From: Mike Kravetz <mike.kravetz@oracle.com>
To: Christopher Lameter <cl@linux.com>,
Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linux-api@vger.kernel.org,
Marek Szyprowski <m.szyprowski@samsung.com>,
Michal Nazarewicz <mina86@mina86.com>,
"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Guy Shattah <sguy@mellanox.com>
Subject: Re: [RFC] mmap(MAP_CONTIG)
Date: Wed, 4 Oct 2017 10:38:57 -0700 [thread overview]
Message-ID: <434a5870-0115-b8ab-bd6c-b7f4db847dc4@oracle.com> (raw)
In-Reply-To: <alpine.DEB.2.20.1710041104310.21484@nuc-kabylake>
On 10/04/2017 09:05 AM, Christopher Lameter wrote:
> On Wed, 4 Oct 2017, Anshuman Khandual wrote:
>
>>> - Using 'pre-allocated' pages in the fault paths may be intrusive.
>>
>> But we have already faulted in all of them for the mapping and they
>> are also locked. Hence there should not be any page faults any more
>> for the VMA. Am I missing something here ?
>
> The PTEs may be torn down and have to reestablished through a page faults.
> Page faults would not allocate memory.
>
>> I am still wondering why wait till fault time not pre fault all of them
>> and populate the page tables.
>
> They are populated but some processes (swap and migration) may tear them
> down.
As mentioned in my reply to Anshuman, the mention of fault paths here
may be a source of confusion. I would expect the entire mapping to be
populated at mmap time, and the pages locked. Therefore, there should
be no swap or migration.
--
Mike Kravetz
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next prev parent reply other threads:[~2017-10-04 17:38 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-03 23:56 [RFC] mmap(MAP_CONTIG) Mike Kravetz
2017-10-04 11:54 ` Michal Nazarewicz
2017-10-04 17:08 ` Mike Kravetz
2017-10-04 21:29 ` Laura Abbott
2017-10-04 13:49 ` Anshuman Khandual
2017-10-04 16:05 ` Christopher Lameter
2017-10-04 17:38 ` Mike Kravetz [this message]
2017-10-04 17:35 ` Mike Kravetz
2017-10-05 7:06 ` Vlastimil Babka
2017-10-05 8:58 ` Guy Shattah
2017-10-05 12:36 ` Guy Shattah
2017-10-05 14:30 ` Christopher Lameter
2017-10-12 1:46 ` [RFC PATCH 0/3] Add mmap(MAP_CONTIG) support Mike Kravetz
2017-10-12 1:46 ` [RFC PATCH 1/3] mm/map_contig: Add VM_CONTIG flag to vma struct Mike Kravetz
2017-10-12 1:46 ` [RFC PATCH 2/3] mm/map_contig: Use pre-allocated pages for VM_CONTIG mappings Mike Kravetz
2017-10-12 11:04 ` Anshuman Khandual
2017-10-12 1:46 ` [RFC PATCH 3/3] mm/map_contig: Add mmap(MAP_CONTIG) support Mike Kravetz
2017-10-12 11:22 ` Anshuman Khandual
2017-10-13 15:14 ` Christopher Lameter
2017-10-12 14:37 ` Michal Hocko
2017-10-12 17:19 ` Mike Kravetz
2017-10-13 8:40 ` Michal Hocko
2017-10-13 15:20 ` Christopher Lameter
2017-10-13 15:28 ` Michal Hocko
2017-10-13 15:42 ` Christopher Lameter
2017-10-13 15:47 ` Michal Hocko
[not found] ` <20171013154747.2jv7rtfqyyagiodn-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>
2017-10-13 15:56 ` Christopher Lameter
2017-10-13 16:17 ` Michal Hocko
2017-10-15 7:50 ` Guy Shattah
2017-10-16 8:24 ` Michal Hocko
[not found] ` <20171016082456.no6ux63uy2rmj4fe-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>
2017-10-16 9:11 ` Guy Shattah
2017-10-16 12:32 ` Michal Hocko
[not found] ` <20171016123248.csntl6luxgafst6q-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>
2017-10-16 16:00 ` Christopher Lameter
2017-10-16 17:42 ` Michal Hocko
[not found] ` <20171016174229.pz3o4uhzz3qbrp6n-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>
2017-10-16 17:56 ` Christopher Lameter
2017-10-16 18:17 ` Michal Hocko
2017-10-23 15:25 ` David Nellans
2017-10-17 10:50 ` Guy Shattah
[not found] ` <AM6PR0502MB378375AF8B569DBCCFE20D7DBD4C0-md96bDB8+JV1k1TWM4Wt8cDSnupUy6xnnBOFsp37pqbUKgpGm//BTAC/G2K4zDHf@public.gmane.org>
2017-10-17 10:59 ` Michal Hocko
2017-10-17 13:22 ` Michal Nazarewicz
2017-10-17 14:20 ` Guy Shattah
2017-10-17 17:44 ` Vlastimil Babka
2017-10-17 18:23 ` Mike Kravetz
2017-10-17 19:56 ` Vlastimil Babka
[not found] ` <752b49eb-55c6-5a34-ab41-6e91dd93ea70-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
2017-10-16 10:33 ` Michal Nazarewicz
[not found] ` <xa1t60bfxtzw.fsf-deATy8a+UHjQT0dZR+AlfA@public.gmane.org>
2017-10-16 11:09 ` Guy Shattah
2017-10-16 17:43 ` Mike Kravetz
[not found] ` <aff6b405-6a06-f84d-c9b1-c6fb166dff81-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2017-10-16 18:07 ` Michal Hocko
2017-10-16 20:32 ` Mike Kravetz
2017-10-16 20:58 ` Michal Hocko
2017-10-16 21:03 ` Laura Abbott
2017-10-16 21:18 ` Mike Kravetz
[not found] ` <e8cf6227-003d-8a82-8b4d-07176b43810c-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2017-10-17 6:59 ` Vlastimil Babka
2017-10-15 6:58 ` Pavel Machek
2017-10-16 8:18 ` Michal Hocko
2017-10-16 9:54 ` Pavel Machek
2017-10-16 12:18 ` Michal Hocko
[not found] ` <20171016121808.m4sq3g5nxeyxoymc-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>
2017-10-16 16:02 ` Christopher Lameter
2017-10-16 17:33 ` Michal Hocko
2017-10-16 17:53 ` Christopher Lameter
2017-10-15 8:07 ` Guy Shattah
2017-10-12 10:36 ` [RFC PATCH 0/3] " Anshuman Khandual
2017-10-12 14:25 ` Anshuman Khandual
2017-10-23 22:10 ` [RFC] mmap(MAP_CONTIG) Dave Hansen
2017-10-24 22:49 ` Mike Kravetz
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