lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date:	Sat,  3 Nov 2012 16:35:08 +0800
From:	Ming Lei <>
Cc:	Alan Stern <>,
	Oliver Neukum <>,
	Minchan Kim <>,
	Greg Kroah-Hartman <>,
	"Rafael J. Wysocki" <>, Jens Axboe <>,
	"David S. Miller" <>,
	Andrew Morton <>,,,,
Subject: [PATCH v4 0/6] solve deadlock caused by memory allocation with I/O

This patchset try to solve one deadlock problem which might be caused
by memory allocation with block I/O during runtime PM and block device
error handling path. Traditionly, the problem is addressed by passing
GFP_NOIO statically to mm, but that is not a effective solution, see
detailed description in patch 1's commit log.

This patch set introduces one process flag and trys to fix the deadlock
problem on block device/network device during runtime PM or usb bus reset.

The 1st one is the change on include/sched.h and mm.

The 2nd patch introduces the flag of memalloc_noio on 'dev_pm_info',
and pm_runtime_set_memalloc_noio(), so that PM Core can teach mm to not
allocate mm with GFP_IOFS during the runtime_resume callback only on
device with the flag set.

The following 2 patches apply the introduced pm_runtime_set_memalloc_noio()
to mark all devices as memalloc_noio_resume in the path from the block or
network device to the root device in device tree.

The last 2 patches are applied again PM and USB subsystem to demonstrate
how to use the introduced mechanism to fix the deadlock problem.

Change logs:
	- patches from the 2nd to the 6th changed	
	- call pm_runtime_set_memalloc_noio() after device_add() as pointed
	by Alan
	- set PF_MEMALLOC_NOIO during runtime_suspend()

        - patch 2/6 and 5/6 changed, see their commit log
        - remove RFC from title since several guys have expressed that
        it is a reasonable solution
        - remove changes on 'may_writepage' and 'may_swap'(1/6)
        - unset GFP_IOFS in try_to_free_pages() path(1/6)
        - introduce pm_runtime_set_memalloc_noio()
        - only apply the meachnism on block/network device and its ancestors
        for runtime resume context
        - take Minchan's change to avoid the check in alloc_page hot path
        - change the helpers' style into save/restore as suggested by Alan
        - memory allocation with no io in usb bus reset path for all devices
        as suggested by Greg and Oliver

 block/genhd.c                |    9 +++++
 drivers/base/power/runtime.c |   89 +++++++++++++++++++++++++++++++++++++++++-
 drivers/usb/core/hub.c       |   13 ++++++
 include/linux/pm.h           |    1 +
 include/linux/pm_runtime.h   |    3 ++
 include/linux/sched.h        |   10 +++++
 mm/page_alloc.c              |   10 ++++-
 mm/vmscan.c                  |   12 ++++++
 net/core/net-sysfs.c         |    5 +++

Ming Lei

To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists