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Date: Wed, 3 Oct 2018 18:27:58 +0200
From: Jan Kara <jack@suse.cz>
Subject: Re: [PATCH 3/4] infiniband/mm: convert to the new put_user_page()
 call
Message-ID: <20181003162758.GI24030@quack2.suse.cz>
References: <20180928053949.5381-1-jhubbard@nvidia.com>
 <20180928053949.5381-3-jhubbard@nvidia.com>
 <20180928153922.GA17076@ziepe.ca>
 <36bc65a3-8c2a-87df-44fc-89a1891b86db@nvidia.com>
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To: John Hubbard <jhubbard@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>, john.hubbard@gmail.com, Matthew Wilcox <willy@infradead.org>, Michal Hocko <mhocko@kernel.org>, Christopher Lameter <cl@linux.com>, Dan Williams <dan.j.williams@intel.com>, Jan Kara <jack@suse.cz>, Al Viro <viro@zeniv.linux.org.uk>, linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>, linux-rdma <linux-rdma@vger.kernel.org>, linux-fsdevel@vger.kernel.org, Doug Ledford <dledford@redhat.com>, Mike Marciniszyn <mike.marciniszyn@intel.com>, Dennis Dalessandro <dennis.dalessandro@intel.com>, Christian Benvenuti <benve@cisco.com>

On Fri 28-09-18 20:12:33, John Hubbard wrote:
>  static inline void release_user_pages(struct page **pages,
> -                                     unsigned long npages)
> +                                     unsigned long npages,
> +                                     bool set_dirty)
>  {
> -       while (npages)
> -               put_user_page(pages[--npages]);
> +       if (set_dirty)
> +               release_user_pages_dirty(pages, npages);
> +       else
> +               release_user_pages_basic(pages, npages);
> +}

Is there a good reason to have this with set_dirty argument? Generally bool
arguments are not great for readability (or greppability for that matter).
Also in this case callers can just as easily do:
	if (set_dirty)
		release_user_pages_dirty(...);
	else
		release_user_pages(...);

And furthermore it makes the code author think more whether he needs
set_page_dirty() or set_page_dirty_lock(), rather than just passing 'true'
and hoping the function magically does the right thing for him.

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR