RE: Large File support and blocks.

From: Linda Walsh (law@sgi.com)
Date: Thu Aug 31 2000 - 17:57:58 EDT

  • Next message: J. Dow: "Re: hfs support for blocksize != 512"

    And the below is what percentage of time doing disk i/o?

    > Just put this in a loop and time it. Change SIZE to long long, and do
    > it again! It doesn't scale well. The long long code is nearly 10 times
    > slower! You can do `gcc -S -o xxx name.c` and see why.
    >
    >
    > #define SIZE long
    >
    > SIZE *foo()
    > {
    > SIZE one;
    > SIZE two;
    > static SIZE answer[8];
    >
    > one = 1;
    > two = 2;
    > answer[0] = one - two;
    > answer[1] = two - one;
    > answer[2] = one + two;
    > answer[3] = two + one;
    > answer[4] = two / one;
    > answer[5] = one / two;
    > answer[6] = one * two;
    > answer[7] = two * one;
    > return answer;
    > }
    >
    >
    > Long long things, even it they work well, are not very nice on 32 bit
    > machines. For the time being, I'd advise increasing cluster size rather
    > than using 64 bit values.
    >
    > In a few years, even Intel machines will be 64 bits. Int will still be
    > long, but it will be 64 bits. ---and they will autoscale for backwards
    > compatibility (one new instruction, used once, for oprand size).
    >
    > Cheers,
    > Dick Johnson
    >
    > Penguin : Linux version 2.2.15 on an i686 machine (797.90 BogoMips).
    >
    > "Memory is like gasoline. You use it up when you are running. Of
    > course you get it all back when you reboot..."; Actual explanation
    > obtained from the Micro$oft help desk.
    >
    >
    >
    -
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