Re: Linux 2.6.29

[Jeff Garzik]

Ric Wheeler wrote:
> Jeff Garzik wrote:
> > Jens Axboe wrote:
> > > Another problem is that FLUSH_CACHE sucks. Really. And not just on
> > > ext3/ordered, generally. Write a 50 byte file, fsync, flush cache and
> > > wit for the world to finish. Pretty hard to teach people to use a nicer
> > > fdatasync(), when the majority of the cost now becomes flushing the
> > > cache of that 1TB drive you happen to have 8 partitions on. Good luck
> > > with that.
> >
> > (responding to an email way back near the start of the thread)
> >
> > I emailed Microsoft about their proposal to add a WRITE BARRIER 
> > command to ATA, documented at
> > http://www.t13.org/Documents/UploadedDocuments/docs2007/e07174r0-Write_Barrier_Command_Proposal.doc 

> > The MSFT engineer said they were definitely still pursuing this proposal.
> >
> > IMO we could look at this too, or perhaps come up with an alternate 
> > proposal like FLUSH CACHE RANGE(s).

> I agree that it is worth getting better mechanisms in place - the cache 
> flush is really primitive. Now we just need a victim to sit in on 
> T13/T10 standards meetings :-)


Heck, we could even do a prototype implementation with the help of Mark 
Lord's sata_mv target mode support...

	Jeff



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