From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Patrick Marlier , Dirk Brandewie , "Rafael J. Wysocki" Subject: [PATCH 3.14 211/228] intel_pstate: remove setting P state to MAX on init Date: Wed, 4 Jun 2014 16:24:00 -0700 Message-Id: <20140604232354.827268316@linuxfoundation.org> In-Reply-To: <20140604232347.966798903@linuxfoundation.org> References: <20140604232347.966798903@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dirk Brandewie commit d40a63c45b506b0681918d7c62a15cc9d48c8681 upstream. Setting the P state of the core to max at init time is a hold over from early implementation of intel_pstate where intel_pstate disabled cpufreq and loaded VERY early in the boot sequence. This was to ensure that intel_pstate did not affect boot time. This in not needed now that intel_pstate is a cpufreq driver. Removing this covers the case where a CPU has gone through a manual CPU offline/online cycle and the P state is set to MAX on init and the CPU immediately goes idle. Due to HW coordination the P state request on the idle CPU will drag all cores to MAX P state until the load is reevaluated when to core goes non-idle. Reported-by: Patrick Marlier Signed-off-by: Dirk Brandewie Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman --- drivers/cpufreq/intel_pstate.c | 13 +------------ 1 file changed, 1 insertion(+), 12 deletions(-) --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -555,12 +555,7 @@ static void intel_pstate_get_cpu_pstates if (pstate_funcs.get_vid) pstate_funcs.get_vid(cpu); - - /* - * goto max pstate so we don't slow up boot if we are built-in if we are - * a module we will take care of it during normal operation - */ - intel_pstate_set_pstate(cpu, cpu->pstate.max_pstate); + intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate); } static inline void intel_pstate_calc_busy(struct cpudata *cpu, @@ -706,11 +701,6 @@ static int intel_pstate_init_cpu(unsigne cpu = all_cpu_data[cpunum]; intel_pstate_get_cpu_pstates(cpu); - if (!cpu->pstate.current_pstate) { - all_cpu_data[cpunum] = NULL; - kfree(cpu); - return -ENODATA; - } cpu->cpu = cpunum; @@ -721,7 +711,6 @@ static int intel_pstate_init_cpu(unsigne cpu->timer.expires = jiffies + HZ/100; intel_pstate_busy_pid_reset(cpu); intel_pstate_sample(cpu); - intel_pstate_set_pstate(cpu, cpu->pstate.max_pstate); add_timer_on(&cpu->timer, cpunum);