[RFC PATCH v2 5/6] PM / Runtime: force memory allocation with no I/O during runtime_resume callbcack
From: Ming Lei <hidden>
Date: 2012-10-22 08:36:16
Also in:
linux-mm, linux-pm, lkml
Subsystem:
driver core, kobjects, debugfs and sysfs, hibernation (aka software suspend, aka swsusp), power management core, suspend to ram, the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Linus Torvalds
This patch applies the introduced memalloc_noio_save() and memalloc_noio_restore() to force memory allocation with no I/O during runtime_resume callback on device which is marked as memalloc_noio_resume. Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Oliver Neukum <redacted> Cc: Rafael J. Wysocki <redacted> Signed-off-by: Ming Lei <redacted> --- drivers/base/power/runtime.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index a75eeca..c61b7b0 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c@@ -556,6 +556,7 @@ static int rpm_resume(struct device *dev, int rpmflags) int (*callback)(struct device *); struct device *parent = NULL; int retval = 0; + unsigned int noio_flag; trace_rpm_resume(dev, rpmflags);
@@ -705,7 +706,20 @@ static int rpm_resume(struct device *dev, int rpmflags) if (!callback && dev->driver && dev->driver->pm) callback = dev->driver->pm->runtime_resume; - retval = rpm_callback(callback, dev); + /* + * Deadlock might be caused if memory allocation with GFP_KERNEL + * happens inside runtime_resume callback 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_resume. + */ + if (dev->power.memalloc_noio_resume) { + memalloc_noio_save(noio_flag); + retval = rpm_callback(callback, dev); + memalloc_noio_restore(noio_flag); + } else { + retval = rpm_callback(callback, dev); + } if (retval) { __update_runtime_status(dev, RPM_SUSPENDED); pm_runtime_cancel_pending(dev);
--
1.7.9.5
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