From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx183.postini.com [74.125.245.183]) by kanga.kvack.org (Postfix) with SMTP id 4A4D16B0069 for ; Mon, 22 Oct 2012 04:36:11 -0400 (EDT) Received: by mail-pa0-f41.google.com with SMTP id fa10so1880654pad.14 for ; Mon, 22 Oct 2012 01:36:10 -0700 (PDT) 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 Message-Id: <1350894794-1494-6-git-send-email-ming.lei@canonical.com> In-Reply-To: <1350894794-1494-1-git-send-email-ming.lei@canonical.com> References: <1350894794-1494-1-git-send-email-ming.lei@canonical.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: Alan Stern , Oliver Neukum , Minchan Kim , Greg Kroah-Hartman , "Rafael J. Wysocki" , Jens Axboe , "David S. Miller" , Andrew Morton , netdev@vger.kernel.org, linux-usb@vger.kernel.org, linux-pm@vger.kernel.org, linux-mm@kvack.org, Ming Lei 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 Cc: Oliver Neukum Cc: Rafael J. Wysocki Signed-off-by: Ming Lei --- 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org