Re: IDE performances, 2.4 vs 2.5

From: Bartlomiej Zolnierkiewicz (B.Zolnierkiewicz@elka.pw.edu.pl)
Date: Tue Jun 10 2003 - 09:36:44 EST


IDE layer is basically the same in 2.4.21-rc and 2.5.70 (but not in -bk).
If you check 2.4.21-rc against 2.5.70 and results will be similar,
it means its not IDE performance problem, but block layer, VM or FS.

Regards,

--
Bartlomiej

On Tue, 10 Jun 2003, Stefano Rivoir wrote:

> Noting that 2.5 is much slower than 2.4 on disk operations (you *touch* > it when you have not-so-fast machine and use KDE, for example), I've > written a silly test that fwrite/fread a single 100Mb file, char by > char, and timing it I have results that I can't understand very well. Of > course, same machine, same hdparm settings, same processes running > (none, it's a notebook without server processes). I've run these test > several time, the results are always more or less the same (ext2):

fwrite/fread is not a good test for IDE performance.

> 2.4.19 > > read: real 0m15.822s > user 0m15.180s > sys 0m0.270s > > write: real 0m12.524s > user 0m11.800s > sys 0m0.690s > > 2.5.70 (up to -bk14, and -mm6) > > read: real 0m20.790s > user 0m14.372s > sys 0m0.949s > > write: real 0m13.148s > user 0m11.901s > sys 0m0.665 > > Writing does not drop, but reading has a 6 seconds difference between > user+sys and real that I can't figure out. And the total difference is > "huge". Actually, using anything that touches the disk (it can be a > trivial "aptitude" loading the cache, or a complex KDE) slows down. > > I've run these tests on a HP Omnibook w/Celeron, but I have the same > slow down on a Athlon K7. > > Is it anyway "normal", something I should expect upgrading from 2.4 to > 2.5/2.6? Or there should be something I should check more accurately? > > Bye all. > > -- > Stefano RIVOIR > > > > > - > 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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