Re: FreeBSD random I/O performance issues

[Matthew Dillon]

:
:>     effects of the I/O being in-progress.  If a user program doesn't access
:>     any of the information it recently wrote the whole mechanism winds up
:>     operating asynchronously in the background.  If a user program does, 
:>     then the write behind mechanism breaks down and you get a stall.
:
:What makes no sense is that it should be perfectly ok to _read_ this 
:information back.

    When we separate out the read vs write access in the buffer
    cache API we *will* be able to read the information back while a
    write is in progress.  At the moment the buffer cache has no clue
    how a buffer is going to be used, which means the buffer is locked
    exclusively.

                                        -Matt
                                        Matthew Dillon 
                                        <[EMAIL PROTECTED]>


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