Messages in this thread | | | Date | Thu, 1 Sep 2005 16:49:56 +0200 | From | DervishD <> | Subject | Re: USB Storage speed regression since 2.6.12 |
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Salut Brice :)
* Brice Goglin <Brice.Goglin@ens-lyon.org> dixit: > Le 01.09.2005 13:36, DervishD a écrit : > > The lack of speed seems to affect only the OHCI driver. My test > > was done over a PCI USB 2.0 card, ALi chipset, OHCI driver (well > > EHCI+OHCI) and using a full speed device capable of 12MBps. The > > average measured speeds are: > > > > - 2.4.31: about 450Kb/seg > > - 2.6.11-Debian: about 800Kb/seg > > - 2.6.11.12: about 820Kb/seg > > - 2.6.12.x: about 200Kb/seg > > - 2.6.13: about 200Kb/seg > Are you mounting this storage with vfat and 'sync' option ?
Yes, that may be the problem, but I think that is not the only problem, see below.
> IIRC, sync support for vfat was added around 2.6.12, making > write way slower since it's now really synchron.
The fact is that if I mount the device under 2.4.31 using the 'sync' option, the speed are the ones shown above, but if I mount them with 'async', the speed is that of the light ;) I mean, the 'sync' option is doing something even in 2.4.31. The same applies to 2.6.11, but I have to test in 2.6.12 & 13.
Thanks for your help. If the problem is just that, the sync option, I'll drop a note to the mailing list. Merci mille fois ;)
Raúl Núñez de Arenas Coronado
-- Linux Registered User 88736 | http://www.dervishd.net http://www.pleyades.net & http://www.gotesdelluna.net It's my PC and I'll cry if I want to... - 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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