All of lore.kernel.org
 help / color / mirror / Atom feed
From: Michal Hocko <mhocko@suse.com>
To: David Hildenbrand <david@redhat.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	Andrew Morton <akpm@linux-foundation.org>,
	Arnd Bergmann <arnd@arndb.de>, Oscar Salvador <osalvador@suse.de>,
	Matthew Wilcox <willy@infradead.org>,
	Andrea Arcangeli <aarcange@redhat.com>,
	Minchan Kim <minchan@kernel.org>, Jann Horn <jannh@google.com>,
	Jason Gunthorpe <jgg@ziepe.ca>,
	Dave Hansen <dave.hansen@intel.com>,
	Hugh Dickins <hughd@google.com>, Rik van Riel <riel@surriel.com>,
	"Michael S . Tsirkin" <mst@redhat.com>,
	"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
	Vlastimil Babka <vbabka@suse.cz>,
	Richard Henderson <rth@twiddle.net>,
	Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
	Matt Turner <mattst88@gmail.com>,
	Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
	"James E.J. Bottomley" <James.Bottomley@hansenpartnership.com>,
	Helge Deller <deller@gmx.de>, Chris Zankel <chris@zankel.net>,
	Max Filippov <jcmvbkbc@gmail.com>,
	linux-alpha@vger.kernel.org, linux-mips@vger.kernel.org,
	linux-parisc@vger.kernel.org, linux-xtensa@linux-xtensa.org,
	linux-arch@vger.kernel.org
Subject: Re: [PATCH RFC] mm/madvise: introduce MADV_POPULATE to prefault/prealloc memory
Date: Mon, 22 Feb 2021 15:02:31 +0100	[thread overview]
Message-ID: <YDO5d+pbPBsjv13T@dhcp22.suse.cz> (raw)
In-Reply-To: <3b5cd68d-c4ac-c6be-8824-34c541d5377b@redhat.com>

On Mon 22-02-21 14:22:37, David Hildenbrand wrote:
> > > Exactly. But for hugetlbfs/shmem ("!RAM-backed files") this is not what we
> > > want.
> > 
> > OK, then I must have misread your requirements. Maybe I just got lost in
> > all the combinations you have listed.
> 
> Another special case could be dax/pmem I think. You might want to fault it
> in readable/writable but not perform an actual read/write unless really
> required.
> 
> QEMU phrases this as "don't cause wear on the storage backing".

Sorry for being dense here but I still do not follow. If you do not want
to read then what do you want to populate from? Only map if it is in the
page cache?
-- 
Michal Hocko
SUSE Labs

WARNING: multiple messages have this Message-ID (diff)
From: Michal Hocko <mhocko@suse.com>
To: David Hildenbrand <david@redhat.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	Andrew Morton <akpm@linux-foundation.org>,
	Arnd Bergmann <arnd@arndb.de>, Oscar Salvador <osalvador@suse.de>,
	Matthew Wilcox <willy@infradead.org>,
	Andrea Arcangeli <aarcange@redhat.com>,
	Minchan Kim <minchan@kernel.org>, Jann Horn <jannh@google.com>,
	Jason Gunthorpe <jgg@ziepe.ca>,
	Dave Hansen <dave.hansen@intel.com>,
	Hugh Dickins <hughd@google.com>, Rik van Riel <riel@surriel.com>,
	"Michael S . Tsirkin" <mst@redhat.com>,
	"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
	Vlastimil Babka <vbabka@suse.cz>,
	Richard Henderson <rth@twiddle.net>,
	Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
	Matt Turner <mattst88@gmail.com>,
	Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
	James E.J. Bottomle
Subject: Re: [PATCH RFC] mm/madvise: introduce MADV_POPULATE to prefault/prealloc memory
Date: Mon, 22 Feb 2021 15:02:31 +0100	[thread overview]
Message-ID: <YDO5d+pbPBsjv13T@dhcp22.suse.cz> (raw)
In-Reply-To: <3b5cd68d-c4ac-c6be-8824-34c541d5377b@redhat.com>

On Mon 22-02-21 14:22:37, David Hildenbrand wrote:
> > > Exactly. But for hugetlbfs/shmem ("!RAM-backed files") this is not what we
> > > want.
> > 
> > OK, then I must have misread your requirements. Maybe I just got lost in
> > all the combinations you have listed.
> 
> Another special case could be dax/pmem I think. You might want to fault it
> in readable/writable but not perform an actual read/write unless really
> required.
> 
> QEMU phrases this as "don't cause wear on the storage backing".

Sorry for being dense here but I still do not follow. If you do not want
to read then what do you want to populate from? Only map if it is in the
page cache?
-- 
Michal Hocko
SUSE Labs

  reply	other threads:[~2021-02-22 14:04 UTC|newest]

Thread overview: 76+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-17 15:48 [PATCH RFC] mm/madvise: introduce MADV_POPULATE to prefault/prealloc memory David Hildenbrand
2021-02-17 15:48 ` David Hildenbrand
2021-02-17 16:46 ` Dave Hansen
2021-02-17 16:46   ` Dave Hansen
2021-02-17 17:06   ` David Hildenbrand
2021-02-17 17:06     ` David Hildenbrand
2021-02-17 17:21 ` Vlastimil Babka
2021-02-17 17:21   ` Vlastimil Babka
2021-02-18 11:07   ` Rolf Eike Beer
2021-02-18 11:07     ` Rolf Eike Beer
2021-02-18 11:27     ` David Hildenbrand
2021-02-18 11:27       ` David Hildenbrand
2021-02-18 10:25 ` Michal Hocko
2021-02-18 10:25   ` Michal Hocko
2021-02-18 10:44   ` David Hildenbrand
2021-02-18 10:44     ` David Hildenbrand
2021-02-18 10:54     ` David Hildenbrand
2021-02-18 10:54       ` David Hildenbrand
2021-02-18 11:28       ` Michal Hocko
2021-02-18 11:28         ` Michal Hocko
2021-02-18 11:27     ` Michal Hocko
2021-02-18 11:27       ` Michal Hocko
2021-02-18 11:38       ` David Hildenbrand
2021-02-18 11:38         ` David Hildenbrand
2021-02-18 12:22 ` [PATCH RFC] madvise.2: Document MADV_POPULATE David Hildenbrand
2021-02-18 12:22   ` David Hildenbrand
2021-02-18 22:59 ` [PATCH RFC] mm/madvise: introduce MADV_POPULATE to prefault/prealloc memory Peter Xu
2021-02-18 22:59   ` Peter Xu
2021-02-19  8:20   ` David Hildenbrand
2021-02-19  8:20     ` David Hildenbrand
2021-02-19 16:31     ` Peter Xu
2021-02-19 16:31       ` Peter Xu
2021-02-19 17:13       ` David Hildenbrand
2021-02-19 17:13         ` David Hildenbrand
2021-02-19 19:14         ` David Hildenbrand
2021-02-19 19:14           ` David Hildenbrand
2021-02-19 19:25           ` Mike Kravetz
2021-02-19 19:25             ` Mike Kravetz
2021-02-20  9:01             ` David Hildenbrand
2021-02-20  9:01               ` David Hildenbrand
2021-02-19 19:23         ` Peter Xu
2021-02-19 19:23           ` Peter Xu
2021-02-19 20:04           ` David Hildenbrand
2021-02-19 20:04             ` David Hildenbrand
2021-02-22 12:46     ` Michal Hocko
2021-02-22 12:46       ` Michal Hocko
2021-02-22 12:52       ` David Hildenbrand
2021-02-22 12:52         ` David Hildenbrand
2021-02-19 10:35 ` Michal Hocko
2021-02-19 10:35   ` Michal Hocko
2021-02-19 10:43   ` David Hildenbrand
2021-02-19 10:43     ` David Hildenbrand
2021-02-19 11:04     ` Michal Hocko
2021-02-19 11:04       ` Michal Hocko
2021-02-19 11:10       ` David Hildenbrand
2021-02-19 11:10         ` David Hildenbrand
2021-02-20  9:12 ` David Hildenbrand
2021-02-20  9:12   ` David Hildenbrand
2021-02-22 12:56   ` Michal Hocko
2021-02-22 12:56     ` Michal Hocko
2021-02-22 12:59     ` David Hildenbrand
2021-02-22 12:59       ` David Hildenbrand
2021-02-22 13:19       ` Michal Hocko
2021-02-22 13:19         ` Michal Hocko
2021-02-22 13:22         ` David Hildenbrand
2021-02-22 13:22           ` David Hildenbrand
2021-02-22 14:02           ` Michal Hocko [this message]
2021-02-22 14:02             ` Michal Hocko
2021-02-22 15:30             ` David Hildenbrand
2021-02-22 15:30               ` David Hildenbrand
2021-02-24 14:25 ` David Hildenbrand
2021-02-24 14:25   ` David Hildenbrand
2021-02-24 14:38   ` David Hildenbrand
2021-02-24 14:38     ` David Hildenbrand
2021-02-25  8:41   ` David Hildenbrand
2021-02-25  8:41     ` David Hildenbrand

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=YDO5d+pbPBsjv13T@dhcp22.suse.cz \
    --to=mhocko@suse.com \
    --cc=James.Bottomley@hansenpartnership.com \
    --cc=aarcange@redhat.com \
    --cc=akpm@linux-foundation.org \
    --cc=arnd@arndb.de \
    --cc=chris@zankel.net \
    --cc=dave.hansen@intel.com \
    --cc=david@redhat.com \
    --cc=deller@gmx.de \
    --cc=hughd@google.com \
    --cc=ink@jurassic.park.msu.ru \
    --cc=jannh@google.com \
    --cc=jcmvbkbc@gmail.com \
    --cc=jgg@ziepe.ca \
    --cc=kirill.shutemov@linux.intel.com \
    --cc=linux-alpha@vger.kernel.org \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mips@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-parisc@vger.kernel.org \
    --cc=linux-xtensa@linux-xtensa.org \
    --cc=mattst88@gmail.com \
    --cc=minchan@kernel.org \
    --cc=mst@redhat.com \
    --cc=osalvador@suse.de \
    --cc=riel@surriel.com \
    --cc=rth@twiddle.net \
    --cc=tsbogend@alpha.franken.de \
    --cc=vbabka@suse.cz \
    --cc=willy@infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.