From: Souptick Joarder <jrdr.linux@gmail.com>
To: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Robin van der Gracht <robin@protonic.nl>,
linux-kernel <linux-kernel@vger.kernel.org>,
Matthew Wilcox <willy@infradead.org>
Subject: Re: [PATCH 2/2] auxdisplay/ht16k33.c: Convert to use vm_map_pages_zero()
Date: Fri, 24 May 2019 11:37:12 +0530 [thread overview]
Message-ID: <CAFqt6zaUhPJYozmq-m_BjJTh5EUmsQoE4yZ+Ovv6F-ymns+JGA@mail.gmail.com> (raw)
In-Reply-To: <CANiq72=zCD7AAE-OBzDYm5GXenoF48SdzwO1LunWSfexqBuH7A@mail.gmail.com>
On Fri, May 24, 2019 at 9:52 AM Miguel Ojeda
<miguel.ojeda.sandonis@gmail.com> wrote:
>
> On Thu, May 23, 2019 at 2:58 PM Miguel Ojeda
> <miguel.ojeda.sandonis@gmail.com> wrote:
> >
> > Taking a quick look now, by the way, why does vm_map_pages_zero() (and
> > __vm_map_pages() etc.) get a pointer to an array instead of a pointer
> > to the first element?
For this particular driver, one page is getting mapped into vma. But
there are other
places where a entire page array ( with more than one pages) mapped into
vma. That's the reason to pass pointer to an array and do rest of the operations
inside __vm_map_pages().
https://lkml.org/lkml/2019/3/18/1265
>
> Also, in __vm_map_pages(), semantically w.r.t. to the comment,
> shouldn't the first check test for equality too? (i.e. for vm_pgoff ==
> num)? (even if such case fails in the second test anyway).
Sorry, didn't get it. Do you mean there should be a separate check for
*vm_pgoff == num* ?
> Cheers,
> Miguel
next prev parent reply other threads:[~2019-05-24 6:07 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-20 15:30 [PATCH 2/2] auxdisplay/ht16k33.c: Convert to use vm_map_pages_zero() Souptick Joarder
2019-05-21 6:55 ` Robin van der Gracht
2019-05-23 8:18 ` Souptick Joarder
2019-05-23 12:58 ` Miguel Ojeda
2019-05-24 4:22 ` Miguel Ojeda
2019-05-24 6:07 ` Souptick Joarder [this message]
2019-05-28 19:03 ` Miguel Ojeda
2019-05-23 13:23 ` Miguel Ojeda
2019-05-24 6:10 ` Souptick Joarder
2019-05-26 16:11 Souptick Joarder
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