Re: [PATCH 09/12] xfs: refactor the ioend merging code

[Christoph Hellwig]

On Mon, Jun 24, 2019 at 07:06:22PM +0300, Nikolay Borisov wrote:
> > +{
> > +	struct list_head	tmp;
> > +
> > +	list_replace_init(&ioend->io_list, &tmp);
> > +	xfs_destroy_ioend(ioend, error);
> > +	while ((ioend = list_pop(&tmp, struct xfs_ioend, io_list)))
> > +		xfs_destroy_ioend(ioend, error);
> 
> nit: I'd prefer if the list_pop patch is right before this one since
> this is the first user of it.

I try to keep generic infrastructure first instead of interveawing
it with subystem-specific patches.

> Additionally, I don't think list_pop is
> really a net-negative win 

What is a "net-negative win" ?

> in comparison to list_for_each_entry_safe
> here. In fact this "delete the list" would seems more idiomatic if
> implemented via list_for_each_entry_safe

I disagree.  The for_each loops require an additional next iterator,
and also don't clearly express what is going on, but require additional
spotting of the list_del.