due to interrupt handling delays, they
      don't conform to OML_sync_control and some are wrong,
      as they aren't taken synchronized to the vblank.
      
      This patch implements support inside the drm core
      for precise and robust timestamping. It consists
      of the following interrelated pieces.
      
      1. Vblank timestamp caching:
      
      A per-crtc ringbuffer stores the most recent vblank
      timestamps corresponding to vblank counts.
      
      The ringbuffer can be read out lock-free via the
      accessor function:
      
      struct timeval timestamp;
      vblankcount = drm_vblank_count_and_time(dev, crtcid, &timestamp).
      
      The function returns the current vblank count and
      the corresponding timestamp for start of video
      scanout following the vblank interval. It can be
      used anywhere between enclosing drm_vblank_get(dev, crtcid)
      and drm_vblank_put(dev,crtcid) statements. It is used
      inside the drmWaitVblank ioctl and in the vblank event
      queueing and handling. It should be used by kms drivers for
      timestamping of bufferswap completion.
      
      The timestamp ringbuffer is reinitialized each time
      vblank irq's get reenabled in drm_vblank_get()/
      drm_update_vblank_count(). It is invalidated when
      vblank irq's get disabled.
      
      The ringbuffer is updated inside drm_handle_vblank()
      at each vblank irq.
      
      2. Calculation of precise vblank timestamps:
      
      drm_get_last_vbltimestamp() is used to compute the
      timestamp for the end of the most recent vblank (if
      inside active scanout), or the expected end of the
      current vblank interval (if called inside a vblank
      interval). The function calls into a new optional kms
      driver entry point dev->driver->get_vblank_timestamp()
      which is supposed to provide the precise timestamp.
      If a kms driver doesn't implement the entry point or
      if the call fails, a simple do_gettimeofday() timestamp
      is returned as crude approximation of the true vblank time.
      
      A new drm module parameter drm.timestamp_precision_usec
      allows to disable high precision timestamps (if set to
      zero) or to specify the maximum acceptable error in
      the timestamps in microseconds.
      
      Kms drivers could implement their get_vblank_timestamp()
      function in a gpu specific way, as long as returned
      timestamps conform to OML_sync_control, e.g., by use
      of gpu specific hardware timestamps.
      
      Optionally, kms drivers can simply wrap and use the new
      utility function drm_calc_vbltimestamp_from_scanoutpos().
      This function calls a new optional kms driver function
      dev->driver->get_scanout_position() which returns the
      current horizontal and vertical video scanout position
      of the crtc. The scanout position together with the
      drm_display_timing of the current video mode is used
      to calculate elapsed time relative to start of active scanout
      for the current video frame. This elapsed time is subtracted
      from the current do_gettimeofday() time to get the timestamp
      corresponding to start of video scanout. Currently
      non-interlaced, non-doublescan video modes, with or
      without panel scaling are handled correctly. Interlaced/
      doublescan modes are tbd in a future patch.
      
      3. Filtering of redundant vblank irq's and removal of
      some race-conditions in the vblank irq enable/disable path:
      
      Some gpu's (e.g., Radeon R500/R600) send spurious vblank
      irq's outside the vblank if vblank irq's get reenabled.
      These get detected by use of the vblank timestamps and
      filtered out to avoid miscounting of vblanks.
      
      Some race-conditions between the vblank irq enable/disable
      functions, the vblank irq handler and the gpu itself (updating
      its hardware vblank counter in the "wrong" moment) are
      fixed inside vblank_disable_and_save() and
      drm_update_vblank_count() by use of the vblank timestamps and
      a new spinlock dev->vblank_time_lock.
      
      The time until vblank irq disable is now configurable via
      a new drm module parameter drm.vblankoffdelay to allow
      experimentation with timeouts that are much shorter than
      the current 5 seconds and should allow longer vblank off
      periods for better power savings.
      
      Followup patches will use these new functions to
      implement precise timestamping for the intel and radeon
      kms drivers.
      Signed-off-by: default avatarMario Kleiner <mario.kleiner@tuebingen.mpg.de>
      Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
      27641c3f
  2. 21 Nov, 2010 1 commit
  3. 20 Nov, 2010 3 commits
    • Linus Torvalds's avatar
      Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 · b86db474
      Linus Torvalds authored
      * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
        ext4: Add EXT4_IOC_TRIM ioctl to handle batched discard
        fs: Do not dispatch FITRIM through separate super_operation
        ext4: ext4_fill_super shouldn't return 0 on corruption
        jbd2: fix /proc/fs/jbd2/<dev> when using an external journal
        ext4: missing unlock in ext4_clear_request_list()
        ext4: fix setting random pages PageUptodate
      b86db474
    • Lukas Czerner's avatar
      ext4: Add EXT4_IOC_TRIM ioctl to handle batched discard · e681c047
      Lukas Czerner authored
      Filesystem independent ioctl was rejected as not common enough to be in
      core vfs ioctl. Since we still need to access to this functionality this
      commit adds ext4 specific ioctl EXT4_IOC_TRIM to dispatch
      ext4_trim_fs().
      
      It takes fstrim_range structure as an argument. fstrim_range is definec in
      the include/linux/fs.h and its definition is as follows.
      
      struct fstrim_range {
      	__u64 start;
      	__u64 len;
      	__u64 minlen;
      }
      
      start	- first Byte to trim
      len	- number of Bytes to trim from start
      minlen	- minimum extent length to trim, free extents shorter than this
        number of Bytes will be ignored. This will be rounded up to fs
        block size.
      
      After the FITRIM is done, the number of actually discarded Bytes is stored
      in fstrim_range.len to give the user better insight on how much storage
      space has been really released for wear-leveling.
      Signed-off-by: default avatarLukas Czerner <lczerner@redhat.com>
      Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
      e681c047
    • Lukas Czerner's avatar
      fs: Do not dispatch FITRIM through separate super_operation · 93bb41f4
      Lukas Czerner authored
      There was concern that FITRIM ioctl is not common enough to be included
      in core vfs ioctl, as Christoph Hellwig pointed out there's no real point
      in dispatching this out to a separate vector instead of just through
      ->ioctl.
      
      So this commit removes ioctl_fstrim() from vfs ioctl and trim_fs
      from super_operation structure.
      Signed-off-by: default avatarLukas Czerner <lczerner@redhat.com>
      Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
      93bb41f4
  4. 19 Nov, 2010 15 commits
  5. 18 Nov, 2010 18 commits