When the kernel is working well and we want to restart cleanly
kernel_restart is the function to use. But in many instances
the kernel wants to reboot when thing are expected to be working
very badly such as from panic or a software watchdog handler.
This patch adds the function emergency_restart() so that
callers can be clear what semantics they expect when calling
restart. emergency_restart() is expected to be callable
from interrupt context and possibly reliable in even more
trying circumstances.
This is an initial generic implementation for all architectures.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
With CONFIG_PCI=n:
In file included from include/linux/pci.h:917,
from lib/iomap.c:6:
include/asm/pci.h:104: warning: `enum pci_dma_burst_strategy' declared inside parameter list
include/asm/pci.h:104: warning: its scope is only this definition or declaration, which is probably not what you want.
include/asm/pci.h: In function `pci_dma_burst_advice':
include/asm/pci.h:106: dereferencing pointer to incomplete type
include/asm/pci.h:106: `PCI_DMA_BURST_INFINITY' undeclared (first use in this function)
include/asm/pci.h:106: (Each undeclared identifier is reported only once
include/asm/pci.h:106: for each function it appears in.)
make[1]: *** [lib/iomap.o] Error 1
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
After seeing, at best, "guesses" as to the following kind
of information in several drivers, I decided that we really
need a way for platforms to specifically give advice in this
area for what works best with their PCI controller implementation.
Basically, this new interface gives DMA bursting advice on
PCI. There are three forms of the advice:
1) Burst as much as possible, it is not necessary to end bursts
on some particular boundary for best performance.
2) Burst on some byte count multiple. A DMA burst to some multiple of
number of bytes may be done, but it is important to end the burst
on an exact multiple for best performance.
The best example of this I am aware of are the PPC64 PCI
controllers, where if you end a burst mid-cacheline then
chip has to refetch the data and the IOMMU translations
which hurts performance a lot.
3) Burst on a single byte count multiple. Bursts shall end
exactly on the next multiple boundary for best performance.
Sparc64 and Alpha's PCI controllers operate this way. They
disconnect any device which tries to burst across a cacheline
boundary.
Actually, newer sparc64 PCI controllers do not have this behavior.
That is why the "pdev" is passed into the interface, so I can
add code later to check which PCI controller the system is using
and give advice accordingly.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The preempt_count member of struct thread_info is currently either defined
as int, unsigned int or __s32 depending on arch. This patch makes the type
of preempt_count an int on all archs.
Having preempt_count be an unsigned type prevents the catching of
preempt_count < 0 bugs, and using int on some archs and __s32 on others is
not exactely "neat" - much nicer when it's just int all over.
A previous version of this patch was already ACK'ed by Robert Love, and the
only change in this version of the patch compared to the one he ACK'ed is
that this one also makes sure the preempt_count member is consistently
commented.
Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
New file - asm-generic/signal.h. Contains declarations of
__sighandler_t, __sigrestore_t, SIG_DFL, SIG_IGN, SIG_ERR and default
definitions of SIG_BLOCK, SIG_UNBLOCK and SIG_SETMASK.
asm-*/signal.h switched to including it. The only exception is
asm-parisc/signal.h that wants its own declaration of __sighandler_t;
that one is left as-is.
asm-ppc64/signal.h required one more thing - unlike everybody else it
used __sigrestorer_t instead of usual __sigrestore_t. PPC64 switched to
common spelling.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The attached patch moves the IRQ-related SA_xxx flags (namely, SA_PROBE,
SA_SAMPLE_RANDOM and SA_SHIRQ) from all the arch-specific headers to
linux/signal.h. This looks like a left-over after the irq-handling code
was consolidated. The code was moved to kernel/irq/*, but the flags are
still left per-arch.
Right now, adding a new IRQ flag to the arch-specific header, like this
patch does:
http://cvs.sourceforge.net/viewcvs.py/*checkout*/alsa/alsa-driver/utils/patches/pcsp-kernel-2.6.10-03.diff?rev=1.1
no longer works, it breaks the compilation for all other arches, unless you
add that flag to all the other arch-specific headers too. So I think such
a clean-up makes sense.
Signed-off-by: Stas Sergeev <stsp@aknet.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch eliminates all kernel BUGs, trims about 35k off the typical
kernel, and makes the system slightly faster.
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Eric W. Biederman