aboutsummaryrefslogtreecommitdiff
path: root/kernel
AgeCommit message (Collapse)Author
2007-10-16m32r: convert to generic sys_ptraceChristoph Hellwig
Convert m32r to the generic sys_ptrace. The conversion requires an architecture hook after ptrace_attach which this patch adds. The hook will also be needed for a conersion of ia64 to the generic ptrace code. Thanks to Hirokazu Takata for fixing a bug in the first version of this code. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Hirokazu Takata <takata@linux-m32r.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16hugetlb: Add hugetlb_dynamic_pool sysctlAdam Litke
The maximum size of the huge page pool can be controlled using the overall size of the hugetlb filesystem (via its 'size' mount option). However in the common case the this will not be set as the pool is traditionally fixed in size at boot time. In order to maintain the expected semantics, we need to prevent the pool expanding by default. This patch introduces a new sysctl controlling dynamic pool resizing. When this is enabled the pool will expand beyond its base size up to the size of the hugetlb filesystem. It is disabled by default. Signed-off-by: Adam Litke <agl@us.ibm.com> Acked-by: Andy Whitcroft <apw@shadowen.org> Acked-by: Dave McCracken <dave.mccracken@oracle.com> Cc: William Irwin <bill.irwin@oracle.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Ken Chen <kenchen@google.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16memory unplug: memory hotplug cleanupKAMEZAWA Hiroyuki
A clean up patch for "scanning memory resource [start, end)" operation. Now, find_next_system_ram() function is used in memory hotplug, but this interface is not easy to use and codes are complicated. This patch adds walk_memory_resouce(start,len,arg,func) function. The function 'func' is called per valid memory resouce range in [start,pfn). [pbadari@us.ibm.com: Error handling in walk_memory_resource()] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16Group short-lived and reclaimable kernel allocationsMel Gorman
This patch marks a number of allocations that are either short-lived such as network buffers or are reclaimable such as inode allocations. When something like updatedb is called, long-lived and unmovable kernel allocations tend to be spread throughout the address space which increases fragmentation. This patch groups these allocations together as much as possible by adding a new MIGRATE_TYPE. The MIGRATE_RECLAIMABLE type is for allocations that can be reclaimed on demand, but not moved. i.e. they can be migrated by deleting them and re-reading the information from elsewhere. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16Memoryless nodes: Use N_HIGH_MEMORY for cpusetsChristoph Lameter
cpusets try to ensure that any node added to a cpuset's mems_allowed is on-line and contains memory. The assumption was that online nodes contained memory. Thus, it is possible to add memoryless nodes to a cpuset and then add tasks to this cpuset. This results in continuous series of oom-kill and apparent system hang. Change cpusets to use node_states[N_HIGH_MEMORY] [a.k.a. node_memory_map] in place of node_online_map when vetting memories. Return error if admin attempts to write a non-empty mems_allowed node mask containing only memoryless-nodes. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Bob Picco <bob.picco@hp.com> Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mel@skynet.ie> Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16Memoryless nodes: Allow profiling data to fall back to other nodesChristoph Lameter
Processors on memoryless nodes must be able to fall back to remote nodes in order to get a profiling buffer. This may lead to excessive NUMA traffic but I think we should allow this rather than failing. Signed-off-by: Christoph Lameter <clameter@sgi.com> Acked-by: Nishanth Aravamudan <nacc@us.ibm.com> Acked-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Acked-by: Bob Picco <bob.picco@hp.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mel@skynet.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16x86: optimize page faults like all other achitectures and kill notifier cruftChristoph Hellwig
x86(-64) are the last architectures still using the page fault notifier cruft for the kprobes page fault hook. This patch converts them to the proper direct calls, and removes the now unused pagefault notifier bits aswell as the cruft in kprobes.c that was related to this mess. I know Andi didn't really like this, but all other architecture maintainers agreed the direct calls are much better and besides the obvious cruft removal a common way of dealing with kprobes across architectures is important aswell. [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: fix sparc64] Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Andi Kleen <ak@suse.de> Cc: <linux-arch@vger.kernel.org> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16Convert cpu_sibling_map to be a per cpu variableMike Travis
Convert cpu_sibling_map from a static array sized by NR_CPUS to a per_cpu variable. This saves sizeof(cpumask_t) * NR unused cpus. Access is mostly from startup and CPU HOTPLUG functions. Signed-off-by: Mike Travis <travis@sgi.com> Cc: Andi Kleen <ak@suse.de> Cc: Christoph Lameter <clameter@sgi.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16slow down printk during bootRandy Dunlap
Optionally add a boot delay after each kernel printk() call, crudely measured in milliseconds, with a maximum delay of 10 seconds per printk. Enable CONFIG_BOOT_PRINTK_DELAY=y and then add (e.g.): "lpj=loops_per_jiffy boot_delay=100" to the kernel command line. It has been useful in cases like "during boot, my machine just reboots or the screen goes black" by slowing down printk, (and adding initcall_debug), we can usually see the last thing that happened before the lights went out which is usually a valuable clue. [akpm@linux-foundation.org: not all architectures implement CONFIG_HZ] [akpm@linux-foundation.org: fix lots of stuff] [bunk@stusta.de: kernel/printk.c: make 2 variables static] [heiko.carstens@de.ibm.com: fix slow down printk on boot compile error] Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16Consolidate PTRACE_DETACHAlexey Dobriyan
Identical handlers of PTRACE_DETACH go into ptrace_request(). Not touching compat code. Not touching archs that don't call ptrace_request. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Acked-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-15Merge git://git.linux-nfs.org/pub/linux/nfs-2.6Linus Torvalds
* git://git.linux-nfs.org/pub/linux/nfs-2.6: (131 commits) NFSv4: Fix a typo in nfs_inode_reclaim_delegation NFS: Add a boot parameter to disable 64 bit inode numbers NFS: nfs_refresh_inode should clear cache_validity flags on success NFS: Fix a connectathon regression in NFSv3 and NFSv4 NFS: Use nfs_refresh_inode() in ops that aren't expected to change the inode SUNRPC: Don't call xprt_release in call refresh SUNRPC: Don't call xprt_release() if call_allocate fails SUNRPC: Fix buggy UDP transmission [23/37] Clean up duplicate includes in [2.6 patch] net/sunrpc/rpcb_clnt.c: make struct rpcb_program static SUNRPC: Use correct type in buffer length calculations SUNRPC: Fix default hostname created in rpc_create() nfs: add server port to rpc_pipe info file NFS: Get rid of some obsolete macros NFS: Simplify filehandle revalidation NFS: Ensure that nfs_link() returns a hashed dentry NFS: Be strict about dentry revalidation when doing exclusive create NFS: Don't zap the readdir caches upon error NFS: Remove the redundant nfs_reval_fsid() NFSv3: Always use directory post-op attributes in nfs3_proc_lookup ... Fix up trivial conflict due to sock_owned_by_user() cleanup manually in net/sunrpc/xprtsock.c
2007-10-15Merge branch 'v2.6.24-lockdep' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/peterz/linux-2.6-lockdep * 'v2.6.24-lockdep' of git://git.kernel.org/pub/scm/linux/kernel/git/peterz/linux-2.6-lockdep: lockdep: annotate dir vs file i_mutex lockdep: per filesystem inode lock class lockdep: annotate kprobes irq fiddling lockdep: annotate rcu_read_{,un}lock{,_bh} lockdep: annotate journal_start() lockdep: s390: connect the sysexit hook lockdep: x86_64: connect the sysexit hook lockdep: i386: connect the sysexit hook lockdep: syscall exit check lockdep: fixup mutex annotations lockdep: fix mismatched lockdep_depth/curr_chain_hash lockdep: Avoid /proc/lockdep & lock_stat infinite output lockdep: maintainers
2007-10-15sched: sync wakeups preempt tooIngo Molnar
make sure sync wakeups preempt too - the scheduler will not overschedule as we've got various throttles against that. As a result, sync wakeups can be used more widely in the kernel (to signal wakeup affinity between tasks), and no arbitrary latencies will be introduced either. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: affine sync wakeupsIngo Molnar
make sync wakeups affine for cache-cold tasks: if a cache-cold task is woken up by a sync wakeup then use the opportunity to migrate it straight away. (the two tasks are 'related' because they communicate) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: guest CPU accounting: maintain stats in account_system_time()Laurent Vivier
modify account_system_time() to add cputime to cpustat->guest if we are running a VCPU. We add this cputime to cpustat->user instead of cpustat->system because this part of KVM code is in fact user code although it is executed in the kernel. We duplicate VCPU time between guest and user to allow an unmodified "top(1)" to display correct value. A modified "top(1)" is able to display good cpu user time and cpu guest time by subtracting cpu guest time from cpu user time. Update "gtime" in task_struct accordingly. Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Acked-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: guest CPU accounting: add guest-CPU /proc/<pid>/stat fieldsLaurent Vivier
like for cpustat, introduce the "gtime" (guest time of the task) and "cgtime" (guest time of the task children) fields for the tasks. Modify signal_struct and task_struct. Modify /proc/<pid>/stat to display these new fields. Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Acked-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: domain sysctl fixes: add terminator commentMilton Miller
we had an incorrect-terminator bug in sd_alloc_ctl_domain_table() before, so add a comment that documents it. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: domain sysctl fixes: do not crash on allocation failureMilton Miller
Now that we are calling this at runtime, a more relaxed error path is suggested. If an allocation fails, we just register the partial table, which will show empty directories. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: domain sysctl fixes: unregister the sysctl table before domainsMilton Miller
Unregister and free the sysctl table before destroying domains, then rebuild and register after creating the new domains. This prevents the sysctl table from pointing to freed memory for root to write. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: domain sysctl fixes: use for_each_online_cpu()Milton Miller
init_sched_domain_sysctl was walking cpus 0-n and referencing per_cpu variables. If the cpus_possible mask is not contigious this will result in a crash referencing unallocated data. If the online mask is not contigious then we would show offline cpus and miss online ones. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: domain sysctl fixes: use kcalloc()Milton Miller
kcalloc checks for n * sizeof(element) overflows and it zeros. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15Make scheduler debug file operations constArjan van de Ven
In general, struct file_operations are const in the kernel, to not have false cacheline sharing and to catch bugs at compiletime with accidental writes to them. The new scheduler code introduces a new non-const one; fix this up. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: allow the immediate migration of cache-cold tasksIngo Molnar
allow the immediate migration of cache-cold tasks. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: debug, improve migration statisticsIngo Molnar
add new migration statistics when SCHED_DEBUG and SCHEDSTATS is enabled. Available in /proc/<PID>/sched. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: debug: increase width of debug lineIngo Molnar
increase width of debug line - in preparation of more debugging info. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: activate task_hot() only on fair-scheduled tasksPeter Zijlstra
activate task_hot() only for fair-scheduled tasks (i.e. disable it for RT tasks). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: reintroduce cache-hot affinityIngo Molnar
reintroduce a simplified version of cache-hot/cold scheduling affinity. This improves performance with certain SMP workloads, such as sysbench. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: speed up context-switches a bitIngo Molnar
speed up context-switches a bit by not clearing p->exec_start. (as a side-effect, this also makes p->exec_start a universal timestamp available to cache-hot estimations.) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: do not wakeup-preempt with SCHED_BATCH tasksIngo Molnar
do not wakeup-preempt with SCHED_BATCH tasks, their preemption is batched too, driven by the tick. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: generate uevents for user creation/destructionSrivatsa Vaddagiri
Generate uevents when a user is being created/destroyed. These events can be used to configure cpu share of a new user. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: do not normalize kernel threads via SysRq-NIngo Molnar
do not normalize kernel threads via SysRq-N: the migration threads, softlockup threads, etc. might be essential for the system to function properly. So only zap user tasks. pointed out by Andi Kleen. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: remove stale comment from sched_group_set_shares()Andi Kleen
remove stale comment from sched_group_set_shares(). Function never returns -EINVAL. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: clean up is_migration_thread()Ingo Molnar
clean up is_migration_thread() and turn it into an inline function. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: cleanup: refactor normalize_rt_tasksAndi Kleen
Replace a particularly ugly ifdef with an inline and a new macro. Also split up the function to be easier to read. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: cleanup: refactor common code of sleep_on / wait_for_completionAndi Kleen
Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: cleanup: remove unnecessary gotosAndi Kleen
Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: update commentIngo Molnar
update comment: clarify time-slices and remove obsolete tuning detail. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: prevent wakeup over-schedulingMike Galbraith
Prevent wakeup over-scheduling. Once a task has been preempted by a task of the same or lower priority, it becomes ineligible for repeated preemption by same until it has been ticked, or slept. Instead, the task is marked for preemption at the next tick. Tasks of higher priority still preempt immediately. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: disable forced preemption by defaultPeter Zijlstra
Implement feature bit to disable forced preemption. This way it can be checked whether a workload is overscheduling or not. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: fix group scheduling for SCHED_BATCHDmitry Adamushko
The following patch (sched: disable sleeper_fairness on SCHED_BATCH) seems to break GROUP_SCHED. Although, it may be 'oops'-less due to the possibility of 'p' being always a valid address. Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: some proc entries are missed in sched_domain sys_ctl debug codeZou Nan hai
cache_nice_tries and flags entry do not appear in proc fs sched_domain directory, because ctl_table entry is skipped. This patch fixes the issue. Signed-off-by: Zou Nan hai <nanhai.zou@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: fix rt ptracer monopolizing CPUGautham R Shenoy
yield() in wait_task_inactive(), can cause a high priority thread to be scheduled back in, and there by loop forever while it is waiting for some lower priority thread which is unfortunately still on the runqueue. Use schedule_timeout_uninterruptible(1) instead. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Credit: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: group scheduling, sysfs tunablesDhaval Giani
Add tunables in sysfs to modify a user's cpu share. A directory is created in sysfs for each new user in the system. /sys/kernel/uids/<uid>/cpu_share Reading this file returns the cpu shares granted for the user. Writing into this file modifies the cpu share for the user. Only an administrator is allowed to modify a user's cpu share. Ex: # cd /sys/kernel/uids/ # cat 512/cpu_share 1024 # echo 2048 > 512/cpu_share # cat 512/cpu_share 2048 # Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: disable sleeper_fairness on SCHED_BATCHPeter Zijlstra
disable sleeper fairness for batch tasks - they are about batch processing after all. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: another wakeup_granularity fixPeter Zijlstra
unit mis-match: wakeup_gran was used against a vruntime Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: export cpu_clock()Paul E. McKenney
export cpu_clock() - the preferred API instead of sched_clock(). Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: fix: move the CPU check into ->task_new_fair()Ingo Molnar
noticed by Peter Zijlstra: fix: move the CPU check into ->task_new_fair(), this way we can call place_entity() and get child ->vruntime right at initial wakeup time. (without this there can be large latencies) Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15sched: cleanup: function prototype cleanupsIngo Molnar
noticed by Thomas Gleixner: cleanup: function prototype cleanups - move into single line wherever possible. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: cleanup: rename task_grp to task_groupIngo Molnar
cleanup: rename task_grp to task_group. No need to save two characters and 'grp' is annoying to read. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15sched: cleanup: rename SCHED_FEAT_USE_TREE_AVG to SCHED_FEAT_TREE_AVGIngo Molnar
cleanup: rename SCHED_FEAT_USE_TREE_AVG to SCHED_FEAT_TREE_AVG, to make SCHED_FEAT_ names more consistent. Signed-off-by: Ingo Molnar <mingo@elte.hu>