Messages in this thread | | | Date | Fri, 12 Apr 2002 13:42:52 +0200 | From | Pavel Machek <> | Subject | Re: faster boots? |
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Hi!
> > It works for me, 2.4.18 on HP omnibook xe3. > > > > You may want to watch /proc/stats to see if it is read or write > > activity that wakes disk up. > > It's write activity, due to atime updates. I was using nodiratime, but > that's not good enough because every time an executable is run a load of > things are accessed. > > I found it interesting that some write activity happens almost > immediately after the access -- and noflushd is connected in some way. > If I do this: > > while :; do cat /proc/stat; sleep 1; done > > Then I see a few writes have occurred at nearly every iteration. I > think that is due to the atime updates, because using "noatime" there > are no writes at most iterations.
Well, that's no problem. noflushd stops kflushd, so it should work even with atime. [It works for me with atimes!]
> But more interesting: I only see those few-per-second atime writes while > noflushd is running. If I kill noflushd then they go away.
?
> I am a bit surprised that "noatime" makes a difference -- I thought that > if noflushd spun down a disk, then pending inode writes should be > delayed until a read or excess memory pressure forces a spin up.
Tha'ts idea behind noflushd. I don't know why it does not work for you.
> So: "noatime" is definitely required, to spin the disk down for more > than an instant. But even that is not good enough. I have 192MB RAM, > btw. Is that enough to expect longer spin down times than 20s?
With noflushd, noatime should not and is not required.
Pavel -- Casualities in World Trade Center: ~3k dead inside the building, cryptography in U.S.A. and free speech in Czech Republic. - 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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