From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 5B8EF2C00A8 for ; Mon, 13 May 2013 18:59:45 +1000 (EST) Message-ID: <1368435563.19924.28.camel@pasglop> Subject: Re: [RFC PATCH v3 0/5] powerpc: Support context tracking for Power pSeries From: Benjamin Herrenschmidt To: Li Zhong Date: Mon, 13 May 2013 18:59:23 +1000 In-Reply-To: <1368432193.2618.30.camel@ThinkPad-T5421> References: <1368422493-9831-1-git-send-email-zhong@linux.vnet.ibm.com> <1368424306.19924.20.camel@pasglop> <1368432193.2618.30.camel@ThinkPad-T5421> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Cc: fweisbec@gmail.com, Anton Blanchard , linux-kernel@vger.kernel.org, paulus@samba.org, paulmck@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 2013-05-13 at 16:03 +0800, Li Zhong wrote: > > To my understanding, it is used to enable RCU user extended quiescent > state, so RCU on that cpu doesn't need scheduler ticks. And together > with some other code(already in 3.10), we are able to remove the ticks > in some cases (e.g. only 1 task running on the cpu, with some other > limitations). Ok, sounds interesting. Once you fix the little cosmetic issue, I don't see any reason not to merge them as it's basically wiring up an existing feature (in that regard the patches are pretty straightforward) and I assume the overhead is only there when you enable it. Cheers, Ben.