Messages in this thread | | | Date | Fri, 18 Jan 2002 17:53:13 +0100 | From | Willi Nüßer <> | Subject | Re: clarification about redhat and vm |
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Alan Cox wrote: > > > "If redhat doesn't use the -aa VM " was a short form of "if redhat > > cannot see the goodness of all the bugfixing work that happened between > > the 2.4.9 VM and any current branch 2.4, and so if they keep shipping > > 2.4.9 VM as the best one for DBMS and critical VM apps like the SAP > > benchmark". > > The RH VM is totally unrelated to the crap in 2.4.9 vanilla. The SAP comment > begs a question. 2.4.10 seems to have problems remembering to actually > do fsync()'s. How much of your SAP benchmark is from fsync's that dont > happen ? Do you get the same values with 2.4.18-aa ?
Well, basically we checked the thing many times with quite different kernels. Our current tests - which show exactly the same results as 2.4.[10,14,15] - run on the new "official" SuSE kernel 2.4.16. Again, we observe a performance increase in high swap situations of about a factor of ten compared to 2.4.[7,9].
IMO, this shows that errors like fsync etc. are _not_ responsible for the improved performance.
But of course, we will check the newer kernels as well. I think we could live with another factor of ten ...
-- Best regards Willi
----------------------------------- Willi Nuesser SAP Linuxlab - 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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