From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754425Ab2A3XOl (ORCPT ); Mon, 30 Jan 2012 18:14:41 -0500 Received: from e28smtp08.in.ibm.com ([122.248.162.8]:55844 "EHLO e28smtp08.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754448Ab2A3XOj (ORCPT ); Mon, 30 Jan 2012 18:14:39 -0500 From: "Srivatsa S. Bhat" Subject: [PATCH v2 1/4] PM/Freezer: Use thaw_kernel_threads() in preparation for changes to thaw_processes() To: rjw@sisk.pl Cc: pavel@ucw.cz, len.brown@intel.com, tj@kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, "Srivatsa S. Bhat" Date: Tue, 31 Jan 2012 04:44:30 +0530 Message-ID: <20120130231418.11129.24809.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20120130231342.11129.87187.stgit@srivatsabhat.in.ibm.com> References: <20120130231342.11129.87187.stgit@srivatsabhat.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit x-cbid: 12013023-2000-0000-0000-0000063E9A9C Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org As of now, thaw_processes() is a superset of thaw_kernel_threads() in the sense that thaw_processes() thaws both userspace tasks and kernel threads. But that is going to change very soon. So, in preparation for that, add some calls to thaw_kernel_threads() like this: * If only kernel threads need to be thawed, _replace_ thaw_processes() with thaw_kernel_threads(). * If everything needs to be thawed, _add_ a call to thaw_kernel_threads() adjacent to the existing call to thaw_processes(). Signed-off-by: Srivatsa S. Bhat --- kernel/power/hibernate.c | 5 +++++ kernel/power/power.h | 15 +++++++++++++-- kernel/power/process.c | 4 ++-- kernel/power/user.c | 8 ++++++++ 4 files changed, 28 insertions(+), 4 deletions(-) diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index a5d4cf0..1670387 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -656,6 +656,11 @@ int hibernate(void) } Thaw: + /* + * Kernel threads had been frozen inside hibernation_snapshot(). + * So thaw them here, on the success path. + */ + thaw_kernel_threads(); thaw_processes(); Finish: free_basic_memory_bitmaps(); diff --git a/kernel/power/power.h b/kernel/power/power.h index 0c4defe..e37a1e0 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -231,12 +231,23 @@ extern int pm_test_level; #ifdef CONFIG_SUSPEND_FREEZER static inline int suspend_freeze_processes(void) { - int error = freeze_processes(); - return error ? : freeze_kernel_threads(); + int error; + + error = freeze_processes(); + if (error) + goto Finish; + + error = freeze_kernel_threads(); + if (error) + thaw_processes(); + +Finish: + return error; } static inline void suspend_thaw_processes(void) { + thaw_kernel_threads(); thaw_processes(); } #else diff --git a/kernel/power/process.c b/kernel/power/process.c index eeca003..3734fb9 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -143,7 +143,7 @@ int freeze_processes(void) /** * freeze_kernel_threads - Make freezable kernel threads go to the refrigerator. * - * On success, returns 0. On failure, -errno and system is fully thawed. + * On success, returns 0. On failure, -errno and all kernel threads are thawed. */ int freeze_kernel_threads(void) { @@ -159,7 +159,7 @@ int freeze_kernel_threads(void) BUG_ON(in_atomic()); if (error) - thaw_processes(); + thaw_kernel_threads(); return error; } diff --git a/kernel/power/user.c b/kernel/power/user.c index 3e10007..eaf5c97 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -119,6 +119,7 @@ static int snapshot_release(struct inode *inode, struct file *filp) free_all_swap_pages(data->swap); if (data->frozen) { pm_restore_gfp_mask(); + thaw_kernel_threads(); thaw_processes(); } pm_notifier_call_chain(data->mode == O_RDONLY ? @@ -237,6 +238,13 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, if (!data->frozen || data->ready) break; pm_restore_gfp_mask(); + + /* + * Be paranoid and thaw kernel threads as well, in order to + * make sure that the system gets thawed fully, irrespective + * of which (error) path we took to come here. + */ + thaw_kernel_threads(); thaw_processes(); usermodehelper_enable(); data->frozen = 0;