linux-kernel - Re: [PATCH] mm, vmacache: Add kconfig VMACACHE

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: <1421943573.4903.24.camel@stgolabs.net>
Date:	Thu, 22 Jan 2015 08:19:33 -0800
From:	Davidlohr Bueso <dave@...olabs.net>
To:	WANG Chao <chaowang@...hat.com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Ingo Molnar <mingo@...hat.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Michel Lespinasse <walken@...gle.com>,
	Rik van Riel <riel@...hat.com>, Mel Gorman <mgorman@...e.de>,
	linux-mm@...ck.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] mm, vmacache: Add kconfig VMACACHE_SHIFT

On Thu, 2015-01-22 at 15:57 +0800, WANG Chao wrote:
> Hi, Davidlohr
> 
> On 01/21/15 at 11:46pm, Davidlohr Bueso wrote:
> > On Thu, 2015-01-22 at 14:29 +0800, WANG Chao wrote:
> > > Add a new kconfig option VMACACHE_SHIFT (as a power of 2) to specify the
> > > number of slots vma cache has for each thread. Range is chosen 0-4 (1-16
> > > slots) to consider both overhead and performance penalty. Default is 2
> > > (4 slots) as it originally is, which provides good enough balance.
> > > 
> > 
> > Nack. I don't feel comfortable making scalability features of core code
> > configurable.
> 
> Out of respect, is this a general rule not making scalability features
> of core code configurable?

I doubt its a rule, just common sense. Users have no business
configuring such low level details. The optimizations need to
transparently work for everyone.

Thanks,
Davidlohr

--
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/