Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755574AbZDGK5l (ORCPT ); Tue, 7 Apr 2009 06:57:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753019AbZDGK4O (ORCPT ); Tue, 7 Apr 2009 06:56:14 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:54127 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752303AbZDGK4M (ORCPT ); Tue, 7 Apr 2009 06:56:12 -0400 Message-ID: <49DB3071.5090200@cn.fujitsu.com> Date: Tue, 07 Apr 2009 18:52:33 +0800 From: Miao Xie Reply-To: miaox@cn.fujitsu.com User-Agent: Thunderbird 2.0.0.6 (Windows/20070728) MIME-Version: 1.0 To: Paul Menage CC: Linux-Kernel , Yasunori Goto Subject: [RFC][PATCH 2/3] cpusets: update tasks' page/slab spread flags in time Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4435 Lines: 137 This patch fixes the bug that the kernel didn't spread page cache/slab object evenly over all the allowed nodes when spread flags were set by updating tasks' page/slab spread flags in time. Signed-off-by: Miao Xie --- kernel/cpuset.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 files changed, 55 insertions(+), 4 deletions(-) diff --git a/kernel/cpuset.c b/kernel/cpuset.c index be0cfcd..8bff8e6 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -406,7 +406,6 @@ void cpuset_update_task_memory_state(void) cs = task_cs(tsk); /* Maybe changed when task not locked */ guarantee_online_mems(cs, &tsk->mems_allowed); tsk->cpuset_mems_generation = cs->mems_generation; - cpuset_update_task_spread_flag(cs, tsk); task_unlock(tsk); mutex_unlock(&callback_mutex); mpol_rebind_task(tsk, &tsk->mems_allowed); @@ -1204,6 +1203,46 @@ static int update_relax_domain_level(struct cpuset *cs, s64 val) } /* + * cpuset_change_flag - make a task's spread flags the same as its cpuset's + * @tsk: task to be updated + * @scan: struct cgroup_scanner containing the cgroup of the task + * + * Called by cgroup_scan_tasks() for each task in a cgroup. + * + * We don't need to re-check for the cgroup/cpuset membership, since we're + * holding cgroup_lock() at this point. + */ +static void cpuset_change_flag(struct task_struct *tsk, + struct cgroup_scanner *scan) +{ + cpuset_update_task_spread_flag(cgroup_cs(scan->cg), tsk); +} + +/* + * update_tasks_flags - update the spread flags of tasks in the cpuset. + * @cs: the cpuset in which each task's spread flags needs to be changed + * @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks() + * + * Called with cgroup_mutex held + * + * The cgroup_scan_tasks() function will scan all the tasks in a cgroup, + * calling callback functions for each. + * + * No return value. It's guaranteed that cgroup_scan_tasks() always returns 0 + * if @heap != NULL. + */ +static void update_tasks_flags(struct cpuset *cs, struct ptr_heap *heap) +{ + struct cgroup_scanner scan; + + scan.cg = cs->css.cgroup; + scan.test_task = NULL; + scan.process_task = cpuset_change_flag; + scan.heap = heap; + cgroup_scan_tasks(&scan); +} + +/* * update_flag - read a 0 or a 1 in a file and update associated flag * bit: the bit to update (see cpuset_flagbits_t) * cs: the cpuset to update @@ -1216,8 +1255,10 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, int turning_on) { struct cpuset *trialcs; - int err; int balance_flag_changed; + int spread_flag_changed; + struct ptr_heap heap; + int err; trialcs = alloc_trial_cpuset(cs); if (!trialcs) @@ -1232,9 +1273,16 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, if (err < 0) goto out; + err = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL); + if (err < 0) + goto out; + balance_flag_changed = (is_sched_load_balance(cs) != is_sched_load_balance(trialcs)); + spread_flag_changed = ((is_spread_slab(cs) != is_spread_slab(trialcs)) + || (is_spread_page(cs) != is_spread_page(trialcs))); + mutex_lock(&callback_mutex); cs->flags = trialcs->flags; mutex_unlock(&callback_mutex); @@ -1242,6 +1290,9 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, if (!cpumask_empty(trialcs->cpus_allowed) && balance_flag_changed) async_rebuild_sched_domains(); + if (spread_flag_changed) + update_tasks_flags(cs, &heap); + heap_free(&heap); out: free_trial_cpuset(trialcs); return err; @@ -1392,6 +1443,8 @@ static void cpuset_attach(struct cgroup_subsys *ss, if (err) return; + cpuset_update_task_spread_flag(cs, tsk); + from = oldcs->mems_allowed; to = cs->mems_allowed; mm = get_task_mm(tsk); @@ -1453,11 +1506,9 @@ static int cpuset_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val) break; case FILE_SPREAD_PAGE: retval = update_flag(CS_SPREAD_PAGE, cs, val); - cs->mems_generation = cpuset_mems_generation++; break; case FILE_SPREAD_SLAB: retval = update_flag(CS_SPREAD_SLAB, cs, val); - cs->mems_generation = cpuset_mems_generation++; break; default: retval = -EINVAL; -- 1.6.0.3 -- 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/