[lkml]   [2004]   [Oct]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [PATCH 1/2] aio: add vectored I/O support
    Joel Becker wrote:

    >>I think what happened was that the number of iocbs submitted (64 iocbs
    >>of 4K each) did not merge because the device queue depth was very large;
    >>no queuing occured because (I imagine) merging happens while a request
    >>is waiting for disk readiness.
    > Why did you submit 64 iocbs of 4K? Was every page virtually
    >discontiguous, or did you arbitrarily decide to create a worst-case?
    The application (a userspace filesystem with its own cache) manages
    memory in 4K pages, but can perform much larger I/Os, for example during
    readahead and after merging writes. After a very short while memory is
    completely fragmented.

    Do not meddle in the internals of kernels, for they are subtle and quick to panic.

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 14:07    [W:0.019 / U:8.596 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site