[PATCH v5 5/6] PM / Runtime: force memory allocation with no I/O during Runtime PM callbcack
flat view
STALE5085d
SUPERSEDED
From: Ming Lei <hidden>
Date: 2012-11-11 12:36:08
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
Revision v5 of 6 in this series.
Revisions (6)
This patch applies 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. Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Oliver Neukum <redacted> Cc: Rafael J. Wysocki <redacted> Signed-off-by: Ming Lei <redacted> --- v5: - use inline memalloc_noio_save() v4: - runtime_suspend need this too because rpm_resume may wait for completion of concurrent runtime_suspend, so deadlock still may be triggered in runtime_suspend path. --- drivers/base/power/runtime.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-)
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 3e198a0..96d99ea 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c@@ -371,6 +371,7 @@ static int rpm_suspend(struct device *dev, int rpmflags) int (*callback)(struct device *); struct device *parent = NULL; int retval; + unsigned int noio_flag; trace_rpm_suspend(dev, rpmflags);
@@ -480,7 +481,20 @@ static int rpm_suspend(struct device *dev, int rpmflags) if (!callback && dev->driver && dev->driver->pm) callback = dev->driver->pm->runtime_suspend; - retval = rpm_callback(callback, dev); + /* + * Deadlock might be caused if memory allocation with GFP_KERNEL + * happens inside runtime_suspend 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. + */ + if (dev->power.memalloc_noio) { + noio_flag = memalloc_noio_save(); + retval = rpm_callback(callback, dev); + memalloc_noio_restore(noio_flag); + } else { + retval = rpm_callback(callback, dev); + } if (retval) goto fail;
@@ -563,6 +577,7 @@ 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);
@@ -712,7 +727,20 @@ 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. + */ + if (dev->power.memalloc_noio) { + noio_flag = memalloc_noio_save(); + 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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