- Glasgow-haskell-users

RE: heap and code in ghci
by Simon Marlow 27 Apr '01

27 Apr '01

> Let, for example, all the .o modules were prepared, and we > command > ghci ... +RTS -Mxxm -RTS > ... > Loading package std ... linking ... done. > Prelude> :l BPrelude > ... > > and then try to find sum [1..n]. > In my experiment > xx = 7 does not allow to load the program, > 8, sum [1..66000] yields "Heap exhausted", > 10, sum [1..77000] yields 2964538500. > > Probably, this xx Mb is for binary program + heap. > ghci loads .o modules, they take some part of xx, > and all the rest is for the heap. > Right? Nope. The -M flag affects the size of the heap only; object files are loaded outside the heap. If you're running out of heap with a maximum size of 8M, it's probably because the heap is full of interfaces (i.e. the in-memory copy of the .hi file). Cheers, Simon

1 0

heap and code in ghci
by S.D.Mechveliani 27 Apr '01

27 Apr '01

To my request >> I cannot find where it is explained the memory distribution used by >> ghci. >> [..] Simon Marlow writes > Interpreted code lives in the heap, and is garbage collected as normal. > Object code is loaded outside the heap. It takes up real memory > in the process, because the data has to be relocated when it is > loaded. > [..] Let, for example, all the .o modules were prepared, and we command ghci ... +RTS -Mxxm -RTS ... Loading package std ... linking ... done. Prelude> :l BPrelude ... and then try to find sum [1..n]. In my experiment xx = 7 does not allow to load the program, 8, sum [1..66000] yields "Heap exhausted", 10, sum [1..77000] yields 2964538500. Probably, this xx Mb is for binary program + heap. ghci loads .o modules, they take some part of xx, and all the rest is for the heap. Right? Thank you in advance for the explanation. ----------------- Serge Mechveliani mechvel(a)botik.ru

1 0

RE: Building nhc98-1.02 with ghc-5.00
by Simon Marlow 27 Apr '01

27 Apr '01

> the building of nhc98-1.02 with ghc-5.00 aborts > with the message: > > Main.hs:8: > Failed to find interface decl for > `PrelGHC.(#,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, > ,,,,,,,,,,,,,,,,,,,,,,,#)' > from module `PrelGHC' > > Any hints for interpretation? Workaround: compile this particular module without -O, or with -fno-cpr. Cheers, Simon

1 0

RE: memory map in ghci
by Simon Marlow 27 Apr '01

27 Apr '01

> I cannot find where it is explained the memory distribution used by > ghci. > For example, after ghci +RTS -M16m -RTS > ... > Prelude> :l XX > ... (YY.o loaded ...) > ... (XX interpreted ...) > > do YY.o, XX take any of these 16Mb ? > > Are there any commands in ghci to get the memory map? > It is something like > space taken by loaded compiled programs, > interpreted programs, > by data, > free space for program, > free space for data, > space for stack. > > Is the interpreted program treated as data? Object code is loaded outside the heap. It takes up real memory in the process, because the data has to be relocated when it is loaded. Object code is never released or unloaded: if you load a newly compiled version of the same module, GHCi just allocates more memory for it. The reason is that objects in the heap may still have references to the old code, and trying to detect/prevent this is hard. Interpreted code lives in the heap, and is garbage collected as normal. Cheers, Simon

1 0

memory map in ghci
by S.D.Mechveliani 27 Apr '01

27 Apr '01

Dear GHC-5.00, I cannot find where it is explained the memory distribution used by ghci. For example, after ghci +RTS -M16m -RTS ... Prelude> :l XX ... (YY.o loaded ...) ... (XX interpreted ...) do YY.o, XX take any of these 16Mb ? Are there any commands in ghci to get the memory map? It is something like space taken by loaded compiled programs, interpreted programs, by data, free space for program, free space for data, space for stack. Is the interpreted program treated as data? ----------------- Serge Mechveliani mechvel(a)botik.ru

1 0

Building nhc98-1.02 with ghc-5.00
by wbuss＠telda.net 26 Apr '01

26 Apr '01

Hello, the building of nhc98-1.02 with ghc-5.00 aborts with the message: Main.hs:8: Failed to find interface decl for `PrelGHC.(#,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,#)' from module `PrelGHC' Any hints for interpretation? Kind regards, Wolfhard.

2 1

RE: :! ghc -c vs :c
by Simon Marlow 26 Apr '01

26 Apr '01

> The ghc interactive ghci compiles the module by the command > > :! ghc -c > > Has it sense to provide a command :compile (:c), > > having a meaningful name and a format similar to other commands, > like say :load > ? Yes, this is another thing we'd like to do, but haven't got around to yet. (you can always define your own :compile command using :def of course, but the benefit of a built-in one would be that it could take advantage of the in-memroy interfaces rather than reading them from the disk). Cheers, Simon

2 1

RE: :l XX libFoo.a
by Simon Marlow 26 Apr '01

26 Apr '01

> The :load command of the ghc-5.00 interpreter > first searches the needed compiled modules (*.o) and loads them > when finds. > But how to make it to search them in the object code library > xxx/libFoo.a ? > For it is better to keep the fixed *.o files in a library. > And `:load' works in the above situation similarly as > ghc -o XX.o ... > I tried :l XX libFoo.a, > but it does not work. GHCi can't load ordinary .a libraries, only .o/.so objects. However, you can make a .o from a .a using something like $ ld --whole-archive -o Foo.o -lFoo Perhaps we'll have a way to make this slightly less painful in the future. Cheers, Simon

1 0

:l XX libFoo.a
by S.D.Mechveliani 26 Apr '01

26 Apr '01

The :load command of the ghc-5.00 interpreter first searches the needed compiled modules (*.o) and loads them when finds. But how to make it to search them in the object code library xxx/libFoo.a ? For it is better to keep the fixed *.o files in a library. And `:load' works in the above situation similarly as ghc -o XX.o ... I tried :l XX libFoo.a, but it does not work. ----------------- Serge Mechveliani mechvel(a)botik.ru

1 0

:! ghc -c vs :c
by S.D.Mechveliani 26 Apr '01

26 Apr '01

The ghc interactive ghci compiles the module by the command :! ghc -c Has it sense to provide a command :compile (:c), having a meaningful name and a format similar to other commands, like say :load ? ----------------- Serge Mechveliani mechvel(a)botik.ru

1 0