Repository files (latest commit first)

Filename	Latest commit message	Latest commit date
Steven Rostedt (VMware) 73a757e631 ring-buffer: Return reader page back into existing ring buffer ... When reading the ring buffer for consuming, it is optimized for splice, where a page is taken out of the ring buffer (zero copy) and sent to the reading consumer. When the read is finished with the page, it calls ring_buffer_free_read_page(), which simply frees the page. The next time the reader needs to get a page from the ring buffer, it must call ring_buffer_alloc_read_page() which allocates and initializes a reader page for the ring buffer to be swapped into the ring buffer for a new filled page for the reader. The problem is that there's no reason to actually free the page when it is passed back to the ring buffer. It can hold it off and reuse it for the next iteration. This completely removes the interaction with the page_alloc mechanism. Using the trace-cmd utility to record all events (causing trace-cmd to require reading lots of pages from the ring buffer, and calling ring_buffer_alloc/free_read_page() several times), and also assigning a stack trace trigger to the mm_page_alloc event, we can see how many times the ring_buffer_alloc_read_page() needed to allocate a page for the ring buffer. Before this change: # trace-cmd record -e all -e mem_page_alloc -R stacktrace sleep 1 # trace-cmd report |grep ring_buffer_alloc_read_page | wc -l 9968 After this change: # trace-cmd record -e all -e mem_page_alloc -R stacktrace sleep 1 # trace-cmd report |grep ring_buffer_alloc_read_page | wc -l 4 Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>		2017-05-01 10:26:40 -04:00
..
bpf	bpf: convert htab map to hlist_nulls	2017-03-09 13:27:17 -08:00
cgroup	Merge branch 'for-4.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2017-03-14 15:11:19 -07:00
configs	config: android-base: enable hardened usercopy and kernel ASLR	2017-02-27 18:43:46 -08:00
debug	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>	2017-03-02 08:42:34 +01:00
events	Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2017-03-17 13:59:52 -07:00
gcov
irq	sched/headers: Prepare to move the get_task_struct()/put_task_struct() and related APIs from <linux/sched.h> to <linux/sched/task.h>	2017-03-02 08:42:40 +01:00
livepatch
locking	locking/rwsem: Fix down_write_killable() for CONFIG_RWSEM_GENERIC_SPINLOCK=y	2017-03-16 09:28:30 +01:00
power	Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2017-03-03 10:16:38 -08:00
printk	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h>	2017-03-02 08:42:36 +01:00
rcu	rcu/tracing: Add rcu_disabled to denote when rcu_irq_enter() will not work	2017-04-10 15:22:03 -04:00
sched	sched/deadline: Use deadline instead of period when calculating overflow	2017-03-16 09:37:38 +01:00
time	Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2017-03-07 14:45:22 -08:00
trace	ring-buffer: Return reader page back into existing ring buffer	2017-05-01 10:26:40 -04:00
.gitignore
acct.c	sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h>	2017-03-02 08:42:39 +01:00
async.c
audit.c	Merge branch 'stable-4.11' of git://git.infradead.org/users/pcmoore/audit	2017-02-21 13:25:50 -08:00
audit.h	Merge branch 'stable-4.11' of git://git.infradead.org/users/pcmoore/audit	2017-02-21 13:25:50 -08:00
audit_fsnotify.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-12-17 18:44:00 -08:00
audit_tree.c	Merge branch 'stable-4.10' of git://git.infradead.org/users/pcmoore/audit	2017-01-05 23:06:06 -08:00
audit_watch.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-12-17 18:44:00 -08:00
auditfilter.c
auditsc.c	Merge branch 'stable-4.11' of git://git.infradead.org/users/pcmoore/audit	2017-02-21 13:25:50 -08:00
backtracetest.c
bounds.c
capability.c	capability: export has_capability	2017-01-12 07:01:56 -07:00
compat.c	Replace <asm/uaccess.h> with <linux/uaccess.h> globally	2016-12-24 11:46:01 -08:00
configs.c	Replace <asm/uaccess.h> with <linux/uaccess.h> globally	2016-12-24 11:46:01 -08:00
context_tracking.c
cpu.c	cpu/hotplug: Serialize callback invocations proper	2017-03-14 19:19:27 +01:00
cpu_pm.c
crash_dump.c
cred.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/coredump.h>	2017-03-02 08:42:28 +01:00
delayacct.c	sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h>	2017-03-02 08:42:39 +01:00
dma.c
elfcore.c
exec_domain.c
exit.c	userfaultfd: non-cooperative: rollback userfaultfd_exit	2017-03-09 17:01:09 -08:00
extable.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2017-02-22 10:15:09 -08:00
fork.c	sched/headers, RCU: Move rcu_copy_process() from <linux/sched/task.h> to kernel/fork.c	2017-03-03 01:43:46 +01:00
freezer.c
futex.c	futex: Add missing error handling to FUTEX_REQUEUE_PI	2017-03-14 21:45:36 +01:00
futex_compat.c	Replace <asm/uaccess.h> with <linux/uaccess.h> globally	2016-12-24 11:46:01 -08:00
groups.c	Replace <asm/uaccess.h> with <linux/uaccess.h> globally	2016-12-24 11:46:01 -08:00
hung_task.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>	2017-03-02 08:42:34 +01:00
irq_work.c
jump_label.c	This release has no new tracing features, just clean ups, minor fixes	2017-02-27 13:26:17 -08:00
kallsyms.c	bpf: make jited programs visible in traces	2017-02-17 13:40:05 -05:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c	kcov: make kcov work properly with KASLR enabled	2016-12-20 09:48:47 -08:00
kexec.c
kexec_core.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk	2017-02-22 17:33:34 -08:00
kexec_file.c	kexec, x86/purgatory: Unbreak it and clean it up	2017-03-10 20:55:09 +01:00
kexec_internal.h	kexec, x86/purgatory: Unbreak it and clean it up	2017-03-10 20:55:09 +01:00
kmod.c	sched/headers, vfs/execve: Prepare to move the do_execve*() prototypes from <linux/sched.h> to <linux/binfmts.h>	2017-03-02 08:42:39 +01:00
kprobes.c	powerpc updates for 4.11 part 1.	2017-02-22 10:30:38 -08:00
ksysfs.c	kernel/ksysfs.c: add __ro_after_init to bin_attribute structure	2017-02-24 17:46:56 -08:00
kthread.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h>	2017-03-02 08:42:35 +01:00
latencytop.c	sched/headers: Prepare to move sched_info_on() and force_schedstat_enabled() from <linux/sched.h> to <linux/sched/stat.h>	2017-03-02 08:42:39 +01:00
Makefile	cgroup: move cgroup files under kernel/cgroup/	2016-12-27 14:49:05 -05:00
membarrier.c	Fix: Disable sys_membarrier when nohz_full is enabled	2017-01-23 11:32:16 -08:00
memremap.c	mm: add private lock to serialize memory hotplug operations	2017-03-16 16:56:18 -07:00
module-internal.h
module.c	Modules updates for v4.11	2017-02-22 17:08:33 -08:00
module_signing.c
notifier.c	kernel/notifier.c: simplify expression	2017-02-24 17:46:56 -08:00
nsproxy.c
padata.c
panic.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>	2017-03-02 08:42:34 +01:00
params.c
pid.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h>	2017-03-02 08:42:35 +01:00
pid_namespace.c	sched/headers: Prepare for the reduction of <linux/sched.h>'s signal API dependency	2017-03-02 08:42:37 +01:00
profile.c	sched/headers: Prepare to move sched_info_on() and force_schedstat_enabled() from <linux/sched.h> to <linux/sched/stat.h>	2017-03-02 08:42:39 +01:00
ptrace.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h>	2017-03-02 08:42:35 +01:00
range.c
reboot.c
relay.c	lib/vsprintf.c: remove %Z support	2017-02-27 18:43:47 -08:00
resource.c
seccomp.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h>	2017-03-02 08:42:36 +01:00
signal.c	sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h>	2017-03-02 08:42:39 +01:00
smp.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/idle.h>	2017-03-02 08:42:26 +01:00
smpboot.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h>	2017-03-02 08:42:35 +01:00
smpboot.h
softirq.c
stacktrace.c	stacktrace, lockdep: Fix address, newline ugliness	2017-02-08 08:21:31 +01:00
stop_machine.c
sys.c	sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h>	2017-03-02 08:42:39 +01:00
sys_ni.c	move aio compat to fs/aio.c	2016-12-22 22:58:37 -05:00
sysctl.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/coredump.h>	2017-03-02 08:42:28 +01:00
sysctl_binary.c
task_work.c
taskstats.c
test_kprobes.c
torture.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h>	2017-03-02 08:42:27 +01:00
tracepoint.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h>	2017-03-02 08:42:35 +01:00
tsacct.c	sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h>	2017-03-02 08:42:39 +01:00
ucount.c	ucount: Remove the atomicity from ucount->count	2017-03-06 15:26:37 -06:00
uid16.c	sched/headers: Prepare to remove <linux/cred.h> inclusion from <linux/sched.h>	2017-03-02 08:42:31 +01:00
up.c
user-return-notifier.c
user.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/user.h>	2017-03-02 08:42:29 +01:00
user_namespace.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h>	2017-03-02 08:42:29 +01:00
utsname.c	sched/headers: Prepare to move the task_lock()/unlock() APIs to <linux/sched/task.h>	2017-03-02 08:42:38 +01:00
utsname_sysctl.c	sched/headers: Remove <linux/rwsem.h> from <linux/sched.h>	2017-03-03 01:45:36 +01:00
watchdog.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>	2017-03-02 08:42:34 +01:00
watchdog_hld.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>	2017-03-02 08:42:34 +01:00
workqueue.c	workqueue: trigger WARN if queue_delayed_work() is called with NULL @wq	2017-03-06 15:33:42 -05:00
workqueue_internal.h