Re: [PATCH 2/9] nsproxy: incorporate fs namespace

["Serge E. Hallyn" <serue@us.ibm.com>]

Quoting Eric W. Biederman (ebiederm@xmission.com):
> "Serge E. Hallyn" <serue@us.ibm.com> writes:
> 
> 
> > @@ -1727,11 +1727,16 @@ static void __init init_mount_tree(void)
> >  	namespace->root = mnt;
> >  	mnt->mnt_namespace = namespace;
> >  
> > -	init_task.namespace = namespace;
> > +	init_task.nsproxy->namespace = namespace;
> >  	read_lock(&tasklist_lock);
> >  	do_each_thread(g, p) {
> > +		/* do we want namespace count to be #nsproxies,
> > +		 * or # processes pointing to the namespace? */
> 
> I am fairly certain we want the count to be #nsproxies.
> 
> >  		get_namespace(namespace);
> > -		p->namespace = namespace;
> > +#if 0
> > +		/* should only be 1 nsproxy so far */
> > +		p->nsproxy->namespace = namespace;
> > +#endif
> >  	} while_each_thread(g, p);
> >  	read_unlock(&tasklist_lock);
> 
> So I think this bit is wrong.

Ok - in that case I need to audit the rest of namespace usage to make
certain nothing depends on the count being #tasks.

BTW - a first set of comparison results showed nsproxy to have better
dbench and tbench throughput, and worse kernbench performance.  Which
may make sense given that nsproxy results in lower memory usage but
likely increased cache misses due to extra pointer dereference.

-serge
-
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