Re: Bug#605009: serious performance regression with ext4

[Raphael Hertzog <hertzog@debian.org>]

On Sat, 27 Nov 2010, Jonathan Nieder wrote:
> > c)  extract(a.dpkg-new);
> >     extract(b.dpkg-new);
> >     extract(c.dpkg-new);
> >     fsync(a.dpkg-new);
> >     fsync(b.dpkg-new);
> >     fsync(c.dpkg-new);
> >     rename(a.dpkg-new, a);
> >     rename(b.dpkg-new, b);
> >     rename(c.dpkg-new, c);
> > 
> > 
> > (c) will perform the best for most file systems, including ext4.
> [...]
> > I am guessing you are doing (a) today --- am I right?  (c) or (d)
> > would be best.
> 
> We are doing (c) today.

Actually we are doing this:
    extract(a.dpkg-new);
    extract(b.dpkg-new);
    extract(c.dpkg-new);
    fsync(a.dpkg-new);
    rename(a.dpkg-new, a);
    fsync(b.dpkg-new);
    rename(b.dpkg-new, b);
    fsync(c.dpkg-new);
    rename(c.dpkg-new, c);

But as I said, I tried (c) and it's not performing noticably better than
the above.

Cheers,
-- 
Raphaël Hertzog ◈ Debian Developer

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