Michal Palka wrote:
No, you should not have to if you have a real write-through drive. It will however, generally improve performance for such drives to enable the barriers, if supported.But you still have to enable barrier code AFAIK.
If you have write-back, then you need the barriers, yes. But you don't have to have them for write-through drives, as they never cache written data without putting it on the platters first. That was the real thrust of my reply.
Well, I misspoke. Most IDE hardware doesn't support tagged flushes, which are faster.If your drive supports it, which isn't many drives.Can you give some references? I would like to determine if my drives lie about flushes.
You still need a drive that doesn't lie about putting out the cache, and that supports it. Older drives do not. ATA-6 drives are supposed to, but we know how that goes:
Anyway, here's a reference to a thread describing some Maxtors that don't support it properly due to implementation issues.
http://lkml.org/lkml/2004/5/12/189 Thanks, Adam