From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755123AbbINN1l (ORCPT ); Mon, 14 Sep 2015 09:27:41 -0400 Received: from relay.parallels.com ([195.214.232.42]:36339 "EHLO relay.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754990AbbINN1i (ORCPT ); Mon, 14 Sep 2015 09:27:38 -0400 Date: Mon, 14 Sep 2015 16:27:16 +0300 From: Vladimir Davydov To: Raghavendra K T CC: , , , , , , , , , , , , Subject: Re: [PATCH 1/2] mm: Replace nr_node_ids for loop with for_each_node in list lru Message-ID: <20150914132716.GJ30743@esperanza> References: <1441737107-23103-1-git-send-email-raghavendra.kt@linux.vnet.ibm.com> <1441737107-23103-2-git-send-email-raghavendra.kt@linux.vnet.ibm.com> <20150914090010.GB30743@esperanza> <55F6B1F3.1010702@linux.vnet.ibm.com> <20150914120455.GD30743@esperanza> <55F6C637.6080807@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <55F6C637.6080807@linux.vnet.ibm.com> X-ClientProxiedBy: US-EXCH.sw.swsoft.com (10.255.249.47) To MSK-EXCH1.sw.swsoft.com (10.67.48.55) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 14, 2015 at 06:35:59PM +0530, Raghavendra K T wrote: > On 09/14/2015 05:34 PM, Vladimir Davydov wrote: > >On Mon, Sep 14, 2015 at 05:09:31PM +0530, Raghavendra K T wrote: > >>On 09/14/2015 02:30 PM, Vladimir Davydov wrote: > >>>On Wed, Sep 09, 2015 at 12:01:46AM +0530, Raghavendra K T wrote: > >>>>The functions used in the patch are in slowpath, which gets called > >>>>whenever alloc_super is called during mounts. > >>>> > >>>>Though this should not make difference for the architectures with > >>>>sequential numa node ids, for the powerpc which can potentially have > >>>>sparse node ids (for e.g., 4 node system having numa ids, 0,1,16,17 > >>>>is common), this patch saves some unnecessary allocations for > >>>>non existing numa nodes. > >>>> > >>>>Even without that saving, perhaps patch makes code more readable. > >>> > >>>Do I understand correctly that node 0 must always be in > >>>node_possible_map? I ask, because we currently test > >>>lru->node[0].memcg_lrus to determine if the list is memcg aware. > >>> > >> > >>Yes, node 0 is always there. So it should not be a problem. > > > >I think it should be mentioned in the comment to list_lru_memcg_aware > >then. > > > > Something like this: ? Yeah, looks good to me. Thanks, Vladimir > static inline bool list_lru_memcg_aware(struct list_lru *lru) > { > /* > * This needs node 0 to be always present, even > * in the systems supporting sparse numa ids. > */ > return !!lru->node[0].memcg_lrus; > } > > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-la0-f45.google.com (mail-la0-f45.google.com [209.85.215.45]) by kanga.kvack.org (Postfix) with ESMTP id 0164F6B025C for ; Mon, 14 Sep 2015 09:27:38 -0400 (EDT) Received: by lahg1 with SMTP id g1so56863629lah.1 for ; Mon, 14 Sep 2015 06:27:37 -0700 (PDT) Received: from relay.parallels.com (relay.parallels.com. [195.214.232.42]) by mx.google.com with ESMTPS id or2si9722370lbb.38.2015.09.14.06.27.35 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 14 Sep 2015 06:27:36 -0700 (PDT) Date: Mon, 14 Sep 2015 16:27:16 +0300 From: Vladimir Davydov Subject: Re: [PATCH 1/2] mm: Replace nr_node_ids for loop with for_each_node in list lru Message-ID: <20150914132716.GJ30743@esperanza> References: <1441737107-23103-1-git-send-email-raghavendra.kt@linux.vnet.ibm.com> <1441737107-23103-2-git-send-email-raghavendra.kt@linux.vnet.ibm.com> <20150914090010.GB30743@esperanza> <55F6B1F3.1010702@linux.vnet.ibm.com> <20150914120455.GD30743@esperanza> <55F6C637.6080807@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <55F6C637.6080807@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Raghavendra K T Cc: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, anton@samba.org, akpm@linux-foundation.org, nacc@linux.vnet.ibm.com, gkurz@linux.vnet.ibm.com, zhong@linux.vnet.ibm.com, grant.likely@linaro.org, nikunj@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org On Mon, Sep 14, 2015 at 06:35:59PM +0530, Raghavendra K T wrote: > On 09/14/2015 05:34 PM, Vladimir Davydov wrote: > >On Mon, Sep 14, 2015 at 05:09:31PM +0530, Raghavendra K T wrote: > >>On 09/14/2015 02:30 PM, Vladimir Davydov wrote: > >>>On Wed, Sep 09, 2015 at 12:01:46AM +0530, Raghavendra K T wrote: > >>>>The functions used in the patch are in slowpath, which gets called > >>>>whenever alloc_super is called during mounts. > >>>> > >>>>Though this should not make difference for the architectures with > >>>>sequential numa node ids, for the powerpc which can potentially have > >>>>sparse node ids (for e.g., 4 node system having numa ids, 0,1,16,17 > >>>>is common), this patch saves some unnecessary allocations for > >>>>non existing numa nodes. > >>>> > >>>>Even without that saving, perhaps patch makes code more readable. > >>> > >>>Do I understand correctly that node 0 must always be in > >>>node_possible_map? I ask, because we currently test > >>>lru->node[0].memcg_lrus to determine if the list is memcg aware. > >>> > >> > >>Yes, node 0 is always there. So it should not be a problem. > > > >I think it should be mentioned in the comment to list_lru_memcg_aware > >then. > > > > Something like this: ? Yeah, looks good to me. Thanks, Vladimir > static inline bool list_lru_memcg_aware(struct list_lru *lru) > { > /* > * This needs node 0 to be always present, even > * in the systems supporting sparse numa ids. > */ > return !!lru->node[0].memcg_lrus; > } > > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.parallels.com (relay.parallels.com [195.214.232.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id BB15F1A2BFA for ; Mon, 14 Sep 2015 23:27:41 +1000 (AEST) Date: Mon, 14 Sep 2015 16:27:16 +0300 From: Vladimir Davydov To: Raghavendra K T CC: , , , , , , , , , , , , Subject: Re: [PATCH 1/2] mm: Replace nr_node_ids for loop with for_each_node in list lru Message-ID: <20150914132716.GJ30743@esperanza> References: <1441737107-23103-1-git-send-email-raghavendra.kt@linux.vnet.ibm.com> <1441737107-23103-2-git-send-email-raghavendra.kt@linux.vnet.ibm.com> <20150914090010.GB30743@esperanza> <55F6B1F3.1010702@linux.vnet.ibm.com> <20150914120455.GD30743@esperanza> <55F6C637.6080807@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" In-Reply-To: <55F6C637.6080807@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, Sep 14, 2015 at 06:35:59PM +0530, Raghavendra K T wrote: > On 09/14/2015 05:34 PM, Vladimir Davydov wrote: > >On Mon, Sep 14, 2015 at 05:09:31PM +0530, Raghavendra K T wrote: > >>On 09/14/2015 02:30 PM, Vladimir Davydov wrote: > >>>On Wed, Sep 09, 2015 at 12:01:46AM +0530, Raghavendra K T wrote: > >>>>The functions used in the patch are in slowpath, which gets called > >>>>whenever alloc_super is called during mounts. > >>>> > >>>>Though this should not make difference for the architectures with > >>>>sequential numa node ids, for the powerpc which can potentially have > >>>>sparse node ids (for e.g., 4 node system having numa ids, 0,1,16,17 > >>>>is common), this patch saves some unnecessary allocations for > >>>>non existing numa nodes. > >>>> > >>>>Even without that saving, perhaps patch makes code more readable. > >>> > >>>Do I understand correctly that node 0 must always be in > >>>node_possible_map? I ask, because we currently test > >>>lru->node[0].memcg_lrus to determine if the list is memcg aware. > >>> > >> > >>Yes, node 0 is always there. So it should not be a problem. > > > >I think it should be mentioned in the comment to list_lru_memcg_aware > >then. > > > > Something like this: ? Yeah, looks good to me. Thanks, Vladimir > static inline bool list_lru_memcg_aware(struct list_lru *lru) > { > /* > * This needs node 0 to be always present, even > * in the systems supporting sparse numa ids. > */ > return !!lru->node[0].memcg_lrus; > } > >