From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx142.postini.com [74.125.245.142]) by kanga.kvack.org (Postfix) with SMTP id 81F7F6B0044 for ; Sat, 3 Nov 2012 04:35:39 -0400 (EDT) Received: by mail-da0-f41.google.com with SMTP id i14so2150213dad.14 for ; Sat, 03 Nov 2012 01:35:38 -0700 (PDT) From: Ming Lei Subject: [PATCH v4 0/6] solve deadlock caused by memory allocation with I/O Date: Sat, 3 Nov 2012 16:35:08 +0800 Message-Id: <1351931714-11689-1-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 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: V4: - 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() V3: - 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 V2: - 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 V1: - 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 +++ Thanks, -- Ming Lei -- 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