From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp09.au.ibm.com (e23smtp09.au.ibm.com [202.81.31.142]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 99C601A06C5 for ; Thu, 18 Sep 2014 13:11:24 +1000 (EST) Received: from /spool/local by e23smtp09.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 18 Sep 2014 13:11:19 +1000 Received: from d23relay04.au.ibm.com (d23relay04.au.ibm.com [9.190.234.120]) by d23dlp01.au.ibm.com (Postfix) with ESMTP id 98D3A2CE8047 for ; Thu, 18 Sep 2014 13:11:17 +1000 (EST) Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by d23relay04.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id s8I2rC7H65011930 for ; Thu, 18 Sep 2014 12:53:12 +1000 Received: from d23av01.au.ibm.com (localhost [127.0.0.1]) by d23av01.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s8I3BFTN010162 for ; Thu, 18 Sep 2014 13:11:16 +1000 Message-ID: <541A4D4F.1090307@linux.vnet.ibm.com> Date: Thu, 18 Sep 2014 08:41:11 +0530 From: Shreyas B Prabhu MIME-Version: 1.0 To: linux-kernel@vger.kernel.org, Michael Ellerman Subject: Re: [PATCH 0/9] powerpc/powernv: Support for fastsleep and winkle References: <1408989673-14137-1-git-send-email-shreyas@linux.vnet.ibm.com> In-Reply-To: <1408989673-14137-1-git-send-email-shreyas@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Cc: devicetree@vger.kernel.org, "Srivatsa S. Bhat" , linux-pm@vger.kernel.org, "Rafael J. Wysocki" , Grant Likely , Rob Herring , Paul Mackerras , "Preeti U. Murthy" , linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi, In this patch series we use winkle for offlined cores. I successfully tested the working of this with subcore functionality. Test scenario was as follows: 1. Set SMT mode to 1, Set subores-per-core to 1 2. Offline a core, in this case cpu 32 (sending it to winkle) 3. Set subcores-per-core to 4 4. Online the core 5. Start a guest (Topology 1 core 2 threads) on a subcore, in this case on cpu 36 This works without any glitch. Thanks, Shreyas On Monday 25 August 2014 11:31 PM, Shreyas B. Prabhu wrote: > Fast sleep is an idle state, where the core and the L1 and L2 > caches are brought down to a threshold voltage. This also means that > the communication between L2 and L3 caches have to be fenced. However > the current P8 chips have a bug wherein this fencing between L2 and > L3 caches get delayed by a cpu cycle. This can delay L3 response to > the other cpus if they request for data during this time. Thus they > would fetch the same data from the memory which could lead to data > corruption if L3 cache is not flushed. > Patch 4 adds support to work around this. > > 'Deep Winkle' is a deeper idle state where core and private L2 are powered > off. While it offers higher power savings, it is at the cost of losing > hypervisor register state and higher latency. > Patch 5-9 adds support for winkle and uses it for offline cpus. > > Patch 1 - Moves parameters required discover idle states to a location > common to both cpuidle driver and powernv core code > Patch 2 - Populates idle state details from device tree > Patch 3 - Enables cpus to run guest after waking up from fastsleep/winkle > > > Cc: Benjamin Herrenschmidt > Cc: Paul Mackerras > Cc: Michael Ellerman > Cc: Rafael J. Wysocki > Cc: Srivatsa S. Bhat > Cc: Preeti U. Murthy > Cc: Vaidyanathan Srinivasan > Cc: Rob Herring > Cc: Grant Likely > Cc: devicetree@vger.kernel.org > Cc: linux-pm@vger.kernel.org > Cc: linuxppc-dev@lists.ozlabs.org > > Preeti U Murthy (2): > cpuidle/powernv: Populate cpuidle state details by querying the > device-tree > powerpc/powernv/cpuidle: Add workaround to enable fastsleep > > Shreyas B. Prabhu (6): > powerpc/kvm/book3s_hv: Enable CPUs to run guest after waking up from > fast-sleep > powerpc/powernv: Add OPAL call to save and restore > powerpc: Adding macro for accessing Thread Switch Control Register > powerpc/powernv: Add winkle infrastructure > powerpc/powernv: Discover and enable winkle > powerpc/powernv: Enter deepest supported idle state in offline > > Srivatsa S. Bhat (1): > powerpc/powernv: Enable Offline CPUs to enter deep idle states > > arch/powerpc/include/asm/machdep.h | 4 + > arch/powerpc/include/asm/opal.h | 10 ++ > arch/powerpc/include/asm/paca.h | 3 + > arch/powerpc/include/asm/ppc-opcode.h | 2 + > arch/powerpc/include/asm/processor.h | 6 +- > arch/powerpc/include/asm/reg.h | 1 + > arch/powerpc/kernel/asm-offsets.c | 1 + > arch/powerpc/kernel/exceptions-64s.S | 37 ++--- > arch/powerpc/kernel/idle.c | 30 ++++ > arch/powerpc/kernel/idle_power7.S | 83 +++++++++- > arch/powerpc/platforms/powernv/opal-wrappers.S | 2 + > arch/powerpc/platforms/powernv/powernv.h | 8 + > arch/powerpc/platforms/powernv/setup.c | 217 +++++++++++++++++++++++++ > arch/powerpc/platforms/powernv/smp.c | 13 +- > arch/powerpc/platforms/powernv/subcore.c | 15 ++ > drivers/cpuidle/cpuidle-powernv.c | 40 ++++- > 16 files changed, 439 insertions(+), 33 deletions(-) >