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Steven Rostedt ea05b57cc1 ring-buffer: discard timestamps that are at the start of the buffer 
Every buffer page in the ring buffer includes its own time stamp.
When an event is recorded to the ring buffer with a delta time greater
than what can be held in the event header, a time stamp event is created.

If the the create timestamp falls over to the next buffer page, it is
redundant because the buffer page holds a full time stamp. This patch
will try to discard the time stamp when it falls to the start of the
next page.

This change also fixes a issues with disarding events. If most events are
discarded, timestamps will start to creep into the ring buffer. If we
do not discard the timestamps then they can fill up the ring buffer over
time and waste space.

This change will keep time stamps from filling up over another page. If
something is recorded in the buffer page, and the rest is filtered, then
the time stamps can only fill up to the end of the page.

[ Impact: prevent time stamps from filling ring buffer ]

Reported-by: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-03 10:15:25 -04:00
..
irq Merge branch 'linus' into tracing/core 2009-05-07 11:17:34 +02:00
power PM/Hibernate: Fix waiting for image device to appear on resume 2009-04-24 15:31:30 -07:00
time clockevents: prevent endless loop in tick_handle_periodic() 2009-05-02 10:22:27 +02:00
trace ring-buffer: discard timestamps that are at the start of the buffer 2009-06-03 10:15:25 -04:00
.gitignore
acct.c [CVE-2009-0029] System call wrappers part 04 2009-01-14 14:15:19 +01:00
async.c async: remove the temporary (2.6.29) "async is off by default" code 2009-03-28 13:05:30 -07:00
audit_tree.c No need for crossing to mountpoint in audit_tag_tree() 2009-04-20 23:01:15 -04:00
audit.c Audit: remove spaces from audit_log_d_path 2009-04-05 13:49:04 -04:00
audit.h fixing audit rule ordering mess, part 1 2009-01-04 15:14:41 -05:00
auditfilter.c inotify: use GFP_NOFS in kernel_event() to work around a lockdep false-positive 2009-05-06 16:36:09 -07:00
auditsc.c Audit: remove spaces from audit_log_d_path 2009-04-05 13:49:04 -04:00
backtracetest.c
bounds.c
capability.c [CVE-2009-0029] System call wrappers part 04 2009-01-14 14:15:19 +01:00
cgroup_debug.c debug cgroup: remove unneeded cgroup_lock 2009-04-02 19:04:54 -07:00
cgroup_freezer.c
cgroup.c Convert obvious places to deactivate_locked_super() 2009-05-09 10:49:40 -04:00
compat.c Allow times and time system calls to return small negative values 2009-01-06 15:59:13 -08:00
configs.c
cpu.c cpumask: use set_cpu_active in init/main.c 2009-03-30 22:05:12 +10:30
cpuset.c cpusets: prevent PF_THREAD_BOUND tasks from attaching to non-root cpusets 2009-04-02 19:04:57 -07:00
cred-internals.h
cred.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6 2009-01-09 13:59:25 -08:00
delayacct.c schedstat: consolidate per-task cpu runtime stats 2008-12-18 13:54:01 +01:00
dma-coherent.c dma-coherent: Restore dma_alloc_from_coherent() large alloc fall back policy. 2009-01-21 18:51:53 +09:00
dma.c
exec_domain.c Get rid of indirect include of fs_struct.h 2009-03-31 23:00:27 -04:00
exit.c tracing/events: move trace point headers into include/trace/events 2009-04-14 22:05:43 -04:00
extable.c Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
fork.c Merge branch 'tracing/hw-branch-tracing' into tracing/core 2009-05-07 13:36:22 +02:00
freezer.c
futex_compat.c
futex.c futex: comment requeue key reference semantics 2009-04-02 23:39:53 +02:00
hrtimer.c hrtimer: fix rq->lock inversion (again) 2009-03-31 14:52:52 +02:00
hung_task.c softlockup: ensure the task has been switched out once 2009-02-11 11:04:16 +01:00
itimer.c timers: split process wide cpu clocks/timers 2009-02-05 13:04:33 +01:00
kallsyms.c Ksplice: Add functions for walking kallsyms symbols 2009-03-31 13:05:32 +10:30
Kconfig.freezer
Kconfig.hz
Kconfig.preempt rcu: provide RCU options on non-preempt architectures too 2008-12-25 09:31:28 +01:00
kexec.c kexec: vmcoreinfo_data[] can become static 2009-04-02 19:05:04 -07:00
kfifo.c
kgdb.c sysrq, intel_fb: fix sysrq g collision 2009-05-15 07:56:24 -05:00
kmod.c module: create a request_module_nowait() 2009-03-31 13:05:35 +10:30
kprobes.c kprobes: fix to use text_mutex around arm/disarm kprobe 2009-05-08 16:23:48 -07:00
ksysfs.c kernel/ksysfs.c:fix dependence on CONFIG_NET 2009-01-06 10:44:31 -08:00
kthread.c tracing/events: move trace point headers into include/trace/events 2009-04-14 22:05:43 -04:00
latencytop.c sched, latencytop: incorporate review feedback from Andrew Morton 2009-02-11 10:18:04 +01:00
lockdep_internals.h lockdep: get_user_chars() redo 2009-02-14 23:28:22 +01:00
lockdep_proc.c lockstat: warn about disabled lock debugging 2009-02-14 23:28:28 +01:00
lockdep_states.h lockdep: move state bit definitions around 2009-02-14 23:27:59 +01:00
lockdep.c Merge branch 'linus' into tracing/core 2009-05-07 11:17:34 +02:00
Makefile Merge commit 'v2.6.30-rc3' into tracing/hw-branch-tracing 2009-04-24 10:11:23 +02:00
marker.c
module.c ftrace: use module notifier for function tracer 2009-04-17 16:59:15 +02:00
mutex-debug.c mutex: implement adaptive spinning 2009-01-14 18:09:02 +01:00
mutex-debug.h mutex: implement adaptive spinning 2009-01-14 18:09:02 +01:00
mutex.c mutex: have non-spinning mutexes on s390 by default 2009-04-09 19:28:24 +02:00
mutex.h mutex: implement adaptive spinning 2009-01-14 18:09:02 +01:00
notifier.c
ns_cgroup.c cgroups: relax ns_can_attach checks to allow attaching to grandchild cgroups 2009-04-02 19:04:53 -07:00
nsproxy.c
panic.c Eliminate thousands of warnings with gcc 3.2 build 2009-05-06 16:36:09 -07:00
params.c param: fix charp parameters set via sysfs 2009-03-31 13:05:30 +10:30
pid_namespace.c signals: zap_pid_ns_process() should use force_sig() 2009-04-02 19:04:58 -07:00
pid.c pids: refactor vnr/nr_ns helpers to make them safe 2009-04-02 19:05:02 -07:00
pm_qos_params.c
posix-cpu-timers.c kernel/posix-cpu-timers.c: fix sparse warning 2009-04-30 08:08:31 +02:00
posix-timers.c [CVE-2009-0029] System call wrappers part 05 2009-01-14 14:15:20 +01:00
printk.c Merge branch 'printk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 10:23:25 -07:00
profile.c profiling: fix broken profiling regression 2009-02-10 00:50:37 +01:00
ptrace.c Merge branch 'tracing/hw-branch-tracing' into tracing/core 2009-05-07 13:36:22 +02:00
rcuclassic.c kmemtrace, rcu: fix linux/rcutree.h and linux/rcuclassic.h dependencies 2009-04-03 12:23:02 +02:00
rcupdate.c RCU: Don't try and predeclare inline funcs as it upsets some versions of gcc 2009-04-15 13:55:14 -07:00
rcupreempt_trace.c "Tree RCU": scalable classic RCU implementation 2008-12-18 21:56:04 +01:00
rcupreempt.c kmemtrace, rcu: fix rcupreempt.c data structure dependencies 2009-04-03 12:23:04 +02:00
rcutorture.c cpumask: convert rcutorture.c 2009-03-30 22:05:16 +10:30
rcutree_trace.c rcu: Make hierarchical RCU less IPI-happy 2009-04-14 11:31:50 +02:00
rcutree.c rcu: Make hierarchical RCU less IPI-happy 2009-04-14 11:31:50 +02:00
rcutree.h kmemtrace, rcu: fix rcu_tree_trace.c data structure dependencies 2009-04-03 12:23:03 +02:00
relay.c Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
res_counter.c memcg: memory cgroup resource counters for hierarchy 2009-01-08 08:31:05 -08:00
resource.c Remove 'recurse into child resources' logic from 'reserve_region_with_split()' 2009-04-18 21:44:24 -07:00
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rwsem.c
sched_clock.c Merge branch 'tracing/core-v2' into tracing-for-linus 2009-04-02 00:49:02 +02:00
sched_cpupri.c sched_rt: don't allocate cpumask in fastpath 2009-04-01 13:24:51 +02:00
sched_cpupri.h cpumask: remove cpumask_t from core 2009-03-30 22:05:17 +10:30
sched_debug.c sched: remove unused fields from struct rq 2009-03-24 23:16:51 +01:00
sched_fair.c Merge branch 'sched/urgent'; commit 'v2.6.29-rc5' into sched/core 2009-02-15 21:15:16 +01:00
sched_features.h Merge branch 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-03-30 17:17:35 -07:00
sched_idletask.c
sched_rt.c Merge commit 'v2.6.30-rc1' into sched/urgent 2009-04-08 17:26:00 +02:00
sched_stats.h sched: remove unused fields from struct rq 2009-03-24 23:16:51 +01:00
sched.c Merge branch 'tracing/hw-branch-tracing' into tracing/core 2009-05-07 13:36:22 +02:00
seccomp.c x86-64: seccomp: fix 32/64 syscall hole 2009-03-02 15:41:30 -08:00
semaphore.c
signal.c tracing/events: move trace point headers into include/trace/events 2009-04-14 22:05:43 -04:00
slow-work.c Delete slow-work timers properly 2009-04-24 07:47:59 -07:00
smp.c generic-ipi: eliminate WARN_ON()s during oops/panic 2009-03-13 10:47:34 +01:00
softirq.c Merge branch 'linus' into tracing/core 2009-05-07 11:17:34 +02:00
softlockup.c softlockup: decouple hung tasks check from softlockup detection 2009-01-16 14:06:04 +01:00
spinlock.c Allow rwlocks to re-enable interrupts 2009-04-02 19:05:11 -07:00
srcu.c
stacktrace.c stacktrace: provide save_stack_trace_tsk() weak alias 2008-12-25 11:44:43 +01:00
stop_machine.c cpumask: remove cpumask_t from core 2009-03-30 22:05:17 +10:30
sys_ni.c [CVE-2009-0029] Make sys_syslog a conditional system call 2009-01-14 14:15:16 +01:00
sys.c kernel/sys.c: clean up sys_shutdown exit path 2009-04-13 15:04:32 -07:00
sysctl_check.c net: add ARP notify option for devices 2009-02-01 01:04:33 -08:00
sysctl.c Revert "mm: add /proc controls for pdflush threads" 2009-05-15 11:32:24 +02:00
taskstats.c cpumask: convert rest of files in kernel/ 2009-01-01 10:12:28 +10:30
test_kprobes.c kprobes: add tests for register_kprobes 2009-01-06 15:59:20 -08:00
time.c [CVE-2009-0029] System call wrappers part 01 2009-01-14 14:15:18 +01:00
timeconst.pl
timer.c Merge branches 'core-fixes-for-linus', 'irq-fixes-for-linus' and 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-09 10:35:30 -07:00
tracepoint.c tracepoints: dont update zero-sized tracepoint sections 2009-03-18 19:55:00 +01:00
tsacct.c Fix fixpoint divide exception in acct_update_integrals 2009-03-09 08:13:35 -07:00
uid16.c [CVE-2009-0029] System call wrappers part 19 2009-01-14 14:15:26 +01:00
up.c smp_call_function_single(): be slightly less stupid, fix #2 2009-01-12 16:04:37 +01:00
user_namespace.c Fix recursive lock in free_uid()/free_user_ns() 2009-02-27 16:26:21 -08:00
user.c Merge branch 'master' into next 2009-03-24 10:52:46 +11:00
utsname_sysctl.c proc_sysctl: use CONFIG_PROC_SYSCTL around ipc and utsname proc_handlers 2009-04-02 19:05:01 -07:00
utsname.c
wait.c wait: prevent exclusive waiter starvation 2009-02-05 12:56:48 -08:00
workqueue.c work_on_cpu(): rewrite it to create a kernel thread on demand 2009-04-09 09:50:37 +09:30