linux-kernel - Re: [PATCH v6] add MAP

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <84144f021001190044s397c6665qb00af48235d2d818@mail.gmail.com>
Date:	Tue, 19 Jan 2010 10:44:23 +0200
From:	Pekka Enberg <penberg@...helsinki.fi>
To:	Gleb Natapov <gleb@...hat.com>
Cc:	Alan Cox <alan@...rguk.ukuu.org.uk>, linux-mm@...ck.org,
	kosaki.motohiro@...fujitsu.com, linux-kernel@...r.kernel.org,
	linux-api@...r.kernel.org, akpm@...ux-foundation.org,
	andrew.c.morrow@...il.com,
	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
	Rik van Riel <riel@...hat.com>,
	Johannes Weiner <hannes@...xchg.org>, minchan.kim@...il.com
Subject: Re: [PATCH v6] add MAP_UNLOCKED mmap flag

Hi Gleb,

On Tue, Jan 19, 2010 at 10:26 AM, Gleb Natapov <gleb@...hat.com> wrote:
>> design would still be broken, no? Did you try using (or extending)
>> posix_madvise(MADV_DONTNEED) for the guest address space? It seems to
> After mlockall() I can't even allocate guest address space. Or do you mean
> instead of mlockall()? Then how MADV_DONTNEED will help? It just drops
> page table for the address range (which is not what I need) and does not
> have any long time effect.

Oh right, MADV_DONTNEED is no good.

On Tue, Jan 19, 2010 at 10:26 AM, Gleb Natapov <gleb@...hat.com> wrote:
>> me that you're trying to use a big hammer (mlock) when a polite hint
>> for the VM would probably be sufficient for it do its job.
>>
> I what to tell to VM "swap this, don't swap that" and as far as I see
> there is no other way to do it currently.

Yeah, which is why I was suggesting that maybe posix_madvise() needs
to be extended to have a MADV_NEED_BUT_LESS_IMPORTANT flag that can be
used as a hint by mm/vmscan.c to first swap the guest address spaces.

                        Pekka
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/