more performance bottleneck stuff
Okay, I'm mystified (at least at this time in the morning). Here's
a vmstat trace, running on inkvine:
procs memory swap io system cpu
r b w swpd free buff cache si so bi bo in cs us sy id 0 0 0 17836 3280 5212 16420 0 0 0 0 107 124 1 1 98
0 0 0 17836 3272 5220 16420 0 0 6 0 110 125 1 1 98
0 0 0 17836 3272 5220 16420 0 0 0 0 114 143 1 2 97
0 0 0 17836 3272 5220 16420 0 0 0 0 107 130 0 2 98
0 0 0 17836 3536 5220 16420 0 0 0 4 121 144 1 2 97
0 0 0 17836 3536 5220 16420 0 0 0 0 108 131 0 2 98
0 0 0 17836 3536 5220 16420 0 0 0 0 105 124 1 1 98
0 0 0 17836 4048 5220 16420 0 0 0 0 110 136 2 0 98
0 0 0 17836 4048 5220 16420 0 0 0 0 105 126 1 1 98
0 0 0 17836 4280 5220 16420 0 0 0 1 122 170 1 2 97
0 0 0 17836 4280 5220 16420 0 0 0 0 105 126 1 1 98
[The intensive page is requested at this point.]
procs memory swap io system cpu
r b w swpd free buff cache si so bi bo in cs us sy id 0 1 0 17832 3580 5352 16520 28 0 60 0 170 253 18 5 77
0 1 0 17832 3240 5628 16564 0 0 80 0 192 287 6 4 90
1 0 0 17832 2928 5880 16616 0 0 75 0 186 275 13 3 85
1 0 0 17832 2588 6160 16672 0 0 84 4 205 317 6 3 91
1 0 0 17832 2284 6404 16720 0 0 78 0 189 279 7 3 90
1 0 0 17832 1968 6668 16772 0 0 79 0 193 292 14 3 83
1 0 0 17832 1632 6944 16828 0 0 83 0 201 304 8 3 89
1 0 0 17832 1444 7080 16884 0 0 80 89 207 298 11 4 86
0 1 1 17832 1548 7012 16840 0 0 4 144 237 336 1 2 97
0 1 0 17832 1544 7016 16840 0 0 1 16 190 159 0 2 98
1 0 0 17832 1432 7096 16872 0 0 60 0 192 248 5 3 92
1 0 0 17832 1256 7244 16900 0 0 76 0 183 276 10 5 85
1 0 0 17832 1076 7376 16952 0 0 78 0 190 281 13 2 85
1 0 0 17832 1024 7428 16952 0 0 85 0 203 316 14 2 84
1 0 0 17832 1248 7224 16932 0 0 16 99 229 198 3 2 95
2 0 0 17828 1144 6248 16804 0 0 75 5 190 306 32 11 57
1 0 0 17828 2480 6152 16768 0 0 79 2 191 295 25 4 71
1 0 0 17828 2164 6408 16824 0 0 78 0 190 290 8 1 91
1 0 0 17828 1872 6656 16868 0 0 73 0 182 270 5 3 92
1 0 0 17828 1560 6912 16920 0 0 82 0 198 306 8 2 90
1 0 0 17828 1380 7068 16944 0 0 77 0 205 305 6 3 91
0 1 0 17828 1468 7024 16900 0 0 10 218 261 323 3 0 97
1 0 0 17828 1396 7096 16900 0 0 50 0 202 247 4 3 93
1 0 0 17828 1196 7284 16912 0 0 82 0 192 297 9 3 88
0 1 1 17828 1160 7352 16876 0 0 80 119 214 336 11 7 83
1 0 0 17828 1288 7276 16824 0 0 0 2 207 177 2 1 97
1 0 0 17828 1092 7452 16848 0 0 82 0 199 311 8 4 88
0 1 0 17828 1156 7416 16816 0 0 55 143 213 327 8 1 91
1 0 0 17828 1400 7328 16664 0 0 4 0 196 152 2 1 97
1 0 0 17828 1228 7492 16672 0 0 75 0 191 282 10 5 86
Assuming a vmstat block is 512 bytes, then I can hardly imagine 40kB/s
over the IDE bus is the bottleneck; and notice how the CPU is mostly
idle. Why is this particular PHP process running so slowly, then?
c.
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