reiser writes:
> Nikita Danilov wrote:
>
> >Tomas Szepe writes:
> > > > This should help:
> > > >
> > > > diff -Nru a/txnmgr.c b/txnmgr.c
> > > > --- a/txnmgr.c Wed Oct 30 18:58:09 2002
> > > > +++ b/txnmgr.c Fri Nov 1 20:13:27 2002
> > > > @@ -1917,7 +1917,7 @@
> > > > return;
> > > > }
> > > >
> > > > - if (!jnode_is_unformatted) {
> > > > + if (jnode_is_znode(node)) {
> > > > if ( /**jnode_get_block(node) &&*/
> > > > !blocknr_is_fake(jnode_get_block(node))) {
> > > > /* jnode has assigned real disk block. Put it into
> > >
> > >
> > > Jup, this fixes the leak, but free space still isn't reported accurately
> > > until after sync gets called, which I believe is a bug too.
> >
> >In reiser4 allocation of disk space is delayed to transaction commit. It
> >is not possible to estimate precisely amount of disk space that will be
> >allocated during commit, and hence statfs(2) results are not updated
> >until one does sync(2) (forcing commit) or transaction is committed due
> >to age (10 minutes by default).
> >
> >
> >
> The above is badly phrased, and the behavior complained of is indeed a
> bug not a feature. Please fix.
>
> statfs should be updated immediately in accordance with estimates used
> by the space reservation code, and then adjusted at commit time in
> accordance with actual usage.
We should not do that unless we implement forcing of commits at out of free
space situation.
>
> Andreas, the performance advantage is achieved using much more than the
> amount of RAM available on the computer, and is therefore mostly
> independent of max transaction age. The appropriate setting of
> transaction max age depends on the user. The setting we chose is
> appropriate for software developers doing compiles. It is not clear to
> me yet what the right setting is. Perhaps 3 minutes is more
> appropriate. I was probably overly influenced by Drew Roselli's
> statistics on how long the cyle is between rewrites. Her statistics are
> probably skewed by having lots of CS students using the machines she got
> her data from. 5 seconds is too short to perform good layout
> optimization for subsequent reads.
>
> Hans
>
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This archive was generated by hypermail 2b29 : Thu Nov 07 2002 - 22:00:36 EST