Daniel Fischer wrote:
Hello, first let me remark that 6.8.1 is really remarkable, compiles faster and produces faster executables than 6.6.1.
However, I have a problem with profiling, the time is always reported as 0.00 secs:
Sun Nov 25 22:58 2007 Time and Allocation Profiling Report (Final)
p28Master +RTS -P -hb -sstderr -RTS MMDataA
total time = 0.00 secs (0 ticks @ 20 ms) total alloc = 1,313,421,840 bytes (excludes profiling overheads)
although it took more than 15 seconds:
INIT time 0.00s ( 0.00s elapsed) MUT time 16.10s ( 16.41s elapsed) GC time 10.76s ( 11.16s elapsed) RP time 0.00s ( 0.00s elapsed) PROF time 0.00s ( 0.00s elapsed) EXIT time 0.00s ( 0.00s elapsed) Total time 26.86s ( 27.57s elapsed)
Very strange, looks like a bug. Can you provide us with code and steps to reproduce?
Could that be caused by commenting out the lines ifeq "$(GhcThreaded)" "YES" SRC_HC_OPTS += -threaded endif
in compiler/Makefile.ghcbin ?
I doubt it - that affects the runtime that GHC itself is linked with, and shouldn't affect any programs built using that GHC.
I did that because if I build ghc with -threaded, the times reported with :set +s in ghci are rubbish (I have a linux 2.4.20 kernel, and the threads don't support process-wide times; and no, I'm not likely to upgrade, SuSE 8.2 is the only OS that ever worked properly for me).
Fair enough, but note that without -threaded you won't be able to run code that expects -threaded in GHCi (sounds obvious, I know!). For example, calling waitForProcess will block all threads.
If that's the cause, too bad, I'll have to revert to 6.4.2 for profiling :(
In 6.6.1, -O2 and -prof -auto-all don't work together well, I have a programme where that combination of options results in an instant wrong output, while the combinations -prof -auto-all -O1 -prof -auto-all -O2 -prof lead to the correct output calculated in 10 to 13 seconds. If you're interested in that bug, I could send you the code, it's short enough.
Yes, please send us the code - better still, open a ticket on the bug tracker. Cheers, Simon