linux-kernel - Re: [PATCH 04/11] Allow CONFIG_MIGRATION to be set without CONFIG

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: <20100325095918.9454.A69D9226@jp.fujitsu.com>
Date:	Thu, 25 Mar 2010 12:28:40 +0900 (JST)
From:	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
To:	Mel Gorman <mel@....ul.ie>
Cc:	kosaki.motohiro@...fujitsu.com,
	Christoph Lameter <cl@...ux-foundation.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Andrea Arcangeli <aarcange@...hat.com>,
	Adam Litke <agl@...ibm.com>, Avi Kivity <avi@...hat.com>,
	David Rientjes <rientjes@...gle.com>,
	Rik van Riel <riel@...hat.com>, linux-kernel@...r.kernel.org,
	linux-mm@...ck.org
Subject: Re: [PATCH 04/11] Allow CONFIG_MIGRATION to be set without CONFIG_NUMA or memory hot-remove

> On Fri, Mar 19, 2010 at 03:21:20PM +0900, KOSAKI Motohiro wrote:
> > > On Thu, Mar 18, 2010 at 08:56:23AM +0900, KOSAKI Motohiro wrote:
> > > > > On Wed, 17 Mar 2010, Mel Gorman wrote:
> > > > > 
> > > > > > > If select MIGRATION works, we can remove "depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE"
> > > > > > > line from config MIGRATION.
> > > > > > >
> > > > > >
> > > > > > I'm not quite getting why this would be an advantage. COMPACTION
> > > > > > requires MIGRATION but conceivable both NUMA and HOTREMOVE can work
> > > > > > without it.
> > > > > 
> > > > > Avoids having to add additional CONFIG_XXX on the page migration "depends"
> > > > > line in the future.
> > > > 
> > > > Yes, Kconfig mess freqently shot ourself in past days. if we have a chance
> > > > to remove unnecessary dependency, we should do. that's my intention of the last mail.
> > > > 
> > > 
> > > But if the depends line is removed, it could be set without NUMA, memory
> > > hot-remove or compaction enabled. That wouldn't be very useful. I'm
> > > missing something obvious.
> > 
> > Perhaps I'm missing something. 
> > 
> > my point is, force enabling useless config is not good idea (yes, i agree). but config 
> > selectability doesn't cause any failure. IOW, usefulness and dependency aren't 
> > related so much. personally I dislike _unnecessary_ dependency.
> > 
> > If my opinion cause any bad thing, I'll withdraw it. of course.
> > 
> 
> I've changed the MIGRATION entry to
> 
> config MIGRATION
>         bool "Page migration"
>         def_bool y
>         depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE 
> 
> i.e. it no longer depends on COMPACTION because the "select MIGRATION"
> in that line is enough.
> 
> I've left NUMA and HOTREMOVE because migration is an optional feature
> for those configurations.

ok... I don't oppose it anymore. Let's dive into Kconfig select hell ;)


--
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/