10-15-2010
High System CPU Usage
I am running a Dell PE R815 with 4 x AMD 12 core CPUs with 128GB of RAM and a RAID 5 array of 6 SAS disks. This is an HPC application and is definitely CPU bound, however once I run 16 of these processes (thus pinning 16 cores) the work performed slows down dramatically, to maybe 5 or 10% of what it normally is capable of. Top shows that all HPC processes are using 100% CPU but they rather dramatically shift to system usage (rather than user). Here is a vmstat output:
Quote:
$ vmstat -S M 1 10
procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
46 0 0 64968 152 50747 0 0 3 41 0 0 11 32 57 0
46 0 0 64967 152 50747 0 0 0 15860 5255 127 6 89 4 0
46 0 0 64967 152 50747 0 0 0 0 5159 104 7 89 4 0
46 0 0 64968 152 50747 0 0 0 0 5153 106 7 89 4 0
46 0 0 64968 152 50747 0 0 0 40 5232 188 7 89 4 0
46 0 0 64968 152 50747 0 0 0 0 5014 102 7 90 3 0
46 0 0 64968 152 50747 0 0 0 4860 4896 107 7 88 5 0
46 0 0 64968 152 50747 0 0 0 0 5125 103 7 90 3 0
46 0 0 64968 152 50747 0 0 0 0 4987 104 7 89 4 0
46 0 0 64968 152 50747 0 0 0 2520 4805 184 7 89 4 0
To me it doesn't look like a RAM or Disk issue, but perhaps an IO or buffering issue. Please help!
-mowmentous
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ASCII(7) Miscellaneous Information Manual ASCII(7)
NAME
ascii - the ASCII character set.
DESCRIPTION
The ASCII character set is as follows:
|000 nul|001 soh|002 stx|003 etx|004 eot|005 enq|006 ack|007 bel|
|010 bs |011 ht |012 nl |013 vt |014 np |015 cr |016 so |017 si |
|020 dle|021 dc1|022 dc2|023 dc3|024 dc4|025 nak|026 syn|027 etb|
|030 can|031 em |032 sub|033 esc|034 fs |035 gs |036 rs |037 us |
|040 sp |041 ! |042 " |043 # |044 $ |045 % |046 & |047 ' |
|050 ( |051 ) |052 * |053 + |054 , |055 - |056 . |057 / |
|060 0 |061 1 |062 2 |063 3 |064 4 |065 5 |066 6 |067 7 |
|070 8 |071 9 |072 : |073 ; |074 < |075 = |076 > |077 ? |
|100 @ |101 A |102 B |103 C |104 D |105 E |106 F |107 G |
|110 H |111 I |112 J |113 K |114 L |115 M |116 N |117 O |
|120 P |121 Q |122 R |123 S |124 T |125 U |126 V |127 W |
|130 X |131 Y |132 Z |133 [ |134 |135 ] |136 ^ |137 _ |
|140 ` |141 a |142 b |143 c |144 d |145 e |146 f |147 g |
|150 h |151 i |152 j |153 k |154 l |155 m |156 n |157 o |
|160 p |161 q |162 r |163 s |164 t |165 u |166 v |167 w |
|170 x |171 y |172 z |173 { |174 | |175 } |176 ~ |177 del|
|00 nul|01 soh|02 stx|03 etx|04 eot|05 enq|06 ack|07 bel|
|08 bs |09 ht |0A nl |0B vt |0C np |0D cr |0E so |0F si |
|10 dle|11 dc1|12 dc2|13 dc3|14 dc4|15 nak|16 syn|17 etb|
|18 can|19 em |1A sub|1B esc|1C fs |1D gs |1E rs |1F us |
|20 sp |21 ! |22 " |23 # |24 $ |25 % |26 & |27 ' |
|28 ( |29 ) |2A * |2B + |2C , |2D - |2E . |2F / |
|30 0 |31 1 |32 2 |33 3 |34 4 |35 5 |36 6 |37 7 |
|38 8 |39 9 |3A : |3B ; |3C < |3D = |3E > |3F ? |
|40 @ |41 A |42 B |43 C |44 D |45 E |46 F |47 G |
|48 H |49 I |4A J |4B K |4C L |4D M |4E N |4F O |
|50 P |51 Q |52 R |53 S |54 T |55 U |56 V |57 W |
|58 X |59 Y |5A Z |5B [ |5C |5D ] |5E ^ |5F _ |
|60 ` |61 a |62 b |63 c |64 d |65 e |66 f |67 g |
|68 h |69 i |6A j |6B k |6C l |6D m |6E n |6F o |
|70 p |71 q |72 r |73 s |74 t |75 u |76 v |77 w |
|78 x |79 y |7A z |7B { |7C | |7D } |7E ~ |7F del|
ASCII(7)