1. 06 Oct, 2014 3 commits
    • Benjamin Marzinski's avatar
      dm mpath: stop queueing IO when no valid paths exist · 1f271972
      Benjamin Marzinski authored
      'queue_io' is set so that IO is queued while paths are being
      initialized.  Clear queue_io in __choose_pgpath if there are no valid
      paths, since there are obviously no paths that can be initialized.
      Otherwise IOs to the device will back up.
      Signed-off-by: default avatarBenjamin Marzinski <bmarzins@redhat.com>
      Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
      1f271972
    • Junichi Nomura's avatar
      dm: use bioset_create_nobvec() · 3d8aab2d
      Junichi Nomura authored
      Since DM core uses bio_clone_fast() for both bio-based and request-based
      DM devices there is no need for DM's bioset to have a bvec mempool.
      
      With this patch, on arch with 4KB page for example, memory usage will be
      reduced by 64KB for each bio-based DM device and 1MB for each
      request-based DM device.
      
      For example, when you create 10,000 bio-based DM devices and 1,000
      request-based DM devices, memory usage of biovec under no load is:
        # grep biovec /proc/slabinfo
      
        biovec-256        418068 418068   4096  ...
        biovec-128             0      0   2048  ...
        biovec-64              0      0   1024  ...
        biovec-16              0      0    256  ...
      
      With this patch series applied, the usage becomes:
        # grep biovec /proc/slabinfo
      
        biovec-256           116    116   4096  ...
        biovec-128             0      0   2048  ...
        biovec-64              0      0   1024  ...
        biovec-16              0      0    256  ...
      
      So 4096 * (418068 - 116) = 1.6GB of memory is saved in this example.
      Signed-off-by: default avatarJun'ichi Nomura <j-nomura@ce.jp.nec.com>
      Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
      3d8aab2d
    • Junichi Nomura's avatar
      dm: remove nr_iovecs parameter from alloc_tio() · 99778273
      Junichi Nomura authored
      alloc_tio() uses bio_alloc_bioset() to allocate a clone-bio for a bio.
      alloc_tio() takes the number of bvecs to allocate for the clone-bio.
      However, with v3.14's immutable biovec changes DM now uses
      __bio_clone_fast() and no longer needs to allocate bvecs.
      
      In practice, the 'nr_iovecs' passed to alloc_tio() is always effectively
      0.  __clone_and_map_simple_bio() looked like it was passing non-zero
      nr_iovecs, but its value was always within the range of inline bvecs and
      no allocation actually happened.  If allocation happened, the BUG_ON() in
      __bio_clone_fast() would've triggered.
      
      Remove the nr_iovecs parameter from alloc_tio() to prevent possible
      future bio_alloc_bioset() mis-use of a new bioset interface that will no
      longer allow bvecs to be allocated.
      
      Also fix extra whitespace before the __bio_clone_fast() call in
      __clone_and_map_simple_bio().
      Signed-off-by: default avatarJun'ichi Nomura <j-nomura@ce.jp.nec.com>
      Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
      99778273
  2. 03 Oct, 2014 2 commits
  3. 01 Oct, 2014 1 commit
  4. 30 Sep, 2014 1 commit
  5. 27 Sep, 2014 14 commits
  6. 25 Sep, 2014 10 commits
  7. 22 Sep, 2014 9 commits