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2012-03-28PM / QoS: add pm_qos_update_request_timeout() APIMyungJoo Ham
The new API, pm_qos_update_request_timeout() is to provide a timeout with pm_qos_update_request. For example, pm_qos_update_request_timeout(req, 100, 1000), means that QoS request on req with value 100 will be active for 1000 microseconds. After 1000 microseconds, the QoS request thru req is reset. If there were another pm_qos_update_request(req, x) during the 1000 us, this new request with value x will override as this is another request on the same req handle. A new request on the same req handle will always override the previous request whether it is the conventional request or it is the new timeout request. Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Acked-by: Mark Gross <markgross@thegnar.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-03-28PM / Sleep: Mitigate race between the freezer and request_firmware()Rafael J. Wysocki
There is a race condition between the freezer and request_firmware() such that if request_firmware() is run on one CPU and freeze_processes() is run on another CPU and usermodehelper_disable() called by it succeeds to grab umhelper_sem for writing before usermodehelper_read_trylock() called from request_firmware() acquires it for reading, the request_firmware() will fail and trigger a WARN_ON() complaining that it was called at a wrong time. However, in fact, it wasn't called at a wrong time and freeze_processes() simply happened to be executed simultaneously. To avoid this race, at least in some cases, modify usermodehelper_read_trylock() so that it doesn't fail if the freezing of tasks has just started and hasn't been completed yet. Instead, during the freezing of tasks, it will try to freeze the task that has called it so that it can wait until user space is thawed without triggering the scary warning. For this purpose, change usermodehelper_disabled so that it can take three different values, UMH_ENABLED (0), UMH_FREEZING and UMH_DISABLED. The first one means that usermode helpers are enabled, the last one means "hard disable" (i.e. the system is not ready for usermode helpers to be used) and the second one is reserved for the freezer. Namely, when freeze_processes() is started, it sets usermodehelper_disabled to UMH_FREEZING which tells usermodehelper_read_trylock() that it shouldn't fail just yet and should call try_to_freeze() if woken up and cannot return immediately. This way all freezable tasks that happen to call request_firmware() right before freeze_processes() is started and lose the race for umhelper_sem with it will be frozen and will sleep until thaw_processes() unsets usermodehelper_disabled. [For the non-freezable callers of request_firmware() the race for umhelper_sem against freeze_processes() is unfortunately unavoidable.] Reported-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@vger.kernel.org
2012-03-28PM / Sleep: Move disabling of usermode helpers to the freezerRafael J. Wysocki
The core suspend/hibernation code calls usermodehelper_disable() to avoid race conditions between the freezer and the starting of usermode helpers and each code path has to do that on its own. However, it is always called right before freeze_processes() and usermodehelper_enable() is always called right after thaw_processes(). For this reason, to avoid code duplication and to make the connection between usermodehelper_disable() and the freezer more visible, make freeze_processes() call it and remove the direct usermodehelper_disable() and usermodehelper_enable() calls from all suspend/hibernation code paths. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@vger.kernel.org
2012-03-28PM / Hibernate: Disable usermode helpers right before freezing tasksRafael J. Wysocki
There is no reason to call usermodehelper_disable() before creating memory bitmaps in hibernate() and software_resume(), so call it right before freeze_processes(), in accordance with the other suspend and hibernation code. Consequently, call usermodehelper_enable() right after the thawing of tasks rather than after freeing the memory bitmaps. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@vger.kernel.org
2012-03-21Merge tag 'pm-for-3.4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates for 3.4 from Rafael Wysocki: "Assorted extensions and fixes including: * Introduction of early/late suspend/hibernation device callbacks. * Generic PM domains extensions and fixes. * devfreq updates from Axel Lin and MyungJoo Ham. * Device PM QoS updates. * Fixes of concurrency problems with wakeup sources. * System suspend and hibernation fixes." * tag 'pm-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (43 commits) PM / Domains: Check domain status during hibernation restore of devices PM / devfreq: add relation of recommended frequency. PM / shmobile: Make MTU2 driver use pm_genpd_dev_always_on() PM / shmobile: Make CMT driver use pm_genpd_dev_always_on() PM / shmobile: Make TMU driver use pm_genpd_dev_always_on() PM / Domains: Introduce "always on" device flag PM / Domains: Fix hibernation restore of devices, v2 PM / Domains: Fix handling of wakeup devices during system resume sh_mmcif / PM: Use PM QoS latency constraint tmio_mmc / PM: Use PM QoS latency constraint PM / QoS: Make it possible to expose PM QoS latency constraints PM / Sleep: JBD and JBD2 missing set_freezable() PM / Domains: Fix include for PM_GENERIC_DOMAINS=n case PM / Freezer: Remove references to TIF_FREEZE in comments PM / Sleep: Add more wakeup source initialization routines PM / Hibernate: Enable usermodehelpers in hibernate() error path PM / Sleep: Make __pm_stay_awake() delete wakeup source timers PM / Sleep: Fix race conditions related to wakeup source timer function PM / Sleep: Fix possible infinite loop during wakeup source destruction PM / Hibernate: print physical addresses consistently with other parts of kernel ...
2012-03-20power: remove the second argument of k[un]map_atomic()Cong Wang
Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Cong Wang <amwang@redhat.com>
2012-03-04Merge branch 'pm-qos'Rafael J. Wysocki
* pm-qos: PM / QoS: unconditionally build the feature PM / QoS: Simplify PM QoS expansion/merge
2012-03-04PM / Freezer: Remove references to TIF_FREEZE in commentsMarcos Paulo de Souza
This patch removes all the references in the code about the TIF_FREEZE flag removed by commit a3201227f803ad7fd43180c5195dbe5a2bf998aa freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE There still are some references to TIF_FREEZE in Documentation/power/freezing-of-tasks.txt, but it looks like that documentation needs more thorough work to reflect how the new freezer works, and hence merely removing the references to TIF_FREEZE won't really help. So I have not touched that part in this patch. Suggested-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Marcos Paulo de Souza <marcos.mage@gmail.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-03-04PM / Hibernate: Enable usermodehelpers in hibernate() error pathSrivatsa S. Bhat
If create_basic_memory_bitmaps() fails, usermodehelpers are not re-enabled before returning. Fix this. And while at it, reword the goto labels so that they look more meaningful. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: stable@vger.kernel.org Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-02-17PM / Hibernate: print physical addresses consistently with other parts of kernelBjorn Helgaas
Print physical address info in a style consistent with the %pR style used elsewhere in the kernel. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-02-17PM / Sleep: Drop suspend_stats_update()Rafael J. Wysocki
Since suspend_stats_update() is only called from pm_suspend(), move its code directly into that function and remove the static inline definition from include/linux/suspend.h. Clean_up pm_suspend() in the process. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
2012-02-17PM / Sleep: Make enter_state() in kernel/power/suspend.c staticRafael J. Wysocki
The enter_state() function in kernel/power/suspend.c should be static and state_store() in kernel/power/suspend.c should call pm_suspend() instead of it, so make that happen (which also reduces code duplication related to suspend statistics). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
2012-02-17PM / Sleep: Unify kerneldoc comments in kernel/power/suspend.cRafael J. Wysocki
The kerneldoc comments in kernel/power/suspend.c are not formatted in the same way and the quality of some of them is questionable. Unify the formatting and improve the contents. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
2012-02-13PM / Sleep: Remove unnecessary label from suspend_freeze_processes()Rafael J. Wysocki
The Finish label in suspend_freeze_processes() is in fact unnecessary and makes the function look more complicated than it really is, so remove that label (along with a few empty lines). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
2012-02-13PM / Sleep: Do not check wakeup too often in try_to_freeze_tasks()Rafael J. Wysocki
Use the observation that it is more efficient to check the wakeup variable once before the loop reporting tasks that were not frozen in try_to_freeze_tasks() than to do that in every step of that loop. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-02-13PM / QoS: unconditionally build the featureJean Pihet
The PM QoS feature originally didn't depend on CONFIG_PM, which was mistakenly changed by commit e8db0be1245de16a6cc6365506abc392c3c212d4 PM QoS: Move and rename the implementation files Later, commit d020283dc694c9ec31b410f522252f7a8397e67d PM / QoS: CPU C-state breakage with PM Qos change partially fixed that by introducing a static inline definition of pm_qos_request(), but that still didn't allow user space to use the PM QoS interface if CONFIG_PM was unset (which had been possible before). For this reason, remove the dependency of PM QoS on CONFIG_PM to make it work (as intended) with CONFIG_PM unset. [rjw: Replaced the original changelog with a new one.] Signed-off-by: Jean Pihet <j-pihet@ti.com> Reported-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-02-13Merge commit 'pm-fixes-for-3.3-rc3' into pm-qosRafael J. Wysocki
New material in the pm-qos branch depends on recent power management fixes.
2012-02-09PM / Hibernate: Refactor and simplify freezer_test_doneSrivatsa S. Bhat
The code related to 'freezer_test_done' is needlessly convoluted. Refactor the code and simplify the implementation. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-02-09PM / Hibernate: Thaw kernel threads in hibernation_snapshot() in error/test pathSrivatsa S. Bhat
In the hibernation call path, the kernel threads are frozen inside hibernation_snapshot(). If we happen to encounter an error further down the road or if we are exiting early due to a successful freezer test, then thaw kernel threads before returning to the caller. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-02-09PM / Suspend: Avoid code duplication in suspend statistics updateMarcos Paulo de Souza
The code if (error) { suspend_stats.fail++; dpm_save_failed_errno(error); } else suspend_stats.success++; Appears in the kernel/power/main.c and kernel/power/suspend.c. This patch just creates a new function to avoid duplicated code. Suggested-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Marcos Paulo de Souza <marcos.mage@gmail.com> Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-02-09Merge commit 'pm-fixes-for-3.3-rc3' into pm-sleepRafael J. Wysocki
New material in the pm-sleep branch depends on recent power management fixes.
2012-02-04PM / Freezer: Thaw only kernel threads if freezing of kernel threads failsSrivatsa S. Bhat
If freezing of kernel threads fails, we are expected to automatically thaw tasks in the error recovery path. However, at times, we encounter situations in which we would like the automatic error recovery path to thaw only the kernel threads, because we want to be able to do some more cleanup before we thaw userspace. Something like: error = freeze_kernel_threads(); if (error) { /* Do some cleanup */ /* Only then thaw userspace tasks*/ thaw_processes(); } An example of such a situation is where we freeze/thaw filesystems during suspend/hibernation. There, if freezing of kernel threads fails, we would like to thaw the frozen filesystems before thawing the userspace tasks. So, modify freeze_kernel_threads() to thaw only kernel threads in case of freezing failure. And change suspend_freeze_processes() accordingly. (At the same time, let us also get rid of the rather cryptic usage of the conditional operator (:?) in that function.) [rjw: In fact, this patch fixes a regression introduced during the 3.3 merge window, because without it thaw_processes() may be called before swsusp_free() in some situations and that may lead to massive memory allocation failures.] Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Nigel Cunningham <nigel@tuxonice.net> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-02-01PM / Hibernate: Thaw kernel threads in SNAPSHOT_CREATE_IMAGE ioctl pathSrivatsa S. Bhat
In the SNAPSHOT_CREATE_IMAGE ioctl, if the call to hibernation_snapshot() fails, the frozen tasks are not thawed. And in the case of success, if we happen to exit due to a successful freezer test, all tasks (including those of userspace) are thawed, whereas actually we should have thawed only the kernel threads at that point. Fix both these issues. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: stable@vger.kernel.org
2012-01-29PM / QoS: Simplify PM QoS expansion/mergeAlex Frid
- Replace class ID #define with enumeration - Loop through PM QoS objects during initialization (rather than initializing them one-by-one) Signed-off-by: Alex Frid <afrid@nvidia.com> Reviewed-by: Antti Miettinen <amiettinen@nvidia.com> Reviewed-by: Diwakar Tundlam <dtundlam@nvidia.com> Reviewed-by: Scott Williams <scwilliams@nvidia.com> Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com> Acked-by: markgross <markgross@thegnar.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-01-29PM / Sleep: Introduce "late suspend" and "early resume" of devicesRafael J. Wysocki
The current device suspend/resume phases during system-wide power transitions appear to be insufficient for some platforms that want to use the same callback routines for saving device states and related operations during runtime suspend/resume as well as during system suspend/resume. In principle, they could point their .suspend_noirq() and .resume_noirq() to the same callback routines as their .runtime_suspend() and .runtime_resume(), respectively, but at least some of them require device interrupts to be enabled while the code in those routines is running. It also makes sense to have device suspend-resume callbacks that will be executed with runtime PM disabled and with device interrupts enabled in case someone needs to run some special code in that context during system-wide power transitions. Apart from this, .suspend_noirq() and .resume_noirq() were introduced as a workaround for drivers using shared interrupts and failing to prevent their interrupt handlers from accessing suspended hardware. It appears to be better not to use them for other porposes, or we may have to deal with some serious confusion (which seems to be happening already). For the above reasons, introduce new device suspend/resume phases, "late suspend" and "early resume" (and analogously for hibernation) whose callback will be executed with runtime PM disabled and with device interrupts enabled and whose callback pointers generally may point to runtime suspend/resume routines. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Reviewed-by: Kevin Hilman <khilman@ti.com>
2012-01-29PM / Hibernate: Fix s2disk regression related to freezing workqueuesRafael J. Wysocki
Commit 2aede851ddf08666f68ffc17be446420e9d2a056 PM / Hibernate: Freeze kernel threads after preallocating memory introduced a mechanism by which kernel threads were frozen after the preallocation of hibernate image memory to avoid problems with frozen kernel threads not responding to memory freeing requests. However, it overlooked the s2disk code path in which the SNAPSHOT_CREATE_IMAGE ioctl was run directly after SNAPSHOT_FREE, which caused freeze_workqueues_begin() to BUG(), because it saw that worqueues had been already frozen. Although in principle this issue might be addressed by removing the relevant BUG_ON() from freeze_workqueues_begin(), that would reintroduce the very problem that commit 2aede851ddf08666f68ffc17be4 attempted to avoid into that particular code path. For this reason, to fix the issue at hand, introduce thaw_kernel_threads() and make the SNAPSHOT_FREE ioctl execute it. Special thanks to Srivatsa S. Bhat for detailed analysis of the problem. Reported-and-tested-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: stable@kernel.org
2012-01-19PM / Hibernate: Correct additional pages number calculationNamhyung Kim
The struct bm_block is allocated by chain_alloc(), so it'd better counting it in LINKED_PAGE_DATA_SIZE. Signed-off-by: Namhyung Kim <namhyung.kim@lge.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-01-14PM / Hibernate: Drop the check of swap space size for compressed imageBarry Song
For compressed image, the space required is not known until we finish compressing and writing all pages. This patch drops the check, and if swap space is not enough finally, system can still restore to normal after writing swap fails for compressed images. Signed-off-by: Barry Song <Baohua.Song@csr.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-01-10PM/Hibernate: do not count debug pages as savableStanislaw Gruszka
When debugging with CONFIG_DEBUG_PAGEALLOC and debug_guardpage_minorder > 0, we have lot of free pages that are not marked so. Snapshot code account them as savable, what cause hibernate memory preallocation failure. It is pretty hard to make hibernate allocation succeed with debug_guardpage_minorder=1. This change at least make it possible when system has relatively big amount of RAM. Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-08Merge branch 'pm-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm * 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (76 commits) PM / Hibernate: Implement compat_ioctl for /dev/snapshot PM / Freezer: fix return value of freezable_schedule_timeout_killable() PM / shmobile: Allow the A4R domain to be turned off at run time PM / input / touchscreen: Make st1232 use device PM QoS constraints PM / QoS: Introduce dev_pm_qos_add_ancestor_request() PM / shmobile: Remove the stay_on flag from SH7372's PM domains PM / shmobile: Don't include SH7372's INTCS in syscore suspend/resume PM / shmobile: Add support for the sh7372 A4S power domain / sleep mode PM: Drop generic_subsys_pm_ops PM / Sleep: Remove forward-only callbacks from AMBA bus type PM / Sleep: Remove forward-only callbacks from platform bus type PM: Run the driver callback directly if the subsystem one is not there PM / Sleep: Make pm_op() and pm_noirq_op() return callback pointers PM/Devfreq: Add Exynos4-bus device DVFS driver for Exynos4210/4212/4412. PM / Sleep: Merge internal functions in generic_ops.c PM / Sleep: Simplify generic system suspend callbacks PM / Hibernate: Remove deprecated hibernation snapshot ioctls PM / Sleep: Fix freezer failures due to racy usermodehelper_is_disabled() ARM: S3C64XX: Implement basic power domain support PM / shmobile: Use common always on power domain governor ... Fix up trivial conflict in fs/xfs/xfs_buf.c due to removal of unused XBT_FORCE_SLEEP bit
2012-01-05PM / Hibernate: Implement compat_ioctl for /dev/snapshotBen Hutchings
This allows uswsusp built for i386 to run on an x86_64 kernel (tested with Debian package version 1.0+20110509-2). References: http://bugs.debian.org/502816 Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-01-03fs: move code out of buffer.cAl Viro
Move invalidate_bdev, block_sync_page into fs/block_dev.c. Export kill_bdev as well, so brd doesn't have to open code it. Reduce buffer_head.h requirement accordingly. Removed a rather large comment from invalidate_bdev, as it looked a bit obsolete to bother moving. The small comment replacing it says enough. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-12-09PM / Hibernate: Remove deprecated hibernation snapshot ioctlsSrivatsa S. Bhat
Several snapshot ioctls were marked for removal quite some time ago, since they were deprecated. Remove them. Suggested-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-12-08PM / Sleep: Replace mutex_[un]lock(&pm_mutex) with [un]lock_system_sleep()Srivatsa S. Bhat
Using [un]lock_system_sleep() is safer than directly using mutex_[un]lock() on 'pm_mutex', since the latter could lead to freezing failures. Hence convert all the present users of mutex_[un]lock(&pm_mutex) to use these safe APIs instead. Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Reviewed-by: Simon Horman <horms@verge.net.au> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-12-06PM / Hibernate: Replace unintuitive 'if' condition in kernel/power/user.c ↵Srivatsa S. Bhat
with 'else' In the snapshot_ioctl() function, under SNAPSHOT_FREEZE, the code below freeze_processes() is a bit unintuitive. Improve it by replacing the second 'if' condition with an 'else' clause. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-12-06Merge branch 'pm-freezer' into pm-sleepRafael J. Wysocki
* pm-freezer: (26 commits) Freezer / sunrpc / NFS: don't allow TASK_KILLABLE sleeps to block the freezer Freezer: fix more fallout from the thaw_process rename freezer: fix wait_event_freezable/__thaw_task races freezer: kill unused set_freezable_with_signal() dmatest: don't use set_freezable_with_signal() usb_storage: don't use set_freezable_with_signal() freezer: remove unused @sig_only from freeze_task() freezer: use lock_task_sighand() in fake_signal_wake_up() freezer: restructure __refrigerator() freezer: fix set_freezable[_with_signal]() race freezer: remove should_send_signal() and update frozen() freezer: remove now unused TIF_FREEZE freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE cgroup_freezer: prepare for removal of TIF_FREEZE freezer: clean up freeze_processes() failure path freezer: kill PF_FREEZING freezer: test freezable conditions while holding freezer_lock freezer: make freezing indicate freeze condition in effect freezer: use dedicated lock instead of task_lock() + memory barrier freezer: don't distinguish nosig tasks on thaw ...
2011-12-06PM / Hibernate: Remove deprecated hibernation test modesSrivatsa S. Bhat
The hibernation test modes 'test' and 'testproc' are deprecated, because the 'pm_test' framework offers much more fine-grained control for debugging suspend and hibernation related problems. So, remove the deprecated 'test' and 'testproc' hibernation test modes. Suggested-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-12-06PM / Hibernate: Thaw processes in SNAPSHOT_CREATE_IMAGE ioctl test pathSrivatsa S. Bhat
Commit 2aede851ddf08666f68ffc17be446420e9d2a056 (PM / Hibernate: Freeze kernel threads after preallocating memory) moved the freezing of kernel threads to hibernation_snapshot() function. So now, if the call to hibernation_snapshot() returns early due to a successful hibernation test, the caller has to thaw processes to ensure that the system gets back to its original state. But in SNAPSHOT_CREATE_IMAGE hibernation ioctl, the caller does not thaw processes in case hibernation_snapshot() returned due to a successful freezer test. Fix this issue. But note we still send the value of 'in_suspend' (which is now 0) to userspace, because we are not in an error path per-se, and moreover, the value of in_suspend correctly depicts the situation here. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-12-06PM / Hibernate: Enable usermodehelpers in software_resume() error pathSrivatsa S. Bhat
In the software_resume() function defined in kernel/power/hibernate.c, if the call to create_basic_memory_bitmaps() fails, the usermodehelpers are not enabled (which had been disabled in the previous step). Fix it. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-11-23PM / Hibernate: Refactor and simplify hibernation_snapshot() codeSrivatsa S. Bhat
The goto statements in hibernation_snapshot() are a bit complex. Refactor the code to remove some of them, thereby simplifying the implementation. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-11-23PM: Fix indentation and remove extraneous whitespaces in kernel/power/main.cSrivatsa S. Bhat
Lack of proper indentation of the goto statement decreases the readability of code significantly. In fact, this made me look twice at the code to check whether it really does what it should be doing. Fix this. And in the same file, there are some extra whitespaces. Get rid of them too. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-11-23Merge branch 'pm-freezer' of ↵Rafael J. Wysocki
git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc into pm-freezer * 'pm-freezer' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc: (24 commits) freezer: fix wait_event_freezable/__thaw_task races freezer: kill unused set_freezable_with_signal() dmatest: don't use set_freezable_with_signal() usb_storage: don't use set_freezable_with_signal() freezer: remove unused @sig_only from freeze_task() freezer: use lock_task_sighand() in fake_signal_wake_up() freezer: restructure __refrigerator() freezer: fix set_freezable[_with_signal]() race freezer: remove should_send_signal() and update frozen() freezer: remove now unused TIF_FREEZE freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE cgroup_freezer: prepare for removal of TIF_FREEZE freezer: clean up freeze_processes() failure path freezer: kill PF_FREEZING freezer: test freezable conditions while holding freezer_lock freezer: make freezing indicate freeze condition in effect freezer: use dedicated lock instead of task_lock() + memory barrier freezer: don't distinguish nosig tasks on thaw freezer: remove racy clear_freeze_flag() and set PF_NOFREEZE on dead tasks freezer: rename thaw_process() to __thaw_task() and simplify the implementation ...
2011-11-23PM / Hibernate: Do not leak memory in error/test code pathsRafael J. Wysocki
The hibernation core code forgets to release memory preallocated for hibernation if there's an error in its early stages or if test modes causing hibernation_snapshot() to return early are used. This causes the system to be hardly usable, because the amount of preallocated memory is usually huge. Fix this problem. Reported-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
2011-11-21freezer: remove unused @sig_only from freeze_task()Tejun Heo
After "freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE", freezing() returns authoritative answer on whether the current task should freeze or not and freeze_task() doesn't need or use @sig_only. Remove it. While at it, rewrite function comment for freeze_task() and rename @sig_only to @user_only in try_to_freeze_tasks(). This patch doesn't cause any functional change. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Oleg Nesterov <oleg@redhat.com>
2011-11-21freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZETejun Heo
Using TIF_FREEZE for freezing worked when there was only single freezing condition (the PM one); however, now there is also the cgroup_freezer and single bit flag is getting clumsy. thaw_processes() is already testing whether cgroup freezing in in effect to avoid thawing tasks which were frozen by both PM and cgroup freezers. This is racy (nothing prevents race against cgroup freezing) and fragile. A much simpler way is to test actual freeze conditions from freezing() - ie. directly test whether PM or cgroup freezing is in effect. This patch adds variables to indicate whether and what type of freezing conditions are in effect and reimplements freezing() such that it directly tests whether any of the two freezing conditions is active and the task should freeze. On fast path, freezing() is still very cheap - it only tests system_freezing_cnt. This makes the clumsy dancing aroung TIF_FREEZE unnecessary and freeze/thaw operations more usual - updating state variables for the new state and nudging target tasks so that they notice the new state and comply. As long as the nudging happens after state update, it's race-free. * This allows use of freezing() in freeze_task(). Replace the open coded tests with freezing(). * p != current test is added to warning printing conditions in try_to_freeze_tasks() failure path. This is necessary as freezing() is now true for the task which initiated freezing too. -v2: Oleg pointed out that re-freezing FROZEN cgroup could increment system_freezing_cnt. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Paul Menage <paul@paulmenage.org> (for the cgroup portions)
2011-11-21cgroup_freezer: prepare for removal of TIF_FREEZETejun Heo
TIF_FREEZE will be removed soon and freezing() will directly test whether any freezing condition is in effect. Make the following changes in preparation. * Rename cgroup_freezing_or_frozen() to cgroup_freezing() and make it return bool. * Make cgroup_freezing() access task_freezer() under rcu read lock instead of task_lock(). This makes the state dereferencing racy against task moving to another cgroup; however, it was already racy without this change as ->state dereference wasn't synchronized. This will be later dealt with using attach hooks. * freezer->state is now set before trying to push tasks into the target state. -v2: Oleg pointed out that freeze_change_state() was setting freeze->state incorrectly to CGROUP_FROZEN instead of CGROUP_FREEZING. Fixed. -v3: Matt pointed out that setting CGROUP_FROZEN used to always invoke try_to_freeze_cgroup() regardless of the current state. Patch updated such that the actual freeze/thaw operations are always performed on invocation. This shouldn't make any difference unless something is broken. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Paul Menage <paul@paulmenage.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com>
2011-11-21freezer: clean up freeze_processes() failure pathTejun Heo
freeze_processes() failure path is rather messy. Freezing is canceled for workqueues and tasks which aren't frozen yet but frozen tasks are left alone and should be thawed by the caller and of course some callers (xen and kexec) didn't do it. This patch updates __thaw_task() to handle cancelation correctly and makes freeze_processes() and freeze_kernel_threads() call thaw_processes() on failure instead so that the system is fully thawed on failure. Unnecessary [suspend_]thaw_processes() calls are removed from kernel/power/hibernate.c, suspend.c and user.c. While at it, restructure error checking if clause in suspend_prepare() to be less weird. -v2: Srivatsa spotted missing removal of suspend_thaw_processes() in suspend_prepare() and error in commit message. Updated. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
2011-11-21freezer: test freezable conditions while holding freezer_lockTejun Heo
try_to_freeze_tasks() and thaw_processes() use freezable() and frozen() as preliminary tests before initiating operations on a task. These are done without any synchronization and hinder with synchronization cleanup without any real performance benefits. In try_to_freeze_tasks(), open code self test and move PF_NOFREEZE and frozen() tests inside freezer_lock in freeze_task(). thaw_processes() can simply drop freezable() test as frozen() test in __thaw_task() is enough. Note: This used to be a part of larger patch to fix set_freezable() race. Separated out to satisfy ordering among dependent fixes. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com>
2011-11-21freezer: make freezing indicate freeze condition in effectTejun Heo
Currently freezing (TIF_FREEZE) and frozen (PF_FROZEN) states are interlocked - freezing is set to request freeze and when the task actually freezes, it clears freezing and sets frozen. This interlocking makes things more complex than necessary - freezing doesn't mean there's freezing condition in effect and frozen doesn't match the task actually entering and leaving frozen state (it's cleared by the thawing task). This patch makes freezing indicate that freeze condition is in effect. A task enters and stays frozen if freezing. This makes PF_FROZEN manipulation done only by the task itself and prevents wakeup from __thaw_task() leaking outside of refrigerator. The only place which needs to tell freezing && !frozen is try_to_freeze_task() to whine about tasks which don't enter frozen. It's updated to test the condition explicitly. With the change, frozen() state my linger after __thaw_task() until the task wakes up and exits fridge. This can trigger BUG_ON() in update_if_frozen(). Work it around by testing freezing() && frozen() instead of frozen(). -v2: Oleg pointed out missing re-check of freezing() when trying to clear FROZEN and possible spurious BUG_ON() trigger in update_if_frozen(). Both fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul Menage <paul@paulmenage.org>
2011-11-21freezer: use dedicated lock instead of task_lock() + memory barrierTejun Heo
Freezer synchronization is needlessly complicated - it's by no means a hot path and the priority is staying unintrusive and safe. This patch makes it simply use a dedicated lock instead of piggy-backing on task_lock() and playing with memory barriers. On the failure path of try_to_freeze_tasks(), locking is moved from it to cancel_freezing(). This makes the frozen() test racy but the race here is a non-issue as the warning is printed for tasks which failed to enter frozen for 20 seconds and race on PF_FROZEN at the last moment doesn't change anything. This simplifies freezer implementation and eases further changes including some race fixes. Signed-off-by: Tejun Heo <tj@kernel.org>