Re: [RFC] Early flush (was: spindown)

[Pavel Machek <pavel@suse.cz>]

Hi!

> > > > I'd like that too, but what about sync writes?  As things stand now,
> > > > there is no option but to spin the disk back up.  To get around this
> > > > we'd have to change the basic behavior of the block device and
> > > > that's doable, but it's an entirely different proposition than the
> > > > little patch above.
> > >
> > > I don't care as much about sync writes. They don't seem to happen very
> > > often on my boxes.
> >
> > syslog and some editors are the most common users of sync writes. vim,
> > e.g., per default keeps fsync()ing its swapfile. Tweaking the configuration
> > of these apps, this can be prevented fairly easy though. Changing sync
> > semantics for this matter on the other hand seems pretty awkward to me. I'd
> > expect an application calling fsync() to have good reason for having its
> > data flushed to disk _now_, no matter what state the disk happens to be in.
> > If it hasn't, fix the app, not the kernel.
> 
> But apps shouldn't have to know about the special requirements of
> laptops.  

If app does fsync(), it hopefully knows what it is doing. [Random apps
should not really do sync even on normal systems -- it hurts
performance.]
								Pavel
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The best software in life is free (not shareware)!		Pavel
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