1. 13 Nov, 2009 7 commits
  2. 11 Nov, 2009 1 commit
  3. 10 Nov, 2009 1 commit
  4. 08 Nov, 2009 1 commit
    • Corrado Zoccolo's avatar
      cfq-iosched: fix next_rq computation · cf7c25cf
      Corrado Zoccolo authored
      
      
      Cfq has a bug in computation of next_rq, that affects transition
      between multiple sequential request streams in a single queue
      (e.g.: two sequential buffered writers of the same priority),
      causing the alternation between the two streams for a transient period.
      
        8,0    1    18737     0.260400660  5312  D   W 141653311 + 256
        8,0    1    20839     0.273239461  5400  D   W 141653567 + 256
        8,0    1    20841     0.276343885  5394  D   W 142803919 + 256
        8,0    1    20843     0.279490878  5394  D   W 141668927 + 256
        8,0    1    20845     0.292459993  5400  D   W 142804175 + 256
        8,0    1    20847     0.295537247  5400  D   W 141668671 + 256
        8,0    1    20849     0.298656337  5400  D   W 142804431 + 256
        8,0    1    20851     0.311481148  5394  D   W 141668415 + 256
        8,0    1    20853     0.314421305  5394  D   W 142804687 + 256
        8,0    1    20855     0.318960112  5400  D   W 142804943 + 256
      
      The fix makes sure that the next_rq is computed from the last
      dispatched request, and not affected by merging.
      
        8,0    1    37776     4.305161306     0  D   W 141738087 + 256
        8,0    1    37778     4.308298091     0  D   W 141738343 + 256
        8,0    1    37780     4.312885190     0  D   W 141738599 + 256
        8,0    1    37782     4.315933291     0  D   W 141738855 + 256
        8,0    1    37784     4.319064459     0  D   W 141739111 + 256
        8,0    1    37786     4.331918431  5672  D   W 142803007 + 256
        8,0    1    37788     4.334930332  5672  D   W 142803263 + 256
        8,0    1    37790     4.337902723  5672  D   W 142803519 + 256
        8,0    1    37792     4.342359774  5672  D   W 142803775 + 256
        8,0    1    37794     4.345318286     0  D   W 142804031 + 256
      Signed-off-by: default avatarCorrado Zoccolo <czoccolo@gmail.com>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      cf7c25cf
  5. 04 Nov, 2009 12 commits
  6. 03 Nov, 2009 7 commits
  7. 02 Nov, 2009 4 commits
  8. 31 Oct, 2009 7 commits