From: Neil R. Smith (neils@ariel.met.tamu.edu)
Date: Tue Dec 14 2004 - 17:58:07 EST
Hi folks,
We've got a user with a model in Fortran code who is seeing
a dramatic slowdown, by a factor of 100 at least, when he increases
the computation grid size past some threshold size; evidently about
2 GB. This is confusing to the user and me since this ES45 4x 1GHz
has 12GB RAM and 24GB swap spread across 3 disks.
What would you suggest I look for?
Some additional info:
Platform: ES 45, 4x 1GHz, 12GB RAM
OS: OSF1 xxx.xxx.xxx V5.1 1885 alpha
swap: 24GB across 3 disk drives;
eager mode
shell: tcsh
> limit
cputime unlimited
filesize unlimited
datasize 12006804 kbytes
stacksize 12006804 kbytes
coredumpsize 0 kbytes
memoryuse 12337880 kbytes
vmemoryuse 12006804 kbytes
descriptors 4096
# sysconfig -q proc
proc:
max_proc_per_user = 512
max_threads_per_user = 2048
per_proc_stack_size = 12294967296
max_per_proc_stack_size = 12294967296
per_proc_data_size = 12294967296
max_per_proc_data_size = 12294967296
max_per_proc_address_space = 12294967296
per_proc_address_space = 12294967296
executable_stack = 0
autonice = 0
autonice_time = 600
autonice_penalty = 4
open_max_soft = 4096
open_max_hard = 4096
ncallout_alloc_size = 8192
round_robin_switch_rate = 0
sched_min_idle = 0
give_boost = 1
maxusers = 2048
num_wait_queues = 2048
num_timeout_hash_queues = 2048
enhanced_core_name = 0
enhanced_core_max_versions = 16
exec_disable_arg_limit = 0
dump_cores = 1
dump_setugid_cores = 0
executable_data = 0
# sysconfig -q vm
vm:
ubc_minpercent = 10
ubc_maxpercent = 100
ubc_borrowpercent = 20
vm_max_wrpgio_kluster = 32768
vm_max_rdpgio_kluster = 16384
vm_cowfaults = 4
vm_segmentation = 1
vm_ubcpagesteal = 24
vm_ubcfilemaxdirtypages = 4294967295
vm_ubcdirtypercent = 40
ubc_maxdirtywrites = 5
ubc_maxdirtymetadata_pcnt = 70
ubc_kluster_cnt = 32
vm_ubcseqstartpercent = 50
vm_ubcseqpercent = 10
vm_csubmapsize = 1048576
vm_ubcbuffers = 256
vm_syncswapbuffers = 128
vm_asyncswapbuffers = 4
vm_clustermap = 1048576
vm_clustersize = 65536
vm_syswiredpercent = 80
vm_troll_percent = 4
vm_inswappedmin = 1
vm_page_free_target = 1024
vm_page_free_swap = 522
vm_page_free_hardswap = 16384
vm_page_free_min = 20
vm_page_free_reserved = 10
vm_page_free_optimal = 522
vm_swap_eager = 1
swapdevice = /dev/disk/dsk9b
vm_page_prewrite_target = 2048
vm_ffl = 1
ubc_ffl = 1
vm_rss_maxpercent = 100
anon_rss_enforce = 0
vm_rss_block_target = 522
vm_rss_wakeup_target = 522
kernel_stack_pages = 0
vm_min_kernel_address = 18446741891866165248
malloc_percpu_cache = 1
vm_aggressive_swap = 0
new_wire_method = 1
vm_segment_cache_max = 50
gh_chunks = 0
rad_gh_regions[0] = 0
rad_gh_regions[1] = 0
rad_gh_regions[2] = 0
rad_gh_regions[3] = 0
rad_gh_regions[4] = 0
rad_gh_regions[5] = 0
rad_gh_regions[6] = 0
rad_gh_regions[7] = 0
rad_gh_regions[8] = 0
rad_gh_regions[9] = 0
rad_gh_regions[10] = 0
rad_gh_regions[11] = 0
rad_gh_regions[12] = 0
rad_gh_regions[13] = 0
rad_gh_regions[14] = 0
rad_gh_regions[15] = 0
rad_gh_regions[16] = 0
rad_gh_regions[17] = 0
rad_gh_regions[18] = 0
rad_gh_regions[19] = 0
rad_gh_regions[20] = 0
rad_gh_regions[21] = 0
rad_gh_regions[22] = 0
rad_gh_regions[23] = 0
rad_gh_regions[24] = 0
rad_gh_regions[25] = 0
rad_gh_regions[26] = 0
rad_gh_regions[27] = 0
rad_gh_regions[28] = 0
rad_gh_regions[29] = 0
rad_gh_regions[30] = 0
rad_gh_regions[31] = 0
rad_gh_regions[32] = 0
rad_gh_regions[33] = 0
rad_gh_regions[34] = 0
rad_gh_regions[35] = 0
rad_gh_regions[36] = 0
rad_gh_regions[37] = 0
rad_gh_regions[38] = 0
rad_gh_regions[39] = 0
rad_gh_regions[40] = 0
rad_gh_regions[41] = 0
rad_gh_regions[42] = 0
rad_gh_regions[43] = 0
rad_gh_regions[44] = 0
rad_gh_regions[45] = 0
rad_gh_regions[46] = 0
rad_gh_regions[47] = 0
rad_gh_regions[48] = 0
rad_gh_regions[49] = 0
rad_gh_regions[50] = 0
rad_gh_regions[51] = 0
rad_gh_regions[52] = 0
rad_gh_regions[53] = 0
rad_gh_regions[54] = 0
rad_gh_regions[55] = 0
rad_gh_regions[56] = 0
rad_gh_regions[57] = 0
rad_gh_regions[58] = 0
rad_gh_regions[59] = 0
rad_gh_regions[60] = 0
rad_gh_regions[61] = 0
rad_gh_regions[62] = 0
rad_gh_regions[63] = 0
gh_min_seg_size = 4194304
gh_fail_if_no_mem = 1
private_cache_percent = 0
gh_keep_sorted = 0
gh_front_alloc = 1
replicate_user_text = 1
enable_yellow_zone = 0
boost_pager_priority = 0
kstack_free_target = 5
wire_audit_count = 0
vm_prepop_percent = 100
-- Neil R. Smith, Comp. Sys. Mngr. neils@tamu.edu Dept. Atmospheric Sci., Texas A&M Univ. 979/845-6272 FAX:979/862-4466
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