John Stultz
da8b44d5a9
timer: convert timer_slack_ns from unsigned long to u64 ...
This patchset introduces a /proc/<pid>/timerslack_ns interface which
would allow controlling processes to be able to set the timerslack value
on other processes in order to save power by avoiding wakeups (Something
Android currently does via out-of-tree patches).
The first patch tries to fix the internal timer_slack_ns usage which was
defined as a long, which limits the slack range to ~4 seconds on 32bit
systems. It converts it to a u64, which provides the same basically
unlimited slack (500 years) on both 32bit and 64bit machines.
The second patch introduces the /proc/<pid>/timerslack_ns interface
which allows the full 64bit slack range for a task to be read or set on
both 32bit and 64bit machines.
With these two patches, on a 32bit machine, after setting the slack on
bash to 10 seconds:
$ time sleep 1
real 0m10.747s
user 0m0.001s
sys 0m0.005s
The first patch is a little ugly, since I had to chase the slack delta
arguments through a number of functions converting them to u64s. Let me
know if it makes sense to break that up more or not.
Other than that things are fairly straightforward.
This patch (of 2):
The timer_slack_ns value in the task struct is currently a unsigned
long. This means that on 32bit applications, the maximum slack is just
over 4 seconds. However, on 64bit machines, its much much larger (~500
years).
This disparity could make application development a little (as well as
the default_slack) to a u64. This means both 32bit and 64bit systems
have the same effective internal slack range.
Now the existing ABI via PR_GET_TIMERSLACK and PR_SET_TIMERSLACK specify
the interface as a unsigned long, so we preserve that limitation on
32bit systems, where SET_TIMERSLACK can only set the slack to a unsigned
long value, and GET_TIMERSLACK will return ULONG_MAX if the slack is
actually larger then what can be stored by an unsigned long.
This patch also modifies hrtimer functions which specified the slack
delta as a unsigned long.
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Oren Laadan <orenl@cellrox.com>
Cc: Ruchi Kandoi <kandoiruchi@google.com>
Cc: Rom Lemarchand <romlem@android.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-17 15:09:34 -07:00
ceph: initial CEPH_FEATURE_FS_FILE_LAYOUT_V2 support
2016-03-04 21:00:37 +01:00
ARM: SoC multiplatform code changes for v4.5
2016-01-20 18:03:56 -08:00
crush: add chooseleaf_stable tunable
2016-02-04 18:25:55 +01:00
gpio: generic: make bgpio_pdata always visible
2016-01-13 16:00:32 +01:00
MIPS: Make smp CMP, CPS and MT use the new generic IPI functions
2016-02-25 10:56:58 +01:00
rtc: max77686: move initialisation of rtc regmap, irq chip locally
2016-03-14 17:08:13 +01:00
net/mlx4_core: Set UAR page size to 4KB regardless of system page size
2016-02-17 10:29:27 -05:00
net/mlx5e: Fix ethtool RX hash func configuration change
2016-03-02 14:37:25 -05:00
hwmon: (ntc_thermistor) Add support for ncpXXxh103
2016-03-05 06:25:34 -08:00
power: bq27xxx_battery: Restore device name
2016-02-21 20:49:34 +01:00
raid6/algos.c : bug fix : Add the missing definitions to the pq.h file
2016-01-21 14:47:08 -08:00
Merge remote-tracking branches 'regulator/topic/discharge', 'regulator/topic/fan53555', 'regulator/topic/gpio', 'regulator/topic/hi655x' and 'regulator/topic/lp872x' into regulator-next
2016-03-13 15:19:35 +07:00
mm: move max_map_count bits into mm.h
2016-03-17 15:09:34 -07:00
soc: ti: knav_dma: rename pad in struct knav_dma_desc to sw_data
2016-02-21 22:03:15 -05:00
Merge remote-tracking branches 'spi/topic/res', 'spi/topic/rockchip', 'spi/topic/sh', 'spi/topic/ti-qspi' and 'spi/topic/xilinx' into spi-next
2016-03-11 14:28:53 +07:00
Initial roundup of 4.5 merge window patches
2016-01-23 18:45:06 -08:00
USB patches for 4.5-rc1
2016-01-13 09:26:40 -08:00
Merge branches 'acpi-pci', 'acpi-irq' and 'acpi-assorted'
2016-01-12 01:10:19 +01:00
libata: fix HDIO_GET_32BIT ioctl
2016-02-11 10:07:18 -05:00
mmc: atmel: get rid of struct mci_dma_data
2016-01-14 13:40:30 +01:00
atomic: Export fetch_or()
2016-02-13 15:34:28 +01:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
2016-01-17 19:13:15 -08:00
autofs4: fix string.h include in auto_dev-ioctl.h
2016-03-15 16:55:16 -07:00
autofs4: coding style fixes
2016-03-15 16:55:16 -07:00
block, badblocks: introduce devm_init_badblocks
2016-01-09 08:39:04 -08:00
MIPS: bcm963xx: Add Broadcom BCM963xx board nvram data structure
2016-01-24 03:47:37 +01:00
MIPS: bcm963xx: Update bcm_tag field image_sequence
2016-01-24 03:49:03 +01:00
block: don't optimize for non-cloned bio in bio_get_last_bvec()
2016-03-12 14:12:10 -07:00
block: fix blk_rq_get_max_sectors for driver private requests
2016-03-03 14:43:45 -07:00
bufferhead: force inlining of buffer head flag operations
2016-03-17 15:09:34 -07:00
arch: Introduce post-init read-only memory
2016-02-22 08:51:38 +01:00
cgroup: make sure a parent css isn't offlined before its children
2016-01-22 10:42:57 -05:00
Merge branch 'for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
2016-01-12 19:20:32 -08:00
include/linux/cleancache.h: Clean up code
2016-01-27 09:10:29 -05:00
clockevents: Rename last parameter of clocks_calc_mult_shift() to maxsec
2016-01-27 12:38:03 +01:00
clocksource: Introduce clocksource_freq2mult()
2016-02-27 08:55:30 +01:00
mm, compaction: introduce kcompactd
2016-03-17 15:09:34 -07:00
Merge commit 'fixes.2015.02.23a' into core/rcu
2016-03-15 09:01:06 +01:00
Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
2016-01-20 17:20:53 -08:00
printk: do cond_resched() between lines while outputting to consoles
2016-01-16 11:17:25 -08:00
rcu: Make CPU_DYING_IDLE an explicit call
2016-03-01 20:36:58 +01:00
Merge branch 'pm-cpufreq-governor' into pm-cpufreq
2016-03-10 20:46:03 +01:00
cpu/hotplug: Make wait for dead cpu completion based
2016-03-01 20:36:58 +01:00
kernel/cpu.c: make set_cpu_* static inlines
2016-01-20 17:09:18 -08:00
cpuset: make mm migration asynchronous
2016-01-22 10:22:46 -05:00
dax: move writeback calls into the filesystems
2016-02-27 10:28:52 -08:00
use ->d_seq to get coherency between ->d_inode and ->d_flags
2016-02-29 12:16:43 -05:00
PM / devfreq: Set the freq_table of devfreq device
2016-01-13 17:30:32 +09:00
dm snapshot: disallow the COW and origin devices from being identical
2016-03-10 17:12:09 -05:00
device core: add device_is_bound()
2016-01-08 01:12:06 +01:00
pty: make sure super_block is still valid in final /dev/tty close
2016-02-06 23:45:46 -08:00
dma-mapping: always provide the dma_map_ops based implementation
2016-01-20 17:09:18 -08:00
Merge branch 'mm-pat-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2016-03-14 16:31:41 -07:00
firmware: dmi_scan: Save SMBIOS Type 9 System Slots
2016-01-15 22:08:45 +01:00
efi: Make efivarfs entries immutable by default
2016-02-10 16:25:52 +00:00
err.h: add (missing) unlikely() to IS_ERR_OR_NULL()
2016-01-16 11:17:24 -08:00
mm: fault-inject take over bootstrap kmem_cache check
2016-03-15 16:55:16 -07:00
fbdev: kill fb_rotate
2016-02-26 13:28:35 +02:00
bpf: cleanup bpf_prog_run_{save,clear}_cb helpers
2016-01-08 21:40:34 -05:00
timer: convert timer_slack_ns from unsigned long to u64
2016-03-17 15:09:34 -07:00
block: revert runtime dax control of the raw block device
2016-01-30 13:35:31 -08:00
Revert "fsnotify: destroy marks with call_srcu instead of dedicated thread"
2016-02-18 16:23:24 -08:00
sched/debug: Fix preempt_disable_ip recording for preempt_disable()
2016-02-29 09:53:10 +01:00
block: kill disk_{check|set|clear|alloc}_badblocks
2016-01-09 22:42:31 -08:00
mm: exclude ZONE_DEVICE from GFP_ZONE_TABLE
2016-03-17 15:09:34 -07:00
timer: convert timer_slack_ns from unsigned long to u64
2016-03-17 15:09:34 -07:00
thp: rewrite freeze_page()/unfreeze_page() with generic rmap walkers
2016-03-17 15:09:34 -07:00
hugetlb: fix compile error on tile
2016-01-15 17:56:32 -08:00
i2c: create builtin_i2c_driver to avoid registration boilerplate
2016-01-13 11:06:03 +01:00
asm-generic: Consolidate mark_rodata_ro()
2016-02-22 08:51:37 +01:00
iommu/vt-d: Clear PPR bit to ensure we get more page request interrupts
2016-02-15 12:42:38 +00:00
x86/ACPI/PCI: Recognize that Interrupt Line 255 means "not connected"
2016-03-09 01:23:35 +01:00
lib/iomap_copy.c: add __ioread32_copy()
2016-01-20 17:09:18 -08:00
iommu: Update struct iommu_ops comments
2016-01-29 12:34:29 +01:00
libnvdimm for 4.6
2016-03-16 17:45:56 -07:00
Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2016-03-15 12:48:48 -07:00
genirq: Add a new generic IPI reservation code to irq core
2016-02-25 10:56:56 +01:00
iscsi_ibft: Add prefix-len attr and display netmask
2016-03-14 10:30:57 -04:00
kasan: add functions to clear stack poison
2016-03-09 15:43:42 -08:00
include/linux/kdev_t.h: remove new_valid_dev()
2016-01-16 11:17:23 -08:00
include/linux/kernel.h: change abs() macro so it uses consistent return type
2016-01-16 11:17:22 -08:00
kexec: move some memembers and definitions within the scope of CONFIG_KEXEC_FILE
2016-01-20 17:09:18 -08:00
KVM: Use simple waitqueue for vcpu->wq
2016-02-25 11:27:16 +01:00
kvm: rename pfn_t to kvm_pfn_t
2016-01-15 17:56:32 -08:00
sched/debug: Make schedstats a runtime tunable that is disabled by default
2016-02-09 11:54:23 +01:00
leds: core: avoid error message when a USB LED device is unplugged
2016-03-14 09:22:20 +01:00
libata: Align ata_device's id on a cacheline
2016-02-25 16:37:06 -05:00
nfit: disable userspace initiated ars during scrub
2016-03-05 12:24:06 -08:00
lightnvm: allow to force mm initialization
2016-02-04 09:19:45 -07:00
list: kill list_force_poison()
2016-03-09 15:43:42 -08:00
mm: memcontrol: move kmem accounting code to CONFIG_MEMCG
2016-01-20 17:09:18 -08:00
kernel/locking/lockdep.c: convert hash tables to hlists
2016-02-11 18:35:48 -08:00
lz4: fix wrong compress buffer size for 64-bits
2016-01-20 17:09:18 -08:00
memblock: fix section mismatch
2016-01-15 17:56:32 -08:00
mm: workingset: make shadow node shrinker memcg aware
2016-03-17 15:09:34 -07:00
memory-hotplug: add automatic onlining policy for the newly added memory
2016-03-15 16:55:16 -07:00
mm/compaction: speed up pageblock_pfn_to_page() when zone is contiguous
2016-03-15 16:55:16 -07:00
mm/mempolicy.c: convert the shared_policy lock to a rwlock
2016-01-14 16:00:49 -08:00
mm, dax, pmem: introduce {get|put}_dev_pagemap() for dax-gup
2016-01-15 17:56:32 -08:00
mm, page_owner: track and print last migrate reason
2016-03-15 16:55:16 -07:00
mm: remove VM_FAULT_MINOR
2016-03-17 15:09:34 -07:00
mm: move lru_to_page to mm_inline.h
2016-01-14 16:00:49 -08:00
Merge branch 'x86/urgent' into x86/asm, to pick up fixes
2016-02-18 09:28:03 +01:00
mm, debug: move bad flags printing to bad_page()
2016-03-15 16:55:16 -07:00
mm: scale kswapd watermarks in proportion to memory
2016-03-17 15:09:34 -07:00
modules: fix longstanding /proc/kallsyms vs module insertion race.
2016-02-03 16:58:15 +10:30
PCI changes for the v4.5 merge window:
2016-01-21 11:52:16 -08:00
nfsd: don't hold i_mutex over userspace upcalls
2016-01-09 03:07:52 -05:00
libnvdimm: async notification support
2016-03-05 12:24:06 -08:00
net: make netdev_for_each_lower_dev safe for device removal
2016-02-19 15:29:26 -05:00
NFS client updates for Linux 4.5
2016-01-14 16:08:23 -08:00
nfs: fix nfs_size_to_loff_t
2016-02-08 15:20:01 -05:00
pnfs/blocklayout: fix a memeory leak when using,vmalloc_to_page
2016-02-17 11:44:45 -05:00
rcu: Make CPU_DYING_IDLE an explicit call
2016-03-01 20:36:58 +01:00
of: drop symbols declared by _OF_DECLARE() from modules
2016-01-25 08:35:50 -06:00
PCI: host: Add of_pci_get_host_bridge_resources() stub
2016-01-15 12:30:35 -06:00
mm: exclude ZONE_DEVICE from GFP_ZONE_TABLE
2016-03-17 15:09:34 -07:00
include/linux/page-flags.h: force inlining of selected page flag modifications
2016-03-17 15:09:34 -07:00
mm, page_owner: track and print last migrate reason
2016-03-15 16:55:16 -07:00
mm, page_owner: dump page owner info from dump_page()
2016-03-15 16:55:16 -07:00
mm/page_ref: add tracepoint to track down page reference manipulation
2016-03-17 15:09:34 -07:00
mm: introduce page reference manipulation functions
2016-03-17 15:09:34 -07:00
PCI: Consolidate PCI DMA constants and interfaces in linux/pci-dma-compat.h
2016-03-07 11:39:16 -06:00
PCI changes for the v4.6 merge window:
2016-03-16 14:45:55 -07:00
PCI: Add PCI_CLASS_SERIAL_USB_DEVICE definition
2016-03-15 08:52:28 -05:00
Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2016-03-14 19:44:38 -07:00
mm: fix pfn_t vs highmem
2016-02-11 18:35:48 -08:00
mm: fix pfn_t vs highmem
2016-02-11 18:35:48 -08:00
pipe: limit the per-user amount of pages allocated in pipes
2016-01-19 19:25:21 -05:00
Power management and ACPI updates for v4.5-rc1
2016-01-12 20:25:09 -08:00
PM / sleep: Go direct_complete if driver has no callbacks
2016-01-08 01:12:06 +01:00
PM / Domains: remove old power on/off latencies
2016-02-15 23:18:15 +01:00
PM / OPP: Add dev_pm_opp_set_rate()
2016-02-10 01:11:54 +01:00
libnvdimm, pmem: clear poison on write
2016-03-09 15:15:32 -08:00
mm/page_poisoning.c: allow for zero poisoning
2016-03-15 16:55:16 -07:00
timer: convert timer_slack_ns from unsigned long to u64
2016-03-17 15:09:34 -07:00
posix-cpu-timers: Migrate to use new tick dependency mask model
2016-03-02 16:44:27 +01:00
time: Remove duplicated code in ktime_get_raw_and_real()
2016-03-02 17:13:02 -08:00
printk: help pr_debug and pr_devel to optimize out arguments
2016-01-16 11:17:29 -08:00
ptp: Add PTP_SYS_OFFSET_PRECISE for driver crosstimestamping
2016-03-03 14:23:43 -08:00
ptrace: use fsuid, fsgid, effective creds for fs access checks
2016-01-20 17:09:18 -08:00
spi: pxa2xx: Add support for both chip selects on Intel Braswell
2016-02-09 19:01:11 +00:00
radix-tree: fix oops after radix_tree_iter_retry
2016-02-05 18:10:40 -08:00
drivers: char: random: add get_random_long()
2016-02-27 10:28:52 -08:00
rbtree: use READ_ONCE in RB_EMPTY_ROOT
2016-01-20 17:09:18 -08:00
Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2016-03-15 13:50:29 -07:00
Merge remote-tracking branch 'regmap/topic/update-bits' into regmap-next
2016-03-05 21:30:41 +09:00
mm: make remove_migration_ptes() beyond mm/migration.c
2016-03-17 15:09:34 -07:00
rtc: Add functions to set and read rtc offset
2016-03-14 17:08:15 +01:00
net, sched: add clsact qdisc
2016-01-10 22:13:15 -05:00
timer: convert timer_slack_ns from unsigned long to u64
2016-03-17 15:09:34 -07:00
ipc/shm.c: is_file_shm_hugepages() can be boolean
2016-01-20 17:09:18 -08:00
make sure that freeing shmem fast symlinks is RCU-delayed
2016-01-22 18:08:52 -05:00
mld, igmp: Fix reserved tailroom calculation
2016-03-03 15:41:07 -05:00
slub: convert SLAB_DEBUG_FREE to SLAB_CONSISTENCY_CHECKS
2016-03-15 16:55:16 -07:00
mm/slab: alternative implementation for DEBUG_SLAB_LEAK
2016-03-15 16:55:16 -07:00
mm/slub: support left redzone
2016-03-15 16:55:16 -07:00
rcu: Document unique-name limitation for DEFINE_STATIC_SRCU()
2016-02-23 19:59:55 -08:00
stmmac: Fix 'eth0: No PHY found' regression
2016-03-03 15:02:05 -05:00
wait.[ch]: Introduce the simple waitqueue (swait) implementation
2016-02-25 11:27:16 +01:00
mm: free swap cache aggressively if memcg swap is full
2016-01-20 17:09:18 -08:00
swiotlb: Make linux/swiotlb.h standalone includible
2016-01-20 17:29:52 -05:00
kmemcg: account certain kmem allocations to memcg
2016-01-14 16:00:49 -08:00
posix-cpu-timers: Migrate to use new tick dependency mask model
2016-03-02 16:44:27 +01:00
time: Add history to cross timestamp interface supporting slower devices
2016-03-02 17:13:17 -08:00
time: Add history to cross timestamp interface supporting slower devices
2016-03-02 17:13:17 -08:00
numa: remove stale node_has_online_mem() define
2016-01-18 14:49:33 -05:00
tracepoints: move trace_print_flags definitions to tracepoint-defs.h
2016-03-15 16:55:16 -07:00
tracepoints: move trace_print_flags definitions to tracepoint-defs.h
2016-03-15 16:55:16 -07:00
tracing: Fix check for cpu online when event is disabled
2016-03-09 11:58:41 -05:00
tty: Wait interruptibly for tty lock on reopen
2016-01-26 23:17:54 -08:00
lib/ucs2_string: Add ucs2 -> utf8 helper functions
2016-02-10 13:19:03 +00:00
virtio: make find_vqs() checkpatch.pl-friendly
2016-01-12 20:47:06 +02:00
virtio_ring: use virt_store_mb
2016-01-12 20:47:02 +02:00
thp, vmstats: count deferred split events
2016-03-17 15:09:34 -07:00
mm, vmalloc: remove VM_VPAGES
2016-01-14 16:00:49 -08:00
mm: memcontrol: hook up vmpressure to socket pressure
2016-01-14 16:00:49 -08:00
vmstat: make vmstat_updater deferrable again and shut down on idle
2016-01-14 16:00:49 -08:00
sched/wait: Fix wait_event_freezable() documentation
2016-02-24 09:09:45 +01:00
watchdog: Drop pointer to watchdog device from struct watchdog_device
2016-01-11 21:53:59 +01:00
workqueue: skip flush dependency checks for legacy workqueues
2016-01-29 13:31:10 -05:00
writeback: flush inode cgroup wb switches instead of pinning super_block
2016-03-03 14:42:50 -07:00
