Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751472AbZGNAQi (ORCPT ); Mon, 13 Jul 2009 20:16:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751337AbZGNAQa (ORCPT ); Mon, 13 Jul 2009 20:16:30 -0400 Received: from easi.embeddedalley.com ([71.6.201.124]:47201 "HELO easi.embeddedalley.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751332AbZGNAQ0 (ORCPT ); Mon, 13 Jul 2009 20:16:26 -0400 From: Vladislav Buzov To: Linux Kernel Mailing List Cc: Linux Containers Mailing List , Linux memory management list , Dan Malek , Andrew Morton , Paul Menage , KAMEZAWA Hiroyuki , Balbir Singh , Vladislav Buzov Subject: [PATCH 1/2] Resource usage threshold notification addition to res_counter (v3) Date: Mon, 13 Jul 2009 17:16:20 -0700 Message-Id: <1247530581-31416-2-git-send-email-vbuzov@embeddedalley.com> X-Mailer: git-send-email 1.5.6.3 In-Reply-To: <1247530581-31416-1-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> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6647 Lines: 214 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/