Commit Graph

10552 Commits

Author SHA1 Message Date
Linus Torvalds
426e1f5cec Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (52 commits)
  split invalidate_inodes()
  fs: skip I_FREEING inodes in writeback_sb_inodes
  fs: fold invalidate_list into invalidate_inodes
  fs: do not drop inode_lock in dispose_list
  fs: inode split IO and LRU lists
  fs: switch bdev inode bdi's correctly
  fs: fix buffer invalidation in invalidate_list
  fsnotify: use dget_parent
  smbfs: use dget_parent
  exportfs: use dget_parent
  fs: use RCU read side protection in d_validate
  fs: clean up dentry lru modification
  fs: split __shrink_dcache_sb
  fs: improve DCACHE_REFERENCED usage
  fs: use percpu counter for nr_dentry and nr_dentry_unused
  fs: simplify __d_free
  fs: take dcache_lock inside __d_path
  fs: do not assign default i_ino in new_inode
  fs: introduce a per-cpu last_ino allocator
  new helper: ihold()
  ...
2010-10-26 17:58:44 -07:00
Randy Dunlap
ee2f154a59 docbook: add more wait/wake/completion to device-drivers docbook
Add more wait, wake, and completion interfaces to the device-drivers
docbook.

Fix kernel-doc notation in the added files.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 17:32:41 -07:00
Namhyung Kim
f5d87d851d printk: declare printk_ratelimit_state in ratelimit.h
Adding declaration of printk_ratelimit_state in ratelimit.h removes
potential build breakage and following sparse warning:

 kernel/printk.c:1426:1: warning: symbol 'printk_ratelimit_state' was not declared. Should it be static?

[akpm@linux-foundation.org: remove unneeded ifdef]
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:16 -07:00
Namhyung Kim
674dff6507 printk: change type of 'boot_delay' to int *
get_option() takes its 2nd arg as int * so passing boot_delay to it
caused following warnings from sparse:

 kernel/printk.c:223:27: warning: incorrect type in argument 2 (different signedness)
 kernel/printk.c:223:27:    expected int *pint
 kernel/printk.c:223:27:    got unsigned int static [toplevel] *<noident>

Since boot_delay can't grow more than 10,000 changing it to 'int *'
will not produce any problem.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:16 -07:00
Namhyung Kim
8155c02a44 printk: add lock context annotation
acquire_console_semaphore_for_printk() releases logbuf_lock but
was missing proper annotation. Add it.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:16 -07:00
Namhyung Kim
6c095efd82 printk: fixup declaration of kmsg_reasons
Move redundant 'const' after '*' to make pointer itself const

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:16 -07:00
Akinobu Mita
4ce6494dbd stop_machine: convert cpu notifier to return encapsulate errno value
In commit e6bde73b07 ("cpu-hotplug: return
better errno on cpu hotplug failure"), the cpu notifier can return an
encapsulated errno value.

This converts the cpu notifier to return an encapsulated errno value for
stop_machine().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:15 -07:00
Rakib Mullick
ca51c5a763 kernel/stop_machine.c: fix unused variable warning
kernel/stop_machine.c: In function `cpu_stopper_thread':
kernel/stop_machine.c:265: warning: unused variable `ksym_buf'

ksym_buf[] is unused if WARN_ON() is a no-op.

Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:15 -07:00
Eric Dumazet
518de9b39e fs: allow for more than 2^31 files
Robin Holt tried to boot a 16TB system and found af_unix was overflowing
a 32bit value :

<quote>

We were seeing a failure which prevented boot.  The kernel was incapable
of creating either a named pipe or unix domain socket.  This comes down
to a common kernel function called unix_create1() which does:

        atomic_inc(&unix_nr_socks);
        if (atomic_read(&unix_nr_socks) > 2 * get_max_files())
                goto out;

The function get_max_files() is a simple return of files_stat.max_files.
files_stat.max_files is a signed integer and is computed in
fs/file_table.c's files_init().

        n = (mempages * (PAGE_SIZE / 1024)) / 10;
        files_stat.max_files = n;

In our case, mempages (total_ram_pages) is approx 3,758,096,384
(0xe0000000).  That leaves max_files at approximately 1,503,238,553.
This causes 2 * get_max_files() to integer overflow.

</quote>

Fix is to let /proc/sys/fs/file-nr & /proc/sys/fs/file-max use long
integers, and change af_unix to use an atomic_long_t instead of atomic_t.

get_max_files() is changed to return an unsigned long.  get_nr_files() is
changed to return a long.

unix_nr_socks is changed from atomic_t to atomic_long_t, while not
strictly needed to address Robin problem.

Before patch (on a 64bit kernel) :
# echo 2147483648 >/proc/sys/fs/file-max
# cat /proc/sys/fs/file-max
-18446744071562067968

After patch:
# echo 2147483648 >/proc/sys/fs/file-max
# cat /proc/sys/fs/file-max
2147483648
# cat /proc/sys/fs/file-nr
704     0       2147483648

Reported-by: Robin Holt <holt@sgi.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: David Miller <davem@davemloft.net>
Reviewed-by: Robin Holt <holt@sgi.com>
Tested-by: Robin Holt <holt@sgi.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:15 -07:00
Namhyung Kim
571428be55 kernel/user.c: add lock release annotation on free_user()
free_user() releases uidhash_lock but was missing annotation.  Add it.
This removes following sparse warnings:

 include/linux/spinlock.h:339:9: warning: context imbalance in 'free_user' - unexpected unlock
 kernel/user.c:120:6: warning: context imbalance in 'free_uid' - wrong count at exit

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Dhaval Giani <dhaval.giani@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:15 -07:00
Andrew Morton
ca1cab37d9 workqueues: s/ON_STACK/ONSTACK/
Silly though it is, completions and wait_queue_heads use foo_ONSTACK
(COMPLETION_INITIALIZER_ONSTACK, DECLARE_COMPLETION_ONSTACK,
__WAIT_QUEUE_HEAD_INIT_ONSTACK and DECLARE_WAIT_QUEUE_HEAD_ONSTACK) so I
guess workqueues should do the same thing.

s/INIT_WORK_ON_STACK/INIT_WORK_ONSTACK/
s/INIT_DELAYED_WORK_ON_STACK/INIT_DELAYED_WORK_ONSTACK/

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:14 -07:00
Jan Beulich
3ecb01df32 use clear_page()/copy_page() in favor of memset()/memcpy() on whole pages
After all that's what they are intended for.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:13 -07:00
Peter Zijlstra
61ecdb801e mm: strictly nested kmap_atomic()
Ensure kmap_atomic() usage is strictly nested

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:08 -07:00
Ying Han
3d5992d2ac oom: add per-mm oom disable count
It's pointless to kill a task if another thread sharing its mm cannot be
killed to allow future memory freeing.  A subsequent patch will prevent
kills in such cases, but first it's necessary to have a way to flag a task
that shares memory with an OOM_DISABLE task that doesn't incur an
additional tasklist scan, which would make select_bad_process() an O(n^2)
function.

This patch adds an atomic counter to struct mm_struct that follows how
many threads attached to it have an oom_score_adj of OOM_SCORE_ADJ_MIN.
They cannot be killed by the kernel, so their memory cannot be freed in
oom conditions.

This only requires task_lock() on the task that we're operating on, it
does not require mm->mmap_sem since task_lock() pins the mm and the
operation is atomic.

[rientjes@google.com: changelog and sys_unshare() code]
[rientjes@google.com: protect oom_disable_count with task_lock in fork]
[rientjes@google.com: use old_mm for oom_disable_count in exec]
Signed-off-by: Ying Han <yinghan@google.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:05 -07:00
Christoph Hellwig
312d3ca856 fs: use percpu counter for nr_dentry and nr_dentry_unused
The nr_dentry stat is a globally touched cacheline and atomic operation
twice over the lifetime of a dentry. It is used for the benfit of userspace
only. Turn it into a per-cpu counter and always decrement it in d_free instead
of doing various batching operations to reduce lock hold times in the callers.

Based on an earlier patch from Nick Piggin <npiggin@suse.de>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:12 -04:00
Christoph Hellwig
85fe4025c6 fs: do not assign default i_ino in new_inode
Instead of always assigning an increasing inode number in new_inode
move the call to assign it into those callers that actually need it.
For now callers that need it is estimated conservatively, that is
the call is added to all filesystems that do not assign an i_ino
by themselves.  For a few more filesystems we can avoid assigning
any inode number given that they aren't user visible, and for others
it could be done lazily when an inode number is actually needed,
but that's left for later patches.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:11 -04:00
Al Viro
7de9c6ee3e new helper: ihold()
Clones an existing reference to inode; caller must already hold one.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:11 -04:00
Dave Chinner
cffbc8aa33 fs: Convert nr_inodes and nr_unused to per-cpu counters
The number of inodes allocated does not need to be tied to the
addition or removal of an inode to/from a list. If we are not tied
to a list lock, we could update the counters when inodes are
initialised or destroyed, but to do that we need to convert the
counters to be per-cpu (i.e. independent of a lock). This means that
we have the freedom to change the list/locking implementation
without needing to care about the counters.

Based on a patch originally from Eric Dumazet.

[AV: cleaned up a bit, fixed build breakage on weird configs

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:09 -04:00
Eric Dumazet
7e360c38ab fs: allow for more than 2^31 files
Andrew,

Could you please review this patch, you probably are the right guy to
take it, because it crosses fs and net trees.

Note : /proc/sys/fs/file-nr is a read-only file, so this patch doesnt
depend on previous patch (sysctl: fix min/max handling in
__do_proc_doulongvec_minmax())

Thanks !

[PATCH V4] fs: allow for more than 2^31 files

Robin Holt tried to boot a 16TB system and found af_unix was overflowing
a 32bit value :

<quote>

We were seeing a failure which prevented boot.  The kernel was incapable
of creating either a named pipe or unix domain socket.  This comes down
to a common kernel function called unix_create1() which does:

        atomic_inc(&unix_nr_socks);
        if (atomic_read(&unix_nr_socks) > 2 * get_max_files())
                goto out;

The function get_max_files() is a simple return of files_stat.max_files.
files_stat.max_files is a signed integer and is computed in
fs/file_table.c's files_init().

        n = (mempages * (PAGE_SIZE / 1024)) / 10;
        files_stat.max_files = n;

In our case, mempages (total_ram_pages) is approx 3,758,096,384
(0xe0000000).  That leaves max_files at approximately 1,503,238,553.
This causes 2 * get_max_files() to integer overflow.

</quote>

Fix is to let /proc/sys/fs/file-nr & /proc/sys/fs/file-max use long
integers, and change af_unix to use an atomic_long_t instead of
atomic_t.

get_max_files() is changed to return an unsigned long.
get_nr_files() is changed to return a long.

unix_nr_socks is changed from atomic_t to atomic_long_t, while not
strictly needed to address Robin problem.

Before patch (on a 64bit kernel) :
# echo 2147483648 >/proc/sys/fs/file-max
# cat /proc/sys/fs/file-max
-18446744071562067968

After patch:
# echo 2147483648 >/proc/sys/fs/file-max
# cat /proc/sys/fs/file-max
2147483648
# cat /proc/sys/fs/file-nr
704     0       2147483648

Reported-by: Robin Holt <holt@sgi.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: David Miller <davem@davemloft.net>
Reviewed-by: Robin Holt <holt@sgi.com>
Tested-by: Robin Holt <holt@sgi.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:18:20 -04:00
David Howells
5260562754 MN10300: Fix the PERCPU() alignment to allow for workqueues
In the MN10300 arch, we occasionally see an assertion being tripped in
alloc_cwqs() at the following line:

        /* just in case, make sure it's actually aligned */
  --->  BUG_ON(!IS_ALIGNED(wq->cpu_wq.v, align));
        return wq->cpu_wq.v ? 0 : -ENOMEM;

The values are:

        wa->cpu_wq.v => 0x902776e0
        align => 0x100

and align is calculated by the following:

        const size_t align = max_t(size_t, 1 << WORK_STRUCT_FLAG_BITS,
                                   __alignof__(unsigned long long));

This is because the pointer in question (wq->cpu_wq.v) loses some of its
lower bits to control flags, and so the object it points to must be
sufficiently aligned to avoid the need to use those bits for pointing to
things.

Currently, 4 control bits and 4 colour bits are used in normal
circumstances, plus a debugging bit if debugging is set.  This requires
the cpu_workqueue_struct struct to be at least 256 bytes aligned (or 512
bytes aligned with debugging).

PERCPU() alignment on MN13000, however, is only 32 bytes as set in
vmlinux.lds.S.  So we set this to PAGE_SIZE (4096) to match most other
arches and stick a comment in alloc_cwqs() for anyone else who triggers
the assertion.

Reported-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Mark Salter <msalter@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-25 16:24:06 -07:00
Linus Torvalds
229aebb873 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
  Update broken web addresses in arch directory.
  Update broken web addresses in the kernel.
  Revert "drivers/usb: Remove unnecessary return's from void functions" for musb gadget
  Revert "Fix typo: configuation => configuration" partially
  ida: document IDA_BITMAP_LONGS calculation
  ext2: fix a typo on comment in ext2/inode.c
  drivers/scsi: Remove unnecessary casts of private_data
  drivers/s390: Remove unnecessary casts of private_data
  net/sunrpc/rpc_pipe.c: Remove unnecessary casts of private_data
  drivers/infiniband: Remove unnecessary casts of private_data
  drivers/gpu/drm: Remove unnecessary casts of private_data
  kernel/pm_qos_params.c: Remove unnecessary casts of private_data
  fs/ecryptfs: Remove unnecessary casts of private_data
  fs/seq_file.c: Remove unnecessary casts of private_data
  arm: uengine.c: remove C99 comments
  arm: scoop.c: remove C99 comments
  Fix typo configue => configure in comments
  Fix typo: configuation => configuration
  Fix typo interrest[ing|ed] => interest[ing|ed]
  Fix various typos of valid in comments
  ...

Fix up trivial conflicts in:
	drivers/char/ipmi/ipmi_si_intf.c
	drivers/usb/gadget/rndis.c
	net/irda/irnet/irnet_ppp.c
2010-10-24 13:41:39 -07:00
Linus Torvalds
02f36038c5 Merge branches 'softirq-for-linus', 'x86-debug-for-linus', 'x86-numa-for-linus', 'x86-quirks-for-linus', 'x86-setup-for-linus', 'x86-uv-for-linus' and 'x86-vm86-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'softirq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  softirqs: Make wakeup_softirqd static

* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, asm: Restore parentheses around one pushl_cfi argument
  x86, asm: Fix ancient-GAS workaround
  x86, asm: Fix CFI macro invocations to deal with shortcomings in gas

* 'x86-numa-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, numa: Assign CPUs to nodes in round-robin manner on fake NUMA

* 'x86-quirks-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: HPET force enable for CX700 / VIA Epia LT

* 'x86-setup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, setup: Use string copy operation to optimze copy in kernel compression

* 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, UV: Use allocated buffer in tlb_uv.c:tunables_read()

* 'x86-vm86-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, vm86: Fix preemption bug for int1 debug and int3 breakpoint handlers.
2010-10-23 08:25:36 -07:00
Linus Torvalds
8814011679 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
  kdb,debug_core: adjust master cpu switch logic against new debug_core locking
  debug_core: refactor locking for master/slave cpus
  x86,kgdb: remove unnecessary call to kgdb_correct_hw_break()
  debug_core: disable hw_breakpoints on all cores in kgdb_cpu_enter()
  kdb,kgdb: fix sparse fixups
  kdb: Fix oops in kdb_unregister
  kdb,ftdump: Remove reference to internal kdb include
  kdb: Allow kernel loadable modules to add kdb shell functions
  debug_core: stop rcu warnings on kernel resume
  debug_core: move all watch dog syncs to a single function
  x86,kgdb: fix debugger hw breakpoint test regression in 2.6.35
2010-10-22 20:35:12 -07:00
Linus Torvalds
91b745016c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: remove in_workqueue_context()
  workqueue: Clarify that schedule_on_each_cpu is synchronous
  memory_hotplug: drop spurious calls to flush_scheduled_work()
  shpchp: update workqueue usage
  pciehp: update workqueue usage
  isdn/eicon: don't call flush_scheduled_work() from diva_os_remove_soft_isr()
  workqueue: add and use WQ_MEM_RECLAIM flag
  workqueue: fix HIGHPRI handling in keep_working()
  workqueue: add queue_work and activate_work trace points
  workqueue: prepare for more tracepoints
  workqueue: implement flush[_delayed]_work_sync()
  workqueue: factor out start_flush_work()
  workqueue: cleanup flush/cancel functions
  workqueue: implement alloc_ordered_workqueue()

Fix up trivial conflict in fs/gfs2/main.c as per Tejun
2010-10-22 17:13:10 -07:00
Jason Wessel
495363d380 kdb,debug_core: adjust master cpu switch logic against new debug_core locking
The kdb shell needs to enforce switching back to the original CPU that
took the exception before restoring normal kernel execution.  Resuming
from a different CPU than what took the original exception will cause
problems with spin locks that are freed from the a different processor
than had taken the lock.

The special logic in dbg_cpu_switch() can go away entirely with
because the state of what cpus want to be masters or slaves will
remain unchanged between entry and exit of the debug_core exception
context.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-22 15:34:13 -05:00