Re: Memory upgrade: not faster / nfs
Keith Rohrer (kwrohrer@uiuc.edu)
Sun, 27 Oct 1996 04:03:36 -0600 (CST)
> On Sat, 26 Oct 1996, Keith Rohrer wrote:
> [...]
> > > I think there is some option that makes the compiler write out in bigger
> > Howsabout -pipe? Saves you all the intermediate files except the
> > .o's...and would cut those out too if it weren't for that "separate
> > compilation" thing.
> Well the kernel has that already, but I think ld writes each section in
> the binary in a differant write and so thats 19 in a single ELF binary I
> have here, and it's only 4963 bytes long (That's AFAIK tho).
Perhaps. Then again, when you're doing a kernel build it's all gcc and
occsionally ar up until the end, same for most packages one would compile.
> Oh, that option could be a compile time option of ld, it basically has the
> effect of coalescing (sp?) the writes,
Solaris ld mmap's the executable and msyncs at the end, and winds up exposing
lusers^H^H^H^H^H^Hstudents who don't know how to "man -k msync" to an
error message that pretty much always means they're out of space (hard or
quota). Presumably, this writes (or should write) in maximal/optimal sized
chunks. I have no clue what gnu ld does, though.
> > Plus, ramdisks are your friend...a version of tmpfs
> > which doesn't crash the system for lack of memory when you
> > cat /dev/zero > /tmp/foo (or otherwise fill up /tmp) which could run in
> > a ramdisk (which would be only one of the swap spaces) would do wonders
> Hmm, I would have thought that this was a bad idea, unless you have loads
> of memory (remember he is also activly swaping over nfs too, so I think
> this is out).
The original poster was complaining about having thrown an additional
32 megs into a dickless workstation and not seeing much performance
improvement. Either using -pipe or using a small ramdisk for /tmp
would reduce the NFS problem for compilation to just the source, .o's,
and executable; tempfs would've reclaimed all unused parts of the ramdisk
as a hunk of swap space (and vice versa). I'm not quite certain what
the aversion to a local hard drive in the machine was, but I'm sure
there's a reason, maybe even a good one.
Keith
Disclaimer: Do not taunt Happy Fun God.