Messages in this thread | | | Date | Wed, 12 May 2004 16:44:21 +0200 | From | Rene Herman <> | Subject | Re: Linux 2.6.6 "IDE cache-flush at shutdown fixes" |
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Bartlomiej Zolnierkiewicz wrote:
>>Vanilla 2.6.6: >> >>rene@7ixe4:~/cache$ grep wcache settings-2.6.6 >>wcache 1 0 1 rw >> >>2.6.6 with the de{flush,spin}ification patches: >> >>rene@7ixe4:~/cache$ grep wcache settings-2.6.6-hackedup >>wcache 0 0 1 rw >> >>Hrmpf. 0? > > Very interesting, can you try vanilla 2.6.5 (or some other 2.6.x)?
2.4.26 : wcache = 0, 0, 1 2.6.6-rc3-mm2 : wcache = 0, 0, 1 2.6.6 : wcache = 1, 0, 1 2.6.6-hackedup : wcache = 0, 0, 1
(on none of these hdparm -W0/1 has any effect, by the way)
> We are getting close to the real problem.
Indeed. I have attached two "tiobench" seq. write results, one for vanilla 2.6.6, and one for 2.6.6-hackedup (your changes). I remember the result for the latter are the normal ones I got with previous kernels as well. The differences are very interesting.
2.6.6-vanilla (ie, the one showing wcache=1): +/- 10MB/s 2.6.6-hackedup (ie, shows wcache=0) : +/- 46MB/s
As said, that 46 is the expected value. Is this a logic inversion bug in either driver (but then both 2.4.26 and 2.6) or drive firmware?
Rene.
Sequential Writes File Blk Num Avg Maximum Lat% Lat% CPU Identifier Size Size Thr Rate (CPU%) Latency Latency >2s >10s Eff ---------------------------- ------ ----- --- ------ ------ --------- ----------- -------- -------- ----- 2.6.6 1534 4096 1 10.74 9.440% 0.298 2641.08 0.00102 0.00000 114 2.6.6 1534 4096 2 10.64 9.999% 0.586 7005.74 0.00331 0.00000 106 2.6.6 1534 4096 4 10.64 9.730% 1.129 17964.34 0.02550 0.00025 109 2.6.6 1534 4096 8 10.12 9.423% 2.099 28425.08 0.04065 0.00256 107 Sequential Writes File Blk Num Avg Maximum Lat% Lat% CPU Identifier Size Size Thr Rate (CPU%) Latency Latency >2s >10s Eff ---------------------------- ------ ----- --- ------ ------ --------- ----------- -------- -------- ----- 2.6.6 1534 4096 1 46.59 57.01% 0.069 598.21 0.00000 0.00000 82 2.6.6 1534 4096 2 42.44 50.34% 0.155 1951.60 0.00000 0.00000 84 2.6.6 1534 4096 4 44.65 52.23% 0.267 1336.76 0.00000 0.00000 85 2.6.6 1534 4096 8 37.78 41.34% 0.604 6720.81 0.00307 0.00000 91
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