Messages in this thread | | | Date | Tue, 11 Jul 2006 16:38:30 +0200 | From | Xavier Roche <> | Subject | Re: Huge performance issue with cciss driver on HP DL385 servers (2.6.13 -> 2.6.17) |
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Erik Mouw a écrit : > AFAIK buffers for direct IO need to be *page* aligned. Use something > like: > I guess you got away with it cause your 512 byte alignment happened to > align on a page, but you shouldn't count on that. However...
This example was actually just a minimal example - the running test is correctly aligned.
> You should check the return value of pwrite().
Also checked in the "real" stress program.
Note that this problem is hard to reproduce, and might be related to very strange I/O (and/or DMA access) operation ordering. The fact that the program must be run just after a reboot (or the problem is not easily reproductible) is something really fishy. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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