Messages in this thread Patch in this message | | | From | Ming Lei <> | Subject | [RFC PATCH v2 5/6] PM / Runtime: force memory allocation with no I/O during runtime_resume callbcack | Date | Mon, 22 Oct 2012 16:33:13 +0800 |
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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 <oneukum@suse.de> Cc: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Ming Lei <ming.lei@canonical.com> --- 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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