This changes the dwarf2 unwinder to do a binary search for CIEs
instead of a linear work. The linker is unfortunately not
able to build a proper lookup table at link time, instead it creates
one at runtime as soon as the bootmem allocator is usable (so you'll continue
using the linear lookup for the first [hopefully] few calls).
The code should be ready to utilize a build-time created table once
a fixed linker becomes available.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
If CONFIG_PROC_FS=n:
kernel/sysctl.c:148: warning: 'proc_do_cad_pid' used but never defined
kernel/built-in.o:(.data+0x1228): undefined reference to `proc_do_cad_pid'
make: *** [.tmp_vmlinux1] Error 1
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The use of blocking notifier by _cpu_up and _cpu_down in cpu.c has two
problem.
1/ An interaction with the workqueue notifier causes lockdep to spit a
warning.
2/ A notifier could conceivable be added or removed while _cpu_up or
_cpu_down are in process. As each notifier is called twice (prepare
then commit/abort) this could be unhealthy.
To fix to we simply take cpu_add_remove_lock while adding or removing
notifiers to/from the list.
This makes the 'blocking' usage unnecessary as all accesses to cpu_chain
are now protected by cpu_add_remove_lock. So change "blocking" to "raw" in
all relevant places. This fixes 1.
Credit: Andrew Morton
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michal Piotrowski <michal.k.k.piotrowski@gmail.com> (reporter)
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
BUG: warning at kernel/rtmutex-debug.c:125/rt_mutex_debug_task_free() (Not tainted)
[<c04051e3>] show_trace_log_lvl+0x58/0x16a
[<c04057f0>] show_trace+0xd/0x10
[<c0405900>] dump_stack+0x19/0x1b
[<c043f03d>] rt_mutex_debug_task_free+0x35/0x6a
[<c04224c0>] free_task+0x15/0x24
[<c042378c>] copy_process+0x12bd/0x1324
[<c0423835>] do_fork+0x42/0x113
[<c04021dd>] sys_fork+0x19/0x1b
[<c0403fb7>] syscall_call+0x7/0xb
In copy_process(), dup_task_struct() also duplicates the ->pi_lock,
->pi_waiters and ->pi_blocked_on members. rt_mutex_debug_task_free()
called from free_task() validates these members. However free_task() can
be invoked before these members are reset for the new task.
Move the initialization code before the first bail that can hit free_task().
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
My fancy new swsusp IO code had a big memory leak. It's somewhat invisible
because the whole mem_map[] gets overwritten after resume, but it can cause us
to get low on memory during the actual suspend process.
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The integer divisions in the timer accounting code can round the result
down to 0. Adding 0 is without effect and the signal delivery stops.
Clamp the division result to minimum 1 to avoid this.
Problem was reported by Seongbae Park <spark@google.com>, who provided
also an inital patch.
Roland sayeth:
I have had some more time to think about the problem, and to reproduce it
using Toyo's test case. For the record, if my understanding of the problem
is correct, this happens only in one very particular case. First, the
expiry time has to be so soon that in cputime_t units (usually 1s/HZ ticks)
it's < nthreads so the division yields zero. Second, it only affects each
thread that is so new that its CPU time accumulation is zero so now+0 is
still zero and ->it_*_expires winds up staying zero. For the VIRT and PROF
clocks when cputime_t is tick granularity (or the SCHED clock on
configurations where sched_clock's value only advances on clock ticks), this
is not hard to arrange with new threads starting up and blocking before they
accumulate a whole tick of CPU time. That's what happens in Toyo's test
case.
Note that in general it is fine for that division to round down to zero,
and set each thread's expiry time to its "now" time. The problem only
arises with thread's whose "now" value is still zero, so that now+0 winds up
0 and is interpreted as "not set" instead of ">= now". So it would be a
sufficient and more precise fix to just use max(ticks, 1) inside the loop
when setting each it_*_expires value.
But, it does no harm to round the division up to one and always advance
every thread's expiry time. If the thread didn't already fire timers for
the expiry time of "now", there is no expectation that it will do so before
the next tick anyway. So I followed Thomas's patch in lifting the max out
of the loops.
This patch also covers the reload cases, which are harder to write a test
for (and I didn't try). I've tested it with Toyo's case and it fixes that.
[toyoa@mvista.com: fix: min_t -> max_t]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Daniel Walker <dwalker@mvista.com>
Cc: Toyo Abe <toyoa@mvista.com>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Seongbae Park <spark@google.com>
Cc: Peter Mattis <pmattis@google.com>
Cc: Rohit Seth <rohitseth@google.com>
Cc: Martin Bligh <mbligh@google.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Avoid possible PIT livelock issues seen on SMP systems (and reported by
Andi), by not allowing it as a clocksource on SMP boxes.
However, since the PIT may no longer be present, we have to properly handle
the cases where SMP systems have TSC skew and fall back from the TSC.
Since the PIT isn't there, it would "fall back" to the TSC again. So this
changes the jiffies rating to 1, and the TSC-bad rating value to 0.
Thus you will get the following behavior priority on i386 systems:
tsc [if present & stable]
hpet [if present]
cyclone [if present]
acpi_pm [if present]
pit [if UP]
jiffies
Rather then the current more complicated:
tsc [if present & stable]
hpet [if present]
cyclone [if present]
acpi_pm [if present]
pit [if cpus < 4]
tsc [if present & unstable]
jiffies
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In general, lockdep warnings are intended to be non-fatal, so I have put in
various practical limits on internal data structure failure modes. We haven't
had a /single/ lockdep-internal crash ever since lockdep went upstream [the
unwinder crashes are outside of lockdep], and that's largely due to the good
internal checks it does.
Recursion within the dependency graph is currently limited to 20, that's
probably not enough on some many-CPU boxes - this patch doubles it to 40. I
have written the lockdep functions to have as small stackframes as possible,
so 40 should be OK too. (The practical recursion limit should be somewhere
between 100 and 200 entries. If we hit that then I'll change the algorithm to
be iteration-based. Graph walking logic is so easy to program via recursion,
so i'd like to keep recursion as long as possible.)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Bug reported and fixed by Tilman Schmidt <tilman@imap.cc>: if lockdep is
enabled then log messages make it to /var/log/messages belatedly. The
reason is a missed wakeup of klogd.
Initially there was only a lockdep_internal() protection against lockdep
recursion within vprintk() - it grew the 'outer' lockdep_off()/on()
protection only later on. But that lockdep_off() made the
release_console_sem() within vprintk() always happen under the
lockdep_internal() condition, causing the bug.
The right solution to remove the inner protection against recursion here -
the outer one is enough.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
lib/bitmap.c:bitmap_parse() is a library function that received as input a
user buffer. This seemed to have originated from the way the write_proc
function of the /proc filesystem operates.
This has been reworked to not use kmalloc and eliminates a lot of
get_user() overhead by performing one access_ok before using __get_user().
We need to test if we are in kernel or user space (is_user) and access the
buffer differently. We cannot use __get_user() to access kernel addresses
in all cases, for example in architectures with separate address space for
kernel and user.
This function will be useful for other uses as well; for example, taking
input for /sysfs instead of /proc, so it was changed to accept kernel
buffers. We have this use for the Linux UWB project, as part as the
upcoming bandwidth allocator code.
Only a few routines used this function and they were changed too.
Signed-off-by: Reinette Chatre <reinette.chatre@linux.intel.com>
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Joe Korty <joe.korty@ccur.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This likely profiling is pretty fun. I found a few possible problems
in sched.c.
This patch may be not measurable, but when I did measure long ago,
nooping (un)likely cost a couple of % on scheduler heavy benchmarks, so
it all adds up.
Tweak some branch hints:
- the 2nd 64 bits in the bitmask is likely to be populated, because it
contains the first 28 bits (nearly 3/4) of the normal priorities.
(ratio of 669669:691 ~= 1000:1).
- it isn't unlikely that context switching switches to another process. it
might be very rapidly switching to and from the idle process (ratio of
475815:419004 and 471330:423544). Let the branch predictor decide.
- preempt_enable seems to be very often called in a nested preempt_disable
or with interrupts disabled (ratio of 3567760:87965 ~= 40:1)
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Daniel Walker <dwalker@mvista.com>
Cc: Hua Zhong <hzhong@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Module taint flags listing in Oops/panic has a couple of issues:
* taint_flags() doesn't null-terminate the buffer after printing the flags
* per-module taints are only set if the kernel is not already tainted
(with that particular flag) => only the first offending module gets its
taint info correctly updated
Some additional changes:
* 'license_gplok' is no longer needed - equivalent to !(taints &
TAINT_PROPRIETARY_MODULE) - so we can drop it from struct module *
exporting module taint info via /proc/module:
pwc 88576 0 - Live 0xf8c32000
evilmod 6784 1 pwc, Live 0xf8bbf000 (PF)
Signed-off-by: Florin Malita <fmalita@gmail.com>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Switch the memory policy of the kevent threads to MPOL_DEFAULT while
leaving the kzalloc of the workqueue structure on interleave. This means
that all code executed in the context of the kevent thread is allocating
node local.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Alok Kataria <alok.kataria@calsoftinc.com>
Cc: Andi Kleen <ak@suse.de>
Cc: <pj@sgi.com>
Cc: <shai@scalex86.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add suspend_console() and resume_console() to the suspend-to-disk code paths
so that the users of netconsole can use swsusp with it.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This annotation makes it possible to assign a subclass on lock init. This
annotation is meant to reduce the _nested() annotations by assigning a
default subclass.
One could do without this annotation and rely on lockdep_set_class()
exclusively, but that would require a manual stack of struct lock_class_key
objects.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Unfortunately one of the recent changes in swsusp has broken the userland
suspend on SMP. Fix it.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
