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Re: [tree-ssa PATCH] Pick memory consumption low hanging fruit


In message <1069209358.30711.663.camel@p4>, Andrew MacLeod writes:
 >On Tue, 2003-11-18 at 18:40, law@redhat.com wrote:
 >> In message <1069194489.30703.332.camel@p4>, Andrew MacLeod writes:
 >>  >Thats overall. If we collected between passes, or free'd SSAisms, or
 >>  >something along those lines, it wouldn't be as bad from function to
 >>  >function. Sure we'd have a highwater mark, but it wouldnt push the
 >>  >envelope as much.  Is there a reason we dont collect bewteen functions? 
 >>  >we know both SSA and RTL aren't going to carry over fom one function to
 >>  >the next.  (Don't we?? :-)
 >> Err, what do you mean we don't collect between functions?  I'm pretty sure
 >> we do collect between functions.  Hell, at the RTL level, we collect betwee
 >n
 >> optimization passes :-)
 >> 
 >> Now, we may have some problems with templates and such since I think
 >> they are considered "nested" functions.  I've got a message from Steven
 >> regarding that issue that I'll need to look at carefully.
 >
 >I ASSUME since I only see the [..->..} message rarely that it occurs
 >whenever we GC.
Yes.  But also remember that we only GC when the heuristics think it's
worth the trouble.  If you've got a lot of memory in your machine and you
do not have checking enabled, then we'll go a lot longer before the GC
system does anything.


 >It seems like a different beast to me. I hate to say it but there were
 >certain characterisitics about obstacks that were good in general
 >intent... probably what spawned them in the first place. It was more the
 >implmementation and actual usage that were bad.  Dont get me wrong, they
 >drove me nuts. For slightly, but important, different reasons than we're
 >talking about here.
Most definitely they had certain characteristics that were helpful and
others which were insanely bad.   The hell of it is we had a "one or
the other" kind of system -- we don't have a scheme which allows us to
mix-n-match based on the characteristics of the objects we are allocating.

Jeff



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