Dave Hansen
5509a5d27b
drop_caches: add some documentation and info message ...
There is plenty of anecdotal evidence and a load of blog posts
suggesting that using "drop_caches" periodically keeps your system
running in "tip top shape". Perhaps adding some kernel documentation
will increase the amount of accurate data on its use.
If we are not shrinking caches effectively, then we have real bugs.
Using drop_caches will simply mask the bugs and make them harder to
find, but certainly does not fix them, nor is it an appropriate
"workaround" to limit the size of the caches. On the contrary, there
have been bug reports on issues that turned out to be misguided use of
cache dropping.
Dropping caches is a very drastic and disruptive operation that is good
for debugging and running tests, but if it creates bug reports from
production use, kernel developers should be aware of its use.
Add a bit more documentation about it, a syslog message to track down
abusers, and vmstat drop counters to help analyze problem reports.
[akpm@linux-foundation.org: checkpatch fixes]
[hannes@cmpxchg.org: add runtime suppression control]
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03 16:21:04 -07:00
KGDB: make kgdb_breakpoint() as noinline
2014-02-26 11:16:25 +00:00
perf: Optimize group_sched_in()
2014-02-27 12:43:26 +01:00
gcov: reuse kbasename helper
2013-11-13 12:09:34 +09:00
genirq: Export symbol no_action()
2014-03-22 11:33:09 +01:00
Merge branch 'x86-asmlinkage-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-03-31 14:13:25 -07:00
Merge branches 'pm-runtime' and 'pm-sleep'
2014-03-20 13:25:54 +01:00
printk: fix syslog() overflowing user buffer
2014-02-17 12:24:45 -08:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-03-31 11:21:19 -07:00
Merge branch 'sched-idle-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-04-02 16:22:27 -07:00
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-04-01 11:00:07 -07:00
Merge branch 'for-3.15/core' of git://git.kernel.dk/linux-block
2014-04-01 19:19:15 -07:00
Ignore generated file kernel/x509_certificate_list
2013-12-10 18:21:34 +00:00
AUDIT: Allow login in non-init namespaces
2014-03-30 17:02:53 -07:00
audit: Use struct net not pid_t to remember the network namespce to reply in
2014-02-28 04:04:33 -08:00
inotify: Fix reporting of cookies for inotify events
2014-02-18 11:17:17 +01:00
inotify: Fix reporting of cookies for inotify events
2014-02-18 11:17:17 +01:00
audit: Update kdoc for audit_send_reply and audit_list_rules_send
2014-03-08 15:31:54 -08:00
execve: use 'struct filename *' for executable name passing
2014-02-05 12:54:53 -08:00
mm: do not allocate page->ptl dynamically, if spinlock_t fits to long
2013-12-20 12:25:45 -08:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
2014-04-03 09:26:18 -07:00
cgroup: fix a failure path in create_css()
2014-03-18 17:15:36 -04:00
cgroup: replace cftype->read_seq_string() with cftype->seq_show()
2013-12-05 12:28:04 -05:00
Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-04-02 12:51:41 -07:00
context_tracking: Wrap static key check into more intuitive function name
2013-12-02 20:43:14 +01:00
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2013-11-14 16:55:11 +09:00
mm: optimize put_mems_allowed() usage
2014-04-03 16:20:58 -07:00
kernel/delayacct.c: remove redundant checking in __delayacct_add_tsk()
2013-11-13 12:09:12 +09:00
switch elf_core_write_extra_phdrs() to dump_emit()
2013-11-09 00:16:23 -05:00
introduce for_each_thread() to replace the buggy while_each_thread()
2014-01-21 16:19:46 -08:00
asmlinkage: Make main_extable_sort_needed visible
2014-02-13 18:13:22 -08:00
sched/numa: Move task_numa_free() to __put_task_struct()
2014-03-11 12:05:43 +01:00
libata, freezer: avoid block device removal while system is frozen
2013-12-19 13:50:32 -05:00
Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-03-31 10:59:39 -07:00
compat: Get rid of (get|put)_compat_time(val|spec)
2014-02-02 14:09:12 -08:00
timer: Remove code redundancy while calling get_nohz_timer_target()
2014-03-20 12:35:46 +01:00
hung_task: Display every hung task warning
2014-01-25 12:13:33 +01:00
perf/x86: Warn to early_printk() in case irq_work is too slow
2014-02-21 21:49:07 +01:00
kernel: remove CONFIG_USE_GENERIC_SMP_HELPERS
2013-11-15 09:32:22 +09:00
kexec/compat: convert to COMPAT_SYSCALL_DEFINE with changing parameter types
2014-03-06 16:30:46 +01:00
execve: use 'struct filename *' for executable name passing
2014-02-05 12:54:53 -08:00
kprobes: use KSYM_NAME_LEN to size identifier buffers
2013-11-13 12:09:26 +09:00
rcu: Fix sparse warning for rcu_expedited from kernel/ksysfs.c
2014-02-26 06:35:16 -08:00
kthread: ensure locality of task_struct allocations
2014-04-03 16:20:49 -07:00
Merge branch 'x86-asmlinkage-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-03-31 14:13:25 -07:00
Merge branch 'x86-asmlinkage-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-03-31 14:13:25 -07:00
notifier: Substitute rcu_access_pointer() for rcu_dereference_raw()
2014-02-26 06:35:13 -08:00
padata: Fix wrong usage of rcu_dereference()
2013-12-05 21:28:42 +08:00
Merge branch 'x86-asmlinkage-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-03-31 14:13:25 -07:00
params: improve standard definitions
2013-12-04 14:09:46 +10:30
pid_namespace: pidns_get() should check task_active_pid_ns() != NULL
2014-04-02 16:20:21 -07:00
posix-timers: Convert abuses of BUG_ON to WARN_ON
2013-12-09 16:56:29 +01:00
mm: fix GFP_THISNODE callers and clarify
2014-03-10 17:26:19 -07:00
kernel/compat: convert to COMPAT_SYSCALL_DEFINE
2014-03-06 15:35:10 +01:00
kexec: migrate to reboot cpu
2013-12-18 19:04:50 -08:00
treewide: Fix typo in Documentation/DocBook
2014-02-19 14:58:17 +01:00
resources: Set type in __request_region()
2014-03-19 15:00:16 -06:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
2014-04-03 09:26:18 -07:00
Merge branch 'master' into for-next
2014-02-20 14:54:28 +01:00
smp: Rename __smp_call_function_single() to smp_call_function_single_async()
2014-02-24 14:47:15 -08:00
softirq: Add linux/irq.h to make it compile again
2014-03-19 11:28:14 +01:00
stop_machine: Fix^2 race between stop_two_cpus() and stop_cpus()
2014-03-11 11:33:47 +01:00
sys: Replace hardcoding of -20 and 19 with MIN_NICE and MAX_NICE
2014-02-22 18:16:19 +01:00
drop_caches: add some documentation and info message
2014-04-03 16:21:04 -07:00
kernel/sysctl_binary.c: use scnprintf() instead of snprintf()
2013-11-13 12:09:33 +09:00
KEYS: correct alignment of system_certificate_list content in assembly file
2013-12-10 18:25:28 +00:00
KEYS: correct alignment of system_certificate_list content in assembly file
2013-12-10 18:25:28 +00:00
genetlink: only pass array to genl_register_family_with_ops()
2013-11-19 16:39:05 -05:00
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-04-01 11:00:07 -07:00
rcutorture: Gracefully handle NULL cleanup hooks
2014-02-23 09:04:39 -08:00
tracing: Do not add event files for modules that fail tracepoints
2014-03-03 21:11:05 -05:00
smp: Rename __smp_call_function_single() to smp_call_function_single_async()
2014-02-24 14:47:15 -08:00
KEYS: fix uninitialized persistent_keyring_register_sem
2013-12-13 15:59:11 +00:00
user_namespace.c: Remove duplicated word in comment
2014-02-20 11:58:35 -08:00
kernel/watchdog.c: touch_nmi_watchdog should only touch local cpu not every one
2014-04-03 16:20:58 -07:00
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-04-01 11:00:07 -07:00
5509a5d27b