Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751933AbZGNAgr (ORCPT ); Mon, 13 Jul 2009 20:36:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751372AbZGNAgq (ORCPT ); Mon, 13 Jul 2009 20:36:46 -0400 Received: from smtp-out.google.com ([216.239.33.17]:31345 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751365AbZGNAgp convert rfc822-to-8bit (ORCPT ); Mon, 13 Jul 2009 20:36:45 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=mime-version:in-reply-to:references:date:message-id:subject:from:to: cc:content-type:content-transfer-encoding:x-system-of-record; b=w4yO+NHAf1/DEYcye+FHIOeG3Neesk4pFt0FqUGrqWiE7tfAz6wAhcH4boSyBwhLM AfCIV6YItcHV73nIg5+Zg== MIME-Version: 1.0 In-Reply-To: <1247530581-31416-2-git-send-email-vbuzov@embeddedalley.com> References: <1246998310-16764-1-git-send-email-vbuzov@embeddedalley.com> <1247530581-31416-1-git-send-email-vbuzov@embeddedalley.com> <1247530581-31416-2-git-send-email-vbuzov@embeddedalley.com> Date: Mon, 13 Jul 2009 17:36:40 -0700 Message-ID: <6599ad830907131736w4397d336xad733f274c812690@mail.gmail.com> Subject: Re: [PATCH 1/2] Resource usage threshold notification addition to res_counter (v3) From: Paul Menage To: Vladislav Buzov Cc: Linux Kernel Mailing List , Linux Containers Mailing List , Linux memory management list , Dan Malek , Andrew Morton , KAMEZAWA Hiroyuki , Balbir Singh Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8075 Lines: 224 As I mentioned in another thread, I think that associating the threshold with the res_counter rather than with each individual waiter is a mistake, since it creates global state and makes it hard to have multiple waiters on the same cgroup. Paul On Mon, Jul 13, 2009 at 5:16 PM, Vladislav Buzov wrote: > This patch updates the Resource Counter to add a configurable resource usage > threshold notification mechanism. > > Signed-off-by: Vladislav Buzov > Signed-off-by: Dan Malek > --- > ?Documentation/cgroups/resource_counter.txt | ? 21 ++++++++- > ?include/linux/res_counter.h ? ? ? ? ? ? ? ?| ? 69 ++++++++++++++++++++++++++++ > ?kernel/res_counter.c ? ? ? ? ? ? ? ? ? ? ? | ? ?7 +++ > ?3 files changed, 95 insertions(+), 2 deletions(-) > > diff --git a/Documentation/cgroups/resource_counter.txt b/Documentation/cgroups/resource_counter.txt > index 95b24d7..1369dff 100644 > --- a/Documentation/cgroups/resource_counter.txt > +++ b/Documentation/cgroups/resource_counter.txt > @@ -39,7 +39,20 @@ to work with it. > ? ? ? ?The failcnt stands for "failures counter". This is the number of > ? ? ? ?resource allocation attempts that failed. > > - c. spinlock_t lock > + e. unsigned long long threshold > + > + ? ? ? The resource usage threshold to notify the resouce controller. This is > + ? ? ? the minimal difference between the resource limit and current usage > + ? ? ? to fire a notification. > + > + f. void (*threshold_notifier)(struct res_counter *counter) > + > + ? ? ? The threshold notification callback installed by the resource > + ? ? ? controller. Called when the usage reaches or exceeds the threshold. > + ? ? ? Should be fast and not sleep because called when interrupts are > + ? ? ? disabled. > + > + g. spinlock_t lock > > ? ? ? ?Protects changes of the above values. > > @@ -140,6 +153,7 @@ counter fields. They are recommended to adhere to the following rules: > ? ? ? ?usage ? ? ? ? ? usage_in_ > ? ? ? ?max_usage ? ? ? max_usage_in_ > ? ? ? ?limit ? ? ? ? ? limit_in_ > + ? ? ? threshold ? ? ? notify_threshold_in_ > ? ? ? ?failcnt ? ? ? ? failcnt > ? ? ? ?lock ? ? ? ? ? ?no file :) > > @@ -153,9 +167,12 @@ counter fields. They are recommended to adhere to the following rules: > ? ? ? ?usage ? ? ? ? ? prohibited > ? ? ? ?max_usage ? ? ? reset to usage > ? ? ? ?limit ? ? ? ? ? set the limit > + ? ? ? threshold ? ? ? set the threshold > ? ? ? ?failcnt ? ? ? ? reset to zero > > - > + d. Notification is enabled by installing the threshold notifier callback. It > + ? ?is up to the resouce controller to communicate the notification to user > + ? ?space tasks. > > ?5. Usage example > > diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h > index 511f42f..5ec98d7 100644 > --- a/include/linux/res_counter.h > +++ b/include/linux/res_counter.h > @@ -9,6 +9,11 @@ > ?* > ?* Author: Pavel Emelianov > ?* > + * Resouce usage threshold notification update > + * Copyright 2009 CE Linux Forum and Embedded Alley Solutions, Inc. > + * Author: Dan Malek > + * Author: Vladislav Buzov > + * > ?* See Documentation/cgroups/resource_counter.txt for more > ?* info about what this counter is. > ?*/ > @@ -35,6 +40,19 @@ struct res_counter { > ? ? ? ? */ > ? ? ? ?unsigned long long limit; > ? ? ? ?/* > + ? ? ? ?* the resource usage threshold to notify the resouce controller. This > + ? ? ? ?* is the minimal difference between the resource limit and current > + ? ? ? ?* usage to fire a notification. > + ? ? ? ?*/ > + ? ? ? unsigned long long threshold; > + ? ? ? /* > + ? ? ? ?* the threshold notification callback installed by the resource > + ? ? ? ?* controller. Called when the usage reaches or exceeds the threshold. > + ? ? ? ?* Should be fast and not sleep because called when interrupts are > + ? ? ? ?* disabled. > + ? ? ? ?*/ > + ? ? ? void (*threshold_notifier)(struct res_counter *counter); > + ? ? ? /* > ? ? ? ? * the number of unsuccessful attempts to consume the resource > ? ? ? ? */ > ? ? ? ?unsigned long long failcnt; > @@ -87,6 +105,7 @@ enum { > ? ? ? ?RES_MAX_USAGE, > ? ? ? ?RES_LIMIT, > ? ? ? ?RES_FAILCNT, > + ? ? ? RES_THRESHOLD, > ?}; > > ?/* > @@ -132,6 +151,21 @@ static inline bool res_counter_limit_check_locked(struct res_counter *cnt) > ? ? ? ?return false; > ?} > > +static inline bool res_counter_threshold_check_locked(struct res_counter *cnt) > +{ > + ? ? ? if (cnt->usage + cnt->threshold < cnt->limit) > + ? ? ? ? ? ? ? return true; > + > + ? ? ? return false; > +} > + > +static inline void res_counter_threshold_notify_locked(struct res_counter *cnt) > +{ > + ? ? ? if (!res_counter_threshold_check_locked(cnt) && > + ? ? ? ? ? cnt->threshold_notifier) > + ? ? ? ? ? ? ? cnt->threshold_notifier(cnt); > +} > + > ?/* > ?* Helper function to detect if the cgroup is within it's limit or > ?* not. It's currently called from cgroup_rss_prepare() > @@ -147,6 +181,21 @@ static inline bool res_counter_check_under_limit(struct res_counter *cnt) > ? ? ? ?return ret; > ?} > > +/* > + * Helper function to detect if the cgroup usage is under it's threshold or > + * not. > + */ > +static inline bool res_counter_check_under_threshold(struct res_counter *cnt) > +{ > + ? ? ? bool ret; > + ? ? ? unsigned long flags; > + > + ? ? ? spin_lock_irqsave(&cnt->lock, flags); > + ? ? ? ret = res_counter_threshold_check_locked(cnt); > + ? ? ? spin_unlock_irqrestore(&cnt->lock, flags); > + ? ? ? return ret; > +} > + > ?static inline void res_counter_reset_max(struct res_counter *cnt) > ?{ > ? ? ? ?unsigned long flags; > @@ -174,6 +223,26 @@ static inline int res_counter_set_limit(struct res_counter *cnt, > ? ? ? ?spin_lock_irqsave(&cnt->lock, flags); > ? ? ? ?if (cnt->usage <= limit) { > ? ? ? ? ? ? ? ?cnt->limit = limit; > + ? ? ? ? ? ? ? if (limit <= cnt->threshold) > + ? ? ? ? ? ? ? ? ? ? ? cnt->threshold = 0; > + ? ? ? ? ? ? ? else > + ? ? ? ? ? ? ? ? ? ? ? res_counter_threshold_notify_locked(cnt); > + ? ? ? ? ? ? ? ret = 0; > + ? ? ? } > + ? ? ? spin_unlock_irqrestore(&cnt->lock, flags); > + ? ? ? return ret; > +} > + > +static inline int res_counter_set_threshold(struct res_counter *cnt, > + ? ? ? ? ? ? ? unsigned long long threshold) > +{ > + ? ? ? unsigned long flags; > + ? ? ? int ret = -EINVAL; > + > + ? ? ? spin_lock_irqsave(&cnt->lock, flags); > + ? ? ? if (cnt->limit > threshold) { > + ? ? ? ? ? ? ? cnt->threshold = threshold; > + ? ? ? ? ? ? ? res_counter_threshold_notify_locked(cnt); > ? ? ? ? ? ? ? ?ret = 0; > ? ? ? ?} > ? ? ? ?spin_unlock_irqrestore(&cnt->lock, flags); > diff --git a/kernel/res_counter.c b/kernel/res_counter.c > index e1338f0..9b36748 100644 > --- a/kernel/res_counter.c > +++ b/kernel/res_counter.c > @@ -5,6 +5,10 @@ > ?* > ?* Author: Pavel Emelianov > ?* > + * Resouce usage threshold notification update > + * Copyright 2009 CE Linux Forum and Embedded Alley Solutions, Inc. > + * Author: Dan Malek > + * Author: Vladislav Buzov > ?*/ > > ?#include > @@ -32,6 +36,7 @@ int res_counter_charge_locked(struct res_counter *counter, unsigned long val) > ? ? ? ?counter->usage += val; > ? ? ? ?if (counter->usage > counter->max_usage) > ? ? ? ? ? ? ? ?counter->max_usage = counter->usage; > + ? ? ? res_counter_threshold_notify_locked(counter); > ? ? ? ?return 0; > ?} > > @@ -101,6 +106,8 @@ res_counter_member(struct res_counter *counter, int member) > ? ? ? ? ? ? ? ?return &counter->limit; > ? ? ? ?case RES_FAILCNT: > ? ? ? ? ? ? ? ?return &counter->failcnt; > + ? ? ? case RES_THRESHOLD: > + ? ? ? ? ? ? ? return &counter->threshold; > ? ? ? ?}; > > ? ? ? ?BUG(); > -- > 1.5.6.3 > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/