Generally it's adviced to sieve the whole set of candidates in one sieve as computation time increases only with the sqrt of the number of candidates. But does this rule still apply in the case of +1 and -1 combined?

If not, then sr1sieve run on two seperate sieves would be more efficient.

I cannot test it right now as I don't have access to the computer.



[QUOTE]but I think srsieve2cl (GPU, not srsieve2 for CPU) is faster than even sr1sieve for a single k.[/QUOTE]Do you know if that's the software PG uses for their Proth Prime Sieves? I tried that on a GTX 730 and it was very slow, likely due to the old card, but it's the only one I have available for sieving.

[CODE]../srsieve2cl -P 5e13 -i candy2.cand -o candy.cand -f A -W 4 -G 1
srsieve2cl v1.5.2, a program to find factors of k*b^n+c numbers for fixed b and variable k and n
Sieving one sequence where abs(c) = 1 for p >= 15175098061843
Split 1 base 13 sequence into 19 base 13^120 sequences.
551218 bytes used for congruence tables
351 bytes used for Legendre tables
*** buffer overflow detected ***: terminated
Aborted (core dumped)

[/CODE]

srsieve2cl is crying. Perhaps I am missing the exact methodology to run the siever with OpenCL, but it seems like any attempt to introduce a GPU worker with -G 1 causes a buffer overflow. GPU is an RTX 2070.

[QUOTE=Gelly;573862][CODE]../srsieve2cl -P 5e13 -i candy2.cand -o candy.cand -f A -W 4 -G 1
srsieve2cl v1.5.2, a program to find factors of k*b^n+c numbers for fixed b and variable k and n
Sieving one sequence where abs(c) = 1 for p >= 15175098061843
Split 1 base 13 sequence into 19 base 13^120 sequences.
551218 bytes used for congruence tables
351 bytes used for Legendre tables
*** buffer overflow detected ***: terminated
Aborted (core dumped)

[/CODE]

srsieve2cl is crying. Perhaps I am missing the exact methodology to run the siever with OpenCL, but it seems like any attempt to introduce a GPU worker with -G 1 causes a buffer overflow. GPU is an RTX 2070.[/QUOTE]

It hasn't started any workers yet. I'm guessing that srsieve2 will fail at the same point. Please post or e-mail your input file and I'll take a look.

Here's the list of candidates. I have been running it under srsieve2 (and, indeed, even with srsieve2cl with no GPU workers) with no issues, so I do think it's a GPU error on my end.

I did find one bug in CisOneWithOneSequenceHelper.cpp and committed a fix, but that bug prevented compilation on OS X. The sequence in this file works on two different GPUs that I've tried, one AMD and one NVIDIA.

If you get the updated file and rebuild (start with make clean), are you able to do any debugging?

Have you run any of the other GPU-enabled sievers built on the framework? Do any of those work?

[QUOTE=rogue;573931]I did find one bug in CisOneWithOneSequenceHelper.cpp and committed a fix, but that bug prevented compilation on OS X. The sequence in this file works on two different GPUs that I've tried, one AMD and one NVIDIA.

If you get the updated file and rebuild (start with make clean), are you able to do any debugging?

Have you run any of the other GPU-enabled sievers built on the framework? Do any of those work?[/QUOTE]

Did what you suggested. Still no dice for srsieve2cl. It seems like most of the other cl sievers work just fine with OpenCL, though I did not make a decimal file for pixsievecl to test with.

Here's another example where I start sieving on a random sequence, leading me to believe it's not a sequence problem, neither:

[CODE]../srsieve2cl -G 1 -P 1e13 -n 1000 -N 1500 -s "2564*2345^n+1"
srsieve2cl v1.5.2, a program to find factors of k*b^n+c numbers for fixed b and variable k and n
Sieving with generic logic for p >= 3
Creating CPU worker to use until p >= 1000000
GPU primes per worker is 56320
Sieve started: 3 < p < 1e13 with 501 terms (1000 < n < 1500, k*2345^n+c) (expecting 482 factors)
Sieving one sequence where abs(c) = 1 for p >= 2564
Split 1 base 2345 sequence into 11 base 2345^30 sequences.
552614 bytes used for congruence tables
376119 bytes used for Legendre tables
Creating CPU worker to use until p >= 1000000
*** buffer overflow detected ***: terminated
Aborted (core dumped)
[/CODE]

[QUOTE=Gelly;573950]Did what you suggested. Still no dice for srsieve2cl. It seems like most of the other cl sievers work just fine with OpenCL, though I did not make a decimal file for pixsievecl to test with.

Here's another example where I start sieving on a random sequence, leading me to believe it's not a sequence problem, neither:

[CODE]../srsieve2cl -G 1 -P 1e13 -n 1000 -N 1500 -s "2564*2345^n+1"
srsieve2cl v1.5.2, a program to find factors of k*b^n+c numbers for fixed b and variable k and n
Sieving with generic logic for p >= 3
Creating CPU worker to use until p >= 1000000
GPU primes per worker is 56320
Sieve started: 3 < p < 1e13 with 501 terms (1000 < n < 1500, k*2345^n+c) (expecting 482 factors)
Sieving one sequence where abs(c) = 1 for p >= 2564
Split 1 base 2345 sequence into 11 base 2345^30 sequences.
552614 bytes used for congruence tables
376119 bytes used for Legendre tables
Creating CPU worker to use until p >= 1000000
*** buffer overflow detected ***: terminated
Aborted (core dumped)
[/CODE][/QUOTE]

Are you able to debug? Getting a stack trace might help me track down the issue.

[QUOTE=rogue;573953]Are you able to debug? Getting a stack trace might help me track down the issue.[/QUOTE]

[CODE]
(gdb) run
Starting program: /home/gelly/Math/mtsieve/mtsieve-svn/srsieve2cl -P 5e13 -o candy.cand -i candy2.cand -f A -W 4 -G 1
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7fffde917640 (LWP 206402)]
[New Thread 0x7fffde116640 (LWP 206403)]
[New Thread 0x7fffdd915640 (LWP 206404)]
[New Thread 0x7fffdd114640 (LWP 206405)]
[New Thread 0x7fffdc913640 (LWP 206406)]
[New Thread 0x7fffd1fff640 (LWP 206407)]
[New Thread 0x7fffd17fe640 (LWP 206408)]
srsieve2cl v1.5.2, a program to find factors of k*b^n+c numbers for fixed b and variable k and n
Sieving one sequence where abs(c) = 1 for p >= 31162066292659
Split 1 base 13 sequence into 19 base 13^120 sequences.
551218 bytes used for congruence tables
351 bytes used for Legendre tables
[New Thread 0x7fffd0ffd640 (LWP 206409)]
[New Thread 0x7fffd07fc640 (LWP 206410)]
[New Thread 0x7fffcfffb640 (LWP 206411)]
[New Thread 0x7fffcf7fa640 (LWP 206412)]
[New Thread 0x7fffceff9640 (LWP 206413)]
*** buffer overflow detected ***: terminated

Thread 1 "srsieve2cl" received signal SIGABRT, Aborted.
__GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:49
49 ../sysdeps/unix/sysv/linux/raise.c: No such file or directory.

(gdb) backtrace
#0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:49
#1 0x00007ffff7a74864 in __GI_abort () at abort.c:79
#2 0x00007ffff7ad7af6 in __libc_message (action=action@entry=do_abort,
fmt=fmt@entry=0x7ffff7bfeedf "*** %s ***: terminated\n") at ../sysdeps/posix/libc_fatal.c:155
#3 0x00007ffff7b7779a in __GI___fortify_fail (msg=msg@entry=0x7ffff7bfee85 "buffer overflow detected") at fortify_fail.c:26
#4 0x00007ffff7b76036 in __GI___chk_fail () at chk_fail.c:28
#5 0x00007ffff7acf99f in _IO_str_chk_overflow (fp=<optimized out>, c=<optimized out>) at iovsprintf.c:35
#6 0x00007ffff7adc594 in __GI__IO_default_xsputn (n=<optimized out>, data=<optimized out>, f=<optimized out>)
at libioP.h:948
#7 __GI__IO_default_xsputn (f=0x7fffffffd7b0, data=<optimized out>, n=50) at genops.c:370
#8 0x00007ffff7ac2846 in outstring_func (done=0, length=50,
string=0x5555555963e0 "#define HAVE_LEGENDRE_TABLES\n#define LEGENDRE_MOD %u\n", s=0x7fffffffd7b0)
at ../libio/libioP.h:948
#9 __vfprintf_internal (s=s@entry=0x7fffffffd7b0,
format=format@entry=0x5555555963e0 "#define HAVE_LEGENDRE_TABLES\n#define LEGENDRE_MOD %u\n",
ap=ap@entry=0x7fffffffd8f0, mode_flags=mode_flags@entry=6) at vfprintf-internal.c:1404
#10 0x00007ffff7acfa49 in __vsprintf_internal (
string=0x7fffffffde10 "#define HAVE_LEGENDRE_TABLES\n#define LEGENDRE_MOD\220\fVUU", maxlen=<optimized out>,
format=0x5555555963e0 "#define HAVE_LEGENDRE_TABLES\n#define LEGENDRE_MOD %u\n", args=args@entry=0x7fffffffd8f0,
mode_flags=6) at iovsprintf.c:95
#11 0x00007ffff7b75b1f in ___sprintf_chk (s=<optimized out>, flag=<optimized out>, slen=<optimized out>,
format=<optimized out>) at sprintf_chk.c:40
#12 0x000055555558c335 in CisOneWithOneSequenceGpuWorker::Prepare(unsigned long, unsigned int) ()
#13 0x0000555555588d8a in CisOneWithOneSequenceHelper::CreateWorker(unsigned int, bool, unsigned long) ()
#14 0x000055555555f207 in App::CreateWorkers(unsigned long) ()
#15 0x00005555555604a7 in App::Run() ()
#16 0x000055555555d8ec in main ()
[/CODE]

gdb stack trace work? Otherwise, I am not opposed to a better suggestion.

That is exactly what I needed. I'm fairly certain the issue is a char array that isn't long enough to hold what the code is trying to stuff into it. I have committed a change. Let me know if that resolves the issue. Obviously the other OSes I have tested this on don't detect this condition.

I will put a new Windows build on sourceforge if anyone needs me to do that.

[QUOTE=rogue;574053]That is exactly what I needed. I'm fairly certain the issue is a char array that isn't long enough to hold what the code is trying to stuff into it. I have committed a change. Let me know if that resolves the issue. Obviously the other OSes I have tested this on don't detect this condition.

I will put a new Windows build on sourceforge if anyone needs me to do that.[/QUOTE]

Works perfectly! The OS is Ubuntu 20.10 (Groovy Gorilla?), and it does not surprise me that it's causing hangups for this, since it also has a recent issue that leaves it unable to compile yafu. Will have to reconsider the OS I use, then.

Thanks much for your time!