Stephane Eranian 8904b18046 perf_events: Fix default watermark calculation ... This patch fixes the default watermark value for the sampling buffer. With the existing calculation (watermark = max(PAGE_SIZE, max_size / 2)), no notification was ever received when the buffer was exactly 1 page. This was because you would never cross the threshold (there is no partial samples). In certain configuration, there was no possibilty detecting the problem because there was not enough space left to store the LOST record.In fact, there may be a more generic problem here. The kernel should ensure that there is alaways enough space to store one LOST record. This patch sets the default watermark to half the buffer size. With such limit, we are guaranteed to get a notification even with a single page buffer assuming no sample is bigger than a page. Signed-off-by: Stephane Eranian <eranian@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <20091120212509.344964101@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1256302576-6169-1-git-send-email-eranian@gmail.com>		2009-11-21 14:11:41 +01:00
..
gcov	microblaze: Enable GCOV_PROFILE_ALL	2009-09-21 14:29:21 +02:00
irq	genirq: try_one_irq() must be called with irq disabled	2009-11-07 21:44:45 +01:00
power	PM / Hibernate: Add newline to load_image() fail path	2009-11-03 11:03:09 +01:00
time	headers: remove sched.h from interrupt.h	2009-10-11 11:20:58 -07:00
trace	Merge branch 'tracing/hw-breakpoints' into perf/core	2009-11-21 14:07:23 +01:00
.gitignore
acct.c	bsdacct: switch credentials for writing to the accounting file	2009-08-24 11:33:40 +10:00
async.c
audit.c	Audit: send signal info if selinux is disabled	2009-09-24 03:50:26 -04:00
audit.h	Fix rule eviction order for AUDIT_DIR	2009-06-24 00:02:38 -04:00
audit_tree.c	Fix rule eviction order for AUDIT_DIR	2009-06-24 00:02:38 -04:00
audit_watch.c	Audit: reorganize struct audit_watch to save 8 bytes	2009-09-24 03:50:25 -04:00
auditfilter.c	Audit: clean up all op= output to include string quoting	2009-06-24 00:00:52 -04:00
auditsc.c	Audit: rearrange audit_context to save 16 bytes per struct	2009-09-24 03:50:26 -04:00
backtracetest.c
bounds.c
capability.c
cgroup.c	cgroup: fix strstrip() misuse	2009-10-29 07:39:25 -07:00
cgroup_freezer.c	cgroups: let ss->can_attach and ss->attach do whole threadgroups at a time	2009-09-24 07:20:58 -07:00
compat.c
configs.c
cpu.c	Merge branch 'x86-pat-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-09-15 09:19:38 -07:00
cpuset.c	cgroups: let ss->can_attach and ss->attach do whole threadgroups at a time	2009-09-24 07:20:58 -07:00
cred-internals.h
cred.c	creds_are_invalid() needs to be exported for use by modules:	2009-09-23 11:02:26 -07:00
delayacct.c	headers: taskstats_kern.h trim	2009-09-18 09:48:52 -07:00
dma.c
exec_domain.c
exit.c	Merge branch 'tracing/hw-breakpoints' into perf/core	2009-11-21 14:07:23 +01:00
extable.c
fork.c	Correct nr_processes() when CPUs have been unplugged	2009-11-03 07:52:39 -08:00
freezer.c	sched: fix nr_uninterruptible accounting of frozen tasks really	2009-07-18 14:19:53 +02:00
futex.c	futex: Fix spurious wakeup for requeue_pi really	2009-10-28 20:34:34 +01:00
futex_compat.c	futex: Fix compat_futex to be same as futex for REQUEUE_PI	2009-08-10 15:41:12 +02:00
groups.c	groups: move code to kernel/groups.c	2009-06-16 19:47:48 -07:00
hrtimer.c	Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-10-05 12:04:16 -07:00
hung_task.c	sysctl: remove "struct file *" argument of ->proc_handler	2009-09-24 07:21:04 -07:00
hw_breakpoint.c	hw-breakpoints: Fix broken hw-breakpoint sample module	2009-11-10 11:23:29 +01:00
itimer.c	itimers: Add tracepoints for itimer	2009-08-29 14:10:07 +02:00
kallsyms.c	hw-breakpoints: Fix broken hw-breakpoint sample module	2009-11-10 11:23:29 +01:00
Kconfig.freezer
Kconfig.hz
Kconfig.preempt
kexec.c	kexec: fix omitting offset in extended crashkernel syntax	2009-07-29 19:10:34 -07:00
kfifo.c	kfifo: Use "const" definitions	2009-09-19 13:13:17 -07:00
kgdb.c
kmod.c	Revert "kmod: fix race in usermodehelper code"	2009-09-23 18:12:10 -07:00
kprobes.c	Merge commit 'v2.6.32-rc5' into perf/probes	2009-10-17 09:58:25 +02:00
ksysfs.c
kthread.c	sched: Fix kthread_bind() by moving the body of kthread_bind() to sched.c	2009-11-03 07:25:00 +01:00
latencytop.c
lockdep.c	tracing: Rename 'lockdep' event subsystem into 'lock'	2009-11-13 10:48:27 +01:00
lockdep_internals.h	lockdep: BFS cleanup	2009-07-24 10:53:29 +02:00
lockdep_proc.c	seq_file: constify seq_operations	2009-09-23 07:39:29 -07:00
lockdep_states.h
Makefile	Merge commit 'perf/core' into perf/hw-breakpoint	2009-10-18 01:12:33 +02:00
module.c	module: fix up CONFIG_KALLSYMS=n build.	2009-10-01 16:11:11 -07:00
mutex-debug.c	headers: remove sched.h from interrupt.h	2009-10-11 11:20:58 -07:00
mutex-debug.h
mutex.c
mutex.h
notifier.c	kprobes: Fix to add __kprobes to notify_die	2009-08-30 03:08:26 +02:00
ns_cgroup.c	cgroups: let ss->can_attach and ss->attach do whole threadgroups at a time	2009-09-24 07:20:58 -07:00
nsproxy.c	nsproxy: extract create_nsproxy()	2009-06-18 13:03:56 -07:00
panic.c	Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-10-08 12:16:35 -07:00
params.c	param: fix setting arrays of bool	2009-10-29 08:56:20 +10:30
perf_event.c	perf_events: Fix default watermark calculation	2009-11-21 14:11:41 +01:00
pid.c	mm: also use alloc_large_system_hash() for the PID hash table	2009-09-22 07:17:38 -07:00
pid_namespace.c	pidns: deny CLONE_PARENT|CLONE_NEWPID combination	2009-09-24 07:21:04 -07:00
pm_qos_params.c
posix-cpu-timers.c	itimers: Add tracepoints for itimer	2009-08-29 14:10:07 +02:00
posix-timers.c	time: Introduce CLOCK_REALTIME_COARSE	2009-08-21 21:43:46 +02:00
printk.c	printk: add printk_delay to make messages readable for some scenarios	2009-09-23 07:39:28 -07:00
profile.c	kernel/profile.c: Switch /proc/irq/prof_cpu_mask to seq_file	2009-09-20 20:15:40 +02:00
ptrace.c	ptrace: __ptrace_detach: do __wake_up_parent() if we reap the tracee	2009-09-24 07:20:59 -07:00
rcupdate.c	rcu: Move rcu_barrier() to rcutree	2009-10-07 08:11:20 +02:00
rcutorture.c	rcu: Clean up code to address Ingo's checkpatch feedback	2009-09-23 19:46:30 +02:00
rcutree.c	rcu: Fix long-grace-period race between forcing and initialization	2009-11-02 16:06:21 +01:00
rcutree.h	rcu: Fix long-grace-period race between forcing and initialization	2009-11-02 16:06:21 +01:00
rcutree_plugin.h	rcu: Fix TREE_PREEMPT_RCU CPU_HOTPLUG bad-luck hang	2009-10-15 20:33:01 +02:00
rcutree_trace.c	rcu: Make hot-unplugged CPU relinquish its own RCU callbacks	2009-10-07 08:11:20 +02:00
relay.c	const: mark struct vm_struct_operations	2009-09-27 11:39:25 -07:00
res_counter.c	memcg: some modification to softlimit under hierarchical memory reclaim.	2009-10-01 16:11:13 -07:00
resource.c	walk system ram range	2009-09-23 07:39:41 -07:00
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c	rtmutex: Avoid deadlock in rt_mutex_start_proxy_lock()	2009-08-06 05:50:21 +02:00
rtmutex.h
rtmutex_common.h
rwsem.c
sched.c	sched: Use root_task_group_empty only with FAIR_GROUP_SCHED	2009-11-08 13:15:48 +01:00
sched_clock.c	sched_clock: Fix atomicity/continuity bug by using cmpxchg64()	2009-09-30 22:56:10 +02:00
sched_cpupri.c	sched: Add new prio to cpupri before removing old prio	2009-08-02 14:26:09 +02:00
sched_cpupri.h
sched_debug.c	sched: Add new wakeup preemption mode: WAKEUP_RUNNING	2009-09-17 10:17:25 +02:00
sched_fair.c	sched: Strengthen buddies and mitigate buddy induced latencies	2009-10-23 23:48:28 +02:00
sched_features.h	sched: Add new wakeup preemption mode: WAKEUP_RUNNING	2009-09-17 10:17:25 +02:00
sched_idletask.c	sched: Simplify sys_sched_rr_get_interval() system call	2009-09-21 09:53:55 +02:00
sched_rt.c	sched: Simplify sys_sched_rr_get_interval() system call	2009-09-21 09:53:55 +02:00
sched_stats.h
seccomp.c
semaphore.c
signal.c	signals: inline __fatal_signal_pending	2009-09-24 07:21:01 -07:00
slow-work.c	sysctl: remove "struct file *" argument of ->proc_handler	2009-09-24 07:21:04 -07:00
smp.c	cpumask: remove arch_send_call_function_ipi	2009-09-24 09:34:47 +09:30
softirq.c	softirq: add BLOCK_IOPOLL to softirq_to_name	2009-09-17 15:53:44 -04:00
softlockup.c	sysctl: remove "struct file *" argument of ->proc_handler	2009-09-24 07:21:04 -07:00
spinlock.c	locking: Allow arch-inlined spinlocks	2009-08-31 18:08:50 +02:00
srcu.c
stacktrace.c
stop_machine.c
sys.c	Merge branch 'hwpoison-2.6.32' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6	2009-10-29 08:20:00 -07:00
sys_ni.c	Merge branch 'master' of /home/davem/src/GIT/linux-2.6/	2009-09-24 15:13:11 -07:00
sysctl.c	Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6	2009-09-24 07:53:22 -07:00
sysctl_check.c	sysctl: fix false positives when PROC_SYSCTL=n	2009-10-29 07:39:30 -07:00
taskstats.c	genetlink: make netns aware	2009-07-12 14:03:27 -07:00
test_kprobes.c
time.c	time: Prevent 32 bit overflow with set_normalized_timespec()	2009-09-15 10:17:30 +02:00
timeconst.pl
timer.c	Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-09-23 09:46:15 -07:00
tracepoint.c	trivial: fix typo "to to" in multiple files	2009-09-21 15:14:55 +02:00
tsacct.c
uid16.c	headers: utsname.h redux	2009-09-23 18:13:10 -07:00
up.c
user.c	uids: Prevent tear down race	2009-11-02 16:02:39 +01:00
user_namespace.c
utsname.c	utsns: extract creeate_uts_ns()	2009-06-18 13:03:55 -07:00
utsname_sysctl.c	sysctl: remove "struct file *" argument of ->proc_handler	2009-09-24 07:21:04 -07:00
wait.c	locking, sched: Give waitqueue spinlocks their own lockdep classes	2009-08-10 14:43:09 +02:00
workqueue.c	Merge branch 'hwpoison-2.6.32' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6	2009-10-29 08:20:00 -07:00