* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (29 commits)
sched: Export account_system_vtime()
sched: Call tick_check_idle before __irq_enter
sched: Remove irq time from available CPU power
sched: Do not account irq time to current task
x86: Add IRQ_TIME_ACCOUNTING
sched: Add IRQ_TIME_ACCOUNTING, finer accounting of irq time
sched: Add a PF flag for ksoftirqd identification
sched: Consolidate account_system_vtime extern declaration
sched: Fix softirq time accounting
sched: Drop group_capacity to 1 only if local group has extra capacity
sched: Force balancing on newidle balance if local group has capacity
sched: Set group_imb only a task can be pulled from the busiest cpu
sched: Do not consider SCHED_IDLE tasks to be cache hot
sched: Drop all load weight manipulation for RT tasks
sched: Create special class for stop/migrate work
sched: Unindent labels
sched: Comment updates: fix default latency and granularity numbers
tracing/sched: Add sched_pi_setprio tracepoint
sched: Give CPU bound RT tasks preference
sched: Try not to migrate higher priority RT tasks
...
Provide a mechanism that allows running code in IRQ context. It is
most useful for NMI code that needs to interact with the rest of the
system -- like wakeup a task to drain buffers.
Perf currently has such a mechanism, so extract that and provide it as
a generic feature, independent of perf so that others may also
benefit.
The IRQ context callback is generated through self-IPIs where
possible, or on architectures like powerpc the decrementer (the
built-in timer facility) is set to generate an interrupt immediately.
Architectures that don't have anything like this get to do with a
callback from the timer tick. These architectures can call
irq_work_run() at the tail of any IRQ handlers that might enqueue such
work (like the perf IRQ handler) to avoid undue latencies in
processing the work.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
[ various fixes ]
Signed-off-by: Huang Ying <ying.huang@intel.com>
LKML-Reference: <1287036094.7768.291.camel@yhuang-dev>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Use the extended cpu topology information that z11 machines provide
to improve the scheduler's decision making.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100831082844.604956770@de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Now that all arches have been converted over to use generic time via
clocksources or arch_gettimeoffset(), we can remove the GENERIC_TIME
config option and simplify the generic code.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <1279068988-21864-4-git-send-email-johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
All distros have this option switched on, so lets get rid of at least
one of the tons of config options that are available.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The exception-trace facility on x86 and other architectures prints
traces to dmesg whenever a user space application crashes.
s390 has such a feature since ages however it is called
userprocess_debug and is enabled differently.
This patch makes sure that whenever one of the two procfs files
/proc/sys/kernel/userprocess_debug
/proc/sys/debug/exception-trace
is modified the contents of the second one changes as well.
That way we keep backwards compatibilty but also support the same
interface like other architectures do.
Besides that the output of the traces is improved since it will now
also contain the corresponding filename of the vma (when available)
where the process caused a fault or trap.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (28 commits)
ftrace: Add function names to dangling } in function graph tracer
tracing: Simplify memory recycle of trace_define_field
tracing: Remove unnecessary variable in print_graph_return
tracing: Fix typo of info text in trace_kprobe.c
tracing: Fix typo in prof_sysexit_enable()
tracing: Remove CONFIG_TRACE_POWER from kernel config
tracing: Fix ftrace_event_call alignment for use with gcc 4.5
ftrace: Remove memory barriers from NMI code when not needed
tracing/kprobes: Add short documentation for HAVE_REGS_AND_STACK_ACCESS_API
s390: Add pt_regs register and stack access API
tracing/kprobes: Make Kconfig dependencies generic
tracing: Unify arch_syscall_addr() implementations
tracing: Add notrace to TRACE_EVENT implementation functions
ftrace: Allow to remove a single function from function graph filter
tracing: Add correct/incorrect to sort keys for branch annotation output
tracing: Simplify test for function_graph tracing start point
tracing: Drop the tr check from the graph tracing path
tracing: Add stack dump to trace_printk if stacktrace option is set
tracing: Use appropriate perl constructs in recordmcount.pl
tracing: optimize recordmcount.pl for offsets-handling
...
Add the "bzImage" compile target and the necessary code to generate
compressed kernel images. The old style uncompressed "image" target
is preserved, a simple make will build them both.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Reduces the size of the bug table entries by 50% on 64bit kernels.
Saves around 30kb on a defconfig kernel.
s390 version of b93a531e "allow bug table entries to use relative
pointers (and use it on x86-64)".
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This API is needed for the kprobe-based event tracer.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
LKML-Reference: <20100212123840.GB27548@osiris.boeblingen.de.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Introduce user_mode to replace the two variables switch_amode and
s390_noexec. There are three valid combinations of the old values:
1) switch_amode == 0 && s390_noexec == 0
2) switch_amode == 1 && s390_noexec == 0
3) switch_amode == 1 && s390_noexec == 1
They get replaced by
1) user_mode == HOME_SPACE_MODE
2) user_mode == PRIMARY_SPACE_MODE
3) user_mode == SECONDARY_SPACE_MODE
The new kernel parameter user_mode=[primary,secondary,home] lets
you choose the address space mode the user space processes should
use. In addition the CONFIG_S390_SWITCH_AMODE config option
is removed.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
commit 892a7c67 (locking: Allow arch-inlined spinlocks) implements the
selection of which lock functions are inlined based on defines in
arch/.../spinlock.h: #define __always_inline__LOCK_FUNCTION
Despite of the name __always_inline__* the lock functions can be built
out of line depending on config options. Also if the arch does not set
some inline defines the generic code might set them; again depending on
config options.
This makes it unnecessary hard to figure out when and which lock
functions are inlined. Aside of that it makes it way harder and
messier for -rt to manipulate the lock functions.
Convert the inlining decision to CONFIG switches. Each lock function
is inlined depending on CONFIG_INLINE_*. The configs implement the
existing dependencies. The architecture code can select ARCH_INLINE_*
to signal that it wants the corresponding lock function inlined.
ARCH_INLINE_* is necessary as Kconfig ignores "depends on"
restrictions when a config element is selected.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <20091109151428.504477141@linutronix.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Bye-bye Performance Counters, welcome Performance Events!
In the past few months the perfcounters subsystem has grown out its
initial role of counting hardware events, and has become (and is
becoming) a much broader generic event enumeration, reporting, logging,
monitoring, analysis facility.
Naming its core object 'perf_counter' and naming the subsystem
'perfcounters' has become more and more of a misnomer. With pending
code like hw-breakpoints support the 'counter' name is less and
less appropriate.
All in one, we've decided to rename the subsystem to 'performance
events' and to propagate this rename through all fields, variables
and API names. (in an ABI compatible fashion)
The word 'event' is also a bit shorter than 'counter' - which makes
it slightly more convenient to write/handle as well.
Thanks goes to Stephane Eranian who first observed this misnomer and
suggested a rename.
User-space tooling and ABI compatibility is not affected - this patch
should be function-invariant. (Also, defconfigs were not touched to
keep the size down.)
This patch has been generated via the following script:
FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')
sed -i \
-e 's/PERF_EVENT_/PERF_RECORD_/g' \
-e 's/PERF_COUNTER/PERF_EVENT/g' \
-e 's/perf_counter/perf_event/g' \
-e 's/nb_counters/nb_events/g' \
-e 's/swcounter/swevent/g' \
-e 's/tpcounter_event/tp_event/g' \
$FILES
for N in $(find . -name perf_counter.[ch]); do
M=$(echo $N | sed 's/perf_counter/perf_event/g')
mv $N $M
done
FILES=$(find . -name perf_event.*)
sed -i \
-e 's/COUNTER_MASK/REG_MASK/g' \
-e 's/COUNTER/EVENT/g' \
-e 's/\<event\>/event_id/g' \
-e 's/counter/event/g' \
-e 's/Counter/Event/g' \
$FILES
... to keep it as correct as possible. This script can also be
used by anyone who has pending perfcounters patches - it converts
a Linux kernel tree over to the new naming. We tried to time this
change to the point in time where the amount of pending patches
is the smallest: the end of the merge window.
Namespace clashes were fixed up in a preparatory patch - and some
stylistic fallout will be fixed up in a subsequent patch.
( NOTE: 'counters' are still the proper terminology when we deal
with hardware registers - and these sed scripts are a bit
over-eager in renaming them. I've undone some of that, but
in case there's something left where 'counter' would be
better than 'event' we can undo that on an individual basis
instead of touching an otherwise nicely automated patch. )
Suggested-by: Stephane Eranian <eranian@google.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Reviewed-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-arch@vger.kernel.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (105 commits)
ring-buffer: only enable ring_buffer_swap_cpu when needed
ring-buffer: check for swapped buffers in start of committing
tracing: report error in trace if we fail to swap latency buffer
tracing: add trace_array_printk for internal tracers to use
tracing: pass around ring buffer instead of tracer
tracing: make tracing_reset safe for external use
tracing: use timestamp to determine start of latency traces
tracing: Remove mentioning of legacy latency_trace file from documentation
tracing/filters: Defer pred allocation, fix memory leak
tracing: remove users of tracing_reset
tracing: disable buffers and synchronize_sched before resetting
tracing: disable update max tracer while reading trace
tracing: print out start and stop in latency traces
ring-buffer: disable all cpu buffers when one finds a problem
ring-buffer: do not count discarded events
ring-buffer: remove ring_buffer_event_discard
ring-buffer: fix ring_buffer_read crossing pages
ring-buffer: remove unnecessary cpu_relax
ring-buffer: do not swap buffers during a commit
ring-buffer: do not reset while in a commit
...
Get rid of the PAGE_STATES config option and enable guest page hinting
by default.
It can be disabled by specifying "cmma=off" at the command line.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use compare double and swap to implement efficient atomic64 ops for 31 bit.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s/HAVE_FTRACE_SYSCALLS/HAVE_SYSCALL_TRACEPOINTS/g
s/TIF_SYSCALL_FTRACE/TIF_SYSCALL_TRACEPOINT/g
The syscall enter/exit tracing is no longer specific to just ftrace, so
they now have names that reflect their tie to tracepoints instead.
Signed-off-by: Josh Stone <jistone@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Jiaying Zhang <jiayingz@google.com>
Cc: Martin Bligh <mbligh@google.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
LKML-Reference: <1251150194-1713-2-git-send-email-jistone@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
32-bit s390 has efficient support for 64/32-bit conversions, define
KTIME_SCALAR to enable the use of the plain scalar nanosecond based
representation of ktime.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Performance counters need 64 bit atomic operations.
To keep the patch small we use the simple generic atomic64_t implementation.
The native implementation follows with the next kernel.
Fixes this build bug:
In file included from kernel/sched.c:42:
include/linux/perf_counter.h:427: error: expected specifier-qualifier-list before 'atomic64_t'
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch introduces the hibernation backend support to the
s390 architecture. Now it is possible to suspend a mainframe Linux
guest using the following command:
echo disk > /sys/power/state
Signed-off-by: Hans-Joachim Picht <hans@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
System call tracer support for s390.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Function graph tracer support for s390.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add support for early test if the function tracer is enabled or
disabled. Saves some extra function calls.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Enable secure computing on s390 as well.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Impact: performance regression fix for s390
The adaptive spinning mutexes will not always do what one would expect on
virtualized architectures like s390. Especially the cpu_relax() loop in
mutex_spin_on_owner might hurt if the mutex holding cpu has been scheduled
away by the hypervisor.
We would end up in a cpu_relax() loop when there is no chance that the
state of the mutex changes until the target cpu has been scheduled again by
the hypervisor.
For that reason we should change the default behaviour to no-spin on s390.
We do have an instruction which allows to yield the current cpu in favour of
a different target cpu. Also we have an instruction which allows us to figure
out if the target cpu is physically backed.
However we need to do some performance tests until we can come up with
a solution that will do the right thing on s390.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
LKML-Reference: <20090409184834.7a0df7b2@osiris.boeblingen.de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
CONFIG_DEBUG_PAGEALLOC is now supported by x86, powerpc, sparc64, and
s390. This patch implements it for the rest of the architectures by
filling the pages with poison byte patterns after free_pages() and
verifying the poison patterns before alloc_pages().
This generic one cannot detect invalid page accesses immediately but
invalid read access may cause invalid dereference by poisoned memory and
invalid write access can be detected after a long delay.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The zcore code switches to real addressing mode when creating a kernel dump.
This is not possible, if it is built as a kernel module. With this patch
zcore (zfcpdump) can't be built as a kernel module any more.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Everybody enables it so there is no point for an extra config option.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
With CONFIG_NET not set appldata build breaks on s390.
arch/s390/appldata/built-in.o: In function appldata_get_net_sum_data:
appldata_net_sum.c:(.text+0x2684): undefined reference to dev_get_stats
appldata_net_sum.c:(.text+0x2688): undefined reference to init_net
appldata_net_sum.c:(.text+0x268c): undefined reference to init_net
appldata_net_sum.c:(.text+0x2694): undefined reference to dev_base_lock
The following patch fixes the issue for me.
Signed-off-by: Sachin Sant <sachinp@in.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* 'cpus4096-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (66 commits)
x86: export vector_used_by_percpu_irq
x86: use logical apicid in x2apic_cluster's x2apic_cpu_mask_to_apicid_and()
sched: nominate preferred wakeup cpu, fix
x86: fix lguest used_vectors breakage, -v2
x86: fix warning in arch/x86/kernel/io_apic.c
sched: fix warning in kernel/sched.c
sched: move test_sd_parent() to an SMP section of sched.h
sched: add SD_BALANCE_NEWIDLE at MC and CPU level for sched_mc>0
sched: activate active load balancing in new idle cpus
sched: bias task wakeups to preferred semi-idle packages
sched: nominate preferred wakeup cpu
sched: favour lower logical cpu number for sched_mc balance
sched: framework for sched_mc/smt_power_savings=N
sched: convert BALANCE_FOR_xx_POWER to inline functions
x86: use possible_cpus=NUM to extend the possible cpus allowed
x86: fix cpu_mask_to_apicid_and to include cpu_online_mask
x86: update io_apic.c to the new cpumask code
x86: Introduce topology_core_cpumask()/topology_thread_cpumask()
x86: xen: use smp_call_function_many()
x86: use work_on_cpu in x86/kernel/cpu/mcheck/mce_amd_64.c
...
Fixed up trivial conflict in kernel/time/tick-sched.c manually
On s390 we always want to run with precise cputime accounting.
Remove the config options VIRT_TIMER and VIRT_CPU_ACCOUNTING.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch adds the code generation option for IBM System z10 and
adds a check in head[31,64].S to prevents the execution of a kernel
compiled for a new processor type on an old machine.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This implements just the basic function tracer (_mcount) backend for s390.
The dynamic variant will come later.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
- make qdio_trace a per device view
- remove s390dbf exceptions
- remove CONFIG_QDIO_DEBUG, not needed anymore if we check for the level
before calling sprintf
- use snprintf for dbf entries
- add start markers to see if the dbf view wrapped
- add a global error view for all queues
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Since etr/stp don't need the old smp_call_function semantics anymore
we can convert s390 to the generic IPI infrastructure.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add a vdso to speed up gettimeofday and clock_getres/clock_gettime for
CLOCK_REALTIME/CLOCK_MONOTONIC.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Impact: cleanup
Each SMP arch defines these themselves. Move them to a central
location.
Twists:
1) Some archs (m32, parisc, s390) set possible_map to all 1, so we add a
CONFIG_INIT_ALL_POSSIBLE for this rather than break them.
2) mips and sparc32 '#define cpu_possible_map phys_cpu_present_map'.
Those archs simply have phys_cpu_present_map replaced everywhere.
3) Alpha defined cpu_possible_map to cpu_present_map; this is tricky
so I just manipulate them both in sync.
4) IA64, cris and m32r have gratuitous 'extern cpumask_t cpu_possible_map'
declarations.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Grant Grundler <grundler@parisc-linux.org>
Tested-by: Tony Luck <tony.luck@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Mike Travis <travis@sgi.com>
Cc: ink@jurassic.park.msu.ru
Cc: rmk@arm.linux.org.uk
Cc: starvik@axis.com
Cc: tony.luck@intel.com
Cc: takata@linux-m32r.org
Cc: ralf@linux-mips.org
Cc: grundler@parisc-linux.org
Cc: paulus@samba.org
Cc: schwidefsky@de.ibm.com
Cc: lethal@linux-sh.org
Cc: wli@holomorphy.com
Cc: davem@davemloft.net
Cc: jdike@addtoit.com
Cc: mingo@redhat.com
allyesconfig and allmodconfig built kernels have a tape IPL record.
A the vmreader record makes much more sense, since hardly anybody will
ever IPL a kernel from tape. So change the default.
As I side effect I can test these kernels without fiddling around with
the kernel config ;)
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch implements a new freezer subsystem in the control groups
framework. It provides a way to stop and resume execution of all tasks in
a cgroup by writing in the cgroup filesystem.
The freezer subsystem in the container filesystem defines a file named
freezer.state. Writing "FROZEN" to the state file will freeze all tasks
in the cgroup. Subsequently writing "RUNNING" will unfreeze the tasks in
the cgroup. Reading will return the current state.
* Examples of usage :
# mkdir /containers/freezer
# mount -t cgroup -ofreezer freezer /containers
# mkdir /containers/0
# echo $some_pid > /containers/0/tasks
to get status of the freezer subsystem :
# cat /containers/0/freezer.state
RUNNING
to freeze all tasks in the container :
# echo FROZEN > /containers/0/freezer.state
# cat /containers/0/freezer.state
FREEZING
# cat /containers/0/freezer.state
FROZEN
to unfreeze all tasks in the container :
# echo RUNNING > /containers/0/freezer.state
# cat /containers/0/freezer.state
RUNNING
This is the basic mechanism which should do the right thing for user space
task in a simple scenario.
It's important to note that freezing can be incomplete. In that case we
return EBUSY. This means that some tasks in the cgroup are busy doing
something that prevents us from completely freezing the cgroup at this
time. After EBUSY, the cgroup will remain partially frozen -- reflected
by freezer.state reporting "FREEZING" when read. The state will remain
"FREEZING" until one of these things happens:
1) Userspace cancels the freezing operation by writing "RUNNING" to
the freezer.state file
2) Userspace retries the freezing operation by writing "FROZEN" to
the freezer.state file (writing "FREEZING" is not legal
and returns EIO)
3) The tasks that blocked the cgroup from entering the "FROZEN"
state disappear from the cgroup's set of tasks.
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: export thaw_process]
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Acked-by: Serge E. Hallyn <serue@us.ibm.com>
Tested-by: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current help text for CONFIG_S390_GUEST is not very helpful.
Lets add more text.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
* System call parameter and result access functions
* Add tracehook calls
* Split syscall_trace into two functions do_syscall_trace_enter and
do_syscall_trace_exit
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Martin Schwidefsky