Messages in this thread | | | Date | Mon, 4 Nov 2013 13:19:33 +0100 | From | Pavel Machek <> | Subject | Re: Disabling in-memory write cache for x86-64 in Linux II |
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Hi!
> > Yes, but then the temp-file is long-lived enough that it *will* hit > > the disk anyway. So it's only the "create temporary file and pretty > > much immediately delete it" case that changes behavior (ie compiler > > assembly files etc). > > > > If the temp-file is for something like burning an ISO image, the > > burning part is slow enough that the temp-file will hit the disk > > regardless of when we start writing it. > > The temp-file IO avoidance is an optimization not a guarantee. If a > user want to avoid IO seriously, he will probably use tmpfs and > disable swap.
No, sorry, they can't. Assuming ISO image fits in tmpfs would be cruel.
> So if we have to do some trade-offs in the optimization, I agree that > we should optimize more towards the "large copies to USB stick" use case. > > The alternative solution, per-bdi dirty thresholds, could eliminate > the need to do such trade-offs. So it's worth looking at the two > solutions side by side.
Yes, please. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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