From: Juerg Haefliger <juerg.haefliger@hpe.com>
To: Dave Hansen <dave.hansen@intel.com>,
kernel-hardening@lists.openwall.com,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
linux-x86_64@vger.kernel.org
Cc: vpk@cs.columbia.edu
Subject: Re: [kernel-hardening] [RFC PATCH v2 2/3] xpfo: Only put previous userspace pages into the hot cache
Date: Wed, 14 Sep 2016 16:40:49 +0200 [thread overview]
Message-ID: <7badeb6c-e343-4327-29ed-f9c9c0b6654b@hpe.com> (raw)
In-Reply-To: <57D95FA3.3030103@intel.com>
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Hi Dave,
On 09/14/2016 04:33 PM, Dave Hansen wrote:
> On 09/14/2016 12:19 AM, Juerg Haefliger wrote:
>> Allocating a page to userspace that was previously allocated to the
>> kernel requires an expensive TLB shootdown. To minimize this, we only
>> put non-kernel pages into the hot cache to favor their allocation.
>
> Hi, I had some questions about this the last time you posted it. Maybe
> you want to address them now.
I did reply: https://lkml.org/lkml/2016/9/5/249
...Juerg
> --
>
> But kernel allocations do allocate from these pools, right? Does this
> just mean that kernel allocations usually have to pay the penalty to
> convert a page?
>
> So, what's the logic here? You're assuming that order-0 kernel
> allocations are more rare than allocations for userspace?
>
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next prev parent reply other threads:[~2016-09-14 14:41 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-26 14:21 [RFC PATCH] Add support for eXclusive Page Frame Ownership (XPFO) Juerg Haefliger
2016-03-01 1:31 ` Laura Abbott
2016-03-21 8:37 ` Juerg Haefliger
2016-03-28 19:29 ` Laura Abbott
2016-03-01 2:10 ` Balbir Singh
2016-03-21 8:44 ` Juerg Haefliger
2016-04-01 0:21 ` Balbir Singh
2016-09-02 11:39 ` [RFC PATCH v2 0/3] " Juerg Haefliger
2016-09-02 11:39 ` [RFC PATCH v2 1/3] " Juerg Haefliger
2016-09-02 11:39 ` [RFC PATCH v2 2/3] xpfo: Only put previous userspace pages into the hot cache Juerg Haefliger
2016-09-02 20:39 ` Dave Hansen
2016-09-05 11:54 ` Juerg Haefliger
2016-09-02 11:39 ` [RFC PATCH v2 3/3] block: Always use a bounce buffer when XPFO is enabled Juerg Haefliger
2016-09-14 7:18 ` [RFC PATCH v2 0/3] Add support for eXclusive Page Frame Ownership (XPFO) Juerg Haefliger
2016-09-14 7:18 ` [RFC PATCH v2 1/3] " Juerg Haefliger
2016-09-14 7:19 ` [RFC PATCH v2 2/3] xpfo: Only put previous userspace pages into the hot cache Juerg Haefliger
2016-09-14 14:33 ` [kernel-hardening] " Dave Hansen
2016-09-14 14:40 ` Juerg Haefliger [this message]
2016-09-14 14:48 ` Dave Hansen
2016-09-21 5:32 ` Juerg Haefliger
2016-09-14 7:19 ` [RFC PATCH v2 3/3] block: Always use a bounce buffer when XPFO is enabled Juerg Haefliger
2016-09-14 7:33 ` Christoph Hellwig
2016-09-14 7:23 ` [RFC PATCH v2 0/3] Add support for eXclusive Page Frame Ownership (XPFO) Juerg Haefliger
2016-09-14 9:36 ` [kernel-hardening] " Mark Rutland
2016-09-14 9:49 ` Mark Rutland
2016-11-04 14:45 ` [RFC PATCH v3 0/2] " Juerg Haefliger
2016-11-04 14:45 ` [RFC PATCH v3 1/2] " Juerg Haefliger
2016-11-04 14:50 ` Christoph Hellwig
2016-11-10 5:53 ` [kernel-hardening] " ZhaoJunmin Zhao(Junmin)
2016-11-10 19:11 ` Kees Cook
2016-11-15 11:15 ` Juerg Haefliger
2016-11-10 19:24 ` Kees Cook
2016-11-15 11:18 ` Juerg Haefliger
2016-11-24 10:56 ` AKASHI Takahiro
2016-11-28 11:15 ` Juerg Haefliger
2016-12-09 9:02 ` AKASHI Takahiro
2016-11-04 14:45 ` [RFC PATCH v3 2/2] xpfo: Only put previous userspace pages into the hot cache Juerg Haefliger
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