1. 01 Apr, 2016 1 commit
    • Eric Nelson's avatar
      drivers: block: add block device cache · e40cf34a
      Eric Nelson authored
      Add a block device cache to speed up repeated reads of block devices by
      various filesystems.
      
      This small amount of cache can dramatically speed up filesystem
      operations by skipping repeated reads of common areas of a block
      device (typically directory structures).
      
      This has shown to have some benefit on FAT filesystem operations of
      loading a kernel and RAM disk, but more dramatic benefits on ext4
      filesystems when the kernel and/or RAM disk are spread across
      multiple extent header structures as described in commit fc0fc50f
      
      .
      
      The cache is implemented through a minimal list (block_cache) maintained
      in most-recently-used order and count of the current number of entries
      (cache_count). It uses a maximum block count setting to prevent copies
      of large block reads and an upper bound on the number of cached areas.
      
      The maximum number of entries in the cache defaults to 32 and the maximum
      number of blocks per cache entry has a default of 2, which has shown to
      produce the best results on testing of ext4 and FAT filesystems.
      
      The 'blkcache' command (enabled through CONFIG_CMD_BLOCK_CACHE) allows
      changing these values and can be used to tune for a particular filesystem
      layout.
      Signed-off-by: default avatarEric Nelson <eric@nelint.com>
      e40cf34a
  2. 14 Mar, 2016 1 commit
  3. 24 Jan, 2016 1 commit
  4. 24 Sep, 2014 1 commit
  5. 30 Jul, 2014 1 commit
    • Masahiro Yamada's avatar
      kconfig: add board Kconfig and defconfig files · dd84058d
      Masahiro Yamada authored
      
      
      This commit adds:
       - arch/${ARCH}/Kconfig
          provide a menu to select target boards
       - board/${VENDOR}/${BOARD}/Kconfig or board/${BOARD}/Kconfig
          set CONFIG macros to the appropriate values for each board
       - configs/${TARGET_BOARD}_defconfig
          default setting of each board
      
      (This commit was automatically generated by a conversion script
      based on boards.cfg)
      
      In Linux Kernel, defconfig files are located under
      arch/${ARCH}/configs/ directory.
      It works in Linux Kernel since ARCH is always given from the
      command line for cross compile.
      
      But in U-Boot, ARCH is not given from the command line.
      Which means we cannot know ARCH until the board configuration is done.
      That is why all the "*_defconfig" files should be gathered into a
      single directory ./configs/.
      Signed-off-by: default avatarMasahiro Yamada <yamada.m@jp.panasonic.com>
      Acked-by: default avatarSimon Glass <sjg@chromium.org>
      dd84058d