Wanpeng Li
2a42eb9594
sched/cputime: Accumulate vtime on top of nsec clocksource ...
Currently the cputime source used by vtime is jiffies. When we cross
a context boundary and jiffies have changed since the last snapshot, the
pending cputime is accounted to the switching out context.
This system works ok if the ticks are not aligned across CPUs. If they
instead are aligned (ie: all fire at the same time) and the CPUs run in
userspace, the jiffies change is only observed on tick exit and therefore
the user cputime is accounted as system cputime. This is because the
CPU that maintains timekeeping fires its tick at the same time as the
others. It updates jiffies in the middle of the tick and the other CPUs
see that update on IRQ exit:
CPU 0 (timekeeper) CPU 1
------------------- -------------
jiffies = N
... run in userspace for a jiffy
tick entry tick entry (sees jiffies = N)
set jiffies = N + 1
tick exit tick exit (sees jiffies = N + 1)
account 1 jiffy as stime
Fix this with using a nanosec clock source instead of jiffies. The
cputime is then accumulated and flushed everytime the pending delta
reaches a jiffy in order to mitigate the accounting overhead.
[ fweisbec: changelog, rebase on struct vtime, field renames, add delta
on cputime readers, keep idle vtime as-is (low overhead accounting),
harmonize clock sources. ]
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Luiz Capitulino <lcapitulino@redhat.com>
Tested-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wanpeng Li <kernellwp@gmail.com>
Link: http://lkml.kernel.org/r/1498756511-11714-6-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-05 09:54:15 +02:00
Merge branch 'topic/pl330' into for-linus
2017-05-04 16:08:52 +05:30
scripts/spelling.txt: add regsiter -> register spelling mistake
2017-05-08 17:15:13 -07:00
can: complete initial namespace support
2017-04-25 09:04:29 +02:00
libceph: use kbasename() and kill ceph_file_part()
2017-05-23 20:32:10 +02:00
firmware /meson
gpiolib: Add stubs for gpiod lookup table interface
2017-05-22 10:39:11 +02:00
Merge branch 'for-4.12/asus' into for-linus
2017-05-02 11:02:41 +02:00
KVM: arm/arm64: Fix isues with GICv2 on GICv3 migration
2017-05-24 09:44:07 +02:00
lockd: Introduce nlmclnt_operations
2017-04-21 10:45:01 -04:00
pci-v4.12-changes
2017-05-08 19:03:25 -07:00
net/mlx4: Fix the check in attaching steering rules
2017-06-04 23:10:05 -04:00
net/mlx5: Define interface bits for fencing UMR wqe
2017-06-01 17:05:04 -04:00
mmc: core: Export API to allow hosts to get the card address
2017-04-24 21:49:15 +02:00
MTD updates for 4.12-rc1:
2017-05-11 10:44:22 -07:00
netfilter: xtables: zero padding in data_to_user
2017-05-15 12:51:38 +02:00
ebtables: arpreply: Add the standard target sanity check
2017-05-16 10:24:27 +02:00
Revert "pinctrl: generic: Add bi-directional and output-enable"
2017-05-22 10:39:10 +02:00
fbdev changes for v4.12:
2017-05-11 11:12:26 -07:00
power: supply: max17042_battery: Add support for the STATUS property
2017-05-01 12:37:29 +02:00
qed*: Fix possible overflow for status block id field.
2017-05-04 12:31:02 -04:00
Merge remote-tracking branches 'regulator/topic/notifier', 'regulator/topic/pfuze100', 'regulator/topic/settle', 'regulator/topic/tps65132' and 'regulator/topic/twl6030' into regulator-next
2017-04-30 22:17:36 +09:00
sched/loadavg: Generalize "_idle" naming to "_nohz"
2017-06-22 11:30:01 +02:00
Renesas ARM Based SoC Fixes for v4.12
2017-05-10 15:33:45 +02:00
Merge remote-tracking branches 'spi/topic/ti-qspi' and 'spi/topic/xlp' into spi-next
2017-04-26 15:58:22 +01:00
sched/wait: Split out the wait_bit*() APIs from <linux/wait.h> into <linux/wait_bit.h>
2017-06-20 12:19:09 +02:00
cdc-ether: divorce initialisation with a filter reset and a generic method
2017-05-23 11:01:28 -04:00
acpi: always include uuid.h
2017-06-08 09:03:33 +02:00
IOMMU Updates for Linux v4.12
2017-05-09 15:15:47 -07:00
libata: remove SCT WRITE SAME support
2017-04-28 18:09:59 -04:00
audit: Use timespec64 to represent audit timestamps
2017-05-02 10:16:05 -04:00
bdi: Drop 'parent' argument from bdi_register[_va]()
2017-04-20 12:09:55 -06:00
bcm47xx: Fix build regression
2017-06-08 18:52:36 -07:00
Merge branch 'for-4.13/block' of git://git.kernel.dk/linux-block
2017-07-03 10:34:51 -07:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2017-07-03 13:08:04 -07:00
block: add support for write hints in a bio
2017-06-27 12:05:27 -06:00
block: remove the queue_bounce_pfn helper
2017-06-27 12:13:45 -06:00
bpf: Add strict alignment flag for BPF_PROG_LOAD.
2017-05-11 14:19:00 -04:00
fs: remove _submit_bh()
2017-04-26 23:54:06 -04:00
cgroup: Prevent kill_css() from being called more than once
2017-05-17 16:58:32 -04:00
cpuset: consider dying css as offline
2017-05-24 12:43:30 -04:00
fs: switch ->s_uuid to uuid_t
2017-06-05 16:59:12 +02:00
Revert "clockevents: Add a clkevt-of mechanism like clksrc-of"
2017-06-12 10:54:47 +02:00
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2017-07-03 16:14:51 -07:00
itimers: Move compat itimer syscalls to native ones
2017-06-14 00:00:44 +02:00
compiler, clang: properly override 'inline' for clang
2017-06-11 15:51:56 -07:00
rcu: Remove SPARSE_RCU_POINTER Kconfig option
2017-06-08 18:52:41 -07:00
configfs: Introduce config_item_get_unless_zero()
2017-06-12 13:20:20 +02:00
cpu/hotplug: Convert hotplug locking to percpu rwsem
2017-05-26 10:10:46 +02:00
Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2017-07-03 18:08:06 -07:00
smp, cpumask: Use non-atomic cpumask_{set,clear}_cpu()
2017-05-23 10:01:32 +02:00
ia64: reuse append_elf_note() and final_note() functions
2017-05-08 17:15:11 -07:00
dax, xfs, ext4: compile out iomap-dax paths in the FS_DAX=n case
2017-05-13 17:52:16 -07:00
thermal: devfreq_cooling: add new interface for direct power read
2017-05-05 15:54:45 +08:00
block: switch bios to blk_status_t
2017-06-09 09:27:32 -06:00
iommu/dma: Fix function declaration
2017-05-30 11:25:45 +02:00
x86, iommu/vt-d: Add an option to disable Intel IOMMU force on
2017-04-26 23:57:53 +02:00
firmware: dmi_scan: Make dmi_walk and dmi_walk_early return real error codes
2017-06-15 13:46:00 +02:00
efi/capsule-loader: Use page addresses rather than struct page pointers
2017-06-05 17:50:41 +02:00
blk-mq-sched: unify request prepare methods
2017-06-18 10:08:55 -06:00
ia64: reuse append_elf_note() and final_note() functions
2017-05-08 17:15:11 -07:00
sched/wait: Rename wait_queue_t => wait_queue_entry_t
2017-06-20 12:18:27 +02:00
f2fs: introduce CP_TRIMMED_FLAG to avoid unneeded discard
2017-05-03 10:04:56 -07:00
fs: add a VALID_OPEN_FLAGS
2017-04-27 05:13:04 -04:00
bpf: add various verifier test cases
2017-05-25 13:44:28 -04:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2017-07-03 13:08:04 -07:00
fscrypt: remove fscrypt_symlink_data_len()
2017-04-30 01:26:34 -04:00
fscrypt: introduce helper function for filename matching
2017-05-04 11:44:37 -04:00
fscrypt: correct collision claim for digested names
2017-05-04 11:44:41 -04:00
scripts/spelling.txt: add regsiter -> register spelling mistake
2017-05-08 17:15:13 -07:00
block: remove blk_part_pack_uuid
2017-06-05 16:59:10 +02:00
include/linux/gfp.h: fix ___GFP_NOLOCKDEP value
2017-06-02 15:07:37 -07:00
hashtable: remove repeated phrase from a comment
2017-06-30 13:49:53 -07:00
Merge branches 'for-4.11/upstream-fixes', 'for-4.12/accutouch', 'for-4.12/cp2112', 'for-4.12/hid-core-null-state-handling', 'for-4.12/hiddev', 'for-4.12/i2c-hid', 'for-4.12/innomedia', 'for-4.12/logitech-hidpp-battery-power-supply', 'for-4.12/multitouch', 'for-4.12/nti', 'for-4.12/upstream' and 'for-4.12/wacom' into for-linus
2017-05-02 11:01:10 +02:00
posix-timers: Make nanosleep timespec argument const
2017-06-14 00:00:47 +02:00
char/misc patches for 4.12-rc1
2017-05-04 19:15:35 -07:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
2017-05-03 12:38:20 -07:00
block: introduce new block status code type
2017-06-09 09:27:32 -06:00
mac80211: Add support for BSS max idle period element
2017-04-28 12:28:45 +02:00
bridge: add per-port broadcast flood flag
2017-04-27 16:34:29 -04:00
vlan: Fix tcp checksum offloads in Q-in-Q vlans
2017-05-24 16:27:14 -04:00
sched/cputime: Move the vtime task fields to their own struct
2017-07-05 09:54:15 +02:00
genirq/timings: Add infrastructure for estimating the next interrupt arrival time
2017-06-24 11:44:39 +02:00
fs: Introduce IOMAP_NOWAIT
2017-06-20 07:12:03 -06:00
Merge branches 'arm/exynos', 'arm/omap', 'arm/rockchip', 'arm/mediatek', 'arm/smmu', 'arm/core', 'x86/vt-d', 'x86/amd' and 'core' into next
2017-05-04 18:06:17 +02:00
sysv,ipc: cacheline align kern_ipc_perm
2017-05-08 17:15:12 -07:00
genirq: Introduce IRQD_SINGLE_TARGET flag
2017-06-22 18:21:25 +02:00
genirq/debugfs: Add proper debugfs interface
2017-06-22 18:21:13 +02:00
genirq/irqdomain: Remove auto-recursive hierarchy support
2017-06-22 18:29:34 +02:00
jbd2: mark the transaction context with the scope GFP_NOFS context
2017-05-03 15:52:09 -07:00
frv: declare jiffies to be located in the .data section
2017-06-02 15:07:37 -07:00
kbuild: fix asm-offset generation to work with clang
2017-04-23 15:51:26 +09:00
init: Introduce SYSTEM_SCHEDULING state
2017-05-23 10:01:38 +02:00
crash: move crashkernel parsing and vmcore related code under CONFIG_CRASH_CORE
2017-05-08 17:15:11 -07:00
KEYS: sanitize key structs before freeing
2017-06-09 13:29:48 +10:00
tracing/kprobes: Enforce kprobes teardown after testing
2017-05-17 21:50:27 -04:00
kref: remove WARN_ON for NULL release functions
2017-05-08 17:15:14 -07:00
mm: make rmap_walk() return void
2017-05-03 15:52:10 -07:00
Revert "ktime: Simplify ktime_compare implementation"
2017-06-26 10:39:40 +02:00
Second round of KVM Changes for v4.12:
2017-05-10 11:29:23 -07:00
sched/wait: Rename wait_queue_t => wait_queue_entry_t
2017-06-20 12:18:27 +02:00
libnvdimm: convert NDD_ flags to use bitops, introduce NDD_LOCKED
2017-05-04 14:01:24 -07:00
llist: Provide a safe version for llist_for_each()
2017-05-23 10:01:33 +02:00
mm: consider memblock reservations for deferred memory initialization sizing
2017-06-02 15:07:38 -07:00
mm: memcontrol: use node page state naming scheme for memcg
2017-05-03 15:52:11 -07:00
include/linux/migrate.h: add arg names to prototype
2017-05-03 15:52:10 -07:00
mm: larger stack guard gap, between vmas
2017-06-19 21:50:20 +08:00
mm, x86/mm: Make the batched unmap TLB flush API more generic
2017-05-24 10:18:27 +02:00
mm: consider memblock reservations for deferred memory initialization sizing
2017-06-02 15:07:38 -07:00
firmware: dmi: Add DMI_PRODUCT_FAMILY identification string
2017-05-23 10:04:41 +02:00
Modules updates for v4.12
2017-05-03 19:12:27 -07:00
moduleparam: fix doc: hwparam_irq configures an IRQ
2017-07-02 15:37:23 -07:00
flow_dissector: add mpls support (v2)
2017-04-24 14:30:46 -04:00
make sure that mntns_install() doesn't end up with referral for root
2017-04-21 14:05:36 -04:00
libnvdimm: add an atomic vs process context flag to rw_bytes
2017-05-10 21:46:22 -07:00
net: update undefined ->ndo_change_mtu() comment
2017-06-14 15:14:51 -04:00
xdp: use common helper for netlink extended ack reporting
2017-05-03 09:51:24 -04:00
NFSv4: Don't special case "launder"
2017-04-26 13:03:04 -04:00
NFS client updates for Linux 4.12
2017-05-10 13:03:38 -07:00
NFS: Add an iocounter wait function for async RPC tasks
2017-04-21 10:45:01 -04:00
NFS append COMMIT after synchronous COPY
2017-05-08 19:01:06 -04:00
nvmet-fc: remove target cpu scheduling flag
2017-05-20 10:11:34 -06:00
nvme: switch to uuid_t
2017-06-05 16:59:16 +02:00
nvme: use a single NVME_AQ_DEPTH and relax it to 32
2017-06-28 08:14:13 -06:00
powerpc updates for 4.12 part 1.
2017-05-05 11:36:44 -07:00
IOMMU Updates for Linux v4.12
2017-05-09 15:15:47 -07:00
of/fdt: introduce of_scan_flat_dt_subnodes and of_get_flat_dt_phandle
2017-05-09 22:55:58 +10:00
Partially Revert "of: fix sparse warnings in fdt, irq, reserved mem, and resolver code"
2017-05-11 10:26:22 -05:00
of/platform: Make of_platform_device_destroy globally visible
2017-05-22 18:01:46 +02:00
padata: Make padata_alloc() static
2017-05-26 10:10:37 +02:00
mm, page_alloc: count movable pages when stealing from pageblock
2017-05-08 17:15:10 -07:00
sched/wait: Rename wait_queue_t => wait_queue_entry_t
2017-06-20 12:18:27 +02:00
ACPI: Switch to use generic guid_t in acpi_evaluate_dsm()
2017-06-07 12:20:49 +02:00
Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2017-07-03 18:08:06 -07:00
PCI: Add device IDs for DRA74x and DRA72x
2017-04-28 10:23:19 -05:00
perf/tracing/cpuhotplug: Fix locking order
2017-05-26 10:10:44 +02:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
2017-04-26 22:39:08 -04:00
ARM: SoC driver updates
2017-05-09 10:01:15 -07:00
PM / wakeup: Integrate mechanism to abort transitions in progress
2017-05-05 22:54:28 +02:00
x86, dax, pmem: remove indirection around memcpy_from_pmem()
2017-04-25 13:20:46 -07:00
sched/wait: Rename wait_queue_t => wait_queue_entry_t
2017-06-20 12:18:27 +02:00
posix-clocks: Remove interval timer facility and mmap/fasync callbacks
2017-06-04 15:40:22 +02:00
time/posix-timers: Move the compat copyouts to the nanosleep implementations
2017-06-14 00:00:42 +02:00
crash: move crashkernel parsing and vmcore related code under CONFIG_CRASH_CORE
2017-05-08 17:15:11 -07:00
pidns: expose task pid_ns_for_children to userspace
2017-05-08 17:15:12 -07:00
ptr_ring: batch ring zeroing
2017-05-09 16:43:23 +03:00
m68k updates for 4.13
2017-07-03 15:12:52 -07:00
ext4: fix quota charging for shared xattr blocks
2017-05-24 18:24:07 -04:00
rcu: Flag need for rcu_node_tree.h and rcu_segcblist.h visibility
2017-06-08 18:52:26 -07:00
rcu: Flag need for rcu_node_tree.h and rcu_segcblist.h visibility
2017-06-08 18:52:26 -07:00
rcu: Remove #ifdef moving rcu_end_inkernel_boot from rcupdate.h
2017-06-08 18:52:40 -07:00
rcu: Remove #ifdef moving rcu_end_inkernel_boot from rcupdate.h
2017-06-08 18:52:40 -07:00
rcu: Remove #ifdef moving rcu_end_inkernel_boot from rcupdate.h
2017-06-08 18:52:40 -07:00
locking/refcount: Remove the half-implemented refcount_sub() API
2017-07-02 11:24:36 +02:00
time/posix-timers: Move the compat copyouts to the nanosleep implementations
2017-06-14 00:00:42 +02:00
rhashtable: compact struct rhashtable_params
2017-05-01 16:22:40 -04:00
ring-buffer: Return reader page back into existing ring buffer
2017-05-01 10:26:40 -04:00
mm: remove SWAP_[SUCCESS|AGAIN|FAIL]
2017-05-03 15:52:10 -07:00
mm: remove rodata_test_data export, add pr_fmt
2017-05-03 15:52:09 -07:00
rt_mutex: Add lockdep annotations
2017-06-08 10:35:49 +02:00
scatterlist: add sg_zero_buffer() helper
2017-06-15 14:30:14 +02:00
sched/cputime: Accumulate vtime on top of nsec clocksource
2017-07-05 09:54:15 +02:00
sysv,ipc: cacheline align kern_ipc_perm
2017-05-08 17:15:12 -07:00
tty/serdev: add serdev registration interface
2017-05-18 17:38:24 +02:00
signal: Move copy_siginfo_to_user to <linux/signal.h>
2017-06-04 15:11:46 +02:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
2017-05-02 16:40:27 -07:00
slub: make sysfs file removal asynchronous
2017-06-23 16:15:55 -07:00
atomics: Add header comment so spin_unlock_wait()
2017-06-08 08:25:29 -07:00
srcu: Remove Classic SRCU
2017-06-08 18:52:42 -07:00
srcu: Apply trivial callback lists to shrink Tiny SRCU
2017-06-08 18:52:35 -07:00
srcu: Use rnp->lock wrappers to replace explicit memory barriers
2017-06-08 18:52:38 -07:00
stop_machine: Provide stop_machine_cpuslocked()
2017-05-26 10:10:36 +02:00
libnvdimm for 4.12
2017-05-05 18:49:20 -07:00
Revert "ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle"
2017-06-07 00:57:37 +02:00
mm, swap: remove unused function prototype
2017-05-03 15:52:11 -07:00
tcp: switch rcv_rtt_est and rcvq_space to high resolution timestamps
2017-04-26 14:44:39 -04:00
A couple hardened usercopy changes:
2017-05-02 10:45:15 -07:00
time: delete CURRENT_TIME_SEC and CURRENT_TIME
2017-05-08 17:15:15 -07:00
time: Clean up CLOCK_MONOTONIC_RAW time handling
2017-06-20 22:13:59 -07:00
tty/serdev: add serdev registration interface
2017-05-18 17:38:24 +02:00
include/linux/uaccess.h: remove expensive WARN_ON in pagefault_disabled_dec
2017-05-08 17:15:14 -07:00
uuid: Take const on input of uuid_is_null() and guid_is_null()
2017-06-20 09:02:04 +02:00
sched/wait: Rename wait_queue_t => wait_queue_entry_t
2017-06-20 12:18:27 +02:00
virtio: virtio_driver doc
2017-05-09 16:43:22 +03:00
virtio: add context flag to find vqs
2017-05-02 23:41:43 +03:00
virtio: add context flag to find vqs
2017-05-02 23:41:43 +03:00
VSOCK: Add virtio vsock vsockmon hooks
2017-04-24 12:35:56 -04:00
mm/vmstat: Make NR_TLB_REMOTE_FLUSH_RECEIVED available even on UP
2017-06-08 09:23:09 +02:00
mm, vmalloc: fix vmalloc users tracking properly
2017-05-12 15:57:15 -07:00
vtime, sched/cputime: Remove vtime_account_user()
2017-07-05 09:54:14 +02:00
sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list naming
2017-06-20 12:19:14 +02:00
sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list naming
2017-06-20 12:19:14 +02:00
