my last letter
Serge D. Mechveliani
mechvel at botik.ru
Tue Apr 21 08:23:12 EDT 2009
Dear GHC team,
I withdraw my last bug report.
It was about processing a long list on a 64 bit machine оn GHC-6.10.2.
First, I cannot reproduce (?) this bug report invitation from GHC on
using +RTS -M4000m
Second, I have found that the process interruption only occurs when
this test program runs out of RAM. And personally, I would rather use
"+RTS -M15000m -RTS" and not to consider at all the system effects
after the RAM overflow.
Third, I apply now a more clear example, whith [Int] instead of
[Integer]:
---------------------------------------------------------
import List (genericReplicate)
main = putStr (shows res "\n")
where
e = -- 22, 23 ...
list = genericReplicate (2^e) 1 :: [Int]
rList = reverse list
res = myMin $ zipWith (+) list rList
myMin [] = error "\nmyMin []\n"
myMin [x] = x
myMin (x: y: xs) = if x > y then myMin (y: xs) else myMin (x: xs)
------------------------------------------------------
ghc -O --make Test64
./Test64 +RTS -M800m -RTS -- for 1 Gb 32 bit machine
./Test64 +RTS -M12000m -RTS -- for 16 Gb 64 bit machine
The last possible e for the small machine (800 Mb) occurs 24,
for the big machine (12000 Mb) occurs 27
-- which looks reasonable.
The timing also looks reasonable.
Regards,
-----------------
Serge Mechveliani
mechvel at botik.ru
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