Currently, the freezer treats all tasks as freezable, except for the kernel
threads that explicitly set the PF_NOFREEZE flag for themselves. This
approach is problematic, since it requires every kernel thread to either
set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't
care for the freezing of tasks at all.
It seems better to only require the kernel threads that want to or need to
be frozen to use some freezer-related code and to remove any
freezer-related code from the other (nonfreezable) kernel threads, which is
done in this patch.
The patch causes all kernel threads to be nonfreezable by default (ie. to
have PF_NOFREEZE set by default) and introduces the set_freezable()
function that should be called by the freezable kernel threads in order to
unset PF_NOFREEZE. It also makes all of the currently freezable kernel
threads call set_freezable(), so it shouldn't cause any (intentional)
change of behaviour to appear. Additionally, it updates documentation to
describe the freezing of tasks more accurately.
[akpm@linux-foundation.org: build fixes]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.
Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6: (231 commits)
[PATCH] i386: Don't delete cpu_devs data to identify different x86 types in late_initcall
[PATCH] i386: type may be unused
[PATCH] i386: Some additional chipset register values validation.
[PATCH] i386: Add missing !X86_PAE dependincy to the 2G/2G split.
[PATCH] x86-64: Don't exclude asm-offsets.c in Documentation/dontdiff
[PATCH] i386: avoid redundant preempt_disable in __unlazy_fpu
[PATCH] i386: white space fixes in i387.h
[PATCH] i386: Drop noisy e820 debugging printks
[PATCH] x86-64: Fix allnoconfig error in genapic_flat.c
[PATCH] x86-64: Shut up warnings for vfat compat ioctls on other file systems
[PATCH] x86-64: Share identical video.S between i386 and x86-64
[PATCH] x86-64: Remove CONFIG_REORDER
[PATCH] x86-64: Print type and size correctly for unknown compat ioctls
[PATCH] i386: Remove copy_*_user BUG_ONs for (size < 0)
[PATCH] i386: Little cleanups in smpboot.c
[PATCH] x86-64: Don't enable NUMA for a single node in K8 NUMA scanning
[PATCH] x86: Use RDTSCP for synchronous get_cycles if possible
[PATCH] i386: Add X86_FEATURE_RDTSCP
[PATCH] i386: Implement X86_FEATURE_SYNC_RDTSC on i386
[PATCH] i386: Implement alternative_io for i386
...
Fix up trivial conflict in include/linux/highmem.h manually.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
set_irq_msi() currently connects an irq_desc to an msi_desc. The archs call
it at some point in their setup routine, and then the generic code sets up the
reverse mapping from the msi_desc back to the irq.
set_irq_msi() should do both connections, making it the one and only call
required to connect an irq with it's MSI desc and vice versa.
The arch code MUST call set_irq_msi(), and it must do so only once it's sure
it's not going to fail the irq allocation.
Given that there's no need for the arch to return the irq anymore, the return
value from the arch setup routine just becomes 0 for success and anything else
for failure.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch just trivial converts from calling kernel_thread and daemonize
to just calling kthread_run.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Many years ago, UNEXPECTED_IO_APIC() contained printk()'s (but nothing more).
Now that it's completely empty for years, we can as well remove it.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andi Kleen <ak@suse.de>
When removing set_native_irq I missed the fact that it was
called in a couple of places that were compiled even when
SMP support is disabled. And since the irq_desc[].affinity
field only exists in SMP things broke.
Thanks to Simon Arlott <simon@arlott.org> for spotting this.
There are a couple of ways to fix this but the simplest one
is to just remove the assignments. The affinity field is only
used to display a value to the user, and nothing on either i386
or x86_64 reads it or depends on it being any particlua value,
so skipping the assignment is safe. The assignment that
is being removed is just for the initial affinity value before
the user explicitly sets it. The irq_desc array initializes
this field to CPU_MASK_ALL so the field is initialized to
a reasonable value in the SMP case without being set.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch replaces all instances of "set_native_irq_info(irq, mask)"
with "irq_desc[irq].affinity = mask". The latter form is clearer
uses fewer abstractions, and makes access to this field uniform
accross different architectures.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a flag so we can prevent the irq balancing of an interrupt. Move the
bits, so we have room for more :)
Necessary for the ability to setup clocksources more flexible (e.g. use the
different HPET channels per CPU)
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The "fasteoi" IRQ handler is named "fasteio" incorrectly. This is a fix.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
The arch hooks arch_setup_msi_irq and arch_teardown_msi_irq are now
responsible for allocating and freeing the linux irq in addition to
setting up the the linux irq to work with the interrupt.
arch_setup_msi_irq now takes a pci_device and a msi_desc and returns
an irq.
With this change in place this code should be useable by all platforms
except those that won't let the OS touch the hardware like ppc RTAS.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When the world was a simple and static place setting up irqs was easy.
It sufficed to allocate a linux irq number and a find a free cpu
vector we could receive that linux irq on. In those days it was
a safe assumption that any allocated vector was actually in use
so after one global pass through all of the vectors we would have
none left.
These days things are much more dynamic with interrupt controllers
(in the form of MSI or MSI-X) appearing on plug in cards and linux
irqs appearing and disappearing. As these irqs come and go vectors
are allocated and freed, invalidating the ancient assumption that all
allocated vectors stayed in use forever.
So this patch modifies the vector allocator to walk through every
possible vector before giving up, and to check to see if a vector
is in use before assigning it. With these changes we stop leaking
freed vectors and it becomes possible to allocate and free irq vectors
all day long.
This changed was modeled after the vector allocator on x86_64 where
this limitation has already been removed. In essence we don't update
the static variables that hold the position of the last vector we
allocated until have successfully allocated another vector. This
allows us to detect if we have completed one complete scan through
all of the possible vectors.
Acked-by: Auke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
gcc 4.2 warns
linux/arch/i386/kernel/io_apic.c: In function ‘create_irq’:
linux/arch/i386/kernel/io_apic.c:2488: warning: ‘vector’ may be used uninitialized in this function
The warning is false, but somewhat legitimate so work around it.
Signed-off-by: Andi Kleen <ak@suse.de>
Move process freezing functions from include/linux/sched.h to freezer.h, so
that modifications to the freezer or the kernel configuration don't require
recompiling just about everything.
[akpm@osdl.org: fix ueagle driver]
Signed-off-by: Nigel Cunningham <nigel@suspend2.net>
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 Coverity checker noted that bad things might happen if
find_isa_irq_apic() returned -1.
[akpm@osdl.org: add debugging checks]
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Acked-by: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Add a way to disable the timer IRQ routing check via a boot option. The
VMI timer code uses this to avoid triggering the pester Mingo code, which
probes for some very unusual and broken motherboard routings. It fires
100% of the time when using a paravirtual delay mechanism instead of using
a realtime delay, since there is no elapsed real time, and the 4 timer IRQs
have not yet been delivered.
In addition, it is entirely possible, though improbable, that this bug
could surface on real hardware which picks a particularly bad time to enter
SMM mode, causing a long latency during one of the timer IRQs.
While here, make check_timer be __init.
Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andi Kleen <ak@suse.de>
[chrisw: use no_timer_check to bring inline with x86_64 as per Andi's request]
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Rafael J. Wysocki
Randy Dunlap
Linus Torvalds
Michael Ellerman
Eric W. Biederman
Adrian Bunk
Andrew Morton
Ingo Molnar
Thomas Gleixner
Zachary Amsden
Maciej W. Rozycki
Al Viro
Andi Kleen
Linus Torvalds
Nigel Cunningham