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    SubjectRe: wierd behaviour...
    Date
    > > main(){ fork();}      /* no while to do several fork(). so its safe */
    > > /* no danger for your computer */
    > >
    > > so when i run it, my harddrive is running. Even if i run it several times
    > > to be sure sure that the code is in buffers. i don't understand why my
    > > hd need to write or read something during or after this little program.
    >
    > i studied vmstat's io bo ("bo: Blocks received from a block device (blocks/s)"
    > from vmstat's manpage) and i see 4 new bo each time i run my source.
    >
    > that comes from fork(), and the following source makes me think something
    > these 4 blocks is read when the child die.
    > main(){ if( !fork()) sleep(4); else sleep(2); }
    >
    > any explaination ?

    too complicated tests give wierd results and wrong conclutions... try

    main(){ pause(); }

    and you'll realize that these writes are ~5-10 secs after you start the image.
    and

    ls -l prog
    ls -lc prog
    ls -lu prog

    will show the reason: every time you run, the "last access" timestamp
    of the file is updated in the inode. and these changes are flushed to disk
    a few seconds later by kflushd...


    Harald
    --
    All SCSI disks will from now on ___ _____
    be required to send an email notice 0--,| /OOOOOOO\
    24 hours prior to complete hardware failure! <_/ / /OOOOOOOOOOO\
    \ \/OOOOOOOOOOOOOOO\
    \ OOOOOOOOOOOOOOOOO|//
    Harald Koenig, \/\/\/\/\/\/\/\/\/
    Inst.f.Theoret.Astrophysik // / \\ \
    koenig@tat.physik.uni-tuebingen.de ^^^^^ ^^^^^

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