1. 12 8月, 2010 3 次提交
    • A
      mmc: add erase, secure erase, trim and secure trim operations · dfe86cba
      Adrian Hunter 提交于
      SD/MMC cards tend to support an erase operation.  In addition, eMMC v4.4
      cards can support secure erase, trim and secure trim operations that are
      all variants of the basic erase command.
      
      SD/MMC device attributes "erase_size" and "preferred_erase_size" have been
      added.
      
      "erase_size" is the minimum size, in bytes, of an erase operation.  For
      MMC, "erase_size" is the erase group size reported by the card.  Note that
      "erase_size" does not apply to trim or secure trim operations where the
      minimum size is always one 512 byte sector.  For SD, "erase_size" is 512
      if the card is block-addressed, 0 otherwise.
      
      SD/MMC cards can erase an arbitrarily large area up to and
      including the whole card.  When erasing a large area it may
      be desirable to do it in smaller chunks for three reasons:
      
          1. A single erase command will make all other I/O on the card
             wait.  This is not a problem if the whole card is being erased, but
             erasing one partition will make I/O for another partition on the
             same card wait for the duration of the erase - which could be a
             several minutes.
      
          2. To be able to inform the user of erase progress.
      
          3. The erase timeout becomes too large to be very useful.
             Because the erase timeout contains a margin which is multiplied by
             the size of the erase area, the value can end up being several
             minutes for large areas.
      
      "erase_size" is not the most efficient unit to erase (especially for SD
      where it is just one sector), hence "preferred_erase_size" provides a good
      chunk size for erasing large areas.
      
      For MMC, "preferred_erase_size" is the high-capacity erase size if a card
      specifies one, otherwise it is based on the capacity of the card.
      
      For SD, "preferred_erase_size" is the allocation unit size specified by
      the card.
      
      "preferred_erase_size" is in bytes.
      Signed-off-by: NAdrian Hunter <adrian.hunter@nokia.com>
      Acked-by: NJens Axboe <axboe@kernel.dk>
      Cc: Kyungmin Park <kmpark@infradead.org>
      Cc: Madhusudhan Chikkature <madhu.cr@ti.com>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Ben Gardiner <bengardiner@nanometrics.ca>
      Cc: <linux-mmc@vger.kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      dfe86cba
    • J
      mm: fix writeback_in_progress() · 81d73a32
      Jan Kara 提交于
      Commit 83ba7b07 ("writeback: simplify the write back thread queue")
      broke writeback_in_progress() as in that commit we started to remove work
      items from the list at the moment we start working on them and not at the
      moment they are finished.  Thus if the flusher thread was doing some work
      but there was no other work queued, writeback_in_progress() returned
      false.  This could in particular cause unnecessary queueing of background
      writeback from balance_dirty_pages() or writeout work from
      writeback_sb_if_idle().
      
      This patch fixes the problem by introducing a bit in the bdi state which
      indicates that the flusher thread is processing some work and uses this
      bit for writeback_in_progress() test.
      
      NOTE: Both callsites of writeback_in_progress() (namely,
      writeback_inodes_sb_if_idle() and balance_dirty_pages()) would actually
      need a different information than what writeback_in_progress() provides.
      They would need to know whether *the kind of writeback they are going to
      submit* is already queued.  But this information isn't that simple to
      provide so let's fix writeback_in_progress() for the time being.
      Signed-off-by: NJan Kara <jack@suse.cz>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Wu Fengguang <fengguang.wu@intel.com>
      Acked-by: NJens Axboe <jaxboe@fusionio.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      81d73a32
    • W
      writeback: avoid unnecessary calculation of bdi dirty thresholds · 16c4042f
      Wu Fengguang 提交于
      Split get_dirty_limits() into global_dirty_limits()+bdi_dirty_limit(), so
      that the latter can be avoided when under global dirty background
      threshold (which is the normal state for most systems).
      Signed-off-by: NWu Fengguang <fengguang.wu@intel.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Christoph Hellwig <hch@infradead.org>
      Cc: Dave Chinner <david@fromorbit.com>
      Cc: Jens Axboe <axboe@kernel.dk>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      16c4042f
  2. 11 8月, 2010 37 次提交