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2010-10-26printk: change type of 'boot_delay' to int *Namhyung Kim1-1/+1
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 <[email protected]> Cc: Ingo Molnar <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2010-10-26printk: add lock context annotationNamhyung Kim1-0/+1
acquire_console_semaphore_for_printk() releases logbuf_lock but was missing proper annotation. Add it. Signed-off-by: Namhyung Kim <[email protected]> Cc: Ingo Molnar <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2010-10-26printk: fixup declaration of kmsg_reasonsNamhyung Kim1-1/+1
Move redundant 'const' after '*' to make pointer itself const Signed-off-by: Namhyung Kim <[email protected]> Cc: Ingo Molnar <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2010-10-26stop_machine: convert cpu notifier to return encapsulate errno valueAkinobu Mita1-2/+2
In commit e6bde73b07edeb703d4c89c1daabc09c303de11f ("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 <[email protected]> Cc: Rusty Russell <[email protected]> Cc: Tejun Heo <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2010-10-26kernel/stop_machine.c: fix unused variable warningRakib Mullick1-1/+1
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 <[email protected]> Cc: Ingo Molnar <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2010-10-26fs: allow for more than 2^31 filesEric Dumazet1-3/+3
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 <[email protected]> Signed-off-by: Eric Dumazet <[email protected]> Acked-by: David Miller <[email protected]> Reviewed-by: Robin Holt <[email protected]> Tested-by: Robin Holt <[email protected]> Cc: Al Viro <[email protected]> Cc: Christoph Hellwig <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2010-10-26kernel/user.c: add lock release annotation on free_user()Namhyung Kim1-0/+1
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 <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Dhaval Giani <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2010-10-26workqueues: s/ON_STACK/ONSTACK/Andrew Morton1-1/+1
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 <[email protected]> Acked-by: Tejun Heo <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2010-10-26use clear_page()/copy_page() in favor of memset()/memcpy() on whole pagesJan Beulich3-11/+11
After all that's what they are intended for. Signed-off-by: Jan Beulich <[email protected]> Cc: Miklos Szeredi <[email protected]> Cc: "Eric W. Biederman" <[email protected]> Cc: "Rafael J. Wysocki" <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2010-10-26mm: strictly nested kmap_atomic()Peter Zijlstra1-2/+2
Ensure kmap_atomic() usage is strictly nested Signed-off-by: Peter Zijlstra <[email protected]> Reviewed-by: Rik van Riel <[email protected]> Acked-by: Chris Metcalf <[email protected]> Cc: David Howells <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Russell King <[email protected]> Cc: Ralf Baechle <[email protected]> Cc: David Miller <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Benjamin Herrenschmidt <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2010-10-26oom: add per-mm oom disable countYing Han2-1/+17
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. [[email protected]: changelog and sys_unshare() code] [[email protected]: protect oom_disable_count with task_lock in fork] [[email protected]: use old_mm for oom_disable_count in exec] Signed-off-by: Ying Han <[email protected]> Signed-off-by: David Rientjes <[email protected]> Cc: KAMEZAWA Hiroyuki <[email protected]> Cc: KOSAKI Motohiro <[email protected]> Cc: Rik van Riel <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2010-10-26resources: support allocating space within a region from the top downBjorn Helgaas1-4/+94
Allocate space from the top of a region first, then work downward, if an architecture desires this. When we allocate space from a resource, we look for gaps between children of the resource. Previously, we always looked at gaps from the bottom up. For example, given this: [mem 0xbff00000-0xf7ffffff] PCI Bus 0000:00 [mem 0xbff00000-0xbfffffff] gap -- available [mem 0xc0000000-0xdfffffff] PCI Bus 0000:02 [mem 0xe0000000-0xf7ffffff] gap -- available we attempted to allocate from the [mem 0xbff00000-0xbfffffff] gap first, then the [mem 0xe0000000-0xf7ffffff] gap. With this patch an architecture can choose to allocate from the top gap [mem 0xe0000000-0xf7ffffff] first. We can't do this across the board because iomem_resource.end is initialized to 0xffffffff_ffffffff on 64-bit architectures, and most machines can't address the entire 64-bit physical address space. Therefore, we only allocate top-down if the arch requests it by clearing "resource_alloc_from_bottom". Signed-off-by: Bjorn Helgaas <[email protected]> Signed-off-by: Jesse Barnes <[email protected]>
2010-10-26resources: handle overflow when aligning start of available areaBjorn Helgaas1-8/+13
If tmp.start is near ~0, ALIGN(tmp.start) may overflow, which would make us think there's more available space than there really is. We would likely return something that conflicts with a previous resource, which would cause a failure when allocate_resource() requests the newly- allocated region. Reference: https://bugzilla.redhat.com/show_bug.cgi?id=646027 Reported-by: Fabrice Bellet <[email protected]> Signed-off-by: Bjorn Helgaas <[email protected]> Signed-off-by: Jesse Barnes <[email protected]>
2010-10-26resources: ensure callback doesn't allocate outside available spaceBjorn Helgaas1-5/+11
The alignment callback returns a proposed location, which may have been adjusted to avoid ISA aliases or for other architecture-specific reasons. We already had a check ("tmp.start < tmp.end") to make sure the callback doesn't return an area that extends past the available area. This patch reworks the check to make sure it doesn't return an area that extends either below or above the available area. Signed-off-by: Bjorn Helgaas <[email protected]> Signed-off-by: Jesse Barnes <[email protected]>
2010-10-26resources: factor out resource_clip() to simplify find_resource()Bjorn Helgaas1-4/+11
This factors out the min/max clipping to simplify find_resource(). No functional change. Signed-off-by: Bjorn Helgaas <[email protected]> Signed-off-by: Jesse Barnes <[email protected]>
2010-10-26resources: add a default alignf to simplify find_resource()Bjorn Helgaas1-2/+13
This removes a test from find_resource(), which is getting cluttered. No functional change. Signed-off-by: Bjorn Helgaas <[email protected]> Signed-off-by: Jesse Barnes <[email protected]>
2010-10-26Merge branch 'tip/perf/ringbuffer-2' of ↵Ingo Molnar1-163/+172
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent
2010-10-25fs: use percpu counter for nr_dentry and nr_dentry_unusedChristoph Hellwig1-1/+1
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 <[email protected]>. Signed-off-by: Christoph Hellwig <[email protected]> Signed-off-by: Al Viro <[email protected]>
2010-10-25fs: do not assign default i_ino in new_inodeChristoph Hellwig1-0/+1
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 <[email protected]> Signed-off-by: Dave Chinner <[email protected]> Signed-off-by: Al Viro <[email protected]>
2010-10-25new helper: ihold()Al Viro1-1/+1
Clones an existing reference to inode; caller must already hold one. Signed-off-by: Al Viro <[email protected]>
2010-10-25fs: Convert nr_inodes and nr_unused to per-cpu countersDave Chinner1-2/+2
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 <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Signed-off-by: Al Viro <[email protected]>
2010-10-25fs: allow for more than 2^31 filesEric Dumazet1-3/+3
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 <[email protected]> Signed-off-by: Eric Dumazet <[email protected]> Acked-by: David Miller <[email protected]> Reviewed-by: Robin Holt <[email protected]> Tested-by: Robin Holt <[email protected]> Signed-off-by: Al Viro <[email protected]>
2010-10-25MN10300: Fix the PERCPU() alignment to allow for workqueuesDavid Howells1-1/+3
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 <[email protected]> Signed-off-by: David Howells <[email protected]> Acked-by: Mark Salter <[email protected]> Cc: Tejun Heo <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2010-10-25kprobes: Remove redundant text_mutex lock in optimizeMasami Hiramatsu1-3/+4
Remove text_mutex locking in optimize_all_kprobes, because this function doesn't modify text. It simply queues probes on optimization list for kprobe_optimizer worker thread. Signed-off-by: Masami Hiramatsu <[email protected]> Cc: Ananth N Mavinakayanahalli <[email protected]> Cc: Anil S Keshavamurthy <[email protected]> Cc: David S. Miller <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Jason Baron <[email protected]> Cc: Peter Zijlstra <[email protected]> LKML-Reference: <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2010-10-24Merge branch 'for-next' of ↵Linus Torvalds2-2/+2
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
2010-10-24sched_stat: Update sched_info_queue/dequeue() code commentsRakib Mullick1-19/+1
Remove some sched_info_queue(), sched_info_dequeue() code comment. We no longer belongs to the era of O(1) and we don't use active or expired array anymore. Signed-off-by: Rakib Mullick <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Peter Zijlstra <[email protected]> LKML-Reference: <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2010-10-23tracing: Fix 'faild' -> 'failed' typoJoe Perches1-1/+1
Signed-off-by: Joe Perches <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Jiri Kosina <[email protected]> LKML-Reference: <cd9855af60d7d90e9f55fc7afd0ed23fcdaa6f52.1287724261.git.joe@perches.com> Signed-off-by: Ingo Molnar <[email protected]>
2010-10-23Merge branch 'perf/core' of ↵Ingo Molnar1-7/+9
git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux-2.6 into perf/urgent
2010-10-23Merge branches 'softirq-for-linus', 'x86-debug-for-linus', ↵Linus Torvalds1-1/+1
'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.
2010-10-22Merge branch 'for_linus' of ↵Linus Torvalds7-127/+85
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
2010-10-22Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds1-116/+194
* '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
2010-10-22kdb,debug_core: adjust master cpu switch logic against new debug_core lockingJason Wessel3-22/+9
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 <[email protected]>
2010-10-22debug_core: refactor locking for master/slave cpusJason Wessel2-50/+56
For quite some time there have been problems with memory barriers and various races with NMI on multi processor systems using the kernel debugger. The algorithm for entering the kernel debug core and resuming kernel execution was racy and had several known edge case problems with attempting to debug something on a heavily loaded system using breakpoints that are hit repeatedly and quickly. The prior "locking" design entry worked as follows: * The atomic counter kgdb_active was used with atomic exchange in order to elect a master cpu out of all the cpus that may have taken a debug exception. * The master cpu increments all elements of passive_cpu_wait[]. * The master cpu issues the round up cpus message. * Each "slave cpu" that enters the debug core increments its own element in cpu_in_kgdb[]. * Each "slave cpu" spins on passive_cpu_wait[] until it becomes 0. * The master cpu debugs the system. The new scheme removes the two arrays of atomic counters and replaces them with 2 single counters. One counter is used to count the number of cpus waiting to become a master cpu (because one or more hit an exception). The second counter is use to indicate how many cpus have entered as slave cpus. The new entry logic works as follows: * One or more cpus enters via kgdb_handle_exception() and increments the masters_in_kgdb. Each cpu attempts to get the spin lock called dbg_master_lock. * The master cpu sets kgdb_active to the current cpu. * The master cpu takes the spinlock dbg_slave_lock. * The master cpu asks to round up all the other cpus. * Each slave cpu that is not already in kgdb_handle_exception() will enter and increment slaves_in_kgdb. Each slave will now spin try_locking on dbg_slave_lock. * The master cpu waits for the sum of masters_in_kgdb and slaves_in_kgdb to be equal to the sum of the online cpus. * The master cpu debugs the system. In the new design the kgdb_active can only be changed while holding dbg_master_lock. Stress testing has not turned up any further entry/exit races that existed in the prior locking design. The prior locking design suffered from atomic variables not being truly atomic (in the capacity as used by kgdb) along with memory barrier races. Signed-off-by: Jason Wessel <[email protected]> Acked-by: Dongdong Deng <[email protected]>
2010-10-22debug_core: disable hw_breakpoints on all cores in kgdb_cpu_enter()Dongdong Deng1-2/+5
The slave cpus do not have the hw breakpoints disabled upon entry to the debug_core and as a result could cause unrecoverable recursive faults on badly placed breakpoints, or get out of sync with the arch specific hw breakpoint operations. This patch addresses the problem by invoking kgdb_disable_hw_debug() earlier in kgdb_enter_cpu for each cpu that enters the debug core. The hw breakpoint dis/enable flow should be: master_debug_cpu slave_debug_cpu \ / kgdb_cpu_enter | kgdb_disable_hw_debug --> uninstall pre-enabled hw_breakpoint | do add/rm dis/enable operates to hw_breakpoints on master_debug_cpu.. | correct_hw_break --> correct/install the enabled hw_breakpoint | leave_kgdb Signed-off-by: Dongdong Deng <[email protected]> Signed-off-by: Jason Wessel <[email protected]>
2010-10-22kdb,kgdb: fix sparse fixupsJason Wessel1-8/+1
Fix the following sparse warnings: kdb_main.c:328:5: warning: symbol 'kdbgetu64arg' was not declared. Should it be static? kgdboc.c:246:12: warning: symbol 'kgdboc_early_init' was not declared. Should it be static? kgdb.c:652:26: warning: incorrect type in argument 1 (different address spaces) kgdb.c:652:26: expected void const *ptr kgdb.c:652:26: got struct perf_event *[noderef] <asn:3>*pev The one in kgdb.c required the (void * __force) because of the return code from register_wide_hw_breakpoint looking like: return (void __percpu __force *)ERR_PTR(err); Signed-off-by: Jason Wessel <[email protected]>
2010-10-22kdb: Fix oops in kdb_unregisterJason Wessel1-1/+1
Nothing should try to use kdb_commands directly as sometimes it is null. Instead, use the for_each_kdbcmd() iterator. This particular problem dates back to the initial kdb merge (2.6.35), but at that point nothing was dynamically unregistering commands from the kdb shell. Signed-off-by: Jason Wessel <[email protected]>
2010-10-22kdb,ftdump: Remove reference to internal kdb includeJason Wessel1-1/+0
Now that include/linux/kdb.h properly exports all the functions required to dynamically add a kdb shell command, the reference to the private kdb header can be removed. Signed-off-by: Jason Wessel <[email protected]>
2010-10-22kdb: Allow kernel loadable modules to add kdb shell functionsJason Wessel3-40/+5
In order to allow kernel modules to dynamically add a command to the kdb shell the kdb_register, kdb_register_repeat, kdb_unregister, and kdb_printf need to be exported as GPL symbols. Any kernel module that adds a dynamic kdb shell function should only need to include linux/kdb.h. Signed-off-by: Jason Wessel <[email protected]>
2010-10-22debug_core: stop rcu warnings on kernel resumeJason Wessel1-0/+2
When returning from the kernel debugger reset the rcu jiffies_stall value to prevent the rcu stall detector from sending NMI events which invoke a stack dump for each cpu in the system. Signed-off-by: Jason Wessel <[email protected]>
2010-10-22debug_core: move all watch dog syncs to a single functionJason Wessel1-6/+9
Move the various clock and watch dog syncs to a single function in advance of adding another sync for the rcu stall detector. Signed-off-by: Jason Wessel <[email protected]>
2010-10-22Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bklLinus Torvalds10-0/+17
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: vfs: make no_llseek the default vfs: don't use BKL in default_llseek llseek: automatically add .llseek fop libfs: use generic_file_llseek for simple_attr mac80211: disallow seeks in minstrel debug code lirc: make chardev nonseekable viotape: use noop_llseek raw: use explicit llseek file operations ibmasmfs: use generic_file_llseek spufs: use llseek in all file operations arm/omap: use generic_file_llseek in iommu_debug lkdtm: use generic_file_llseek in debugfs net/wireless: use generic_file_llseek in debugfs drm: use noop_llseek
2010-10-22Merge branch 'vfs' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bklLinus Torvalds1-4/+0
* 'vfs' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: (30 commits) BKL: remove BKL from freevxfs BKL: remove BKL from qnx4 autofs4: Only declare function when CONFIG_COMPAT is defined autofs: Only declare function when CONFIG_COMPAT is defined ncpfs: Lock socket in ncpfs while setting its callbacks fs/locks.c: prepare for BKL removal BKL: Remove BKL from ncpfs BKL: Remove BKL from OCFS2 BKL: Remove BKL from squashfs BKL: Remove BKL from jffs2 BKL: Remove BKL from ecryptfs BKL: Remove BKL from afs BKL: Remove BKL from USB gadgetfs BKL: Remove BKL from autofs4 BKL: Remove BKL from isofs BKL: Remove BKL from fat BKL: Remove BKL from ext2 filesystem BKL: Remove BKL from do_new_mount() BKL: Remove BKL from cgroup BKL: Remove BKL from NTFS ...
2010-10-22Merge branch 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bklLinus Torvalds2-11/+9
* 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: BKL: introduce CONFIG_BKL. dabusb: remove the BKL sunrpc: remove the big kernel lock init/main.c: remove BKL notations blktrace: remove the big kernel lock rtmutex-tester: make it build without BKL dvb-core: kill the big kernel lock dvb/bt8xx: kill the big kernel lock tlclk: remove big kernel lock fix rawctl compat ioctls breakage on amd64 and itanic uml: kill big kernel lock parisc: remove big kernel lock cris: autoconvert trivial BKL users alpha: kill big kernel lock isapnp: BKL removal s390/block: kill the big kernel lock hpet: kill BKL, add compat_ioctl
2010-10-22genirq: Warn if enable_irq is called before irq is set upThomas Gleixner1-0/+4
The recent changes in the genirq core unearthed a bug in arch/um which called enable_irq() before the interrupt was set up. Warn and return instead of crashing the machine with a NULL pointer dereference. Signed-off-by: Thomas Gleixner <[email protected]> Cc: Richard Weinberger <[email protected]>
2010-10-22Merge branch 'tip/perf/core-2' of ↵Ingo Molnar1-6/+2
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent
2010-10-22perf_events: Fix for transaction recovery in group_sched_in()Stephane Eranian1-2/+20
This new version (see commit 8e5fc1a) is much simpler and ensures that in case of error in group_sched_in() during event_sched_in(), the events up to the failed event go through regular event_sched_out(). But the failed event and the remaining events in the group have their timings adjusted as if they had also gone through event_sched_in() and event_sched_out(). This ensures timing uniformity across all events in a group. This also takes care of the tstamp_stopped problem in case the group could never be scheduled. The tstamp_stopped is updated as if the event had actually run. With this patch, the following now reports correct time_enabled, in case the NMI watchdog is active: $ task -e unhalted_core_cycles,instructions_retired,baclears,baclears noploop 1 noploop for 1 seconds 0 unhalted_core_cycles (100.00% scaling, ena=997,552,872, run=0) 0 instructions_retired (100.00% scaling, ena=997,552,872, run=0) 0 baclears (100.00% scaling, ena=997,552,872, run=0) 0 baclears (100.00% scaling, ena=997,552,872, run=0) And the older test case also works: $ task -einstructions_retired,baclears,baclears -e unhalted_core_cycles,baclears,baclears sleep 5 1680885 instructions_retired (69.39% scaling, ena=950756, run=291006) 10735 baclears (69.39% scaling, ena=950756, run=291006) 10735 baclears (69.39% scaling, ena=950756, run=291006) 0 unhalted_core_cycles (100.00% scaling, ena=817932, run=0) 0 baclears (100.00% scaling, ena=817932, run=0) 0 baclears (100.00% scaling, ena=817932, run=0) Signed-off-by: Stephane Eranian <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> LKML-Reference: <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2010-10-22perf_events: Revert: Fix transaction recovery in group_sched_in()Stephane Eranian1-63/+13
This patch reverts commit 8e5fc1a (perf_events: Fix transaction recovery in group_sched_in()) because it had one flaw in case the group could never be scheduled. It would cause time_enabled to get negative. Signed-off-by: Stephane Eranian <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> LKML-Reference: <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2010-10-22sched, cgroup: Fixup broken cgroup movementPeter Zijlstra2-10/+23
Dima noticed that we fail to correct the ->vruntime of sleeping tasks when we move them between cgroups. Reported-by: Dima Zavin <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Tested-by: Mike Galbraith <[email protected]> LKML-Reference: <1287150604.29097.1513.camel@twins> Signed-off-by: Ingo Molnar <[email protected]>
2010-10-21Merge branch 'next' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (71 commits) powerpc/44x: Update ppc44x_defconfig powerpc/watchdog: Make default timeout for Book-E watchdog a Kconfig option fsl_rio: Add comments for sRIO registers. powerpc/fsl-booke: Add e55xx (64-bit) smp defconfig powerpc/fsl-booke: Add p5020 DS board support powerpc/fsl-booke64: Use TLB CAMs to cover linear mapping on FSL 64-bit chips powerpc/fsl-booke: Add support for FSL Arch v1.0 MMU in setup_page_sizes powerpc/fsl-booke: Add support for FSL 64-bit e5500 core powerpc/85xx: add cache-sram support powerpc/85xx: add ngPIXIS FPGA device tree node to the P1022DS board powerpc: Fix compile error with paca code on ppc64e powerpc/fsl-booke: Add p3041 DS board support oprofile/fsl emb: Don't set MSR[PMM] until after clearing the interrupt. powerpc/fsl-booke: Add PCI device ids for P2040/P3041/P5010/P5020 QoirQ chips powerpc/mpc8xxx_gpio: Add support for 'qoriq-gpio' controllers powerpc/fsl_booke: Add support to boot from core other than 0 powerpc/p1022: Add probing for individual DMA channels powerpc/fsl_soc: Search all global-utilities nodes for rstccr powerpc: Fix invalid page flags in create TLB CAM path for PTE_64BIT powerpc/mpc83xx: Support for MPC8308 P1M board ... Fix up conflict with the generic irq_work changes in arch/powerpc/kernel/time.c
2010-10-21Merge branch 'core-memblock-for-linus' of ↵Linus Torvalds2-591/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-memblock-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (74 commits) x86-64: Only set max_pfn_mapped to 512 MiB if we enter via head_64.S xen: Cope with unmapped pages when initializing kernel pagetable memblock, bootmem: Round pfn properly for memory and reserved regions memblock: Annotate memblock functions with __init_memblock memblock: Allow memblock_init to be called early memblock/arm: Fix memblock_region_is_memory() typo x86, memblock: Remove __memblock_x86_find_in_range_size() memblock: Fix wraparound in find_region() x86-32, memblock: Make add_highpages honor early reserved ranges x86, memblock: Fix crashkernel allocation arm, memblock: Fix the sparsemem build memblock: Fix section mismatch warnings powerpc, memblock: Fix memblock API change fallout memblock, microblaze: Fix memblock API change fallout x86: Remove old bootmem code x86, memblock: Use memblock_memory_size()/memblock_free_memory_size() to get correct dma_reserve x86: Remove not used early_res code x86, memblock: Replace e820_/_early string with memblock_ x86: Use memblock to replace early_res x86, memblock: Use memblock_debug to control debug message print out ... Fix up trivial conflicts in arch/x86/kernel/setup.c and kernel/Makefile