From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tim Blechmann Subject: [PATCH] [RT] avoid preemption in memory controller code Date: Thu, 11 Dec 2008 20:00:45 +0100 Message-ID: <1229022045-31670-1-git-send-email-tim@klingt.org> References: Cc: linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org, mingo@elte.hu, tglx@linutronix.de, Tim Blechmann To: rostedt@goodmis.org Return-path: Received: from mail.klingt.org ([86.59.21.178]:49894 "EHLO klingt.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750767AbYLKTBO (ORCPT ); Thu, 11 Dec 2008 14:01:14 -0500 In-Reply-To: Sender: linux-rt-users-owner@vger.kernel.org List-ID: the lru_lock of struct mem_group_per_zone is used to avoid preemption during the mem_cgroup_charge_statistics function. this does not work correctly, when CONFIG_PREEMPT_RT is enabled. therefore, the preemption is disabled using the preempt_disable_rt macro in these cases. Signed-off-by: Tim Blechmann --- mm/memcontrol.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 562b94f..70493c4 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -158,7 +158,7 @@ pcg_default_flags[NR_CHARGE_TYPE] = { }; /* - * Always modified under lru lock. Then, not necessary to preempt_disable() + * Always modified under lru lock. Disable preemption with preempt_disable_rt() */ static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, struct page_cgroup *pc, @@ -170,6 +170,7 @@ static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, VM_BUG_ON(!irqs_disabled()); + preempt_disable_rt(); cpustat = &stat->cpustat[smp_processor_id()]; if (PageCgroupCache(pc)) __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_CACHE, val); @@ -182,6 +183,7 @@ static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, else __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_PGPGOUT_COUNT, 1); + preempt_enable_rt(); } static struct mem_cgroup_per_zone * -- 1.5.6.3