John Stultz
2d42244ae7
clocksource: introduce CLOCK_MONOTONIC_RAW ...
In talking with Josip Loncaric, and his work on clock synchronization (see
btime.sf.net), he mentioned that for really close synchronization, it is
useful to have access to "hardware time", that is a notion of time that is
not in any way adjusted by the clock slewing done to keep close time sync.
Part of the issue is if we are using the kernel's ntp adjusted
representation of time in order to measure how we should correct time, we
can run into what Paul McKenney aptly described as "Painting a road using
the lines we're painting as the guide".
I had been thinking of a similar problem, and was trying to come up with a
way to give users access to a purely hardware based time representation
that avoided users having to know the underlying frequency and mask values
needed to deal with the wide variety of possible underlying hardware
counters.
My solution is to introduce CLOCK_MONOTONIC_RAW. This exposes a
nanosecond based time value, that increments starting at bootup and has no
frequency adjustments made to it what so ever.
The time is accessed from userspace via the posix_clock_gettime() syscall,
passing CLOCK_MONOTONIC_RAW as the clock_id.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-21 09:50:24 +02:00
genirq: switch /proc/irq/*/smp_affinity et al to seqfiles
2008-08-12 16:07:30 -07:00
kexec jump: save/restore device state
2008-07-26 12:00:04 -07:00
clocksource: introduce CLOCK_MONOTONIC_RAW
2008-08-21 09:50:24 +02:00
Merge branch 'linus' into cpus4096
2008-07-28 23:32:00 +02:00
bsdacct: fix and add comments around acct_process()
2008-07-25 10:53:47 -07:00
[PATCH] Fix the bug of using AUDIT_STATUS_RATE_LIMIT when set fail, no error output.
2008-08-01 12:15:16 -04:00
Re: [PATCH] the loginuid field should be output in all AUDIT_CONFIG_CHANGE audit messages
2008-08-01 12:15:03 -04:00
Re: [PATCH] Fix the kernel panic of audit_filter_task when key field is set
2008-08-04 06:13:50 -04:00
backtrace: replace timer with tasklet + completions
2008-06-27 18:09:16 +02:00
security: Fix setting of PF_SUPERPRIV by __capable()
2008-08-14 22:59:43 +10:00
cgroup: uninline cgroup_has_css_refs()
2008-07-30 09:41:44 -07:00
cpu hotplug: s390 doesn't support additional_cpus anymore.
2008-08-12 16:07:28 -07:00
cpuset: clean up cpuset hierarchy traversal code
2008-07-30 09:41:44 -07:00
per-task-delay-accounting: update taskstats for memory reclaim delay
2008-07-25 10:53:47 -07:00
DMA: make dma-coherent.c documentation kdoc-friendly
2008-08-07 06:52:01 -07:00
[PATCH] kill altroot
2008-07-26 20:53:20 -04:00
tracehook: fix exit_signal=0 case
2008-08-01 12:01:11 -07:00
mmu-notifiers: core
2008-07-28 16:30:21 -07:00
futexes: fix fault handling in futex_lock_pi
2008-06-23 13:31:15 +02:00
Merge branch 'generic-ipi' into generic-ipi-for-linus
2008-07-15 21:55:59 +02:00
kallsyms: fix potential overflow in binary search
2008-07-25 10:53:27 -07:00
sched: fix SCHED_HRTICK dependency
2008-07-28 14:37:38 +02:00
kexec: use a mutex for locking rather than xchg()
2008-08-15 08:35:43 -07:00
kgdb: fix gdb serial thread queries
2008-08-01 08:39:35 -05:00
call_usermodehelper(): increase reliability
2008-07-25 10:53:28 -07:00
kprobes: remove redundant config check
2008-07-25 10:53:30 -07:00
tracehook: wait_task_inactive
2008-07-26 12:00:09 -07:00
lockdep: fix spurious 'inconsistent lock state' warning
2008-08-18 09:42:31 +02:00
lockdep: build fix
2008-08-13 12:55:10 +02:00
lockdep: fix build if CONFIG_PROVE_LOCKING not defined
2008-08-15 19:22:04 +02:00
Merge branch 'linus' into core/generic-dma-coherent
2008-07-29 00:07:55 +02:00
markers: fix markers read barrier for multiple probes
2008-07-30 09:41:45 -07:00
modules: extend initcall_debug functionality to the module loader
2008-08-12 17:52:54 +10:00
locking: fix mutex @key parameter kernel-doc notation
2008-07-28 18:12:36 +02:00
cgroup_clone: use pid of newly created task for new cgroup
2008-07-25 10:53:37 -07:00
cgroup_clone: use pid of newly created task for new cgroup
2008-07-25 10:53:37 -07:00
Add a WARN() macro; this is WARN_ON() + printk arguments
2008-07-25 10:53:29 -07:00
pidns: remove now unused find_pid function.
2008-07-25 10:53:45 -07:00
bsdacct: switch from global bsd_acct_struct instance to per-pidns one
2008-07-25 10:53:47 -07:00
pm_qos: spelling fixes
2008-08-05 14:33:50 -07:00
clocksource: introduce CLOCK_MONOTONIC_RAW
2008-08-21 09:50:24 +02:00
printk: fix comment for printk ratelimiting
2008-07-30 09:41:45 -07:00
build kernel/profile.o only when requested
2008-07-25 10:53:27 -07:00
security: Fix setting of PF_SUPERPRIV by __capable()
2008-08-14 22:59:43 +10:00
stop_machine: Wean existing callers off stop_machine_run()
2008-07-28 12:16:31 +10:00
Merge branch 'generic-ipi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
2008-07-15 14:12:03 -07:00
Merge branch 'linus' into cpus4096
2008-07-16 00:29:07 +02:00
rcu: make rcutorture even more vicious: invoke RCU readers from irq handlers (timers)
2008-06-26 09:24:33 +02:00
relay: fix "full buffer with exactly full last subbuffer" accounting problem
2008-08-05 14:33:46 -07:00
cgroup files: convert res_counter_write() to be a cgroups write_string() handler
2008-07-25 10:53:36 -07:00
resource: add resource_size()
2008-07-30 09:41:43 -07:00
sysdev: Pass the attribute to the low level sysdev show/store function
2008-07-21 21:55:02 -07:00
Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
2008-08-16 17:15:32 -07:00
sched_clock: delay using sched_clock()
2008-08-11 08:59:03 +02:00
sched: fix the cpuprio count really
2008-06-06 15:19:44 +02:00
sched: add full schedstats to /proc/sched_debug
2008-06-27 14:31:31 +02:00
sched: fix mysql+oltp regression
2008-08-11 14:49:29 +02:00
sched: bias effective_load() error towards failing wake_affine().
2008-06-27 14:31:47 +02:00
sched: fix rt-bandwidth hotplug race
2008-08-14 15:50:58 +02:00
sched: fix accounting in task delay accounting & migration
2008-07-04 12:50:23 +02:00
semaphore: __down_common: use signal_pending_state()
2008-08-05 14:33:47 -07:00
tracehook: fix SA_NOCLDWAIT
2008-08-19 20:37:07 -07:00
generic-ipi: fix stack and rcu interaction bug in smp_call_function_mask(), fix
2008-08-12 11:21:27 +02:00
Full conversion to early_initcall() interface, remove old interface
2008-07-26 12:00:04 -07:00
Full conversion to early_initcall() interface, remove old interface
2008-07-26 12:00:04 -07:00
lockdep: spin_lock_nest_lock(), checkpatch fixes
2008-08-13 13:56:51 +02:00
stacktrace: fix modular build, export print_stack_trace and save_stack_trace
2008-06-30 09:20:55 +02:00
stop_machine: remove unused variable
2008-08-12 17:52:55 +10:00
fix setpriority(PRIO_PGRP) thread iterator breakage
2008-08-20 15:40:32 -07:00
signalfd: fix undefined reference to `compat_sys_signalfd4' when !CONFIG_SIGNALFD
2008-07-25 11:35:41 -07:00
lost sysctl fix
2008-07-27 09:45:34 -07:00
sysctl: check for bogus modes
2008-07-25 10:53:45 -07:00
taskstats: remove initialization of static per-cpu variable
2008-07-25 10:53:47 -07:00
Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm
2008-07-14 16:06:58 -07:00
task IO accounting: move all IO statistics in struct task_io_accounting
2008-07-27 16:12:28 -07:00
Merge branch 'core/locking' into core/urgent
2008-08-12 00:11:49 +02:00
2d42244ae7