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Provides support for unloading modular subsystems.
This patch adds a new function cgroup_unload_subsys which is to be used
for removing a loaded subsystem during module deletion. Reference
counting of the subsystems' modules is moved from once (at load time) to
once per attached hierarchy (in parse_cgroupfs_options and
rebind_subsystems) (i.e., 0 or 1).
Signed-off-by: Ben Blum <[email protected]>
Acked-by: Li Zefan <[email protected]>
Cc: Paul Menage <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: Lai Jiangshan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Add interface between cgroups subsystem management and module loading
This patch implements rudimentary module-loading support for cgroups -
namely, a cgroup_load_subsys (similar to cgroup_init_subsys) for use as a
module initcall, and a struct module pointer in struct cgroup_subsys.
Several functions that might be wanted by modules have had EXPORT_SYMBOL
added to them, but it's unclear exactly which functions want it and which
won't.
Signed-off-by: Ben Blum <[email protected]>
Acked-by: Li Zefan <[email protected]>
Cc: Paul Menage <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: Lai Jiangshan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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This patch series provides the ability for cgroup subsystems to be
compiled as modules both within and outside the kernel tree. This is
mainly useful for classifiers and subsystems that hook into components
that are already modules. cls_cgroup and blkio-cgroup serve as the
example use cases for this feature.
It provides an interface cgroup_load_subsys() and cgroup_unload_subsys()
which modular subsystems can use to register and depart during runtime.
The net_cls classifier subsystem serves as the example for a subsystem
which can be converted into a module using these changes.
Patch #1 sets up the subsys[] array so its contents can be dynamic as
modules appear and (eventually) disappear. Iterations over the array are
modified to handle when subsystems are absent, and the dynamic section of
the array is protected by cgroup_mutex.
Patch #2 implements an interface for modules to load subsystems, called
cgroup_load_subsys, similar to cgroup_init_subsys, and adds a module
pointer in struct cgroup_subsys.
Patch #3 adds a mechanism for unloading modular subsystems, which includes
a more advanced rework of the rudimentary reference counting introduced in
patch 2.
Patch #4 modifies the net_cls subsystem, which already had some module
declarations, to be configurable as a module, which also serves as a
simple proof-of-concept.
Part of implementing patches 2 and 4 involved updating css pointers in
each css_set when the module appears or leaves. In doing this, it was
discovered that css_sets always remain linked to the dummy cgroup,
regardless of whether or not any subsystems are actually bound to it
(i.e., not mounted on an actual hierarchy). The subsystem loading and
unloading code therefore should keep in mind the special cases where the
added subsystem is the only one in the dummy cgroup (and therefore all
css_sets need to be linked back into it) and where the removed subsys was
the only one in the dummy cgroup (and therefore all css_sets should be
unlinked from it) - however, as all css_sets always stay attached to the
dummy cgroup anyway, these cases are ignored. Any fix that addresses this
issue should also make sure these cases are addressed in the subsystem
loading and unloading code.
This patch:
Make subsys[] able to be dynamically populated to support modular
subsystems
This patch reworks the way the subsys[] array is used so that subsystems
can register themselves after boot time, and enables the internals of
cgroups to be able to handle when subsystems are not present or may
appear/disappear.
Signed-off-by: Ben Blum <[email protected]>
Acked-by: Li Zefan <[email protected]>
Cc: Paul Menage <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: Lai Jiangshan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Current css_get() and css_put() increment/decrement css->refcnt one by
one.
This patch add a new function __css_get(), which takes "count" as a arg
and increment the css->refcnt by "count". And this patch also add a new
arg("count") to __css_put() and change the function to decrement the
css->refcnt by "count".
These coalesce version of __css_get()/__css_put() will be used to improve
performance of memcg's moving charge feature later, where instead of
calling css_get()/css_put() repeatedly, these new functions will be used.
No change is needed for current users of css_get()/css_put().
Signed-off-by: Daisuke Nishimura <[email protected]>
Acked-by: Paul Menage <[email protected]>
Cc: Balbir Singh <[email protected]>
Acked-by: KAMEZAWA Hiroyuki <[email protected]>
Cc: Li Zefan <[email protected]>
Cc: Daisuke Nishimura <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Add cancel_attach() operation to struct cgroup_subsys. cancel_attach()
can be used when can_attach() operation prepares something for the subsys,
but we should rollback what can_attach() operation has prepared if attach
task fails after we've succeeded in can_attach().
Signed-off-by: Daisuke Nishimura <[email protected]>
Acked-by: Li Zefan <[email protected]>
Reviewed-by: Paul Menage <[email protected]>
Cc: Balbir Singh <[email protected]>
Acked-by: KAMEZAWA Hiroyuki <[email protected]>
Cc: Daisuke Nishimura <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Add generic implementations of the old and really old uname system calls.
Note that sh only implements sys_olduname but not sys_oldolduname, but I'm
not going to bother with another ifdef for that special case.
m32r implemented an old uname but never wired it up, so kill it, too.
Signed-off-by: Christoph Hellwig <[email protected]>
Cc: Ralf Baechle <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mundt <[email protected]>
Cc: Jeff Dike <[email protected]>
Cc: Hirokazu Takata <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: "Luck, Tony" <[email protected]>
Cc: James Morris <[email protected]>
Cc: Andreas Schwab <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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On an architecture that supports 32-bit compat we need to override the
reported machine in uname with the 32-bit value. Instead of doing this
separately in every architecture introduce a COMPAT_UTS_MACHINE define in
<asm/compat.h> and apply it directly in sys_newuname().
Signed-off-by: Christoph Hellwig <[email protected]>
Cc: Ralf Baechle <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mundt <[email protected]>
Cc: Jeff Dike <[email protected]>
Cc: Hirokazu Takata <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: "Luck, Tony" <[email protected]>
Cc: James Morris <[email protected]>
Cc: Andreas Schwab <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Add a generic implementation of the ipc demultiplexer syscall. Except for
s390 and sparc64 all implementations of the sys_ipc are nearly identical.
There are slight differences in the types of the parameters, where mips
and powerpc as the only 64-bit architectures with sys_ipc use unsigned
long for the "third" argument as it gets casted to a pointer later, while
it traditionally is an "int" like most other paramters. frv goes even
further and uses unsigned long for all parameters execept for "ptr" which
is a pointer type everywhere. The change from int to unsigned long for
"third" and back to "int" for the others on frv should be fine due to the
in-register calling conventions for syscalls (we already had a similar
issue with the generic sys_ptrace), but I'd prefer to have the arch
maintainers looks over this in details.
Except for that h8300, m68k and m68knommu lack an impplementation of the
semtimedop sub call which this patch adds, and various architectures have
gets used - at least on i386 it seems superflous as the compat code on
x86-64 and ia64 doesn't even bother to implement it.
[[email protected]: add sys_ipc to sys_ni.c]
Signed-off-by: Christoph Hellwig <[email protected]>
Cc: Ralf Baechle <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mundt <[email protected]>
Cc: Jeff Dike <[email protected]>
Cc: Hirokazu Takata <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Reviewed-by: H. Peter Anvin <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: "Luck, Tony" <[email protected]>
Cc: James Morris <[email protected]>
Cc: Andreas Schwab <[email protected]>
Acked-by: Jesper Nilsson <[email protected]>
Acked-by: Russell King <[email protected]>
Acked-by: David Howells <[email protected]>
Acked-by: Kyle McMartin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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When a process deletes cpu timer or a timer expires we do not clear
the expiration cache sig->cputimer_expires.
As a result the fastpath_timer_check() which prevents us to loop over
all threads in case no timer is active is not working and we run the
slow path needlessly on every tick.
Zero sig->cputimer_expires in stop_process_timers().
Signed-off-by: Stanislaw Gruszka <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Hidetoshi Seto <[email protected]>
Cc: Spencer Candland <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
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These functions forgot to run timer_stats_timer_clear_start_info(). It's
unobvious what effect this has and whether it matters much - we won't be
printing it out anyway if the timer's detached.
Untested, just an Ingo trollpatch.
[ Nevertheless correct - tglx ]
Signed-off-by: Andrew Morton <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: [email protected]
Signed-off-by: Thomas Gleixner <[email protected]>
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The current logic which handles clock events programming failures can
increase min_delta_ns unlimited and even can cause overflows.
Sanitize it by:
- prevent zero increase when min_delta_ns == 1
- limiting min_delta_ns to a jiffie
- bail out if the jiffie limit is hit
- add retries stats for /proc/timer_list so we can gather data
Reported-by: Uwe Kleine-Koenig <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
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Since pick_next_highest_task_rt() already iterates all the cgroups and
is really only interested in tasks, skip over the !task entries.
Reported-by: Dhaval Giani <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
Tested-by: Dhaval Giani <[email protected]>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <[email protected]>
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Export perf_trace_regs and perf_arch_fetch_caller_regs since module will
use these.
Signed-off-by: Xiao Guangrong <[email protected]>
[ use EXPORT_PER_CPU_SYMBOL_GPL() ]
Signed-off-by: Peter Zijlstra <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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execution slot
From : Ananth N Mavinakayanahalli <[email protected]>
When freeing the instruction slot, the arithmetic to calculate
the index of the slot in the page needs to account for the total
size of the instruction on the various architectures.
Calculate the index correctly when freeing the out-of-line
execution slot.
Reported-by: Sachin Sant <[email protected]>
Reported-by: Heiko Carstens <[email protected]>
Signed-off-by: Ananth N Mavinakayanahalli <[email protected]>
Signed-off-by: Masami Hiramatsu <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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We haven't used the "orig_rq" variable since
055a00865d "Fix/add missing update_rq_clock() calls"
Signed-off-by: Dan Carpenter <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Andreas Herrmann <[email protected]>
Cc: Gautham R Shenoy <[email protected]>
Cc: [email protected]
LKML-Reference: <20100306111752.GL4958@bicker>
Signed-off-by: Ingo Molnar <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/urgent
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CONFIG_PROVE_RCU imposes additional overhead on the kernel, so
increase the RCU CPU stall timeouts in an attempt to allow for
this effect.
Signed-off-by: Paul E. McKenney <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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Replace the calls to read_barrier_depends() in
ftrace_list_func() with rcu_dereference_raw() to improve
readability. The reason that we use rcu_dereference_raw() here
is that removed entries are never freed, instead they are simply
leaked. This is one of a very few cases where use of
rcu_dereference_raw() is the long-term right answer. And I
don't yet know of any others. ;-)
Signed-off-by: Paul E. McKenney <[email protected]>
Acked-by: Steven Rostedt <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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Anton Blanchard found that he could reliably make the kernel hit a
BUG_ON in the slab allocator by taking a cpu offline and then online
while a system-wide perf record session was running.
The reason is that when the cpu comes up, we completely reinitialize
the ctx field of the struct perf_cpu_context for the cpu. If there is
a system-wide perf record session running, then there will be a struct
perf_event that has a reference to the context, so its refcount will
be 2. (The perf_event has been removed from the context's group_entry
and event_entry lists by perf_event_exit_cpu(), but that doesn't
remove the perf_event's reference to the context and doesn't decrement
the context's refcount.)
When the cpu comes up, perf_event_init_cpu() gets called, and it calls
__perf_event_init_context() on the cpu's context. That resets the
refcount to 1. Then when the perf record session finishes and the
perf_event is closed, the refcount gets decremented to 0 and the
context gets kfreed after an RCU grace period. Since the context
wasn't kmalloced -- it's part of a per-cpu variable -- bad things
happen.
In fact we don't need to completely reinitialize the context when the
cpu comes up. It's sufficient to initialize the context once at boot,
but we need to do it for all possible cpus.
This moves the context initialization to happen at boot time. With
this, we don't trash the refcount and the context never gets kfreed,
and we don't hit the BUG_ON.
Reported-by: Anton Blanchard <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
Tested-by: Anton Blanchard <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Cc: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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Lars-Peter pointed out that the oneshot threaded interrupt handler
code has the following race:
CPU0 CPU1
hande_level_irq(irq X)
mask_ack_irq(irq X)
handle_IRQ_event(irq X)
wake_up(thread_handler)
thread handler(irq X) runs
finalize_oneshot(irq X)
does not unmask due to
!(desc->status & IRQ_MASKED)
return from irq
does not unmask due to
(desc->status & IRQ_ONESHOT)
This leaves the interrupt line masked forever.
The reason for this is the inconsistent handling of the IRQ_MASKED
flag. Instead of setting it in the mask function the oneshot support
sets the flag after waking up the irq thread.
The solution for this is to set/clear the IRQ_MASKED status whenever
we mask/unmask an interrupt line. That's the easy part, but that
cleanup opens another race:
CPU0 CPU1
hande_level_irq(irq)
mask_ack_irq(irq)
handle_IRQ_event(irq)
wake_up(thread_handler)
thread handler(irq) runs
finalize_oneshot_irq(irq)
unmask(irq)
irq triggers again
handle_level_irq(irq)
mask_ack_irq(irq)
return from irq due to IRQ_INPROGRESS
return from irq
does not unmask due to
(desc->status & IRQ_ONESHOT)
This requires that we synchronize finalize_oneshot_irq() with the
primary handler. If IRQ_INPROGESS is set we wait until the primary
handler on the other CPU has returned before unmasking the interrupt
line again.
We probably have never seen that problem because it does not happen on
UP and on SMP the irqbalancer protects us by pinning the primary
handler and the thread to the same CPU.
Reported-by: Lars-Peter Clausen <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: [email protected]
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Drop the obsolete "profile" naming used by perf for trace events.
Perf can now do more than simple events counting, so generalize
the API naming.
Signed-off-by: Frederic Weisbecker <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Jason Baron <[email protected]>
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We are taking a wrong regs snapshot when a trace event triggers.
Either we use get_irq_regs(), which gives us the interrupted
registers if we are in an interrupt, or we use task_pt_regs()
which gives us the state before we entered the kernel, assuming
we are lucky enough to be no kernel thread, in which case
task_pt_regs() returns the initial set of regs when the kernel
thread was started.
What we want is different. We need a hot snapshot of the regs,
so that we can get the instruction pointer to record in the
sample, the frame pointer for the callchain, and some other
things.
Let's use the new perf_fetch_caller_regs() for that.
Comparison with perf record -e lock: -R -a -f -g
Before:
perf [kernel] [k] __do_softirq
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--- __do_softirq
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|--55.16%-- __open
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--44.84%-- __write_nocancel
After:
perf [kernel] [k] perf_tp_event
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--- perf_tp_event
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|--41.07%-- lock_acquire
| |
| |--39.36%-- _raw_spin_lock
| | |
| | |--7.81%-- hrtimer_interrupt
| | | smp_apic_timer_interrupt
| | | apic_timer_interrupt
The old case was producing unreliable callchains. Now having
right frame and instruction pointers, we have the trace we
want.
Also syscalls and kprobe events already have the right regs,
let's use them instead of wasting a retrieval.
v2: Follow the rename perf_save_regs() -> perf_fetch_caller_regs()
Signed-off-by: Frederic Weisbecker <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Jason Baron <[email protected]>
Cc: Archs <[email protected]>
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Events that trigger overflows by interrupting a context can
use get_irq_regs() or task_pt_regs() to retrieve the state
when the event triggered. But this is not the case for some
other class of events like trace events as tracepoints are
executed in the same context than the code that triggered
the event.
It means we need a different api to capture the regs there,
namely we need a hot snapshot to get the most important
informations for perf: the instruction pointer to get the
event origin, the frame pointer for the callchain, the code
segment for user_mode() tests (we always use __KERNEL_CS as
trace events always occur from the kernel) and the eflags
for further purposes.
v2: rename perf_save_regs to perf_fetch_caller_regs as per
Masami's suggestion.
Signed-off-by: Frederic Weisbecker <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Jason Baron <[email protected]>
Cc: Archs <[email protected]>
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There are rcu locked read side areas in the path where we submit
a trace event. And these rcu_read_(un)lock() trigger lock events,
which create recursive events.
One pair in do_perf_sw_event:
__lock_acquire
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|--96.11%-- lock_acquire
| |
| |--27.21%-- do_perf_sw_event
| | perf_tp_event
| | |
| | |--49.62%-- ftrace_profile_lock_release
| | | lock_release
| | | |
| | | |--33.85%-- _raw_spin_unlock
Another pair in perf_output_begin/end:
__lock_acquire
|--23.40%-- perf_output_begin
| | __perf_event_overflow
| | perf_swevent_overflow
| | perf_swevent_add
| | perf_swevent_ctx_event
| | do_perf_sw_event
| | perf_tp_event
| | |
| | |--55.37%-- ftrace_profile_lock_acquire
| | | lock_acquire
| | | |
| | | |--37.31%-- _raw_spin_lock
The problem is not that much the trace recursion itself, as we have a
recursion protection already (though it's always wasteful to recurse).
But the trace events are outside the lockdep recursion protection, then
each lockdep event triggers a lock trace, which will trigger two
other lockdep events. Here the recursive lock trace event won't
be taken because of the trace recursion, so the recursion stops there
but lockdep will still analyse these new events:
To sum up, for each lockdep events we have:
lock_*()
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trace lock_acquire
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----- rcu_read_lock()
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| lock_acquire()
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| trace_lock_acquire() (stopped)
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| lockdep analyze
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----- rcu_read_unlock()
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lock_release
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trace_lock_release() (stopped)
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lockdep analyze
And you can repeat the above two times as we have two rcu read side
sections when we submit an event.
This is fixed in this patch by moving the lock trace event under
the lockdep recursion protection.
Signed-off-by: Frederic Weisbecker <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Hitoshi Mitake <[email protected]>
Cc: Li Zefan <[email protected]>
Cc: Lai Jiangshan <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Jens Axboe <[email protected]>
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Try to avoid useless rotation and PMU disables.
[ Could be improved by keeping a nr_runnable count to better account
for the < PERF_STAT_INACTIVE counters ]
Signed-off-by: Peter Zijlstra <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <[email protected]>
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Currently we always call hw_perf_disable(), even if its already disabled,
this seems superflous, esp. since it cannot be made NMI safe (see further
patches).
Signed-off-by: Peter Zijlstra <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: Arnaldo Carvalho de Melo <[email protected]>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <[email protected]>
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Remove the hw_perf_event_*() hotplug hooks in favour of per PMU hotplug
notifiers. This has the advantage of reducing the static weak interface
as well as exposing all hotplug actions to the PMU.
Use this to fix x86 hotplug usage where we did things in ONLINE which
should have been done in UP_PREPARE or STARTING.
Signed-off-by: Peter Zijlstra <[email protected]>
Cc: Paul Mundt <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: Arnaldo Carvalho de Melo <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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This makes it easier to extend perf_sample_data and fixes a bug on arm
and sparc, which failed to set ->raw to NULL, which can cause crashes
when combined with PERF_SAMPLE_RAW.
It also optimizes PowerPC and tracepoint, because the struct
initialization is forced to zero out the whole structure.
Signed-off-by: Peter Zijlstra <[email protected]>
Acked-by: Jean Pihet <[email protected]>
Reviewed-by: Frederic Weisbecker <[email protected]>
Acked-by: David S. Miller <[email protected]>
Cc: Jamie Iles <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: [email protected]
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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Conflicts:
tools/perf/util/probe-event.c
Merge reason: Pick up -rc1 and resolve the conflict as well.
Signed-off-by: Ingo Molnar <[email protected]>
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Conflicts:
Documentation/filesystems/proc.txt
arch/arm/mach-u300/include/mach/debug-macro.S
drivers/net/qlge/qlge_ethtool.c
drivers/net/qlge/qlge_main.c
drivers/net/typhoon.c
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A little more whack-a-mole annotating the dynamic sysfs attributes. I
had everything built into my earlier test kernel, and so I missed
these.
Signed-off-by: Eric W. Biederman <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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These are the non-static sysfs attributes that exist on
my test machine. Fix them to use sysfs_attr_init or
sysfs_bin_attr_init as appropriate. It simply requires
making a sysfs attribute present to see this. So this
is a little bit tedious but otherwise not too bad.
Signed-off-by: Eric W. Biederman <[email protected]>
Acked-by: WANG Cong <[email protected]>
Cc: Tejun Heo <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Constify struct sysfs_ops.
This is part of the ops structure constification
effort started by Arjan van de Ven et al.
Benefits of this constification:
* prevents modification of data that is shared
(referenced) by many other structure instances
at runtime
* detects/prevents accidental (but not intentional)
modification attempts on archs that enforce
read-only kernel data at runtime
* potentially better optimized code as the compiler
can assume that the const data cannot be changed
* the compiler/linker move const data into .rodata
and therefore exclude them from false sharing
Signed-off-by: Emese Revfy <[email protected]>
Acked-by: David Teigland <[email protected]>
Acked-by: Matt Domsch <[email protected]>
Acked-by: Maciej Sosnowski <[email protected]>
Acked-by: Hans J. Koch <[email protected]>
Acked-by: Pekka Enberg <[email protected]>
Acked-by: Jens Axboe <[email protected]>
Acked-by: Stephen Hemminger <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Constify struct kset_uevent_ops.
This is part of the ops structure constification
effort started by Arjan van de Ven et al.
Benefits of this constification:
* prevents modification of data that is shared
(referenced) by many other structure instances
at runtime
* detects/prevents accidental (but not intentional)
modification attempts on archs that enforce
read-only kernel data at runtime
* potentially better optimized code as the compiler
can assume that the const data cannot be changed
* the compiler/linker move const data into .rodata
and therefore exclude them from false sharing
Signed-off-by: Emese Revfy <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Passing the attribute to the low level IO functions allows all kinds
of cleanups, by sharing low level IO code without requiring
an own function for every piece of data.
Also drivers can extend the attributes with own data fields
and use that in the low level function.
Similar to sysdev_attributes and normal attributes.
This is a tree-wide sweep, converting everything in one go.
No functional changes in this patch other than passing the new
argument everywhere.
Tested on x86, the non x86 parts are uncompiled.
Signed-off-by: Andi Kleen <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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The current ELF dumper implementation can produce broken corefiles if
program headers exceed 65535. This number is determined by the number of
vmas which the process have. In particular, some extreme programs may use
more than 65535 vmas. (If you google max_map_count, you can find some
users facing this problem.) This kind of program never be able to generate
correct coredumps.
This patch implements ``extended numbering'' that uses sh_info field of
the first section header instead of e_phnum field in order to represent
upto 4294967295 vmas.
This is supported by
AMD64-ABI(http://www.x86-64.org/documentation.html) and
Solaris(http://docs.sun.com/app/docs/doc/817-1984/).
Of course, we are preparing patches for gdb and binutils.
Signed-off-by: Daisuke HATAYAMA <[email protected]>
Cc: "Luck, Tony" <[email protected]>
Cc: Jeff Dike <[email protected]>
Cc: David Howells <[email protected]>
Cc: Greg Ungerer <[email protected]>
Cc: Roland McGrath <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Alan Cox <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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elf_core_dump() and elf_fdpic_core_dump() use #ifdef and the corresponding
macro for hiding _multiline_ logics in functions. This patch removes
#ifdef and replaces ELF_CORE_EXTRA_* by corresponding functions. For
architectures not implemeonting ELF_CORE_EXTRA_*, we use weak functions in
order to reduce a range of modification.
This cleanup is for my next patches, but I think this cleanup itself is
worth doing regardless of my firnal purpose.
Signed-off-by: Daisuke HATAYAMA <[email protected]>
Cc: "Luck, Tony" <[email protected]>
Cc: Jeff Dike <[email protected]>
Cc: David Howells <[email protected]>
Cc: Greg Ungerer <[email protected]>
Cc: Roland McGrath <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Alan Cox <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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kernel/printk.c:72: warning: `saved_console_loglevel' defined but not used
Signed-off-by: Gustavo F. Padovan <[email protected]>
Cc: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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tasklist_lock does protect the task and its pid, it can't go away. The
problem is that find_pid_ns() itself is unsafe without rcu lock, it can
race with copy_process()->free_pid(any_pid).
Protecting copy_process()->free_pid(any_pid) with tasklist_lock would make
it possible to call find_task_by_pid_ns() under tasklist safely, but we
don't do so because we are trying to get rid of the read_lock sites of
tasklist_lock.
Signed-off-by: Tetsuo Handa <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: "Paul E. McKenney" <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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I've had some complaints about panic_timeout being wildly innacurate on
shared processor PowerPC partitions (a 3 minute panic_timeout taking 30
minutes).
The problem is we loop on mdelay(1) and with a 1ms in 10ms hypervisor
timeslice each of these will take 10ms (ie 10x) longer. I expect other
platforms with shared processor hypervisors will see the same issue.
This patch keeps the old behaviour if we have a panic_blink (only keyboard
LEDs right now) and does 1 second mdelays if we don't.
Signed-off-by: Anton Blanchard <[email protected]>
Cc: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Make sure compiler won't do weird things with limits. E.g. fetching them
twice may return 2 different values after writable limits are implemented.
I.e. either use rlimit helpers added in commit 3e10e716abf3 ("resource:
add helpers for fetching rlimits") or ACCESS_ONCE if not applicable.
Signed-off-by: Jiri Slaby <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: john stultz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Fetch rlimit (both hard and soft) values only once and work on them. It
removes many accesses through sig structure and makes the code cleaner.
Mostly a preparation for writable resource limits support.
Signed-off-by: Jiri Slaby <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: john stultz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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kernel/exit.c:1183:26: warning: symbol 'status' shadows an earlier one
kernel/exit.c:1173:21: originally declared here
Signed-off-by: Thiago Farina <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Fix the following 'make includecheck' warning:
kernel/params.c: linux/string.h is included more than once.
Signed-off-by: Jaswinder Singh Rajput <[email protected]>
Cc: André Goddard Rosa <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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"ret" needs to be signed or the error handling for splice_to_pipe() won't
work correctly.
Signed-off-by: Dan Carpenter <[email protected]>
Cc: Tom Zanussi <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Lai Jiangshan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Additional_cpus is only supported for IA64 now. X86_64 should not be
included.
Signed-off-by: Chen Gong <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Rusty Russell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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There are quite a few GFP_KERNEL memory allocations made during
suspend/hibernation and resume that may cause the system to hang, because
the I/O operations they depend on cannot be completed due to the
underlying devices being suspended.
Avoid this problem by clearing the __GFP_IO and __GFP_FS bits in
gfp_allowed_mask before suspend/hibernation and restoring the original
values of these bits in gfp_allowed_mask durig the subsequent resume.
[[email protected]: fix CONFIG_PM=n linkage]
Signed-off-by: Rafael J. Wysocki <[email protected]>
Reported-by: Maxim Levitsky <[email protected]>
Cc: Sebastian Ott <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: KOSAKI Motohiro <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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The old anon_vma code can lead to scalability issues with heavily forking
workloads. Specifically, each anon_vma will be shared between the parent
process and all its child processes.
In a workload with 1000 child processes and a VMA with 1000 anonymous
pages per process that get COWed, this leads to a system with a million
anonymous pages in the same anon_vma, each of which is mapped in just one
of the 1000 processes. However, the current rmap code needs to walk them
all, leading to O(N) scanning complexity for each page.
This can result in systems where one CPU is walking the page tables of
1000 processes in page_referenced_one, while all other CPUs are stuck on
the anon_vma lock. This leads to catastrophic failure for a benchmark
like AIM7, where the total number of processes can reach in the tens of
thousands. Real workloads are still a factor 10 less process intensive
than AIM7, but they are catching up.
This patch changes the way anon_vmas and VMAs are linked, which allows us
to associate multiple anon_vmas with a VMA. At fork time, each child
process gets its own anon_vmas, in which its COWed pages will be
instantiated. The parents' anon_vma is also linked to the VMA, because
non-COWed pages could be present in any of the children.
This reduces rmap scanning complexity to O(1) for the pages of the 1000
child processes, with O(N) complexity for at most 1/N pages in the system.
This reduces the average scanning cost in heavily forking workloads from
O(N) to 2.
The only real complexity in this patch stems from the fact that linking a
VMA to anon_vmas now involves memory allocations. This means vma_adjust
can fail, if it needs to attach a VMA to anon_vma structures. This in
turn means error handling needs to be added to the calling functions.
A second source of complexity is that, because there can be multiple
anon_vmas, the anon_vma linking in vma_adjust can no longer be done under
"the" anon_vma lock. To prevent the rmap code from walking up an
incomplete VMA, this patch introduces the VM_LOCK_RMAP VMA flag. This bit
flag uses the same slot as the NOMMU VM_MAPPED_COPY, with an ifdef in mm.h
to make sure it is impossible to compile a kernel that needs both symbolic
values for the same bitflag.
Some test results:
Without the anon_vma changes, when AIM7 hits around 9.7k users (on a test
box with 16GB RAM and not quite enough IO), the system ends up running
>99% in system time, with every CPU on the same anon_vma lock in the
pageout code.
With these changes, AIM7 hits the cross-over point around 29.7k users.
This happens with ~99% IO wait time, there never seems to be any spike in
system time. The anon_vma lock contention appears to be resolved.
[[email protected]: cleanups]
Signed-off-by: Rik van Riel <[email protected]>
Cc: KOSAKI Motohiro <[email protected]>
Cc: Larry Woodman <[email protected]>
Cc: Lee Schermerhorn <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Considering the nature of per mm stats, it's the shared object among
threads and can be a cache-miss point in the page fault path.
This patch adds per-thread cache for mm_counter. RSS value will be
counted into a struct in task_struct and synchronized with mm's one at
events.
Now, in this patch, the event is the number of calls to handle_mm_fault.
Per-thread value is added to mm at each 64 calls.
rough estimation with small benchmark on parallel thread (2threads) shows
[before]
4.5 cache-miss/faults
[after]
4.0 cache-miss/faults
Anyway, the most contended object is mmap_sem if the number of threads grows.
[[email protected]: coding-style fixes]
Signed-off-by: KAMEZAWA Hiroyuki <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Lee Schermerhorn <[email protected]>
Cc: David Rientjes <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Presently, per-mm statistics counter is defined by macro in sched.h
This patch modifies it to
- defined in mm.h as inlinf functions
- use array instead of macro's name creation.
This patch is for reducing patch size in future patch to modify
implementation of per-mm counter.
Signed-off-by: KAMEZAWA Hiroyuki <[email protected]>
Reviewed-by: Minchan Kim <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Lee Schermerhorn <[email protected]>
Cc: David Rientjes <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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