From db88175f41a29c1ffff1a6938a7969d206a47326 Mon Sep 17 00:00:00 2001 From: Ming Lei 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 Cc: "David S. Miller" Cc: Eric Dumazet Cc: David Decotigny Cc: Tom Herbert Cc: Ingo Molnar Cc: Jens Axboe Cc: Minchan Kim Cc: Alan Stern Cc: Oliver Neukum Cc: Jiri Kosina Cc: Mel Gorman Cc: KAMEZAWA Hiroyuki Cc: Michal Hocko Cc: Ingo Molnar Cc: Peter Zijlstra Cc: "Rafael J. Wysocki" Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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 cd92e1c..1244930 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; -- 2.7.4