inaccurate migration cost calculation?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Across different boots using the same 2.6.19 kernel on a quad-core xeon
I see huge variance in the migration_cost being reported during boot.

-migration_cost=39,3940
+migration_cost=25,4941

This CPU has a very large cache which could be key here...
 L1 Instruction cache: 32KB, 8-way associative. 64 byte line size.
 L1 Data cache: 32KB, 8-way associative. 64 byte line size.
 L3 unified cache: 4MB, 16-way associative. 64 byte line size.


Here's the output of migration_debug=1 for another two boots..

-> [0][1][  65536]   0.0 [  0.0] (1): (   42507    21253)
-> [0][1][  72817]   0.0 [  0.0] (1): (   46350    12548)
-> [0][1][  80907]   0.0 [  0.0] (1): (   58571    12384)
-> [0][1][  89896]   0.0 [  0.0] (1): (   57738     6608)
-> [0][1][  99884]   0.0 [  0.0] (1): (   60743     4806)
-> [0][1][ 110982]   0.0 [  0.0] (1): (   67393     5728)
-> [0][1][ 123313]   0.0 [  0.0] (1): (   72416     5375)
-> [0][1][ 137014]   0.0 [  0.0] (1): (   73890     3424)
-> [0][1][ 152237]   0.0 [  0.0] (1): (   75735     2634)
-> [0][1][ 169152]   0.0 [  0.0] (1): (   91870     9384)
-> [0][1][ 187946]   0.0 [  0.0] (1): (   88701     6276)
-> [0][1][ 208828]   0.1 [  0.1] (1): (  102106     9840)
-> [0][1][ 232031]   0.1 [  0.1] (1): (  112433    10083)
-> [0][1][ 257812]   0.1 [  0.1] (1): (  118441     8045)
-> [0][1][ 286457]   0.1 [  0.1] (1): (  126302     7953)
-> [0][1][ 318285]   0.1 [  0.1] (1): (  135442     8546)
-> [0][1][ 353650]   0.1 [  0.1] (1): (  165438    19271)
-> [0][1][ 392944]   0.1 [  0.1] (1): (  196143    24988)
-> [0][1][ 436604]   0.1 [  0.1] (1): (  180626    20252)
-> [0][1][ 485115]   0.2 [  0.2] (1): (  209017    24321)
-> [0][1][ 539016]   0.2 [  0.2] (1): (  231664    23484)
-> [0][1][ 598906]   0.2 [  0.2] (1): (  277569    34694)
-> [0][1][ 665451]   0.2 [  0.2] (1): (  276351    17956)
-> [0][1][ 739390]   0.3 [  0.3] (1): (  318707    30156)
-> [0][1][ 821544]   0.3 [  0.3] (1): (  382865    47157)
-> [0][1][ 912826]   0.3 [  0.3] (1): (  398566    31429)
-> [0][1][1014251]   0.4 [  0.4] (1): (  441757    37310)
-> [0][1][1126945]   0.5 [  0.5] (1): (  516100    55826)
-> [0][1][1252161]   0.5 [  0.5] (1): (  543549    41637)
-> [0][1][1391290]   0.6 [  0.6] (1): (  603068    50578)
-> [0][1][1545877]   0.6 [  0.6] (1): (  637083    42296)
-> [0][1][1717641]   0.8 [  0.8] (1): (  800596   102904)
-> [0][1][1908490]   0.8 [  0.8] (1): (  856786    79547)
-> [0][1][2120544]   0.9 [  0.9] (1): (  919895    71328)
-> [0][1][2356160]   0.9 [  0.9] (1): (  973085    62259)
-> [0][1][2617955]   1.1 [  1.1] (1): ( 1114043   101608)
-> [0][1][2908838]   1.2 [  1.2] (1): ( 1219850   103707)
-> [0][1][3232042]   1.3 [  1.3] (1): ( 1327969   105913)
-> [0][1][3591157]   1.4 [  1.4] (1): ( 1463296   120620)
-> [0][1][3990174]   1.6 [  1.6] (1): ( 1630438   143881)
-> [0][1][4433526]   1.7 [  1.7] (1): ( 1729272   121357)
-> [0][1][4926140]   1.7 [  1.7] (1): ( 1733278    62681)
-> [0][1][5473488]   1.9 [  1.9] (1): ( 1958482   143942)
-> [0][1][6081653]   1.8 [  1.9] (1): ( 1872926   114749)
-> [0][1][6757392]   1.7 [  1.9] (1): ( 1713013   137331)
-> [0][1][7508213]   1.3 [  1.9] (1): ( 1392757   228793)
-> [0][1][8342458]   1.1 [  1.9] (1): ( 1116378   252586)
-> found max.
[0][1] working set size found: 5473488, cost: 1958482
-> [0][2][  65536]   0.0 [  0.0] (0): (    9187     4593)
-> [0][2][  72817]   0.0 [  0.0] (0): (   13719     4562)
-> [0][2][  80907]   0.0 [  0.0] (0): (    8008     5136)
-> [0][2][  89896]   0.0 [  0.0] (0): (    7924     2610)
-> [0][2][  99884]   0.0 [  0.0] (0): (    2640     3947)
-> found max.
[0][2] working set size found: 72817, cost: 13719
migration: max_cache_size: 0, cpu: 2666 MHz:
migration_cost=27,3916
migration: 0 seconds



-> [0][1][  65536]   0.0 [  0.0] (1): (   36355    18177)
-> [0][1][  72817]   0.0 [  0.0] (1): (   49107    15464)
-> [0][1][  80907]   0.0 [  0.0] (1): (   57124    11740)
-> [0][1][  89896]   0.0 [  0.0] (1): (   57766     6191)
-> [0][1][  99884]   0.0 [  0.0] (1): (   72324    10374)
-> [0][1][ 110982]   0.0 [  0.0] (1): (   80125     9087)
-> [0][1][ 123313]   0.0 [  0.0] (1): (   74042     7585)
-> [0][1][ 137014]   0.0 [  0.0] (1): (   78227     5885)
-> [0][1][ 152237]   0.0 [  0.0] (1): (   80157     3907)
-> [0][1][ 169152]   0.0 [  0.0] (1): (   88881     6315)
-> [0][1][ 187946]   0.0 [  0.0] (1): (   99344     8389)
-> [0][1][ 208828]   0.1 [  0.1] (1): (  104998     7021)
-> [0][1][ 232031]   0.1 [  0.1] (1): (  113660     7841)
-> [0][1][ 257812]   0.1 [  0.1] (1): (  124690     9435)
-> [0][1][ 286457]   0.1 [  0.1] (1): (  135835    10290)
-> [0][1][ 318285]   0.1 [  0.1] (1): (  153135    13795)
-> [0][1][ 353650]   0.1 [  0.1] (1): (  145024    10953)
-> [0][1][ 392944]   0.2 [  0.2] (1): (  215998    40963)
-> [0][1][ 436604]   0.2 [  0.2] (1): (  212086    22437)
-> [0][1][ 485115]   0.2 [  0.2] (1): (  250632    30491)
-> [0][1][ 539016]   0.2 [  0.2] (1): (  221014    30054)
-> [0][1][ 598906]   0.2 [  0.2] (1): (  281687    45363)
-> [0][1][ 665451]   0.2 [  0.2] (1): (  296981    30328)
-> [0][1][ 739390]   0.3 [  0.3] (1): (  351999    42673)
-> [0][1][ 821544]   0.4 [  0.4] (1): (  413272    51973)
-> [0][1][ 912826]   0.4 [  0.4] (1): (  402094    31575)
-> [0][1][1014251]   0.4 [  0.4] (1): (  461726    45603)
-> [0][1][1126945]   0.5 [  0.5] (1): (  504549    44213)
-> [0][1][1252161]   0.5 [  0.5] (1): (  570889    55276)
-> [0][1][1391290]   0.6 [  0.6] (1): (  637668    61027)
-> [0][1][1545877]   0.6 [  0.6] (1): (  660241    41800)
-> [0][1][1717641]   0.8 [  0.8] (1): (  820951   101255)
-> [0][1][1908490]   0.8 [  0.8] (1): (  860249    70276)
-> [0][1][2120544]   0.9 [  0.9] (1): (  947017    78522)
-> [0][1][2356160]   0.9 [  0.9] (1): (  999742    65623)
-> [0][1][2617955]   1.1 [  1.1] (1): ( 1152233   109057)
-> [0][1][2908838]   1.2 [  1.2] (1): ( 1247362   102093)
-> [0][1][3232042]   1.3 [  1.3] (1): ( 1371438   113084)
-> [0][1][3591157]   1.5 [  1.5] (1): ( 1518791   130218)
-> [0][1][3990174]   1.6 [  1.6] (1): ( 1621385   116406)
-> [0][1][4433526]   1.7 [  1.7] (1): ( 1775523   135272)
-> [0][1][4926140]   1.7 [  1.7] (1): ( 1784080    71914)
-> [0][1][5473488]   1.9 [  1.9] (1): ( 1970125   128979)
-> [0][1][6081653]   1.9 [  1.9] (1): ( 1926772    86166)
-> [0][1][6757392]   1.7 [  1.9] (1): ( 1722660   145139)
-> [0][1][7508213]   1.4 [  1.9] (1): ( 1405442   231178)
-> [0][1][8342458]   1.1 [  1.9] (1): ( 1107804   264408)
-> found max.
[0][1] working set size found: 5473488, cost: 1970125
-> [0][2][  65536]   0.0 [  0.0] (0): (    8829     4414)
-> [0][2][  72817]   0.0 [  0.0] (0): (    8027     2608)
-> [0][2][  80907]   0.0 [  0.0] (0): (    7606     1514)
-> [0][2][  89896]   0.0 [  0.0] (0): (    8161     1034)
-> [0][2][  99884]   0.0 [  0.0] (0): (    7894      650)
-> [0][2][ 110982]   0.0 [  0.0] (0): (    8264      510)
-> [0][2][ 123313]   0.0 [  0.0] (0): (    7581      596)
-> [0][2][ 137014]   0.0 [  0.0] (0): (    7079      549)
-> [0][2][ 152237]   0.0 [  0.0] (0): (    7230      350)
-> [0][2][ 169152]   0.0 [  0.0] (0): (    7699      409)
-> [0][2][ 187946]   0.0 [  0.0] (0): (    5896     1106)
-> [0][2][ 208828]   0.0 [  0.0] (0): (    9608     2409)
-> [0][2][ 232031]   0.0 [  0.0] (0): (   12809     2805)
-> [0][2][ 257812]   0.0 [  0.0] (0): (    7996     3809)
-> [0][2][ 286457]   0.0 [  0.0] (0): (   18848     7330)
-> [0][2][ 318285]   0.0 [  0.0] (0): (    7747     9215)
-> [0][2][ 353650]   0.0 [  0.0] (0): (   11258     6363)
-> [0][2][ 392944]   0.0 [  0.0] (0): (   18775     6940)
-> [0][2][ 436604]   0.0 [  0.0] (0): (   12380     6667)
-> [0][2][ 485115]   0.0 [  0.0] (0): (   19986     7136)
-> [0][2][ 539016]   0.0 [  0.0] (0): (   -6102    16612)
-> [0][2][ 598906]   0.0 [  0.0] (0): (    3783    13248)
-> [0][2][ 665451]   0.0 [  0.0] (0): (   -3546    10288)
-> found max.
[0][2] working set size found: 485115, cost: 19986
migration: max_cache_size: 0, cpu: 2666 MHz:
migration_cost=39,3940
migration: 0 seconds



		Dave

-- 
http://www.codemonkey.org.uk
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux