From: Andi K. <ak...@su...> - 2002-08-10 02:13:14
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On Fri, Aug 09, 2002 at 05:30:47PM -0700, Gerrit Huizenga wrote: > Thanks, Jenny - even failures are interesting at this point. There > is a good chance that the kernel did something mean to the application, > so if you can figure out through strace or a debugger or a collection > of the exit values what led to the failure that might be useful. > > Also, do you know if sapdb uses AIO (asynchronous IO) on any platforms? > Would it benefit from AIO on Linux? There is some posix AIO support in the source code for other Unixes. Last time I looked it wasn't used on linux though, it uses threaded IO instead. It could be enabled by fixing some ifdefs and recompiling. Another useful change would be probably to change it to use O_DIRECT. Then it could work with files instead of raw partitions and it would be also possible to measure differences between rawio and O_DIRECT. I checked with the sapdb developers some time ago and they told me that all the IO buffers should be already sufficiently aligned for O_DIRECT, so changing it should be very simple. -Andi |