From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [RFC PATCH v2 1/4] arm64: defconfig: increase NR_CPUS range to 2-128 Date: Tue, 09 Dec 2014 09:27:13 +0100 Message-ID: <2054688.iIEQnOEqVy@wuerfel> References: <1416605010-10442-1-git-send-email-ganapatrao.kulkarni@caviumnetworks.com> <3519779.ILzEnWe9lP@wuerfel> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Zi Shen Lim Cc: Ganapatrao Kulkarni , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Steve Capper , al.stone-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, Catalin Marinas , Will Deacon , leif.lindholm-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, roy.franz-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, Hanjun Guo , msalter-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, grant.likely-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, jchandra-dY08KVG/lbpWk0Htik3J/w@public.gmane.org, "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , Ganapatrao Kulkarni List-Id: devicetree@vger.kernel.org On Monday 08 December 2014 17:57:03 Zi Shen Lim wrote: > Hi Arnd, > > On Mon, Nov 24, 2014 at 3:53 AM, Arnd Bergmann wrote: > > > > On Saturday 22 November 2014 02:53:27 Ganapatrao Kulkarni wrote: > > > Raising the maximum limit to 128. This is needed for Cavium's > > > Thunder system that will have 96 cores on Multi-node system. > > > > > > Signed-off-by: Ganapatrao Kulkarni > > > > > > > Could we please raise the compile-time limit to the highest number that > > you are able to boot successfully on some existing machine? > > > > There isn't much point in doubling this every few months. > > Agreed. If we look back at [1], Mark Rutland has actually compiled and > boot-tested NR_CPUS=4096 on Juno. > > [1] https://lkml.org/lkml/2014/9/8/537 Ok, 4096 sounds like a good NR_CPUS limit then, it should last for a while. For the defconfig, we probably want a much smaller value, either one that covers all known machines (96 at this time), or something that covers 95% of all users (maybe 32?) and does not have an serious impact on memory consumption or performance on small machines. Arnd -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html