In article <1992Aug12.011334.17155@ultb.isc.rit.edu> axi0349@ultb.isc.rit.edu (A.X. Ivasyuk ) writes:
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>
>
>First of all, how do you get the executables to be so tiny on the root disk
>and the mj distribution?  I can't get mine under 9K, even a 'hello, world'
>program.  I'd like to be able to squeeze my 80MB drive to the max.
>It can't be just the -O flag on gcc.

By using shared libraries, and the "-N" flag, and stripping the result
you can often make trivial binaries that are much less than 9kB. BUT
they won't demand-load nor share pages, so it's worth it only if the
binary is truly small. Using "-N" on bigger binaries will result in bad
performance and memory waste when running it.

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> [ Q two deleted ]
>Third, where is the one-line patch to hd.c (0.97) that everyone has been talking
>about?  I think I missed it on the net.  Could someone send it to me, please?
>(I already applied patch1 and the buffer patch, and it did improve performance
>noticeably, esp. patch1 - Thanks Linus!!!)

It's not to hd.c but to linux/fs/buffer.c - in the function
grow_buffers(). 0.97.pl1 has code that looks something like this:

        for (i = 0 ; i+size <= 4096 ; i += size) {
                bh = get_unused_buffer_head();
                ....
-               i += size;
        }

As you can see, 'i' is updated twice ('i += size' both inside the
for-loop and as the terminating expression), resulting in using only
half the available space in a page for buffers.  The fix is to remove
the line I have marked with a "-".  The above simple fix results in much
better free memory utilization, and a marked improvement in performance
under some circumstances. 

                Linus