From db88175f41a29c1ffff1a6938a7969d206a47326 Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@canonical.com>
Date: Fri, 22 Feb 2013 16:34:19 -0800
Subject: [PATCH] pm / runtime: force memory allocation with no I/O during
Runtime PM callbcack
Apply the introduced memalloc_noio_save() and memalloc_noio_restore() to
force memory allocation with no I/O during runtime_resume/runtime_suspend
callback on device with the flag of 'memalloc_noio' set.
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Decotigny <david.decotigny@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Oliver Neukum <oneukum@suse.de>
Cc: Jiri Kosina <jiri.kosina@suse.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
drivers/base/power/runtime.c | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index cd92e1c77cb7..1244930e3d7a 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -348,7 +348,24 @@ static int rpm_callback(int (*cb)(struct device *), struct device *dev)
if (!cb)
return -ENOSYS;
- retval = __rpm_callback(cb, dev);
+ if (dev->power.memalloc_noio) {
+ unsigned int noio_flag;
+
+ /*
+ * Deadlock might be caused if memory allocation with
+ * GFP_KERNEL happens inside runtime_suspend and
+ * runtime_resume callbacks of one block device's
+ * ancestor or the block device itself. Network
+ * device might be thought as part of iSCSI block
+ * device, so network device and its ancestor should
+ * be marked as memalloc_noio too.
+ */
+ noio_flag = memalloc_noio_save();
+ retval = __rpm_callback(cb, dev);
+ memalloc_noio_restore(noio_flag);
+ } else {
+ retval = __rpm_callback(cb, dev);
+ }
dev->power.runtime_error = retval;
return retval != -EACCES ? retval : -EIO;
--
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