sched: clean up fastcall uses of sched_fork()/sched_exit()
sched_fork()/sched_exit() does not need to specify fastcall anymore,
as the x86 kernel defaults to regparm3, and no assembly code calls
these functions.
track TSC-unstable events and propagate it to the scheduler code.
Also allow sched_clock() to be used when the TSC is unstable,
the rq_clock() wrapper creates a reliable clock out of it.
this change switches over the scheduler core to CFS's modular
design and makes use of kernel/sched_fair/rt/idletask.c to implement
Linux's scheduling policies.
thanks to Andrew Morton and Thomas Gleixner for lots of detailed review
feedback and for fixlets.
remove the sleep_type heuristics from the core scheduler - scheduling
policy is implemented in the scheduling-policy modules. (and CFS does
not use this type of sleep-type heuristics)
add rq_clock()/__rq_clock(), a robust wrapper around sched_clock(),
used by CFS. It protects against common type of sched_clock() problems
(caused by hardware): time warps forwards and backwards.
add kernel/sched_idletask.c - which implements the idle thread
scheduling class. This further simplifies sched.c (under CFS),
for example a number of 'if (p == rq->idle)' type of special-cases
can be removed from sched.c, and schedule() gets simpler too.
add the init_idle_bootup_task() callback to the bootup thread,
unused at the moment. (CFS will use it to switch the scheduling
class of the boot thread to the idle class)
sched: zap the migration init / cache-hot balancing code
the SMP load-balancer uses the boot-time migration-cost estimation
code to attempt to improve the quality of balancing. The reason for
this code is that the discrete priority queues do not preserve
the order of scheduling accurately, so the load-balancer skips
tasks that were running on a CPU 'recently'.
this code is fundamental fragile: the boot-time migration cost detector
doesnt really work on systems that had large L3 caches, it caused boot
delays on large systems and the whole cache-hot concept made the
balancing code pretty undeterministic as well.
(and hey, i wrote most of it, so i can say it out loud that it sucks ;-)
under CFS the same purpose of cache affinity can be achieved without
any special cache-hot special-case: tasks are sorted in the 'timeline'
tree and the SMP balancer picks tasks from the left side of the
tree, thus the most cache-cold task is balanced automatically.
enum idle_type (used by the load-balancer) clashes with the
SCHED_IDLE name that we want to introduce. 'CPU_IDLE' instead
of 'SCHED_IDLE' is more descriptive as well.
Fix permission checking for the new utimensat() system call
Commit 1c710c896eb461895d3c399e15bb5f20b39c9073 added the utimensat()
system call, but didn't handle the case of checking for the writability
of the target right, when the target was a file descriptor, not a
filename.
We cannot use vfs_permission(MAY_WRITE) for that case, and need to
simply check whether the file descriptor is writable. The oops from
using the wrong function was noticed and narrowed down by Markus
Trippelsdorf.
Cc: Ulrich Drepper <drepper@redhat.com> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Andrew Morton <akpm@linux-foundation.org> Acked-by: Al Viro <viro@ftp.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
PIO4 is a maximum PIO mode supported by a driver. Using "255" as a max_mode
argument to ide_get_best_pio_mode() could result in wrong timings being used
by a driver (for "pio" equal to 5) or OOPS (for "pio" values > 5 && < 255).
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com> Reviewed-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
If the chipset is using this PCI-ID, the primary channel is connected to the
first PATA-port. The secondary channel is connected to SATA-ports in IDE
emulation mode. The legacy IO-ports are used.
The including of the PCI-ID into pata_sis is not sufficient, because the legacy
driver in drivers/ide is initialized before pata_sis.
Adrian Bunk [Sat, 7 Jul 2007 04:14:02 +0000 (06:14 +0200)]
DLM must depend on SYSFS
The dependency of DLM on SYSFS got lost in
commit 6ed7257b46709e87d79ac2b6b819b7e0c9184998 resulting in the
following compile error with CONFIG_DLM=y, CONFIG_SYSFS=n:
<-- snip -->
...
LD .tmp_vmlinux1
fs/built-in.o: In function `dlm_lockspace_init':
/home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/fs/dlm/lockspace.c:231: undefined reference to `kernel_subsys'
fs/built-in.o: In function `configfs_init':
/home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/fs/configfs/mount.c:143: undefined reference to `kernel_subsys'
make[1]: *** [.tmp_vmlinux1] Error 1
<-- snip -->
Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Adrian Bunk [Fri, 6 Jul 2007 22:54:09 +0000 (00:54 +0200)]
include/linux/kallsyms.h must #include <linux/errno.h>
This patch fixes the following 2.6.22 regression with CONFIG_KALLSYMS=n:
<-- snip -->
...
CC arch/m32r/kernel/traps.o
In file included from /home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/arch/m32r/kernel/traps.c:14:
/home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/include/linux/kallsyms.h: In function 'lookup_symbol_name':
/home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/include/linux/kallsyms.h:66: error: 'ERANGE' undeclared (first use in this function)
/home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/include/linux/kallsyms.h:66: error: (Each undeclared identifier is reported only once
/home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/include/linux/kallsyms.h:66: error: for each function it appears in.)
/home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/include/linux/kallsyms.h: In function 'lookup_symbol_attrs':
/home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/include/linux/kallsyms.h:71: error: 'ERANGE' undeclared (first use in this function)
make[2]: *** [arch/m32r/kernel/traps.o] Error 1
<-- snip -->
Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Woodhouse [Sat, 7 Jul 2007 18:58:39 +0000 (14:58 -0400)]
Fix use-after-free oops in Bluetooth HID.
When cleaning up HIDP sessions, we currently close the ACL connection
before deregistering the input device. Closing the ACL connection
schedules a workqueue to remove the associated objects from sysfs, but
the input device still refers to them -- and if the workqueue happens to
run before the input device removal, the kernel will oops when trying to
look up PHYSDEVPATH for the removed input device.
Fix this by deregistering the input device before closing the
connections.
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
* 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6:
[NETPOLL]: Fixups for 'fix soft lockup when removing module'
[NET]: net/core/netevent.c should #include <net/netevent.h>
[NETFILTER]: nf_conntrack_h323: add checking of out-of-range on choices' index values
[NET] skbuff: remove export of static symbol
SCTP: Add scope_id validation for link-local binds
SCTP: Check to make sure file is valid before setting timeout
SCTP: Fix thinko in sctp_copy_laddrs()
He correctly updated many of the function definitions that were using this
extra regs pointer parameter but forgot to update some caller sites of
those functions. The reason the modifications was not properly done on all
drivers is that some drivers were rarely compiled because they are for
AMIGA, or that some code sites were inside #ifdefs where the option is not
set or inside #if 0.
Here is the semantic patch that found the occurences
and fixed the problem.
arch/i386/kernel/built-in.o(.init.text+0x4fa9): In function `acpi_parse_madt':
: undefined reference to `acpi_madt_oem_check'
arch/i386/kernel/built-in.o(.init.text+0x7406): In function `smp_read_mpc':
: undefined reference to `mps_oem_check'
arch/i386/kernel/built-in.o(.init.text+0x8990): In function
`connect_bsp_APIC':
: undefined reference to `enable_apic_mode'
make: *** [.tmp_vmlinux1] Error 1
o Fix the build issue. Provided the definitions of missing functions.
o Don't have ES7000 machine. Only compile tested.
Cc: Len Brown <lenb@kernel.org> Cc: Natalie Protasevich <protasnb@gmail.com> Cc: Roland Dreier <rolandd@cisco.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
PNP SMCf010 quirk: work around Toshiba Portege 4000 ACPI issues
When we enable the SMCf010 IR device, the Toshiba Portege 4000 BIOS claims
the device is working, but it really isn't configured correctly. The BIOS
*will* configure it, but only if we call _SRS after (1) reversing the order
of the SIR and FIR I/O port regions and (2) changing the IRQ from
active-high to active-low.
This patch addresses the 2.6.22 regression:
"no irda0 interface (2.6.21 was OK), smsc does not find chip"
I tested this on a Portege 4000. The smsc-ircc2 driver correctly detects
the device, and "irattach irda0 -s && irdadump" shows transmitted and
received packets.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Cc: Andrey Borzenkov <arvidjaar@mail.ru> Cc: Samuel Ortiz <samuel@sortiz.org> Cc: "Linus Walleij (LD/EAB)" <linus.walleij@ericsson.com> Cc: Michal Piotrowski <michal.k.k.piotrowski@gmail.com> Cc: Adam Belay <ambx1@neo.rr.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Woodhouse [Fri, 6 Jul 2007 09:39:52 +0000 (02:39 -0700)]
x86_64: fix headers_install
A bug in headers_install for ARCH=x86_64 yields an asm/ directory full of
files all of which are using the same #ifdef guard, "__ASM_STUB_" with no
postfix. So the second and later asm files #included in the same C file
(often through standard headers like ioctl.h) yields no symbols.
Strangeness with the Ubuntu 'tell me if I support something that's not
explcitly mentioned in POSIX, and I'll strip it out' shell, I believe.
We don't need the 'export' but we do need a semicolon at the end of the
FNAME line:
Signed-off-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Rob Landley <rob@landley.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
MTRR: Fix race causing set_mtrr to go into infinite loop
Processors synchronization in set_mtrr requires the .gate field to be set
after .count field is properly initialized. Without an explicit barrier,
the compiler was reordering those memory stores. That was sometimes
causing a processor (in ipi_handler) to see the .gate change and decrement
.count before the latter is set by set_mtrr() (which then hangs in a
infinite loop with irqs disabled).
Jason Wessel [Fri, 6 Jul 2007 09:39:50 +0000 (02:39 -0700)]
i386: fix regression, endless loop in ptrace singlestep over an int80
The commit 635cf99a80f4ebee59d70eb64bb85ce829e4591f introduced a
regression. Executing a ptrace single step after certain int80
accesses will infinitely loop and never advance the PC.
The TIF_SINGLESTEP check should be done on the return from the syscall
and not before it.
I loops on each single step on the pop right after the int80 which writes out
to the console. At that point you can issue as many single steps as you want
and it will not advance any further.
The test case is below:
/* Test whether singlestep through an int80 syscall works.
*/
#define _GNU_SOURCE
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/ptrace.h>
#include <sys/wait.h>
#include <sys/mman.h>
#include <asm/user.h>
#include <string.h>
static int child, status;
static struct user_regs_struct regs;
Fix elf_core_dump() when writing arch specific notes (spu coredumps)
elf_core_dump() supports dumping arch specific ELF notes, via the #define
ELF_CORE_WRITE_EXTRA_NOTES. Currently the only user of this is the powerpc
spu coredump code.
There is a bug in the handling of foffset WRT the arch notes, which causes
us to erroneously increment foffset by the size of the arch notes, leaving
a block of zeroes in the file, and causing all subsequent data in the file
to be at <supposed position> + <arch note size>. eg:
LOAD 0x050000 0x00100000 0x00000000 0x20000 0x20000 R E 0x10000
Tells us we should have a chunk of data at 0x50000. The truth is the data
is at 0x90dbc = 0x50000 + 0x40dbc (the size of the arch notes).
This bug prevents gdb from reading the core file correctly.
The simplest fix is to simply remember the size of the arch notes, and add
it to foffset after we've written the arch notes. The only drawback is
that if the arch code doesn't write as many bytes as it said it would, we
end up with a broken core dump again. For now I think that's a reasonable
requirement.
Tested on a Cell blade, gdb no longer complains about the core file being
bogus.
While I'm here I should point out that the spu coredump code does not work
if we're dumping to a pipe - we'll have to wait for 23 to fix that.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ralf Baechle [Wed, 20 Jun 2007 23:22:34 +0000 (00:22 +0100)]
[MIPS] Fix scheduling latency issue on 24K, 34K and 74K cores
The idle loop goes to sleep using the WAIT instruction if !need_resched().
This has is suffering from from a race condition that if if just after
need_resched has returned 0 an interrupt might set TIF_NEED_RESCHED but
we've just completed the test so go to sleep anyway. This would be
trivial to fix by just disabling interrupts during that sequence as in:
local_irq_disable();
if (!need_resched())
__asm__("wait");
local_irq_enable();
but the processor architecture leaves it undefined if a processor calling
WAIT with interrupts disabled will ever restart its pipeline and indeed
some processors have made use of the freedom provided by the architecture
definition. This has been resolved and the Config7.WII bit indicates that
the use of WAIT is safe on 24K, 24KE and 34K cores. It also is safe on
74K starting revision 2.1.0 so enable the use of WAIT with interrupts
disabled for 74K based on a c0_prid of at least that.
Older processors used to encode processor version and revision in two
4-bit bitfields, the 4K seems to simply count up and even newer MTI cores
have switched to use the 8-bits as 3:3:2 bitfield with the last field as
the patch number.
The RM7000 processors and the E9000 cores have a bug (though PMC-Sierra
opposes it being called that) where invalid instructions in the same
I-cache line worth of instructions being fetched may case spurious
exceptions.
The workaround for this was only enabled for E9000 cores; enable it also
for all RM7000-based platforms.
[NETPOLL]: Fixups for 'fix soft lockup when removing module'
>From my recent patch:
> > #1
> > Until kernel ver. 2.6.21 (including) cancel_rearming_delayed_work()
> > required a work function should always (unconditionally) rearm with
> > delay > 0 - otherwise it would endlessly loop. This patch replaces
> > this function with cancel_delayed_work(). Later kernel versions don't
> > require this, so here it's only for uniformity.
But Oleg Nesterov <oleg@tv-sign.ru> found:
> But 2.6.22 doesn't need this change, why it was merged?
>
> In fact, I suspect this change adds a race,
...
His description was right (thanks), so this patch reverts #1.
Signed-off-by: Jarek Poplawski <jarkao2@o2.pl> Signed-off-by: David S. Miller <davem@davemloft.net>
[NETFILTER]: nf_conntrack_h323: add checking of out-of-range on choices' index values
Choices' index values may be out of range while still encoded in the fixed
length bit-field. This bug may cause access to undefined types (NULL
pointers) and thus crashes (Reported by Zhongling Wen).
This patch also adds checking of decode flag when decoding SEQUENCEs.
Signed-off-by: Jing Min Zhao <zhaojingmin@vivecode.com> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
SCTP: Add scope_id validation for link-local binds
SCTP currently permits users to bind to link-local addresses,
but doesn't verify that the scope id specified at bind matches
the interface that the address is configured on. It was report
that this can hang a system.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
SCTP: Check to make sure file is valid before setting timeout
In-kernel sockets created with sock_create_kern don't usually
have a file and file descriptor allocated to them. As a result,
when SCTP tries to check the non-blocking flag, we Oops when
dereferencing a NULL file pointer.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* master.kernel.org:/home/rmk/linux-2.6-arm:
[ARM] always allow dump_stack() to produce a backtrace
[ARM] Fix non-page aligned boot time mappings
[ARM] 4458/1: pxa: Fix CKEN usage and hence fix pxa suspend/resume
[ARM] 4454/1: Use word accesses in Versatile PCI config reads
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: document some of keycodes
Input: add a new EV_SW SW_RADIO event, for radio switches on laptops
Input: serio - take drv_mutex in serio_cleanup()
Input: atkbd - use printk_ratelimit for spurious ACK messages
Input: atkbd - throttle LED switching
Input: i8042 - add HP Pavilion ZT1000 to the MUX blacklist
Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
[POWERPC] Update defconfigs
[POWERPC] Uninline and export virq_to_hw() for the pasemi_mac driver
[POWERPC] Fix PMI breakage in cbe_cbufreq driver
[POWERPC] Disable old EMAC driver in arch/powerpc
David Woodhouse [Thu, 5 Jul 2007 01:26:44 +0000 (21:26 -0400)]
Fix slab redzone alignment
Commit b46b8f19c9cd435ecac4d9d12b39d78c137ecd66 fixed a couple of bugs
by switching the redzone to 64 bits. Unfortunately, it neglected to
ensure that the _second_ redzone, after the slab object, is aligned
correctly. This caused illegal instruction faults on sparc32, which for
some reason not entirely clear to me are not trapped and fixed up.
Two things need to be done to fix this:
- increase the object size, rounding up to alignof(long long) so
that the second redzone can be aligned correctly.
- If SLAB_STORE_USER is set but alignof(long long)==8, allow a
full 64 bits of space for the user word at the end of the buffer,
even though we may not _use_ the whole 64 bits.
This patch should be a no-op on any 64-bit architecture or any 32-bit
architecture where alignof(long long) == 4. Of the others, it's tested
on ppc32 by myself and a very similar patch was tested on sparc32 by
Mark Fortescue, who reported the new problem.
Also, fix the conditions for FORCED_DEBUG, which hadn't been adjusted to
the new sizes. Again noticed by Mark.
Signed-off-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yeah, we could have just disabled it, but there's work on a new one that
isn't as fundamentally broken, so there really doesn't seem to be any
point in keeping it around.
The recent timer cleanup broke the only valid use, and when I say
"valid", I obviously mean "totally broken". So it's not like it works,
or really even can work in the current format that uses the unsafe
"panic" LED blinking routines..
Russell King [Wed, 4 Jul 2007 20:16:33 +0000 (21:16 +0100)]
[ARM] Fix non-page aligned boot time mappings
AT91SAM9260 stopped booting with the recent changes to MM
initialisation - it was asking for a non-aligned virtual address
which caused loops to be non-terminal. Fix this by rounding
virtual addresses down, but remember to include the offset in
the length, and round the length up to the following page.
This means that asking for a mapping of 4K starting at 2K into
a page maps two pages as one would expect.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus
* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
[MIPS] VSMP: Fix initialization ordering bug.
[MIPS] Add whitelists for checksyscalls.sh
[MIPS] die(): Properly declare as non-returning
[MIPS] Fix include wrapper symbol definitions in IP32 code.
This marks the declaration of die() correctly, removing "control reaches
end of non-void function" warnings from non-void functions that die() at
the end.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
David Woodhouse [Tue, 3 Jul 2007 20:51:19 +0000 (16:51 -0400)]
[JFFS2] Fix readinode failure when read_dnode() detects CRC failure.
We should have stopped returning 1 from read_dnode() to indicate
failure. We can just mark the damn thing obsolete immediately. But I
missed a case where we don't.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
When Andi reverted the HPET resource reservation (in commit 0f8dc2f06560e2ca126d1670a24126ba08357d38), he didn't remove the now
unused variables, which just causes gcc to be noisy.
Zach Brown [Tue, 3 Jul 2007 22:28:55 +0000 (15:28 -0700)]
dio: remove bogus refcounting BUG_ON
Badari Pulavarty reported a case of this BUG_ON is triggering during
testing. It's completely bogus and should be removed.
It's trying to notice if we left references to the dio hanging around in
the sync case. They should have been dropped as IO completed while this
path was in dio_await_completion(). This condition will also be
checked, via some twisty logic, by the BUG_ON(ret != -EIOCBQUEUED) a few
lines lower. So to start this BUG_ON() is redundant.
More fatally, it's dereferencing dio-> after having dropped its
reference. It's only safe to dereference the dio after releasing the
lock if the final reference was just dropped. Another CPU might free
the dio in bio completion and reuse the memory after this path drops the
dio lock but before the BUG_ON() is evaluated.
This patch passed aio+dio regression unit tests and aio-stress on ext3.
Signed-off-by: Zach Brown <zach.brown@oracle.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andi Kleen [Fri, 29 Jun 2007 14:16:36 +0000 (16:16 +0200)]
Revert HPET resource reservation
Matthias Lenk reports that the PCI subsystem would move the HPET on
SB400/SB600-based systems, where the HPET is in BAR1 of the SMbus
controller.
The reason? The ACPI layer registered the PCI MMIO range as being busy
too early, before PCI enumeration had happened, causing the PCI layer to
decide that it should relocate the resources somewhere else.
Firmware resources should be marked busy _after_ the PCI enumeration and
probing has happened, not before.
Remove the too-early reservation, we'll fix it up to do it properly
later. In the meantime, this solves the regression.
Merge branch 'master' of ssh://master.kernel.org/pub/scm/linux/kernel/git/mchehab/v4l-dvb
* 'master' of ssh://master.kernel.org/pub/scm/linux/kernel/git/mchehab/v4l-dvb:
V4L/DVB (5822): Fix the return value in ttpci_budget_init()
V4L/DVB (5818): CinergyT2: fix flush_workqueue() vs work->func() deadlock
V4L/DVB (5816): Cx88-blackbird: fix vidioc_g_tuner never ending list of tuners
V4L/DVB (5808): Bttv: fix v4l1 breaking the driver
SLUB: Make lockdep happy by not calling add_partial with interrupts enabled during bootstrap
If we move the local_irq_enable() to the end of the function then
add_partial() in early_kmem_cache_node_alloc() will be called
with interrupts disabled like during regular operations.
This makes lockdep happy.
Signed-off-by: Christoph Lameter <clameter@sgi.com> Tested-by: Andre Noll <maan@systemlinux.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Thomas Gleixner [Tue, 3 Jul 2007 18:05:20 +0000 (20:05 +0200)]
NTP: remove clock_was_set() call to prevent deadlock
The clock_was_set() call in seconds_overflow() which happens only when
leap seconds are inserted / deleted is wrong in two aspects:
1. it results in a call to on_each_cpu() with interrupts disabled
2. it is potential deadlock source vs. call_lock in smp_call_function()
The only possible side effect of the removal might be, that an absolute
CLOCK_REALTIME timer fires 1 second too late, in the rare case of leap
second deletion and an absolute CLOCK_REALTIME timer which expires in
the affected time frame. It will never fire too early.
This was probably observed by the reporter of a June 30th -> July 1st
hang: http://lkml.org/lkml/2007/7/3/103
A similar problem was observed by Dave Jones, who provided a screen shot
with a lockdep back trace, which allowed to analyse the problem.
projects / linux-2.6 / log