* 'semaphore' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc:
Remove DEBUG_SEMAPHORE from Kconfig
Improve semaphore documentation
Simplify semaphore implementation
Add down_timeout and change ACPI to use it
Introduce down_killable()
Generic semaphore implementation
Add semaphore.h to kernel_lock.c
Fix quota.h includes
This patch adds in the ability to compile the kgdb internal test
string into the kernel so as to run the tests at boot without changing
the kernel boot arguments. This patch also changes all the error
paths to invoke WARN_ON(1) which will emit the line number of the file
and dump the kernel stack when an error occurs.
You can disable the tests in a kernel that is built this way
using "kgdbts="
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch adds regression tests for testing the kgdb core and arch
specific implementation.
The kgdb test suite is designed to be built into the kernel and not as
a module because it uses a number of low level kernel and kgdb
primitives which should not be exported externally.
The kgdb test suite is designed as a KGDB I/O module which
simulates the communications that a debugger would have with kgdb.
The tests are broken up in to a line by line and referenced here as
a "get" which is kgdb requesting input and "put" which is kgdb
sending a response.
The kgdb suite can be invoked from the kernel command line
arguments system or executed dynamically at run time. The test
suite uses the variable "kgdbts" to obtain the information about
which tests to run and to configure the verbosity level. The
following are the various characters you can use with the kgdbts=
line:
When using the "kgdbts=" you only choose one of the following core
test types:
A = Run all the core tests silently
V1 = Run all the core tests with minimal output
V2 = Run all the core tests in debug mode
You can also specify optional tests:
N## = Go to sleep with interrupts of for ## seconds
to test the HW NMI watchdog
F## = Break at do_fork for ## iterations
S## = Break at sys_open for ## iterations
NOTE: that the do_fork and sys_open tests are mutually exclusive.
To invoke the kgdb test suite from boot you use a kernel start
argument as follows:
kgdbts=V1 kgdbwait
Or if you wanted to perform the NMI test for 6 seconds and do_fork
test for 100 forks, you could use:
kgdbts=V1N6F100 kgdbwait
The test suite can also be invoked at run time with:
echo kgdbts=V1N6F100 > /sys/module/kgdbts/parameters/kgdbts
Or as another example:
echo kgdbts=V2 > /sys/module/kgdbts/parameters/kgdbts
When developing a new kgdb arch specific implementation or
using these tests for the purpose of regression testing,
several invocations are required.
1) Boot with the test suite enabled by using the kernel arguments
"kgdbts=V1F100 kgdbwait"
## If kgdb arch specific implementation has NMI use
"kgdbts=V1N6F100
2) After the system boot run the basic test.
echo kgdbts=V1 > /sys/module/kgdbts/parameters/kgdbts
3) Run the concurrency tests. It is best to use n+1
while loops where n is the number of cpus you have
in your system. The example below uses only two
loops.
## This tests break points on sys_open
while [ 1 ] ; do find / > /dev/null 2>&1 ; done &
while [ 1 ] ; do find / > /dev/null 2>&1 ; done &
echo kgdbts=V1S10000 > /sys/module/kgdbts/parameters/kgdbts
fg # and hit control-c
fg # and hit control-c
## This tests break points on do_fork
while [ 1 ] ; do date > /dev/null ; done &
while [ 1 ] ; do date > /dev/null ; done &
echo kgdbts=V1F1000 > /sys/module/kgdbts/parameters/kgdbts
fg # and hit control-c
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
kgdb core code. Handles the protocol and the arch details.
[ mingo@elte.hu: heavily modified, simplified and cleaned up. ]
[ xemul@openvz.org: use find_task_by_pid_ns ]
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Alpha and FRV mutexes had an option to print lots of debugging messages
in their semaphore implementation. This feature has not been carried
over to the generic semaphores, so remove the stale Kconfig option.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Semaphores are no longer performance-critical, so a generic C
implementation is better for maintainability, debuggability and
extensibility. Thanks to Peter Zijlstra for fixing the lockdep
warning. Thanks to Harvey Harrison for pointing out that the
unlikely() was unnecessary.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
kernel_lock.c uses DECLARE_MUTEX, up() and down() without explicitly
including asm/semaphore.h. This is fragile and leaves it vulnerable
to breakage during header reorganisations.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
There is a potential bug in __lmb_alloc_base where we subtract `size'
from the base address of a reserved region without checking whether
the subtraction could wrap around and produce a very large unsigned
value. In fact it probably isn't possible to hit the bug in practice
since it would only occur in the situation where we can't satisfy the
allocation request and there is a reserved region starting at 0.
This fixes the potential bug by breaking out of the loop when we get
to the point where the base of the reserved region is less than the
size requested. This also restructures the loop to be a bit easier to
follow.
The same logic got copied into lmb_alloc_nid_unreserved, so this makes
a similar change there. Here the bug is more likely to be hit because
the outer loop (in lmb_alloc_nid) goes through the memory regions in
increasing order rather than decreasing order as __lmb_alloc_base
does, and we are therefore more likely to hit the case where we are
testing against a reserved region with a base address of 0.
Signed-off-by: Paul Mackerras <paulus@samba.org>
This makes no semantic changes. It fixes the whitespace and formatting
a bit, gets rid of a local DBG macro and uses the equivalent pr_debug
instead, and restructures one while loop that had a function call and
assignment in the condition to be a bit more readable. Some comments
about functions being called with relocation disabled were also removed
as they would just be confusing to most readers now that the code is
in lib/.
Signed-off-by: Paul Mackerras <paulus@samba.org>
A variant of lmb_alloc() that tries to allocate memory on a specified
NUMA node 'nid' but falls back to normal lmb_alloc() if that fails.
The caller provides a 'nid_range' function pointer which assists the
allocator. It is given args 'start', 'end', and pointer to integer
'this_nid'.
It places at 'this_nid' the NUMA node id that corresponds to 'start',
and returns the end address within 'start' to 'end' at which memory
assosciated with 'nid' ends.
This callback allows a platform to use lmb_alloc_nid() in just
about any context, even ones in which early_pfn_to_nid() might
not be working yet.
This function will be used by the NUMA setup code on sparc64, and also
it can be used by powerpc, replacing it's hand crafted
"careful_allocation()" function in arch/powerpc/mm/numa.c
If x86 ever converts it's NUMA support over to using the LMB helpers,
it can use this too as it has something entirely similar.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
count_partial() is used by both slabinfo and the sysfs proc support. Move
the function directly before the beginning of the sysfs code so that it can
be easily found. Rework the preprocessor conditional to take into account
that slub sysfs support depends on CONFIG_SYSFS *and* CONFIG_SLUB_DEBUG.
Make CONFIG_SLUB_STATS depend on CONFIG_SLUB_DEBUG and CONFIG_SYSFS. There
is no point of keeping statistics if no one can restrive them.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Shift of a LE value seems strange, probably meant to shift the cpu-order
variable as in the prvious section of the switch statement.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Acked-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds new three helper functions to copy data between an SG
list and a linear buffer.
- sg_copy_from_buffer copies data from linear buffer to an SG list
- sg_copy_to_buffer copies data from an SG list to a linear buffer
When the APIs copy data from a linear buffer to an SG list,
flush_kernel_dcache_page is called. It's not necessary for everyone
but it's a no-op on most architectures and in general the API is not
used in performance critical path.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
- Let it update the state of all CPUs. The network stack goes
into pains to feed the current IP addresses in, but it is not very
effective if that is only done for some random CPU instead of all.
So change it to feed bits into all CPUs. I decided to do that lockless
because well somewhat random results are ok.
v2: Drop rename so that this patch doesn't depend on x86 maintainers
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This does not look good, but there is no other choice. The compilation
without CONFIG_NET is broken and can not be fixed with ease.
After that there is no need for the following commits:
1567ca7eec3edf8fa5cc2d38f9a4f8
Revert them.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Mark Lord wrote:
>
> On boot, syslog is flooded with "uevent: unsupported action-string;" messages.
..
> Mar 28 14:43:29 shrimp kernel: tty ptyqd: uevent: unsupported
> action-string; this will be ignored in a future kernel version
> Mar 28 14:43:29 shrimp kernel: tty ptyqe: uevent: unsupported
> action-string; this will be ignored in a future kernel version
> Mar 28 14:43:29 shrimp kernel: tty ptyqf: uevent: unsupported
> action-string; this will be ignored in a future kernel version
> Mar 28 14:43:29 shrimp kernel: tty ptyr0: uevent: unsupported
> action-string; this will be ignored in a future kernel version
..
These messages are a regression compared with 2.6.24, which did not
flood the syslog with them.
The actual underlying problem was introduced in 2.6.23, when somebody
made the string parsing no longer accept nul-terminated strings as a
valid input to store_uevent().
Eg. "add\0" was valid prior to 2.6.23, where the code regressed to
require "add" without the '\0'.
This patch fixes the 2.6.23 / 2.6.24 regressions, by having the code
once again tolerate the trailing '\0', if present.
According to GregKH, this mainly affects older Ubuntu systems, such as
the one I have here that requires this fix.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The knock-out. The pcounter abstraction is not used any longer in the
kernel.
Not sure whether this should go via netdev tree, but as far as I
remember it was added via this one, and besides Eric thinks that
Andrew shouldn't mind this.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This fix broken compilation for 'allnoconfig'. This was introduced by
Introduced by commit 1218854afa ("[NET]
NETNS: Omit seq_net_private->net without CONFIG_NET_NS.")
Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
It appears that 64-bit PCI resources cannot possibly ever have worked on
x86-32 even when the RESOURCES_64BIT config option was set, because any
driver that tried to [pci_]ioremap() the resource would have been unable
to do so because the high 32 bits would have been silently dropped on
the floor by the ioremap() routines that only used "unsigned long".
Change them to use "resource_size_t" instead, which properly encodes the
whole 64-bit resource data if RESOURCES_64BIT is enabled.
Acked-by: H. Peter Anvin <hpa@kernel.org>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
