Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932872Ab3CHAoJ (ORCPT ); Thu, 7 Mar 2013 19:44:09 -0500 Received: from mga09.intel.com ([134.134.136.24]:41102 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759872Ab3CHAoH (ORCPT ); Thu, 7 Mar 2013 19:44:07 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,804,1355126400"; d="scan'208";a="273602205" From: "Liu, Chuansheng" To: Daniel Lezcano CC: "lenb@kernel.org" , "Brown, Len" , "linux-pm@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: RE: [PATCH] intel_idle: set the state_tables array into __initdata to save mem Thread-Topic: [PATCH] intel_idle: set the state_tables array into __initdata to save mem Thread-Index: AQHOGxkprK74y/p4O0uM1mid7uLXxpia9UbA Date: Fri, 8 Mar 2013 00:44:01 +0000 Message-ID: <27240C0AC20F114CBF8149A2696CBE4A2534DF@SHSMSX101.ccr.corp.intel.com> References: <1362674529.31506.17.camel@cliu38-desktop-build> <513862A5.7060600@linaro.org> In-Reply-To: <513862A5.7060600@linaro.org> Accept-Language: zh-CN, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id r280iAxo025406 Content-Length: 4958 Lines: 134 > -----Original Message----- > From: Daniel Lezcano [mailto:daniel.lezcano@linaro.org] > Sent: Thursday, March 07, 2013 5:49 PM > To: Liu, Chuansheng > Cc: lenb@kernel.org; Brown, Len; linux-pm@vger.kernel.org; > linux-kernel@vger.kernel.org > Subject: Re: [PATCH] intel_idle: set the state_tables array into __initdata to > save mem > > On 03/07/2013 05:42 PM, Chuansheng Liu wrote: > > > > Currently, in intel_idle.c, there are 5 state_tables array, every > > array size is sizeof(struct cpuidle_state) * CPUIDLE_STATE_MAX. > > > > But after intel_idle_probe(), just only one array is useful. > > > > Here we can just define one static state_table, and initialize it > > in intel_idle_probe(), and set other data state_tables as __initdata. > > > > It can save about 3K, which also benefits mobile devices. > > > > Signed-off-by: liu chuansheng > > --- > > drivers/idle/intel_idle.c | 19 ++++++++++++------- > > 1 files changed, 12 insertions(+), 7 deletions(-) > > > > diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c > > index 5d66750..0642bfe 100644 > > --- a/drivers/idle/intel_idle.c > > +++ b/drivers/idle/intel_idle.c > > @@ -99,7 +99,7 @@ static int intel_idle(struct cpuidle_device *dev, > > struct cpuidle_driver *drv, int index); > > static int intel_idle_cpu_init(int cpu); > > > > -static struct cpuidle_state *cpuidle_state_table; > > +static struct cpuidle_state cpuidle_state_table[CPUIDLE_STATE_MAX]; > > > > /* > > * Set this flag for states where the HW flushes the TLB for us > > @@ -124,7 +124,7 @@ static struct cpuidle_state *cpuidle_state_table; > > * which is also the index into the MWAIT hint array. > > * Thus C0 is a dummy. > > */ > > -static struct cpuidle_state nehalem_cstates[CPUIDLE_STATE_MAX] = { > > +static struct cpuidle_state nehalem_cstates[CPUIDLE_STATE_MAX] > __initdata = { > > { > > .name = "C1-NHM", > > .desc = "MWAIT 0x00", > > @@ -157,7 +157,7 @@ static struct cpuidle_state > nehalem_cstates[CPUIDLE_STATE_MAX] = { > > .enter = NULL } > > }; > > > > -static struct cpuidle_state snb_cstates[CPUIDLE_STATE_MAX] = { > > +static struct cpuidle_state snb_cstates[CPUIDLE_STATE_MAX] __initdata = { > > { > > .name = "C1-SNB", > > .desc = "MWAIT 0x00", > > @@ -197,7 +197,7 @@ static struct cpuidle_state > snb_cstates[CPUIDLE_STATE_MAX] = { > > .enter = NULL } > > }; > > > > -static struct cpuidle_state ivb_cstates[CPUIDLE_STATE_MAX] = { > > +static struct cpuidle_state ivb_cstates[CPUIDLE_STATE_MAX] __initdata = { > > { > > .name = "C1-IVB", > > .desc = "MWAIT 0x00", > > @@ -237,7 +237,7 @@ static struct cpuidle_state > ivb_cstates[CPUIDLE_STATE_MAX] = { > > .enter = NULL } > > }; > > > > -static struct cpuidle_state hsw_cstates[CPUIDLE_STATE_MAX] = { > > +static struct cpuidle_state hsw_cstates[CPUIDLE_STATE_MAX] __initdata = > { > > { > > .name = "C1-HSW", > > .desc = "MWAIT 0x00", > > @@ -277,7 +277,7 @@ static struct cpuidle_state > hsw_cstates[CPUIDLE_STATE_MAX] = { > > .enter = NULL } > > }; > > > > -static struct cpuidle_state atom_cstates[CPUIDLE_STATE_MAX] = { > > +static struct cpuidle_state atom_cstates[CPUIDLE_STATE_MAX] __initdata > = { > > { > > .name = "C1E-ATM", > > .desc = "MWAIT 0x00", > > @@ -504,7 +504,12 @@ static int intel_idle_probe(void) > > pr_debug(PREFIX "MWAIT substates: 0x%x\n", mwait_substates); > > > > icpu = (const struct idle_cpu *)id->driver_data; > > - cpuidle_state_table = icpu->state_table; > > + /* Copy the icpu->state_table into cpuidle_state_table, > > + * The pointing array by icpu->state_table is with __initdata, > > + * which will be freed after kernel init ending. > > + */ > > + memcpy(cpuidle_state_table, icpu->state_table, > > + sizeof(cpuidle_state_table)); > > The idea is good but it could be pushed a bit further. > > Instead of changing cpuidle_state_table to an array, change it to an > initdata and the functions intel_idle_cpuidle_driver_init, > intel_idle_probe to init functions. You are right. The global variable intel_idle_driver will has the copy of cpuidle_state_table[], will update the new patch. Thanks. > > That would also be nice to get rid of a global variable to store the > current cpu data and let the intel_idle_probe to return the pointer to > the right table. Sounds reasonable, will have a try also. Thanks again. > > > > if (boot_cpu_has(X86_FEATURE_ARAT)) /* Always Reliable APIC Timer */ > > lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE; > > > > > -- > Linaro.org │ Open source software for ARM SoCs > > Follow Linaro: Facebook | > Twitter | > Blog ????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay?ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?