From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752517Ab1G2QNw (ORCPT ); Fri, 29 Jul 2011 12:13:52 -0400 Received: from mail-ww0-f44.google.com ([74.125.82.44]:39536 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752430Ab1G2QNu (ORCPT ); Fri, 29 Jul 2011 12:13:50 -0400 From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Andrew Morton , Li Zefan , Johannes Weiner , Aditya Kali , Oleg Nesterov Subject: [PATCH 4/8] cgroups: New cancel_attach_task subsystem callback Date: Fri, 29 Jul 2011 18:13:26 +0200 Message-Id: <1311956010-32076-5-git-send-email-fweisbec@gmail.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1311956010-32076-1-git-send-email-fweisbec@gmail.com> References: <1311956010-32076-1-git-send-email-fweisbec@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org To cancel a process attachment on a subsystem, we only call the cancel_attach() callback once on the leader but we have no way to cancel the attachment individually for each member of the process group. This is going to be needed for the max number of tasks susbystem that is coming. To prepare for this integration, call a new cancel_attach_task() callback on each task of the group until we reach the member that failed to attach. Signed-off-by: Frederic Weisbecker Acked-by: Paul Menage Cc: Li Zefan Cc: Johannes Weiner Cc: Aditya Kali Cc: Oleg Nesterov --- include/linux/cgroup.h | 1 + kernel/cgroup.c | 15 ++++++++++++--- 2 files changed, 13 insertions(+), 3 deletions(-) diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index e8288a0..94454143 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -472,6 +472,7 @@ struct cgroup_subsys { struct task_struct *tsk); void (*cancel_attach)(struct cgroup_subsys *ss, struct cgroup *cgrp, struct task_struct *tsk); + void (*cancel_attach_task)(struct cgroup *cgrp, struct task_struct *tsk); void (*pre_attach)(struct cgroup *cgrp); void (*attach_task)(struct cgroup *cgrp, struct cgroup *old_cgrp, struct task_struct *tsk); void (*attach)(struct cgroup_subsys *ss, struct cgroup *cgrp, diff --git a/kernel/cgroup.c b/kernel/cgroup.c index c3ee4cf..210dc05 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1989,7 +1989,7 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) { int retval, i, group_size; struct cgroup_subsys *ss, *failed_ss = NULL; - bool cancel_failed_ss = false; + struct task_struct *failed_task = NULL; /* guaranteed to be initialized later, but the compiler needs this */ struct cgroup *oldcgrp = NULL; struct css_set *oldcg; @@ -2077,7 +2077,7 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) retval = ss->can_attach_task(cgrp, oldcgrp, tsk); if (retval) { failed_ss = ss; - cancel_failed_ss = true; + failed_task = tsk; goto out_cancel_attach; } } @@ -2172,8 +2172,17 @@ out_cancel_attach: /* same deal as in cgroup_attach_task */ if (retval) { for_each_subsys(root, ss) { + if (ss->cancel_attach_task && (ss != failed_ss || failed_task)) { + for (i = 0; i < group_size; i++) { + tsk = flex_array_get_ptr(group, i); + if (tsk == failed_task) + break; + ss->cancel_attach_task(cgrp, tsk); + } + } + if (ss == failed_ss) { - if (cancel_failed_ss && ss->cancel_attach) + if (failed_task && ss->cancel_attach) ss->cancel_attach(ss, cgrp, leader); break; } -- 1.7.5.4