calculate runtime for carver

calculate_queue.py

# Never waste brainpower on selecting your queue again.
# Future unnecessary feature: weigh queue options based on current wait times.

import math, time

t = float( raw_input('Time per solution (hr) : '))
c = int(   raw_input('Number of problems     : '))
m = int(   raw_input('Memory per core (GB)   : '))

max_mem = 20
if m <= 4:
    max_ppn = 3 
elif m <= 5:
    max_ppn = 4
elif m <= 6.826:
    max_ppn = 3
elif m <= 10:
    max_ppn = 2
elif m <= max_mem:
    max_ppn = 1
else:
    raise Exception('memory requirement must be less than %d Mb' % max_mem)

max_nodes = [64, 32, 16]
max_time = [24, 36, 48]                   # hours
walltime_sec = None
for m_n, m_t in zip(max_nodes, max_time):
    total_time = t * c
    max_cores = 512
    desired_cores = min(max_cores, c)
    nodes = min(m_n, math.ceil(desired_cores/max_ppn))
    cores = nodes * max_ppn

    desired_walltime = t * math.ceil(float(c) / float(cores))   # hr
    if desired_walltime <= m_t: 
        walltime_sec = desired_walltime * 3600
        break
    
if walltime_sec==None:
    raise Exception('Cannot find matching solution')

hr = math.floor(walltime_sec / 3600)
min = math.floor((walltime_sec - hr*3600) / 60)
sec = math.ceil(walltime_sec - hr*3600 - min*60)
print '#PBS -l walltime=%02d:%02d:%02d' % (hr, min, sec)
print '#PBS -l nodes=%d:ppn=%d' % (nodes, max_ppn)
print '#PBS -l pvmem=%dGB' % m