From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752695Ab1IFANj (ORCPT ); Mon, 5 Sep 2011 20:13:39 -0400 Received: from mail-vw0-f46.google.com ([209.85.212.46]:53534 "EHLO mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752142Ab1IFANc (ORCPT ); Mon, 5 Sep 2011 20:13:32 -0400 From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Paul Menage , Li Zefan , Johannes Weiner , Aditya Kali , Oleg Nesterov , Andrew Morton , Kay Sievers , Tim Hockin , Tejun Heo Subject: [PATCH 01/12] cgroups: Add res_counter_write_u64() API Date: Tue, 6 Sep 2011 02:12:55 +0200 Message-Id: <1315267986-28937-2-git-send-email-fweisbec@gmail.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1315267986-28937-1-git-send-email-fweisbec@gmail.com> References: <1315267986-28937-1-git-send-email-fweisbec@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Extend the resource counter API with a mirror of res_counter_read_u64() to make it handy to update a resource counter value from a cgroup subsystem u64 value file. Signed-off-by: Frederic Weisbecker Acked-by: Paul Menage Cc: Li Zefan Cc: Johannes Weiner Cc: Aditya Kali Cc: Oleg Nesterov Cc: Andrew Morton Cc: Kay Sievers Cc: Tim Hockin Cc: Tejun Heo --- include/linux/res_counter.h | 2 ++ kernel/res_counter.c | 25 +++++++++++++++++++------ 2 files changed, 21 insertions(+), 6 deletions(-) diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h index c9d625c..1b3fe05 100644 --- a/include/linux/res_counter.h +++ b/include/linux/res_counter.h @@ -82,6 +82,8 @@ int res_counter_memparse_write_strategy(const char *buf, int res_counter_write(struct res_counter *counter, int member, const char *buffer, write_strategy_fn write_strategy); +void res_counter_write_u64(struct res_counter *counter, int member, u64 val); + /* * the field descriptors. one for each member of res_counter */ diff --git a/kernel/res_counter.c b/kernel/res_counter.c index 34683ef..0faafcc 100644 --- a/kernel/res_counter.c +++ b/kernel/res_counter.c @@ -168,12 +168,26 @@ int res_counter_memparse_write_strategy(const char *buf, return 0; } +void res_counter_write_u64(struct res_counter *counter, int member, u64 val) +{ + unsigned long long *target; + unsigned long flags; + + /* + * We need the lock to protect against concurrent add/dec on 32 bits. + * No need to ifdef it's seldom used. + */ + spin_lock_irqsave(&counter->lock, flags); + target = res_counter_member(counter, member); + *target = val; + spin_unlock_irqrestore(&counter->lock, flags); +} + int res_counter_write(struct res_counter *counter, int member, const char *buf, write_strategy_fn write_strategy) { char *end; - unsigned long flags; - unsigned long long tmp, *val; + unsigned long long tmp; if (write_strategy) { if (write_strategy(buf, &tmp)) @@ -183,9 +197,8 @@ int res_counter_write(struct res_counter *counter, int member, if (*end != '\0') return -EINVAL; } - spin_lock_irqsave(&counter->lock, flags); - val = res_counter_member(counter, member); - *val = tmp; - spin_unlock_irqrestore(&counter->lock, flags); + + res_counter_write_u64(counter, member, tmp); + return 0; } -- 1.7.5.4