"Chen, Kenneth W" <[EMAIL PROTECTED]> wrote: > > On Mon, 21 Mar 2005, Andrew Morton wrote: > > Holger, this problem remains unresolved, does it not? Have you done any > > more experimentation? > > > > I must say that something funny seems to be happening here. I have two > > MPT-based Dell machines, neither of which is using a modular driver: > > > > akpm:/usr/src/25> 0 hdparm -t /dev/sda > > > > /dev/sda: > > Timing buffered disk reads: 64 MB in 5.00 seconds = 12.80 MB/sec > > > Holger Kiehl wrote on Tuesday, March 22, 2005 12:31 AM > > Got the same result when compiled in, always between 12 and 13 MB/s. As > > module it is approx. 75 MB/s. > > > Half guess, half with data to prove: it must be the variable driver_setup > initialization. If compiled as built-in, driver_setup is initialized to > zero for all of its member variables, which isn't the fastest setting. If > compiled as module, it gets first class treatment with shinny performance > setting. Goofing around, this patch appears to be giving higher throughput.
ooh, you actually looked at the code ;) > Before: > /dev/sdc: > Timing buffered disk reads: 92 MB in 3.03 seconds = 30.32 MB/sec > > After: > /dev/sdc: > Timing buffered disk reads: 174 MB in 3.02 seconds = 57.61 MB/sec > Yes, that's it. Eric, you owe me about 10000 hours ;) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
