From: Andy Lutomirski <luto@amacapital.net>
To: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>,
Matthew Wilcox <willy@linux.intel.com>,
Kees Cook <keescook@chromium.org>,
Andrew Morton <akpm@linux-foundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>
Subject: Re: [PATCH 3/3] dax: Handle write faults more efficiently
Date: Mon, 25 Jan 2016 09:38:19 -0800 [thread overview]
Message-ID: <CALCETrWuPa2SoUcMCtDiv1UDodNqKcQzsZV5PxQx5Xhb524f7w@mail.gmail.com> (raw)
In-Reply-To: <1453742717-10326-4-git-send-email-matthew.r.wilcox@intel.com>
On Mon, Jan 25, 2016 at 9:25 AM, Matthew Wilcox
<matthew.r.wilcox@intel.com> wrote:
> From: Matthew Wilcox <willy@linux.intel.com>
>
> When we handle a write-fault on a DAX mapping, we currently insert a
> read-only mapping and then take the page fault again to convert it to
> a writable mapping. This is necessary for the case where we cover a
> hole with a read-only zero page, but when we have a data block already
> allocated, it is inefficient.
>
> Use the recently added vmf_insert_pfn_prot() to insert a writable mapping,
> even though the default VM flags say to use a read-only mapping.
Conceptually, I like this. Do you need to make sure to do all the
do_wp_page work, though? (E.g. we currently update mtime in there.
Some day I'll fix that, but it'll be replaced with a set_bit to force
a deferred mtime update.)
--Andy
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next prev parent reply other threads:[~2016-01-25 17:38 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-25 17:25 [PATCH 0/3] Fixes for vm_insert_pfn_prot() Matthew Wilcox
2016-01-25 17:25 ` [PATCH 1/3] x86: Honour passed pgprot in track_pfn_insert() and track_pfn_remap() Matthew Wilcox
2016-01-25 17:33 ` Andy Lutomirski
2016-01-25 17:46 ` Andy Lutomirski
2016-01-27 4:40 ` Matthew Wilcox
2016-01-27 5:44 ` Andy Lutomirski
2016-01-29 14:49 ` Matthew Wilcox
2016-01-29 22:19 ` Andy Lutomirski
2016-02-09 14:24 ` Ingo Molnar
2016-02-10 3:06 ` Andy Lutomirski
2016-01-25 17:25 ` [PATCH 2/3] mm: Convert vm_insert_pfn_prot to vmf_insert_pfn_prot Matthew Wilcox
2016-01-25 17:35 ` Andy Lutomirski
2016-01-27 4:18 ` Matthew Wilcox
2016-01-25 17:25 ` [PATCH 3/3] dax: Handle write faults more efficiently Matthew Wilcox
2016-01-25 17:38 ` Andy Lutomirski [this message]
2016-01-27 4:17 ` Matthew Wilcox
2016-01-27 5:22 ` Andy Lutomirski
2016-01-27 6:01 ` Andy Lutomirski
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