Anyway, JIT memOk. There is a test in config/auto/jit/test_exec_openbsd.in,
Ok, I've looked at the test_exec_linux source, and tried it out separately; it's clear what happens to me now: I've enabled the following GrSecurity option, which makes the mprotect system call fail with a permission error - the test even outputs this as the line "failure: Permission denied".
CONFIG_GRKERNSEC_PAX_MPROTECT
Enabling this option will prevent programs from
- changing the executable status of memory pages that were
not originally created as executable,
- making read-only executable pages writable again,
- creating executable pages from anonymous memory.
You should say Y here to complete the protection provided by
the enforcement of non-executable pages.
NOTE: you can use the 'chpax' utility to control this
feature on a per file basis. chpax is available at
<http://pax.grsecurity.net>I've not yet hat the time to reboot that machine with a kernel w/o that option, so I'm not sure it'd work with the other grsecurity/PAX features. (In any case, the problem remains that one cannot build the JIT if GRKERNSEC_PAX_MPROTECT is enabled because the user has no chance running chpax; it should be possible to switch PAX off for some path using GrSecurity's ACL rules but I don't know if that reads the inodes into the kernel as LIDS does, if so then it's a real conflict.)
But I've built parrot now on another machine which is not running GrSecurity. This machine is running a not up-to-date Debian Sarge (gcc 3.3.2) and has a Intel PentiumIII 1Ghz CPU.
I did perl Configure.pl --optimize. I still get a parrot that is about 4 times slower than perl5, and for which none of the -f,-g,-P,-S,-C,-j options does seem to make a significant difference in speed. (see data below).
I checked the Makefile, it has:
CFLAGS = -D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -DDEBIAN -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -O3 -DDISABLE_GC_DEBUG=1 -DNDEBUG -g -Dan_Sugalski -Larry -Wall -Wstrict-prototypes -Wmissing-prototypes -Winline -Wshadow -Wpointer-arith -Wcast-qual -Wcast-align -Wwrite-strings -Waggregate-return -Winline -W -Wno-unused -Wsign-compare -Wformat-nonliteral -Wformat-security -Wpacked -Wdisabled-optimization -mno-accumulate-outgoing-args -Wno-shadow -falign-functions=16 -I./include -I./blib/include -DHAS_JIT -DI386 -DHAVE_COMPUTED_GOTO
and include/parrot/config.h has: #define PARROT_JIT_CAPABLE 1
Below are some timings, and the output of the configuration.
Does this indicate that something is wrong or not?
Thanks Christian.
time perl -w fib.pl fib(28) = 317811 real 0m2.193s user 0m2.180s sys 0m0.010s
time python fib.py fib(28) = 317811 real 0m1.723s user 0m1.700s
time ../../parrot fib.imc fib(28) = 317811 11.031775s real 0m11.113s user 0m8.130s sys 0m0.030s with -f: real 0m17.399s user 0m8.060s real 0m8.540s user 0m7.900s with -g: real 0m8.904s user 0m7.590s with -P: real 0m11.088s user 0m8.860s with -S: real 0m8.607s user 0m8.220s with -j: real 0m7.884s user 0m7.860s real 0m11.019s user 0m9.040s with -j -O: real 0m8.292s user 0m8.280s with -j -O8: real 0m7.873s user 0m7.870s with -j --optimize=9: real 0m7.401s user 0m7.340s
time perl -w oo6.pl 500000 real 0m2.567s user 0m2.550s
time python oo6.py 500000 real 0m2.679s user 0m2.560s
time ../../parrot oo6.imc 500000 real 0m7.539s user 0m7.470s with -j: real 0m8.080s user 0m8.040s with -C: real 0m7.345s user 0m7.190s real 0m7.619s user 0m7.360s with -j: real 0m9.734s user 0m7.630s
Output from perl Configure.pl --optimize --verbose-step=JIT :
...
Determining architecture, OS and JIT capability.......................
Setting Configuration Data:
(
archname => 'i386-linux-thread-multi',
cpuarch => 'i386',
osname => 'linux',
);
-e "jit/i386/core.jit" = yes
Setting Configuration Data:
(
asmfun_o => '',
);
Setting Configuration Data:
(
jitarchname => 'i386-linux',
jitcpuarch => 'i386',
jitcpu => 'I386',
jitosname => 'LINUX',
jitcapable => '1',
cc_hasjit => ' -DHAS_JIT -DI386',
TEMP_jit_h => '$(INC)/jit.h',
TEMP_jit_o => '$(SRC)/jit$(O) $(SRC)/jit_cpu$(O) $(SRC)/jit_debug$(O) $(SRC)/jit_debug_xcoff$(O)',
);
Setting Configuration Data:
(
TEMP_exec_h => '$(INC)/jit.h $(INC)/exec.h $(INC)/exec_dep.h $(INC)/exec_save.h',
TEMP_exec_o => '$(SRC)/exec$(O) $(SRC)/exec_cpu$(O) $(SRC)/exec_save$(O)',
execcapable => '1',
);
(has_exec_protect cc -D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -DDEBIAN -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -O3 -DDISABLE_GC_DEBUG=1 -DNDEBUG -I./include -c test.c
c++ -L/usr/local/lib -Wl,-E test.o -o test -ldl -lm -lpthread -lcrypt
./test 0
ok
no) cc -D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -DDEBIAN -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -O3 -DDISABLE_GC_DEBUG=1 -DNDEBUG -I./include -c test.c
c++ -L/usr/local/lib -Wl,-E test.o -o test -ldl -lm -lpthread -lcrypt
./test
ok
Setting Configuration Data:
(
jit_i386 => 'fcomip',
);
...done.
Running CPU specific stuff............................................Setting Configuration Data:
(
verbose => undef,
);
done.
Verifying that the compiler supports function pointer casts...........done.
...
