Fundamental defect of the concept of shared libraries

Alex Goykhman goykhman_a at apollo.HP.COM
Thu May 23 04:37:00 AEST 1991


In article <213 at titccy.cc.titech.ac.jp> mohta at necom830.cc.titech.ac.jp (Masataka Ohta) writes:
>In article <MWM.91May17132439 at raven.pa.dec.com>
>	mwm at pa.dec.com (Mike (My Watch Has Windows) Meyer) writes:
>
>>   Even worse, with some architechture, it is impossible to map several virtual
>>   addresses to a physical address. Virtually tagged cache and inverted
>>   page tables are notable examples.
>
>>So some architechtures can't support shared libraries? Well, don't put
>>shared libraries on them.
>
>That's what I am saying.

    I confess, I am not familiar enough with such marvels of computer architecture
    as the fifth generation and tron.  Perhaps, that is why I can not think
    of one that would make it "impossible to map several virtual addresses to a 
    physical address".   Could you name such an architecture?
>
>>Some architechtures can't support demand
>>paged memory, or virtual address spaces, or preemptive scheduling.
>>Does that mean we have to live without them on machines that can
>>support them?  No; it doesn't.
>
>You don't know about hardware enough. Because address translation is time
>consuming, fast cache is always indexed by virtual address. Thesedays,
>virtually indexed cache is quite common.

    So what?  Are you sure you understand the difference between a cache
    and a TLB?

[deleted]
>
>						Masataka Ohta



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