From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f42.google.com (mail-pa0-f42.google.com [209.85.220.42]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 419431A0EC2 for ; Wed, 7 Jan 2015 20:38:00 +1100 (AEDT) Received: by mail-pa0-f42.google.com with SMTP id et14so3809195pad.1 for ; Wed, 07 Jan 2015 01:37:58 -0800 (PST) Message-ID: <54ACFE6D.3070308@ozlabs.ru> Date: Wed, 07 Jan 2015 20:37:49 +1100 From: Alexey Kardashevskiy MIME-Version: 1.0 To: "linuxppc-dev@lists.ozlabs.org" , "Shreyas B. Prabhu" Subject: offlining cpus breakage Content-Type: text/plain; charset=koi8-r Cc: Paul Mackerras List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi! "ppc64_cpu --smt=off" produces multiple error on the latest upstream kernel (sha1 bdec419): NMI watchdog: BUG: soft lockup - CPU#20 stuck for 23s! [swapper/20:0] or INFO: rcu_sched detected stalls on CPUs/tasks: { 2 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 2 4 25 26 27 28 29 30 31} (detected by 6, t=2102 jiffies, g=1617, c=1616, q=1441) and many others, all about lockups I did bisecting and found out that reverting these helps: 77b54e9f213f76a23736940cf94bcd765fc00f40 powernv/powerpc: Add winkle support for offline cpus 7cba160ad789a3ad7e68b92bf20eaad6ed171f80 powernv/cpuidle: Redesign idle states management 8eb8ac89a364305d05ad16be983b7890eb462cc3 powerpc/powernv: Enable Offline CPUs to enter deep idle states btw reverting just two of them produces a compile error. It is pseries_le_defconfig, POWER8 machine: timebase : 512000000 platform : PowerNV model : palmetto machine : PowerNV palmetto firmware : OPAL v3 Please help to fix it. Thanks. -- Alexey