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Subject: Re: [RFC PATCH 1/21] relay - Clean up relay_switch_subbuf() and
	make waking up consumers optional.
From: Tom Zanussi <zanussi@comcast.net>
To: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
       Martin Bligh <mbligh@google.com>,
       Peter Zijlstra <a.p.zijlstra@chello.nl>, prasad@linux.vnet.ibm.com,
       Linus Torvalds <torvalds@linux-foundation.org>,
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       Mathieu Desnoyers <compudj@krystal.dyndns.org>,
       Steven Rostedt <rostedt@goodmis.org>, od@suse.com,
       "Frank Ch. Eigler" <fche@redhat.com>,
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       Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
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Date: Sun, 19 Oct 2008 00:00:48 -0500
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Hi Pekka,

On Sat, 2008-10-18 at 11:54 +0300, Pekka Enberg wrote:
> Hi Tom,
> 
> Tom Zanussi wrote:
> > +static inline void relay_update_filesize(struct rchan_buf *buf, size_t length)
> > +{
> > +	if (buf->dentry)
> > +		buf->dentry->d_inode->i_size +=	length;
> > +	else
> > +		buf->early_bytes += length;
> > +
> > +	smp_mb();
> > +}
> 
> A minor nit: you should probably add a comment for that memory barrier. 
> That is, explain why it is needed. It makes a world of a difference to 
> anyone trying to understand what's going on here.

You're right, but it actually goes away in one of the following patches.

I'm wondering whether it even makes sense to post the individual patches
or instead just the full squashed patch and/or the end-result files,
which are really the things it would useful to review.

I've made some new changes following more testing and actually plan to
post another round sometime soon - I'll probably skip posting the
individual patches then unless it makes sense to.

Thanks for the comments.

Tom