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2011-02-08Revert "lockdep, timer: Fix del_timer_sync() annotation"Peter Zijlstra
Both attempts at trying to allow softirq usage for del_timer_sync() failed (produced bogus warnings), so revert the commit for this release: f266a5110d45: lockdep, timer: Fix del_timer_sync() annotation and try again later. Reported-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Yong Zhang <yong.zhang0@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <1297174680.13327.107.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-07tracing/syscalls: Early terminate search for sys_ni_syscallIan Munsie
Many system calls are unimplemented and mapped to sys_ni_syscall, but at boot ftrace would still search through every syscall metadata entry for a match which wouldn't be there. This patch adds causes the search to terminate early if the system call is not mapped. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> LKML-Reference: <1296703645-18718-7-git-send-email-imunsie@au1.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/syscalls: Allow arch specific syscall symbol matchingIan Munsie
Some architectures have unusual symbol names and the generic code to match the symbol name with the function name for the syscall metadata will fail. For example, symbols on PPC64 start with a period and the generic code will fail to match them. This patch moves the match logic out into a separate function which an arch can override by defining ARCH_HAS_SYSCALL_MATCH_SYM_NAME in asm/ftrace.h and implementing arch_syscall_match_sym_name. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> LKML-Reference: <1296703645-18718-5-git-send-email-imunsie@au1.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/syscalls: Make arch_syscall_addr weakIan Munsie
Some architectures use non-trivial system call tables and will not work with the generic arch_syscall_addr code. For example, PowerPC64 uses a table of twin long longs. This patch makes the generic arch_syscall_addr weak to allow architectures with non-trivial system call tables to override it. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> LKML-Reference: <1296703645-18718-4-git-send-email-imunsie@au1.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/syscalls: Convert redundant syscall_nr checks into WARN_ONIan Munsie
With the ftrace events now checking if the syscall_nr is valid upon initialisation it should no longer be possible to register or unregister a syscall event without a valid syscall_nr since they should not be created. This adds a WARN_ON_ONCE in the register and unregister functions to locate potential regressions in the future. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> LKML-Reference: <1296703645-18718-3-git-send-email-imunsie@au1.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/syscalls: Don't add events for unmapped syscallsIan Munsie
FTRACE_SYSCALLS would create events for each and every system call, even if it had failed to map the system call's name with it's number. This resulted in a number of events being created that would not behave as expected. This could happen, for example, on architectures who's symbol names are unusual and will not match the system call name. It could also happen with system calls which were mapped to sys_ni_syscall. This patch changes the default system call number in the metadata to -1. If the system call name from the metadata is not successfully mapped to a system call number during boot, than the event initialisation routine will now return an error, preventing the event from being created. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> LKML-Reference: <1296703645-18718-2-git-send-email-imunsie@au1.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Remove synchronize_sched() from __alloc_preds()Steven Rostedt
Because the filters are processed first and then activated (added to the call), we no longer need to worry about the preds of the filter in __alloc_preds() being used. As the filter that is allocating preds is not activated yet. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Swap entire filter of eventsSteven Rostedt
When creating a new filter, instead of allocating the filter to the event call first and then processing the filter, it is easier to process a temporary filter and then just swap it with the call filter. By doing this, it simplifies the code. A filter is allocated and processed, when it is done, it is swapped with the call filter, synchronize_sched() is called to make sure all callers are done with the old filter (filters are called with premption disabled), and then the old filter is freed. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Increase the max preds to 2^14Steven Rostedt
Now that the filter logic does not require to save the pred results on the stack, we can increase the max number of preds we allow. As the preds are index by a short value, and we use the MSBs as flags we can increase the max preds to 2^14 (16384) which should be way more than enough. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Move MAX_FILTER_PRED to local tracing directorySteven Rostedt
The MAX_FILTER_PRED is only needed by the kernel/trace/*.c files. Move it to kernel/trace/trace.h. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Optimize filter by folding the treeSteven Rostedt
There are many cases that a filter will contain multiple ORs or ANDs together near the leafs. Walking up and down the tree to get to the next compare can be a waste. If there are several ORs or ANDs together, fold them into a single pred and allocate an array of the conditions that they check. This will speed up the filter by linearly walking an array and can still break out if a short circuit condition is met. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Check the created pred treeSteven Rostedt
Since the filter walks a tree to determine if a match is made or not, if the tree was incorrectly created, it could cause an infinite loop. Add a check to walk the entire tree before assigning it as a filter to make sure the tree is correct. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Optimize short ciruit checkSteven Rostedt
The test if we should break out early for OR and AND operations can be optimized by comparing the current result with (pred->op == OP_OR) That is if the result is true and the op is an OP_OR, or if the result is false and the op is not an OP_OR (thus an OP_AND) we can break out early in either case. Otherwise we continue processing. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Use a tree instead of stack for filter_match_preds()Steven Rostedt
Currently the filter_match_preds() requires a stack to push and pop the preds to determine if the filter matches the record or not. This has two drawbacks: 1) It requires a stack to store state information. As this is done in fast paths we can't allocate the storage for this stack, and we can't use a global as it must be re-entrant. The stack is stored on the kernel stack and this greatly limits how many preds we may allow. 2) All conditions are calculated even when a short circuit exists. a || b will always calculate a and b even though a was determined to be true. Using a tree we can walk a constant structure that will save the state as we go. The algorithm is simply: pred = root; do { switch (move) { case MOVE_DOWN: if (OR or AND) { pred = left; continue; } if (pred == root) break; match = pred->fn(); pred = pred->parent; move = left child ? MOVE_UP_FROM_LEFT : MOVE_UP_FROM_RIGHT; continue; case MOVE_UP_FROM_LEFT: /* Only OR or AND can be a parent */ if (match && OR || !match && AND) { /* short circuit */ if (pred == root) break; pred = pred->parent; move = left child ? MOVE_UP_FROM_LEFT : MOVE_UP_FROM_RIGHT; continue; } pred = pred->right; move = MOVE_DOWN; continue; case MOVE_UP_FROM_RIGHT: if (pred == root) break; pred = pred->parent; move = left child ? MOVE_UP_FROM_LEFT : MOVE_UP_FROM_RIGHT; continue; } done = 1; } while (!done); This way there's no strict limit to how many preds we allow and it also will short circuit the logical operations when possible. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Free pred array on disabling of filterSteven Rostedt
When a filter is disabled, free the preds. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Allocate the preds in an arraySteven Rostedt
Currently we allocate an array of pointers to filter_preds, and then allocate a separate filter_pred for each item in the array. This adds slight overhead in the filters as it needs to derefernce twice to get to the op condition. Allocating the preds themselves in a single array removes a dereference as well as helps on the cache footprint. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Call synchronize_sched() just once for system filtersSteven Rostedt
By separating out the reseting of the filter->n_preds to zero from the reallocation of preds for the filter, we can reset groups of filters first, call synchronize_sched() just once, and then reallocate each of the filters in the system group. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Dynamically allocate predsSteven Rostedt
For every filter that is made, we create predicates to hold every operation within the filter. We have a max of 32 predicates that we can hold. Currently, we allocate all 32 even if we only need to use one. Part of the reason we do this is that the filter can be used at any moment by any event. Fortunately, the filter is only used with preemption disabled. By reseting the count of preds used "n_preds" to zero, then performing a synchronize_sched(), we can safely free and reallocate a new array of preds. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Move OR and AND logic out of fn() methodSteven Rostedt
The ops OR and AND act different from the other ops, as they are the only ones to take other ops as their arguements. These ops als change the logic of the filter_match_preds. By removing the OR and AND fn's we can also remove the val1 and val2 that is passed to all other fn's and are unused. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Have no filter return a matchSteven Rostedt
The n_preds field of a file can change at anytime, and even can become zero, just as the filter is about to be processed by an event. In the case that is zero on entering the filter, return 1, telling the caller the event matchs and should be trace. Also use a variable and assign it with ACCESS_ONCE() such that the count stays consistent within the function. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07CRED: Fix memory and refcount leaks upon security_prepare_creds() failureTetsuo Handa
In prepare_kernel_cred() since 2.6.29, put_cred(new) is called without assigning new->usage when security_prepare_creds() returned an error. As a result, memory for new and refcount for new->{user,group_info,tgcred} are leaked because put_cred(new) won't call __put_cred() unless old->usage == 1. Fix these leaks by assigning new->usage (and new->subscribers which was added in 2.6.32) before calling security_prepare_creds(). Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-07CRED: Fix BUG() upon security_cred_alloc_blank() failureTetsuo Handa
In cred_alloc_blank() since 2.6.32, abort_creds(new) is called with new->security == NULL and new->magic == 0 when security_cred_alloc_blank() returns an error. As a result, BUG() will be triggered if SELinux is enabled or CONFIG_DEBUG_CREDENTIALS=y. If CONFIG_DEBUG_CREDENTIALS=y, BUG() is called from __invalid_creds() because cred->magic == 0. Failing that, BUG() is called from selinux_cred_free() because selinux_cred_free() is not expecting cred->security == NULL. This does not affect smack_cred_free(), tomoyo_cred_free() or apparmor_cred_free(). Fix these bugs by (1) Set new->magic before calling security_cred_alloc_blank(). (2) Handle null cred->security in creds_are_invalid() and selinux_cred_free(). Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-07tracing/kprobes: Add bitfield typeMasami Hiramatsu
Add bitfield type for tracing arguments on kprobe-tracer. The syntax of a bitfield type is: b<bit-size>@<bit-offset>/<container-size> e.g. Accessing 2 bits-width field with 4 bits-offset in 32 bits-width data at 4 bytes offseted from the address pointed by AX register: +4(%ax):b2@4/32 Since the width of container data depends on the arch, so I just added the container-size at the end. Cc: 2nddept-manager@sdl.hitachi.co.jp Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <20110204125205.9507.11363.stgit@ltc236.sdl.hitachi.co.jp> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-02-07tracing/kprobes: Support longer (>128 bytes) commandMasami Hiramatsu
Expand command line buffer of kprobe-tracer to 4096 bytes. Reported-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: 2nddept-manager@sdl.hitachi.co.jp Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <20110204125159.9507.20895.stgit@ltc236.sdl.hitachi.co.jp> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-02-07tracing/kprobes: Cleanup strict_strtol() using codeMasami Hiramatsu
Since strict_strtol() accepts minus digits started with '-', it doesn't need to invert after converting. Cc: 2nddept-manager@sdl.hitachi.co.jp Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <20110204125153.9507.49335.stgit@ltc236.sdl.hitachi.co.jp> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-02-07Merge branch 'linus' into perf/coreIngo Molnar
Merge reason: Pick up perf fixes that are now upstream Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-06Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: lockdep, timer: Fix del_timer_sync() annotation RTC: Prevents a division by zero in kernel code.
2011-02-05Merge branch 'irq/urgent' into irq/coreThomas Gleixner
Reason: Get mainline fixes integrated. Further patches conflict with them Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-04Merge branch 'tip/perf/urgent-2' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent
2011-02-04lockdep, timer: Fix del_timer_sync() annotationPeter Zijlstra
Calling local_bh_enable() will want to actually start processing softirqs, which isn't a good idea since this can get called with IRQs disabled. Cure this by using _local_bh_enable() which doesn't start processing softirqs, and use raw_local_irq_save() to avoid any softirqs from happening without letting lockdep think IRQs are in fact disabled. Reported-by: Nick Bowler <nbowler@elliptictech.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Yong Zhang <yong.zhang0@gmail.com> LKML-Reference: <20110203141548.039540914@chello.nl> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-03Merge branch 'irq-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: genirq: Prevent irq storm on migration
2011-02-03Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Fix update_curr_rt() sched, docs: Update schedstats documentation to version 15
2011-02-03Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf: Fix reading in perf_event_read() watchdog: Don't change watchdog state on read of sysctl watchdog: Fix sysctl consistency watchdog: Fix broken nowatchdog logic perf: Fix Pentium4 raw event validation perf: Fix alloc_callchain_buffers()
2011-02-03tracing: Replace syscall_meta_data struct array with pointer arraySteven Rostedt
Currently the syscall_meta structures for the syscall tracepoints are placed in the __syscall_metadata section, and at link time, the linker makes one large array of all these syscall metadata structures. On boot up, this array is read (much like the initcall sections) and the syscall data is processed. The problem is that there is no guarantee that gcc will place complex structures nicely together in an array format. Two structures in the same file may be placed awkwardly, because gcc has no clue that they are suppose to be in an array. A hack was used previous to force the alignment to 4, to pack the structures together. But this caused alignment issues with other architectures (sparc). Instead of packing the structures into an array, the structures' addresses are now put into the __syscall_metadata section. As pointers are always the natural alignment, gcc should always pack them tightly together (otherwise initcall, extable, etc would also fail). By having the pointers to the structures in the section, we can still iterate the trace_events without causing unnecessary alignment problems with other architectures, or depending on the current behaviour of gcc that will likely change in the future just to tick us kernel developers off a little more. The __syscall_metadata section is also moved into the .init.data section as it is now only needed at boot up. Suggested-by: David Miller <davem@davemloft.net> Acked-by: David S. Miller <davem@davemloft.net> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-03tracepoints: Fix section alignment using pointer arrayMathieu Desnoyers
Make the tracepoints more robust, making them solid enough to handle compiler changes by not relying on anything based on compiler-specific behavior with respect to structure alignment. Implement an approach proposed by David Miller: use an array of const pointers to refer to the individual structures, and export this pointer array through the linker script rather than the structures per se. It will consume 32 extra bytes per tracepoint (24 for structure padding and 8 for the pointers), but are less likely to break due to compiler changes. History: commit 7e066fb8 tracepoints: add DECLARE_TRACE() and DEFINE_TRACE() added the aligned(32) type and variable attribute to the tracepoint structures to deal with gcc happily aligning statically defined structures on 32-byte multiples. One attempt was to use a 8-byte alignment for tracepoint structures by applying both the variable and type attribute to tracepoint structures definitions and declarations. It worked fine with gcc 4.5.1, but broke with gcc 4.4.4 and 4.4.5. The reason is that the "aligned" attribute only specify the _minimum_ alignment for a structure, leaving both the compiler and the linker free to align on larger multiples. Because tracepoint.c expects the structures to be placed as an array within each section, up-alignment cause NULL-pointer exceptions due to the extra unexpected padding. (this patch applies on top of -tip) Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: David S. Miller <davem@davemloft.net> LKML-Reference: <20110126222622.GA10794@Krystal> CC: Frederic Weisbecker <fweisbec@gmail.com> CC: Ingo Molnar <mingo@elte.hu> CC: Thomas Gleixner <tglx@linutronix.de> CC: Andrew Morton <akpm@linux-foundation.org> CC: Peter Zijlstra <peterz@infradead.org> CC: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-03sched: Add yield_to(task, preempt) functionalityMike Galbraith
Currently only implemented for fair class tasks. Add a yield_to_task method() to the fair scheduling class. allowing the caller of yield_to() to accelerate another thread in it's thread group, task group. Implemented via a scheduler hint, using cfs_rq->next to encourage the target being selected. We can rely on pick_next_entity to keep things fair, so noone can accelerate a thread that has already used its fair share of CPU time. This also means callers should only call yield_to when they really mean it. Calling it too often can result in the scheduler just ignoring the hint. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110201095051.4ddb7738@annuminas.surriel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-03sched: Use a buddy to implement yield_task_fair()Rik van Riel
Use the buddy mechanism to implement yield_task_fair. This allows us to skip onto the next highest priority se at every level in the CFS tree, unless doing so would introduce gross unfairness in CPU time distribution. We order the buddy selection in pick_next_entity to check yield first, then last, then next. We need next to be able to override yield, because it is possible for the "next" and "yield" task to be different processen in the same sub-tree of the CFS tree. When they are, we need to go into that sub-tree regardless of the "yield" hint, and pick the correct entity once we get to the right level. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110201095103.3a79e92a@annuminas.surriel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-03sched: Limit the scope of clear_buddiesRik van Riel
The clear_buddies function does not seem to play well with the concept of hierarchical runqueues. In the following tree, task groups are represented by 'G', tasks by 'T', next by 'n' and last by 'l'. (nl) / \ G(nl) G / \ \ T(l) T(n) T This situation can arise when a task is woken up T(n), and the previously running task T(l) is marked last. When clear_buddies is called from either T(l) or T(n), the next and last buddies of the group G(nl) will be cleared. This is not the desired result, since we would like to be able to find the other type of buddy in many cases. This especially a worry when implementing yield_task_fair through the buddy system. The fix is simple: only clear the buddy type that the task itself is indicated to be. As an added bonus, we stop walking up the tree when the buddy has already been cleared or pointed elsewhere. Signed-off-by: Rik van Riel <riel@redhat.coM> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110201094837.6b0962a9@annuminas.surriel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-03sched: Check the right ->nr_running in yield_task_fair()Rik van Riel
With CONFIG_FAIR_GROUP_SCHED, each task_group has its own cfs_rq. Yielding to a task from another cfs_rq may be worthwhile, since a process calling yield typically cannot use the CPU right now. Therefor, we want to check the per-cpu nr_running, not the cgroup local one. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110201094715.798c4f86@annuminas.surriel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-03sched: Fix update_curr_rt()Peter Zijlstra
cpu_stopper_thread() migration_cpu_stop() __migrate_task() deactivate_task() dequeue_task() dequeue_task_rq() update_curr_rt() Will call update_curr_rt() on rq->curr, which at that time is rq->stop. The problem is that rq->stop.prio matches an RT prio and thus falsely assumes its a rt_sched_class task. Reported-Debuged-Tested-Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Cc: stable@kernel.org # .37 Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-03perf: Fix reading in perf_event_read()Peter Zijlstra
It is quite possible for the event to have been disabled between perf_event_read() sending the IPI and the CPU servicing the IPI and calling __perf_event_read(), hence revalidate the state. Reported-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-03perf: Cure task_oncpu_function_call() racesPeter Zijlstra
Oleg reported that on architectures with __ARCH_WANT_INTERRUPTS_ON_CTXSW the IPI from task_oncpu_function_call() can land before perf_event_task_sched_in() and cause interesting situations for eg. perf_install_in_context(). This patch reworks the task_oncpu_function_call() interface to give a more usable primitive as well as rework all its users to hopefully be more obvious as well as remove the races. While looking at the code I also found a number of races against perf_event_task_sched_out() which can flip contexts between tasks so plug those too. Reported-and-reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-02tracing: Replace trace_event struct array with pointer arraySteven Rostedt
Currently the trace_event structures are placed in the _ftrace_events section, and at link time, the linker makes one large array of all the trace_event structures. On boot up, this array is read (much like the initcall sections) and the events are processed. The problem is that there is no guarantee that gcc will place complex structures nicely together in an array format. Two structures in the same file may be placed awkwardly, because gcc has no clue that they are suppose to be in an array. A hack was used previous to force the alignment to 4, to pack the structures together. But this caused alignment issues with other architectures (sparc). Instead of packing the structures into an array, the structures' addresses are now put into the _ftrace_event section. As pointers are always the natural alignment, gcc should always pack them tightly together (otherwise initcall, extable, etc would also fail). By having the pointers to the structures in the section, we can still iterate the trace_events without causing unnecessary alignment problems with other architectures, or depending on the current behaviour of gcc that will likely change in the future just to tick us kernel developers off a little more. The _ftrace_event section is also moved into the .init.data section as it is now only needed at boot up. Suggested-by: David Miller <davem@davemloft.net> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-02genirq: Prevent irq storm on migrationThomas Gleixner
move_native_irq() masks and unmasks the interrupt line unconditionally, but the interrupt line might be masked due to a threaded oneshot handler in progress. Unmasking the line in that case can lead to interrupt storms. Observed on PREEMPT_RT. Originally-from: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org
2011-02-02posix clocks: Introduce dynamic clocksRichard Cochran
This patch adds support for adding and removing posix clocks. The clock lifetime cycle is patterned after usb devices. Each clock is represented by a standard character device. In addition, the driver may optionally implement custom character device operations. The posix clock and timer system calls listed below now work with dynamic posix clocks, as well as the traditional static clocks. The following system calls are affected: - clock_adjtime (brand new syscall) - clock_gettime - clock_getres - clock_settime - timer_create - timer_delete - timer_gettime - timer_settime [ tglx: Adapted to the posix-timer cleanup. Moved clock_posix_dynamic to posix-clock.c and made all referenced functions static ] Signed-off-by: Richard Cochran <richard.cochran@omicron.at> Acked-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <20110201134420.164172635@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-02posix-timers: Cleanup namespaceThomas Gleixner
Rename register_posix_clock() to posix_timers_register_clock(). That's what the function really does. As a side effect this cleans up the posix_clock namespace for the upcoming dynamic posix_clock infrastructure. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Richard Cochran <richard.cochran@omicron.at> Cc: John Stultz <johnstul@us.ibm.com> LKML-Reference: <alpine.LFD.2.00.1102021222240.31804@localhost6.localdomain6>
2011-02-02posix-timers: Add support for fd based clocksRichard Cochran
Extend the negative clockids which are currently used by posix cpu timers to encode the PID with a file descriptor based type which encodes the fd in the upper bits. Originally-from: Richard Cochran <richard.cochran@omicron.at> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <20110201134420.062860200@linutronix.de>
2011-02-02posix-timers: Introduce a syscall for clock tuning.Richard Cochran
A new syscall is introduced that allows tuning of a POSIX clock. The new call, clock_adjtime, takes two parameters, the clock ID and a pointer to a struct timex. Any ADJTIMEX(2) operation may be requested via this system call, but various POSIX clocks may or may not support tuning. [ tglx: Adapted to the posix-timer cleanup series. Avoid copy_to_user in the error case ] Signed-off-by: Richard Cochran <richard.cochran@omicron.at> Acked-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <20110201134419.869804645@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-02time: Splitout compat timex accessorsRichard Cochran
Split out the compat timex accessors into separate functions. Preparatory patch for a new syscall. [ tglx: Split that patch from Richards "posix-timers: Introduce a syscall for clock tuning.". Keeps the changes strictly separate ] Originally-from: Richard Cochran <richardcochran@gmail.com> Acked-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <20110201134419.772343089@linutronix.de>
2011-02-02ntp: Add ADJ_SETOFFSET mode bitRichard Cochran
This patch adds a new mode bit into the timex structure. When set, the bit instructs the kernel to add the given time value to the current time. Signed-off-by: Richard Cochran <richard.cochran@omicron.at> Acked-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <20110201134320.688829863@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>