Huge pages are not movable so are not allocated from ZONE_MOVABLE. However,
as ZONE_MOVABLE will always have pages that can be migrated or reclaimed, it
can be used to satisfy hugepage allocations even when the system has been
running a long time. This allows an administrator to resize the hugepage pool
at runtime depending on the size of ZONE_MOVABLE.
This patch adds a new sysctl called hugepages_treat_as_movable. When a
non-zero value is written to it, future allocations for the huge page pool
will use ZONE_MOVABLE. Despite huge pages being non-movable, we do not
introduce additional external fragmentation of note as huge pages are always
the largest contiguous block we care about.
[akpm@linux-foundation.org: various fixes]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All of the clockevent notifiers expect a pointer to
an "unsigned int" cpu argument, but hrtimer_cpu_notify()
passes in a pointer to a long.
[ Discussed with and ok by Thomas Gleixner ]
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Randy Dunlap noticed that the recent comment clarifications from Andrew
had somehow gotten duplicated. Quoth Andrew: "hm, that could have been
some late-night reject-fixing."
Fix it up.
Cc: From: Andrew Morton <akpm@linux-foundation.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel/printk.c: document possible deadlock against scheduler
The printk's comment states that it can be called from every context,
which might lead to false illusion that it could be called from everywhere
without any restrictions.
This is however not true - a call to printk() could deadlock if called from
scheduler code (namely from schedule(), wake_up(), etc) on runqueue lock
when it tries to wake up klogd. Document this.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now we always use stop_machine for module insertion or deletion, we no
longer need the modlist_lock: merely disabling preemption is sufficient to
block against list manipulation. This avoids deadlock on OOPSen where we
can potentially grab the lock twice.
Bug: 8695
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Tobias Oed <tobiasoed@hotmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change cancel_work_sync() and cancel_delayed_work_sync() to return a boolean
indicating whether the work was actually cancelled. A zero return value means
that the work was not pending/queued.
Without that kind of change it is not possible to avoid flush_workqueue()
sometimes, see the next patch as an example.
Also, this patch unifies both functions and kills the (unlikely) busy-wait
loop.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Jarek Poplawski <jarkao2@o2.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Imho, the current naming of cancel_xxx workqueue functions is very confusing.
cancel_delayed_work()
cancel_rearming_delayed_work()
cancel_rearming_delayed_workqueue() // obsolete
cancel_work_sync()
This looks as if the first 2 functions differ in "type" of their argument
which is not true any longer, nowadays the difference is the behaviour.
The semantics of cancel_rearming_delayed_work(dwork) was changed
significantly, it doesn't require that dwork rearms itself, and cancels dwork
synchronously.
Rename it to cancel_delayed_work_sync(). This matches cancel_delayed_work()
and cancel_work_sync(). Re-create cancel_rearming_delayed_work() as a simple
inline obsolete wrapper, like cancel_rearming_delayed_workqueue().
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Jarek Poplawski <jarkao2@o2.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This follows a suggestion from Chuck Ebbert on how to make seccomp
absolutely zerocost in schedule too. The only remaining footprint of
seccomp is in terms of the bzImage size that becomes a few bytes (perhaps
even a few kbytes) larger, measure it if you care in the embedded.
Signed-off-by: Andrea Arcangeli <andrea@cpushare.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reduces the memory footprint and it enforces that only the current
task can enable seccomp on itself (this is a requirement for a
strightforward [modulo preempt ;) ] TIF_NOTSC implementation).
Signed-off-by: Andrea Arcangeli <andrea@cpushare.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hopefully this will help people to understand the new regime.
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The recent PRIVATE and REQUEUE_PI changes to the futex code made it hard to
read. Tidy it up.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Improve performance of sys_time(). sys_time() returns time in seconds, but
it does so by calling do_gettimeofday() and then returning the tv_sec
portion of the GTOD time. But the data structure "xtime", which is updated
by every timer/scheduler tick, already offers HZ granularity time.
The patch improves the sysbench OLTP macrobenchmark significantly:
2.6.22-rc6:
#threads
1: transactions: 3733 (373.21 per sec.)
2: transactions: 6676 (667.46 per sec.)
3: transactions: 6957 (695.50 per sec.)
4: transactions: 7055 (705.48 per sec.)
5: transactions: 6596 (659.33 per sec.)
2.6.22-rc6 + sys_time.patch:
1: transactions: 4005 (400.47 per sec.)
2: transactions: 7379 (737.77 per sec.)
3: transactions: 7347 (734.49 per sec.)
4: transactions: 7468 (746.65 per sec.)
5: transactions: 7428 (742.47 per sec.)
Mixed API uses of gettimeofday() and time() are guaranteed to be coherent
via the use of a at-most-once-per-second slowpath that updates xtime.
[akpm@linux-foundation.org: build fixes]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While working on unshare support for the network namespace I noticed we
were putting clone flags in an int. Which is weird because the syscall
uses unsigned long and we at least need an unsigned to properly hold all of
the unshare flags.
So to make the code consistent, this patch updates the code to use
unsigned long instead of int for the clone flags in those places
where we get it wrong today.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
OpenVZ Linux kernel team has discovered the problem with 32bit quota tools
working on 64bit architectures. In 2.6.10 kernel sys32_quotactl() function
was replaced by sys_quotactl() with the comment "sys_quotactl seems to be
32/64bit clean, enable it for 32bit" However this isn't right. Look at
if_dqblk structure:
struct if_dqblk {
__u64 dqb_bhardlimit;
__u64 dqb_bsoftlimit;
__u64 dqb_curspace;
__u64 dqb_ihardlimit;
__u64 dqb_isoftlimit;
__u64 dqb_curinodes;
__u64 dqb_btime;
__u64 dqb_itime;
__u32 dqb_valid;
};
For 32 bit quota tools sizeof(if_dqblk) == 0x44.
But for 64 bit kernel its size is 0x48, 'cause of alignment!
Thus we got a problem. Attached patch reintroduce sys32_quotactl() function,
that handles this and related situations.
[michal.k.k.piotrowski@gmail.com: build fix]
[akpm@linux-foundation.org: Make it link with CONFIG_QUOTA=n]
Signed-off-by: Vasily Tarasov <vtaras@openvz.org>
Cc: Andi Kleen <ak@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Jan Kara <jack@ucw.cz>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix parameter name in audit_core_dumps for kerneldoc.
Signed-off-by: Henrik Kretzschmar <henne@nachtwindheim.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It should improve performance in some scenarii where a lot of
these nsproxy objects are created by unsharing namespaces. This is
a typical use of virtual servers that are being created or entered.
This is also a good tool to find leaks and gather statistics on
namespace usage.
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dup_mnt_ns() and clone_uts_ns() return NULL on failure. This is wrong,
create_new_namespaces() uses ERR_PTR() to catch an error. This means that the
subsequent create_new_namespaces() will hit BUG_ON() in copy_mnt_ns() or
copy_utsname().
Modify create_new_namespaces() to also use the errors returned by the
copy_*_ns routines and not to systematically return ENOMEM.
[oleg@tv-sign.ru: better changelog]
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch enables the unshare of user namespaces.
It adds a new clone flag CLONE_NEWUSER and implements copy_user_ns() which
resets the current user_struct and adds a new root user (uid == 0)
For now, unsharing the user namespace allows a process to reset its
user_struct accounting and uid 0 in the new user namespace should be contained
using appropriate means, for instance selinux
The plan, when the full support is complete (all uid checks covered), is to
keep the original user's rights in the original namespace, and let a process
become uid 0 in the new namespace, with full capabilities to the new
namespace.
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Acked-by: Pavel Emelianov <xemul@openvz.org>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Andrew Morgan <agm@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Basically, it will allow a process to unshare its user_struct table,
resetting at the same time its own user_struct and all the associated
accounting.
A new root user (uid == 0) is added to the user namespace upon creation.
Such root users have full privileges and it seems that theses privileges
should be controlled through some means (process capabilities ?)
The unshare is not included in this patch.
Changes since [try #4]:
- Updated get_user_ns and put_user_ns to accept NULL, and
get_user_ns to return the namespace.
Changes since [try #3]:
- moved struct user_namespace to files user_namespace.{c,h}
Changes since [try #2]:
- removed struct user_namespace* argument from find_user()
Changes since [try #1]:
- removed struct user_namespace* argument from find_user()
- added a root_user per user namespace
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: Pavel Emelianov <xemul@openvz.org>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Andrew Morgan <agm@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CONFIG_UTS_NS and CONFIG_IPC_NS have very little value as they only
deactivate the unshare of the uts and ipc namespaces and do not improve
performance.
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Acked-by: "Serge E. Hallyn" <serue@us.ibm.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add TTY input auditing, used to audit system administrator's actions. This is
required by various security standards such as DCID 6/3 and PCI to provide
non-repudiation of administrator's actions and to allow a review of past
actions if the administrator seems to overstep their duties or if the system
becomes misconfigured for unknown reasons. These requirements do not make it
necessary to audit TTY output as well.
Compared to an user-space keylogger, this approach records TTY input using the
audit subsystem, correlated with other audit events, and it is completely
transparent to the user-space application (e.g. the console ioctls still
work).
TTY input auditing works on a higher level than auditing all system calls
within the session, which would produce an overwhelming amount of mostly
useless audit events.
Add an "audit_tty" attribute, inherited across fork (). Data read from TTYs
by process with the attribute is sent to the audit subsystem by the kernel.
The audit netlink interface is extended to allow modifying the audit_tty
attribute, and to allow sending explanatory audit events from user-space (for
example, a shell might send an event containing the final command, after the
interactive command-line editing and history expansion is performed, which
might be difficult to decipher from the TTY input alone).
Because the "audit_tty" attribute is inherited across fork (), it would be set
e.g. for sshd restarted within an audited session. To prevent this, the
audit_tty attribute is cleared when a process with no open TTY file
descriptors (e.g. after daemon startup) opens a TTY.
See https://www.redhat.com/archives/linux-audit/2007-June/msg00000.html for a
more detailed rationale document for an older version of this patch.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Miloslav Trmac <mitr@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Paul Fulghum <paulkf@microgate.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently we handle spurious IRQ activity based upon seeing a lot of
invalid interrupts, and we clear things back on the base of lots of valid
interrupts.
Unfortunately in some cases you get legitimate invalid interrupts caused by
timing asynchronicity between the PCI bus and the APIC bus when disabling
interrupts and pulling other tricks. In this case although the spurious
IRQs are not a problem our unhandled counters didn't clear and they act as
a slow running timebomb. (This is effectively what the serial port/tty
problem that was fixed by clearing counters when registering a handler
showed up)
It's easy enough to add a second parameter - time. This means that if we
see a regular stream of harmless spurious interrupts which are not harming
processing we don't go off and do something stupid like disable the IRQ
after a month of running. OTOH lockups and performance killers show up a
lot more than 10/second
[akpm@linux-foundation.org: cleanup]
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make available to the user the following task and process performance
statistics:
* Involuntary Context Switches (task_struct->nivcsw)
* Voluntary Context Switches (task_struct->nvcsw)
Statistics information is available from:
1. taskstats interface (Documentation/accounting/)
2. /proc/PID/status (task only).
This data is useful for detecting hyperactivity patterns between processes.
[akpm@linux-foundation.org: cleanup]
Signed-off-by: Maxim Uvarov <muvarov@ru.mvista.com>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jay Lan <jlan@engr.sgi.com>
Cc: Jonathan Lim <jlim@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I forgot to remove capability.h from mm.h while removing sched.h! This
patch remedies that, because the only inline function which was using
CAP_something was made out of line.
Cross-compile tested without regressions on:
all powerpc defconfigs
all mips defconfigs
all m68k defconfigs
all arm defconfigs
all ia64 defconfigs
alpha alpha-allnoconfig alpha-defconfig alpha-up
arm
i386 i386-allnoconfig i386-defconfig i386-up
ia64 ia64-allnoconfig ia64-defconfig ia64-up
m68k
mips
parisc parisc-allnoconfig parisc-defconfig parisc-up
powerpc powerpc-up
s390 s390-allnoconfig s390-defconfig s390-up
sparc sparc-allnoconfig sparc-defconfig sparc-up
sparc64 sparc64-allnoconfig sparc64-defconfig sparc64-up
um-x86_64
x86_64 x86_64-allnoconfig x86_64-defconfig x86_64-up
as well as my two usual configs.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a flag in /proc/timer_stats to indicate deferrable timers. This will
let developers/users to differentiate between types of tiemrs in
/proc/timer_stats.
Deferrable timer and normal timer will appear in /proc/timer_stats as below.
10D, 1 swapper queue_delayed_work_on (delayed_work_timer_fn)
10, 1 swapper queue_delayed_work_on (delayed_work_timer_fn)
Also version of timer_stats changes from v0.1 to v0.2
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow printk_time to be enabled or disabled at boot time. Previously it
could be enabled only, but not disabled.
Change printk_time from an int to a bool since that's what it is. Make its
logical (exposed) name just be "time" (was "printk_time").
Note: Changes kernel boot option syntax from "time" to "printk.time=value".
Since printk_time is declared as a module_param, it can also be
changed at run-time by modifying
/sys/module/printk/parameters/time
to a value of 1/Y/y to enabled it or 0/N/n to disable it.
Since printk_time is declared as a module_param, its value can also
be set at boot-time by using
linux printk.time=<bool>
If the "time" boot option is used, print a message that it is deprecated
and will be removed.
Note its planned removal in feature-removal-schedule.txt.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Not called by anything in tree.
Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
cpuset.c:update_nodemask() uses a write_lock_irq() on tasklist_lock to
block concurrent forks; a read_lock() suffices and is less intrusive.
Signed-off-by: Paul Menage<menage@google.com>
Acked-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add the print-fatal-signals=1 boot option and the
/proc/sys/kernel/print-fatal-signals runtime switch.
This feature prints some minimal information about userspace segfaults to
the kernel console. This is useful to find early bootup bugs where
userspace debugging is very hard.
Defaults to off.
[akpm@linux-foundation.org: Don't add new sysctl numbers]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Here there is not need even in .show callback altering. The original code
passes list_head in *v.
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix ksoftirqd termination on cpu hotplug with naughty real time process.
Assuming the following case:
- Try to hot remove CPU2 from CPU1.
- There is a real time process on CPU2, and that process doesn't sleep at all.
- That rt process and ksoftirqd/2 is migrated to the CPU0
Then ksoftirqd/2 can't stop becasue that rt process runs everlastingly on
CPU0, and CPU1 waiting the ksoftirqd/2's termination hangs up. To fix this
problem, set the priority of ksoftirqd/2 to max one before kthread_stop().
[akpm@linux-foundation.org: fix warning]
Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
stop_machine_run() does its work on "kstopmachine" thread having max
priority. However that thread get such priority after woken up.
Therefore, in the following case ...
- "kstopmachine" try to run on CPU1
- There is a real time process which doesn't relinquish CPU time
voluntary on CPU1
... "kstopmachine" can't start to run and the CPU on which
stop_machine_run() is runing hangs up. To fix this problem, call
sched_setscheduler() before waking up that thread.
Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 411187fb05 caused uptime not to increase
during suspend. This may cause confusion so I restore the old behaviour by
using the boot based time instead of monotonic for uptime.
Signed-off-by: Tomas Janousek <tjanouse@redhat.com>
Acked-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 411187fb05 caused boot time to move and
process start times to become invalid after suspend. Using boot based time
for those restores the old behaviour and fixes the issue.
[akpm@linux-foundation.org: little cleanup]
Signed-off-by: Tomas Janousek <tjanouse@redhat.com>
Cc: Tomas Smetana <tsmetana@redhat.com>
Acked-by: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The commits
411187fb05 (GTOD: persistent clock support)
c1d370e167 (i386: use GTOD persistent clock
support)
changed the monotonic time so that it no longer jumps after resume, but it's
not possible to use it for boot time and process start time calculations then.
Also, the uptime no longer increases during suspend.
I add a variable to track the wall_to_monotonic changes, a function to get the
real boot time and a function to get the boot based time from the monotonic
one.
[akpm@linux-foundation.org: remove exports, add comment]
Signed-off-by: Tomas Janousek <tjanouse@redhat.com>
Cc: Tomas Smetana <tsmetana@redhat.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
.. which modpost started warning about.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make zonelist creation policy selectable from sysctl/boot option v6.
This patch makes NUMA's zonelist (of pgdat) order selectable.
Available order are Default(automatic)/ Node-based / Zone-based.
[Default Order]
The kernel selects Node-based or Zone-based order automatically.
[Node-based Order]
This policy treats the locality of memory as the most important parameter.
Zonelist order is created by each zone's locality. This means lower zones
(ex. ZONE_DMA) can be used before higher zone (ex. ZONE_NORMAL) exhausion.
IOW. ZONE_DMA will be in the middle of zonelist.
current 2.6.21 kernel uses this.
Pros.
* A user can expect local memory as much as possible.
Cons.
* lower zone will be exhansted before higher zone. This may cause OOM_KILL.
Maybe suitable if ZONE_DMA is relatively big and you never see OOM_KILL
because of ZONE_DMA exhaution and you need the best locality.
(example)
assume 2 node NUMA. node(0) has ZONE_DMA/ZONE_NORMAL, node(1) has ZONE_NORMAL.
*node(0)'s memory allocation order:
node(0)'s NORMAL -> node(0)'s DMA -> node(1)'s NORMAL.
*node(1)'s memory allocation order:
node(1)'s NORMAL -> node(0)'s NORMAL -> node(0)'s DMA.
[Zone-based order]
This policy treats the zone type as the most important parameter.
Zonelist order is created by zone-type order. This means lower zone
never be used bofere higher zone exhaustion.
IOW. ZONE_DMA will be always at the tail of zonelist.
Pros.
* OOM_KILL(bacause of lower zone) occurs only if the whole zones are exhausted.
Cons.
* memory locality may not be best.
(example)
assume 2 node NUMA. node(0) has ZONE_DMA/ZONE_NORMAL, node(1) has ZONE_NORMAL.
*node(0)'s memory allocation order:
node(0)'s NORMAL -> node(1)'s NORMAL -> node(0)'s DMA.
*node(1)'s memory allocation order:
node(1)'s NORMAL -> node(0)'s NORMAL -> node(0)'s DMA.
bootoption "numa_zonelist_order=" and proc/sysctl is supporetd.
command:
%echo N > /proc/sys/vm/numa_zonelist_order
Will rebuild zonelist in Node-based order.
command:
%echo Z > /proc/sys/vm/numa_zonelist_order
Will rebuild zonelist in Zone-based order.
Thanks to Lee Schermerhorn, he gives me much help and codes.
[Lee.Schermerhorn@hp.com: add check_highest_zone to build_zonelists_in_zone_order]
[akpm@linux-foundation.org: build fix]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: "jesse.barnes@intel.com" <jesse.barnes@intel.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Beacuse SERIAL_PORT_DFNS is removed from include/asm-i386/serial.h and
include/asm-x86_64/serial.h. the serial8250_ports need to be probed late in
serial initializing stage. the console_init=>serial8250_console_init=>
register_console=>serial8250_console_setup will return -ENDEV, and console
ttyS0 can not be enabled at that time. need to wait till uart_add_one_port in
drivers/serial/serial_core.c to call register_console to get console ttyS0.
that is too late.
Make early_uart to use early_param, so uart console can be used earlier. Make
it to be bootconsole with CON_BOOT flag, so can use console handover feature.
and it will switch to corresponding normal serial console automatically.
new command line will be:
console=uart8250,io,0x3f8,9600n8
console=uart8250,mmio,0xff5e0000,115200n8
or
earlycon=uart8250,io,0x3f8,9600n8
earlycon=uart8250,mmio,0xff5e0000,115200n8
it will print in very early stage:
Early serial console at I/O port 0x3f8 (options '9600n8')
console [uart0] enabled
later for console it will print:
console handover: boot [uart0] -> real [ttyS0]
Signed-off-by: <yinghai.lu@sun.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Gerd Hoffmann <kraxel@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
for earlyprintk=ttyS0,9600 console=tty0 console=ttyS0,9600n8
the handover will happen from earlyser0 to tty0. but what we want is to
hand over to ttyS0.
Later with serial-convert-early_uart-to-earlycon-for-8250.patch,
console=tty0 console=uart8250,io,0x3f8,9600n8
will handover to ttyS0 instead of tty0.
Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Gerd Hoffmann <kraxel@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change name to buf according to the usage as name + index
Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Gerd Hoffmann <kraxel@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
KVM wants a notification when a cpu is about to die, so it can disable
hardware extensions, but at a time when user processes cannot be scheduled
on the cpu, so it doesn't try to use virtualization extensions after they
have been disabled.
This adds a CPU_DYING notification. The notification is called in atomic
context on the doomed cpu.
Signed-off-by: Avi Kivity <avi@qumranet.com>
improve the comments around the wmult array (which controls the weight
of niced tasks). Clarify that to achieve a 10% difference in CPU
utilization, a weight multiplier of 1.25 has to be used.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Roman Zippel noticed another inconsistency of the wmult table.
wmult[16] has a missing digit.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'splice-2.6.23' of git://git.kernel.dk/data/git/linux-2.6-block:
splice: fix offset mangling with direct splicing (sendfile)
security: revalidate rw permissions for sys_splice and sys_vmsplice
relay: fixup kerneldoc comment
relay: fix bogus cast in subbuf_splice_actor()
* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched:
[PATCH] sched: small topology.h cleanup
[PATCH] sched: fix show_task()/show_tasks() output
[PATCH] sched: remove stale version info from kernel/sched_debug.c
[PATCH] sched: allow larger granularity
[PATCH] sched: fix prio_to_wmult[] for nice 1
[ I re-did the commits to get rid of some bogus merge commit that
Ingo had. - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fix show_task()/show_tasks() output:
- there's no sibling info anymore
- the fields were not aligned properly with the description
- get rid of the lazy-TLB output: it's been quite some time since
we last had a bug there, and when we had a bug it wasnt helped a
bit by this debug output.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel/sched_debug.c referred to CFS -v20, but there's no CFS versioning
needed within the upstream kernel.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There's a typo in the values in prio_to_wmult[] for nice level 1. While
it did not cause bad CPU distribution, but caused more rescheduling
between nice-0 and nice-1 tasks than necessary.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current code that sets the read position in subbuf_splice_actor may
give erroneous results if the buffer size isn't a power of 2. This
patch fixes the problem.
Signed-off-by: Tom Zanussi <zanussi@us.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/selinux-2.6:
security: unexport mmap_min_addr
SELinux: use SECINITSID_NETMSG instead of SECINITSID_UNLABELED for NetLabel
security: Protection for exploiting null dereference using mmap
SELinux: Use %lu for inode->i_no when printing avc
SELinux: allow preemption between transition permission checks
selinux: introduce schedule points in policydb_destroy()
selinux: add selinuxfs structure for object class discovery
selinux: change sel_make_dir() to specify inode counter.
selinux: rename sel_remove_bools() for more general usage.
selinux: add support for querying object classes and permissions from the running policy
Add a new security check on mmap operations to see if the user is attempting
to mmap to low area of the address space. The amount of space protected is
indicated by the new proc tunable /proc/sys/vm/mmap_min_addr and defaults to
0, preserving existing behavior.
This patch uses a new SELinux security class "memprotect." Policy already
contains a number of allow rules like a_t self:process * (unconfined_t being
one of them) which mean that putting this check in the process class (its
best current fit) would make it useless as all user processes, which we also
want to protect against, would be allowed. By taking the memprotect name of
the new class it will also make it possible for us to move some of the other
memory protect permissions out of 'process' and into the new class next time
we bump the policy version number (which I also think is a good future idea)
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
sysfs is now completely out of driver/module lifetime game. After
deletion, a sysfs node doesn't access anything outside sysfs proper,
so there's no reason to hold onto the attribute owners. Note that
often the wrong modules were accounted for as owners leading to
accessing removed modules.
This patch kills now unnecessary attribute->owner. Note that with
this change, userland holding a sysfs node does not prevent the
backing module from being unloaded.
For more info regarding lifetime rule cleanup, please read the
following message.
http://article.gmane.org/gmane.linux.kernel/510293
(tweaked by Greg to not delete the field just yet, to make it easier to
merge things properly.)
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The name 'pin' was badly chosen, it doesn't pin a pipe buffer
in the most commonly used sense in the kernel. So change the
name to 'confirm', after debating this issue with Hugh
Dickins a bit.
A good return from ->confirm() means that the buffer is really
there, and that the contents are good.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
It cleans up the relay splice implementation a lot, and gets rid of
a lot of internal pipe knowledge that should not be in there.
Plus fixes for padding and partial first page (and lots more) from
Tom Zanussi.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
We need to move even more stuff into the header so that folks can use
the splice_to_pipe() implementation instead of open-coding a lot of
pipe knowledge (see relay implementation), so move to our own header
file finally.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
add credits for recent major scheduler contributions:
Con Kolivas, for pioneering the fair-scheduling approach
Peter Williams, for smpnice
Mike Galbraith, for interactivity tuning of CFS
Srivatsa Vaddagiri, for group scheduling enhancements
Signed-off-by: Ingo Molnar <mingo@elte.hu>
clean up the sleep_on() APIs:
- do not use fastcall
- replace fragile macro magic with proper inline functions
Signed-off-by: Ingo Molnar <mingo@elte.hu>
4 small style cleanups to sched.c: checkpatch.pl is now happy about
the totality of sched.c [ignoring false positives] - yay! ;-)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
do not set softirqs to nice +19. _If_ for whatever reason
we missed to process some high-prio softirq and woke up
ksoftirqd, we should give it a fair chance to actually
get some work done, even if the system is under load.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
add CFS debug sysctls: only tweakable if SCHED_DEBUG is enabled.
This allows for faster debugging of scheduler problems.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
track TSC-unstable events and propagate it to the scheduler code.
Also allow sched_clock() to be used when the TSC is unstable,
the rq_clock() wrapper creates a reliable clock out of it.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
apply the CFS core code.
this change switches over the scheduler core to CFS's modular
design and makes use of kernel/sched_fair/rt/idletask.c to implement
Linux's scheduling policies.
thanks to Andrew Morton and Thomas Gleixner for lots of detailed review
feedback and for fixlets.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
remove the sleep-bonus interactivity code from the core scheduler.
scheduling policy is implemented in the policy modules, and CFS does
not need such type of heuristics.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
remove the expired_starving() heuristics from the core scheduler.
CFS does not need it, and this did not really work well in practice
anyway, due to the rq->nr_running multiplier to STARVATION_LIMIT.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
remove the sleep_type heuristics from the core scheduler - scheduling
policy is implemented in the scheduling-policy modules. (and CFS does
not use this type of sleep-type heuristics)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
cleanup: move dequeue/enqueue_task() to a more logical place, to
not split up __normal_prio()/normal_prio().
Signed-off-by: Ingo Molnar <mingo@elte.hu>
move resched_task()/resched_cpu() into the 'public interfaces'
section of sched.c, for use by kernel/sched_fair/rt/idletask.c
Signed-off-by: Ingo Molnar <mingo@elte.hu>
add rq_clock()/__rq_clock(), a robust wrapper around sched_clock(),
used by CFS. It protects against common type of sched_clock() problems
(caused by hardware): time warps forwards and backwards.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
add the CFS rq data types to sched.c.
(the old scheduler fields are still intact, they are removed
by a later patch)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
add kernel/sched_idletask.c - which implements the idle thread
scheduling class. This further simplifies sched.c (under CFS),
for example a number of 'if (p == rq->idle)' type of special-cases
can be removed from sched.c, and schedule() gets simpler too.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
add kernel/sched_rt.c: SCHED_FIFO/SCHED_RR support. The behavior
and semantics of SCHED_FIFO/SCHED_RR tasks is unchanged.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
create sched_stats.h and move sched.c schedstats code into it.
This cleans up sched.c a bit.
no code changes are caused by this patch.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
add the init_idle_bootup_task() callback to the bootup thread,
unused at the moment. (CFS will use it to switch the scheduling
class of the boot thread to the idle class)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
remove sched_exit(): the elaborate dance of us trying to recover
timeslices given to child tasks never really worked.
CFS does not need it either.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
the SMP load-balancer uses the boot-time migration-cost estimation
code to attempt to improve the quality of balancing. The reason for
this code is that the discrete priority queues do not preserve
the order of scheduling accurately, so the load-balancer skips
tasks that were running on a CPU 'recently'.
this code is fundamental fragile: the boot-time migration cost detector
doesnt really work on systems that had large L3 caches, it caused boot
delays on large systems and the whole cache-hot concept made the
balancing code pretty undeterministic as well.
(and hey, i wrote most of it, so i can say it out loud that it sucks ;-)
under CFS the same purpose of cache affinity can be achieved without
any special cache-hot special-case: tasks are sorted in the 'timeline'
tree and the SMP balancer picks tasks from the left side of the
tree, thus the most cache-cold task is balanced automatically.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
enum idle_type (used by the load-balancer) clashes with the
SCHED_IDLE name that we want to introduce. 'CPU_IDLE' instead
of 'SCHED_IDLE' is more descriptive as well.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
