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From: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
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" <srivatsa.bhat@linux.vnet.ibm.com>
Subject: [PATCH 1/4] PM/Freezer: Make thaw_processes() thaw only userspace tasks
Date: Tue, 31 Jan 2012 03:34:57 +0530	[thread overview]
Message-ID: <20120130220419.9442.39596.stgit@srivatsabhat.in.ibm.com> (raw)
In-Reply-To: <20120130220259.9442.70091.stgit@srivatsabhat.in.ibm.com>

Currently the situation is:

freeze_processes() - freezes only userspace tasks
freeze_kernel_threads() - freezes only kernel threads
thaw_kernel_threads() - thaws only kernel threads
thaw_processes() - thaws *everything* (both userspace tasks and kernel threads)

The point that thaw_processes() thaws everything is rather unintuitive
and can lead to bugs. So, modify thaw_processes() so that it thaws only
userspace processes. This way we can also have more control over what
exactly gets thawed in different situations.

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
---

 kernel/power/process.c |    6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/kernel/power/process.c b/kernel/power/process.c
index eeca003..def6b1b 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -170,17 +170,15 @@ void thaw_processes(void)
 	if (pm_freezing)
 		atomic_dec(&system_freezing_cnt);
 	pm_freezing = false;
-	pm_nosig_freezing = false;
 
 	oom_killer_enable();
 
 	printk("Restarting tasks ... ");
 
-	thaw_workqueues();
-
 	read_lock(&tasklist_lock);
 	do_each_thread(g, p) {
-		__thaw_task(p);
+		if (!(p->flags & (PF_KTHREAD | PF_WQ_WORKER)))
+			__thaw_task(p);
 	} while_each_thread(g, p);
 	read_unlock(&tasklist_lock);
 


  reply	other threads:[~2012-01-30 22:05 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-30 22:04 [PATCH 0/4] PM / Freezer: Fix the semantics of thaw_processes() and thaw_kernel_threads() Srivatsa S. Bhat
2012-01-30 22:04 ` Srivatsa S. Bhat [this message]
2012-01-30 22:09   ` [PATCH 1/4] PM/Freezer: Make thaw_processes() thaw only userspace tasks Tejun Heo
2012-01-30 22:23     ` Srivatsa S. Bhat
2012-01-30 22:27       ` Tejun Heo
2012-01-30 22:05 ` [PATCH 2/4] PM/Freezer: Use thaw_processes() and thaw_kernel_threads() correctly Srivatsa S. Bhat
2012-01-30 22:05 ` [PATCH 3/4] PM/Hibernate: Thaw kernel threads in hibernation_snapshot() in error/test path Srivatsa S. Bhat
2012-01-30 22:05 ` [PATCH 4/4] PM/Hibernate: Refactor and simplify freezer_test_done Srivatsa S. Bhat

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