Eric B Munson 5bbe3547aa mm: allow compaction of unevictable pages ... Currently, pages which are marked as unevictable are protected from compaction, but not from other types of migration. The POSIX real time extension explicitly states that mlock() will prevent a major page fault, but the spirit of this is that mlock() should give a process the ability to control sources of latency, including minor page faults. However, the mlock manpage only explicitly says that a locked page will not be written to swap and this can cause some confusion. The compaction code today does not give a developer who wants to avoid swap but wants to have large contiguous areas available any method to achieve this state. This patch introduces a sysctl for controlling compaction behavior with respect to the unevictable lru. Users who demand no page faults after a page is present can set compact_unevictable_allowed to 0 and users who need the large contiguous areas can enable compaction on locked memory by leaving the default value of 1. To illustrate this problem I wrote a quick test program that mmaps a large number of 1MB files filled with random data. These maps are created locked and read only. Then every other mmap is unmapped and I attempt to allocate huge pages to the static huge page pool. When the compact_unevictable_allowed sysctl is 0, I cannot allocate hugepages after fragmenting memory. When the value is set to 1, allocations succeed. Signed-off-by: Eric B Munson <emunson@akamai.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Christoph Lameter <cl@linux.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Christoph Lameter <cl@linux.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2015-04-15 16:35:17 -07:00
..
bpf	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2015-04-15 09:00:47 -07:00
configs	x86: Add "make tinyconfig" to configure the tiniest possible kernel	2014-08-08 16:30:24 -07:00
debug	debug: prevent entering debug mode on panic/exception.	2015-02-19 12:39:03 -06:00
events	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2015-04-15 09:00:47 -07:00
gcov	kbuild,gcov: simplify kernel/gcov/Makefile more	2015-01-09 17:25:44 +01:00
irq	irqchip core change for v4.1 (round 3)	2015-04-11 11:17:28 +02:00
livepatch	Merge branch 'for-4.1/core-noarch' into for-linus	2015-04-13 23:57:20 +02:00
locking	Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-04-13 10:27:28 -07:00
power	Merge back earlier suspend/hibernate material for v4.1.	2015-04-10 12:01:59 +02:00
printk	Merge branch 'iocb' into for-next	2015-04-11 22:24:41 -04:00
rcu	Merge branches 'doc.2015.02.26a', 'earlycb.2015.03.03a', 'fixes.2015.03.03a', 'gpexp.2015.02.26a', 'hotplug.2015.03.20a', 'sysidle.2015.02.26b' and 'tiny.2015.02.26a' into HEAD	2015-03-20 08:31:01 -07:00
sched	Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-04-14 13:58:48 -07:00
time	timers/PM: Drop unnecessary braces from tick_freeze()	2015-04-03 15:15:52 +02:00
trace	Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-04-14 14:37:47 -07:00
.gitignore	Ignore generated file kernel/x509_certificate_list	2013-12-10 18:21:34 +00:00
Kconfig.freezer	…
Kconfig.hz	kernel: remove CONFIG_USE_GENERIC_SMP_HELPERS	2013-11-15 09:32:22 +09:00
Kconfig.locks	locking/mcs: Better differentiate between MCS variants	2015-01-14 15:07:32 +01:00
Kconfig.preempt	…
Makefile	Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2015-02-11 20:25:11 -08:00
acct.c	new fs_pin killing logics	2015-01-25 23:17:28 -05:00
async.c	kernel/async.c: switch to pr_foo()	2014-10-09 22:26:04 -04:00
audit.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2014-12-30 10:45:47 -08:00
audit.h	audit: replace getname()/putname() hacks with reference counters	2015-01-23 00:23:58 -05:00
audit_tree.c	fsnotify: unify inode and mount marks handling	2014-12-13 12:42:53 -08:00
audit_watch.c	audit: invalid op= values for rules	2014-09-23 16:37:53 -04:00
auditfilter.c	Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit	2015-02-11 20:07:47 -08:00
auditsc.c	Merge branch 'getname2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2015-02-17 15:27:47 -08:00
backtracetest.c	kernel/backtracetest.c: replace no level printk by pr_info()	2014-06-04 16:54:14 -07:00
bounds.c	page-cgroup: get rid of NR_PCG_FLAGS	2014-08-08 15:57:18 -07:00
capability.c	CAPABILITIES: remove undefined caps from all processes	2014-07-24 21:53:47 +10:00
cgroup.c	memcg: zap mem_cgroup_lookup()	2015-04-15 16:35:16 -07:00
cgroup_freezer.c	cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes	2014-07-15 11:05:09 -04:00
compat.c	all arches, signal: move restart_block to struct task_struct	2015-02-12 18:54:12 -08:00
configs.c	…
context_tracking.c	context_tracking: Export context_tracking_user_enter/exit	2015-03-09 15:43:00 +01:00
cpu.c	Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-04-14 13:36:04 -07:00
cpu_pm.c	…
cpuset.c	kernel, cpuset: remove exception for __GFP_THISNODE	2015-04-14 16:49:03 -07:00
crash_dump.c	crash_dump: Make is_kdump_kernel() accessible from modules	2014-08-25 15:42:19 -07:00
cred.c	…
delayacct.c	delayacct: Remove braindamaged type conversions	2014-07-23 10:18:06 -07:00
dma.c	…
elfcore.c	switch elf_core_write_extra_phdrs() to dump_emit()	2013-11-09 00:16:23 -05:00
exec_domain.c	kernel/exec_domain.c: code clean-up	2014-06-04 16:54:15 -07:00
exit.c	oom, PM: make OOM detection in the freezer path raceless	2015-02-11 17:06:03 -08:00
extable.c	ftrace/x86/extable: Add is_ftrace_trampoline() function	2014-11-19 15:25:26 -05:00
fork.c	mm: do not use mm->nr_pmds on !MMU configurations	2015-02-12 18:54:10 -08:00
freezer.c	freezer: remove obsolete comments in __thaw_task()	2014-10-21 23:44:20 +02:00
futex.c	Linux 34.0-rc1	2015-02-24 08:41:07 +01:00
futex_compat.c	compat: Get rid of (get|put)_compat_time(val|spec)	2014-02-02 14:09:12 -08:00
groups.c	userns: Don't allow setgroups until a gid mapping has been setablished	2014-12-09 16:58:40 -06:00
hung_task.c	kernel/hung_task.c: convert simple_strtoul to kstrtouint	2014-06-04 16:54:15 -07:00
irq_work.c	percpu: Convert remaining __get_cpu_var uses in 3.18-rcX	2014-10-29 11:18:18 -04:00
jump_label.c	…
kallsyms.c	kernel/kallsyms.c: use __seq_open_private()	2014-10-14 02:18:16 +02:00
kcmp.c	kcmp: fix standard comparison bug	2014-09-10 15:42:12 -07:00
kexec.c	kexec: simplify conditional	2015-02-17 14:34:51 -08:00
kmod.c	usermodehelper: kill the kmod_thread_locker logic	2014-12-10 17:41:17 -08:00
kprobes.c	kprobes: makes kprobes/enabled works correctly for optimized kprobes.	2015-02-13 21:21:42 -08:00
ksysfs.c	kobject: Make support for uevent_helper optional.	2014-04-25 12:00:49 -07:00
kthread.c	kernel/kthread.c: partial revert of 81c98869fa ("kthread: ensure locality of task_struct allocations")	2014-10-09 22:25:51 -04:00
latencytop.c	kernel/latencytop.c: convert seq_printf to seq_puts	2014-06-04 16:54:15 -07:00
module-internal.h	…
module.c	Some clean ups and small fixes, but the biggest change is the addition	2015-04-14 10:49:03 -07:00
module_signing.c	…
notifier.c	rcu: Make SRCU optional by using CONFIG_SRCU	2015-01-06 11:04:29 -08:00
nsproxy.c	bury struct proc_ns in fs/proc	2014-12-04 14:34:54 -05:00
padata.c	padata: use %*pb[l] to print bitmaps including cpumasks and nodemasks	2015-02-13 21:21:38 -08:00
panic.c	livepatch: kernel: add TAINT_LIVEPATCH	2014-12-22 15:40:48 +01:00
params.c	param: fix uninitialized read with CONFIG_DEBUG_LOCK_ALLOC	2015-01-20 11:38:31 +10:30
pid.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2014-12-16 15:53:03 -08:00
pid_namespace.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2014-12-16 15:53:03 -08:00
profile.c	profile: use %*pb[l] to print bitmaps including cpumasks and nodemasks	2015-02-13 21:21:38 -08:00
ptrace.c	ptrace: remove linux/compat.h inclusion under CONFIG_COMPAT	2015-02-17 14:34:51 -08:00
range.c	kernel: avoid overflow in cmp_range	2015-01-17 10:02:23 +13:00
reboot.c	kernel: add support for kernel restart handler call chain	2014-09-26 00:00:06 -07:00
relay.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2014-04-12 14:49:50 -07:00
resource.c	resources: Move struct resource_list_entry from ACPI into resource core	2015-02-05 15:09:25 +01:00
seccomp.c	seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO	2015-02-17 14:34:55 -08:00
signal.c	signal: use current->state helpers	2015-02-17 14:34:51 -08:00
smp.c	Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu	2014-10-15 07:48:18 +02:00
smpboot.c	smpboot: Add common code for notification from dying CPU	2015-03-11 13:20:25 -07:00
smpboot.h	…
softirq.c	Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-02-09 15:24:03 -08:00
stacktrace.c	stacktrace: introduce snprint_stack_trace for buffer output	2014-12-13 12:42:48 -08:00
stop_machine.c	kernel/stop_machine.c: kernel-doc warning fix	2014-06-04 16:54:15 -07:00
sys.c	kernel/sys.c: fix UNAME26 for 4.0	2015-02-28 09:57:51 -08:00
sys_ni.c	syscalls: implement execveat() system call	2014-12-13 12:42:51 -08:00
sysctl.c	mm: allow compaction of unevictable pages	2015-04-15 16:35:17 -07:00
sysctl_binary.c	kernel: add panic_on_warn	2014-12-10 17:41:10 -08:00
system_certificates.S	KEYS: correct alignment of system_certificate_list content in assembly file	2013-12-10 18:25:28 +00:00
system_keyring.c	KEYS: validate certificate trust only with builtin keys	2014-07-17 09:35:17 -04:00
task_work.c	…
taskstats.c	netlink: make nlmsg_end() and genlmsg_end() void	2015-01-18 01:03:45 -05:00
test_kprobes.c	kernel/test_kprobes.c: use current logging functions	2014-08-08 15:57:18 -07:00
torture.c	torture: Address race in module cleanup	2014-09-16 13:41:06 -07:00
tracepoint.c	tracing: syscall_regfunc() should not skip kernel threads	2014-06-21 00:15:26 -04:00
tsacct.c	sched: Make task->start_time nanoseconds based	2014-07-23 10:18:05 -07:00
uid16.c	groups: Consolidate the setgroups permission checks	2014-12-05 17:19:27 -06:00
up.c	smp: Rename __smp_call_function_single() to smp_call_function_single_async()	2014-02-24 14:47:15 -08:00
user-return-notifier.c	scheduler: Replace __get_cpu_var with this_cpu_ptr	2014-08-26 13:45:45 -04:00
user.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2014-12-17 12:31:40 -08:00
user_namespace.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2014-12-17 12:31:40 -08:00
utsname.c	copy address of proc_ns_ops into ns_common	2014-12-04 14:34:47 -05:00
utsname_sysctl.c	sysctl: convert use of typedef ctl_table to struct ctl_table	2014-06-06 16:08:16 -07:00
watchdog.c	Merge branch 'akpm' (patches from Andrew)	2015-04-14 16:49:17 -07:00
workqueue.c	workqueue: Reorder sysfs code	2015-04-06 11:16:04 -04:00
workqueue_internal.h	workqueue: rename manager_mutex to attach_mutex	2014-05-20 10:59:32 -04:00