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Date: Tue, 23 Oct 2018 05:59:28 -0700
From: Matthew Wilcox <willy@infradead.org>
Subject: Re: [PATCH v2] mm: Introduce new function vm_insert_kmem_page
Message-ID: <20181023125928.GC20085@bombadil.infradead.org>
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To: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>, Russell King - ARM Linux <linux@armlinux.org.uk>, robin@protonic.nl, stefanr@s5r6.in-berlin.de, hjc@rock-chips.com, Heiko Stuebner <heiko@sntech.de>, airlied@linux.ie, robin.murphy@arm.com, iamjoonsoo.kim@lge.com, Andrew Morton <akpm@linux-foundation.org>, Marek Szyprowski <m.szyprowski@samsung.com>, Kees Cook <keescook@chromium.org>, treding@nvidia.com, Michal Hocko <mhocko@suse.com>, Dan Williams <dan.j.williams@intel.com>, "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>, Mark Rutland <mark.rutland@arm.com>, aryabinin@virtuozzo.com, Dmitry Vyukov <dvyukov@google.com>, Kate Stewart <kstewart@linuxfoundation.org>, tchibo@google.com, riel@redhat.com, Minchan Kim <minchan@kernel.org>, Peter Zijlstra <peterz@infradead.org>, "Huang, Ying" <ying.huang@intel.com>, ak@linux.intel.com, rppt@linux.vnet.ibm.com, linux@dominikbrodowski.net, Arnd Bergmann <arnd@arndb.de>, cpandya@codeaurora.org, hannes@cmpxchg.org, Joe Perches <joe@perches.com>, mcgrof@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux1394-devel@lists.sourceforge.net, dri-devel@lists.freedesktop.org, linux-rockchip@lists.infradead.org, Linux-MM <linux-mm@kvack.org>

On Tue, Oct 23, 2018 at 06:03:42PM +0530, Souptick Joarder wrote:
> On Tue, Oct 23, 2018 at 5:54 PM Matthew Wilcox <willy@infradead.org> wrote:
> > On Tue, Oct 23, 2018 at 05:44:32PM +0530, Souptick Joarder wrote:
> > > Instruction from Matthew  Wilcox who is supervising the entire vm_fault_t
> > > migration work :-)
> >
> > Hang on.  That was for the initial vm_fault_t conversion in which each
> > step was clearly an improvement.  What you're looking at now is far
> > from that.
> 
> Ok. But my understanding was, the approach of vm_insert_range comes
> into discussion as part of converting vm_insert_page into vmf_insert_page
> which is still part of original vm_fault_t conversion discussion.  No ?

No.  The initial part (converting all page fault methods to vm_fault_t)
is done.  What remains undone (looking at akpm's tree) is changing the
typedef of vm_fault_t from int to unsigned int.  That will prevent new
page fault handlers with the wrong type from being added.

I don't necessarily want to get rid of vm_insert_page().  Maybe it will
make sense to do that, and maybe not.  What I do want to see is thought,
and not "Matthew told me to do it", when I didn't.