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2009-10-26rcu: Improve rcutorture diagnostics when bad torture_type specifiedPaul E. McKenney1-1/+5
Make rcutorture list the available torture_type values when it doesn't like the one specified. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Josh Triplett <josh@joshtriplett.org> Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com Cc: avi@redhat.com Cc: mtosatti@redhat.com LKML-Reference: <12565226351868-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-26rcu: Add synchronize_srcu_expedited() to the rcutorture test suitePaul E. McKenney1-3/+22
Adds the "srcu_expedited" torture type, and also renames sched_ops_sync to sched_sync_ops for consistency while we are in this file. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Josh Triplett <josh@joshtriplett.org> Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com Cc: avi@redhat.com Cc: mtosatti@redhat.com LKML-Reference: <12565226353636-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-26rcu: Add synchronize_srcu_expedited()Paul E. McKenney1-23/+51
This patch creates a synchronize_srcu_expedited() that uses synchronize_sched_expedited() where synchronize_srcu() uses synchronize_sched(). The synchronize_srcu() and synchronize_srcu_expedited() functions become one-liners that pass synchronize_sched() or synchronize_sched_expedited(), repectively, to a new __synchronize_srcu() function. While in the file, move the EXPORT_SYMBOL_GPL()s to immediately follow the corresponding functions. Requested-by: Avi Kivity <avi@redhat.com> Tested-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Josh Triplett <josh@joshtriplett.org> Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com Cc: avi@redhat.com LKML-Reference: <12565226354038-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-26rcu: "Tiny RCU", The Bloatwatch EditionPaul E. McKenney3-0/+299
This patch is a version of RCU designed for !SMP provided for a small-footprint RCU implementation. In particular, the implementation of synchronize_rcu() is extremely lightweight and high performance. It passes rcutorture testing in each of the four relevant configurations (combinations of NO_HZ and PREEMPT) on x86. This saves about 1K bytes compared to old Classic RCU (which is no longer in mainline), and more than three kilobytes compared to Hierarchical RCU (updated to 2.6.30): CONFIG_TREE_RCU: text data bss dec filename 183 4 0 187 kernel/rcupdate.o 2783 520 36 3339 kernel/rcutree.o 3526 Total (vs 4565 for v7) CONFIG_TREE_PREEMPT_RCU: text data bss dec filename 263 4 0 267 kernel/rcupdate.o 4594 776 52 5422 kernel/rcutree.o 5689 Total (6155 for v7) CONFIG_TINY_RCU: text data bss dec filename 96 4 0 100 kernel/rcupdate.o 734 24 0 758 kernel/rcutiny.o 858 Total (vs 848 for v7) The above is for x86. Your mileage may vary on other platforms. Further compression is possible, but is being procrastinated. Changes from v7 (http://lkml.org/lkml/2009/10/9/388) o Apply Lai Jiangshan's review comments (aside from might_sleep() in synchronize_sched(), which is covered by SMP builds). o Fix up expedited primitives. Changes from v6 (http://lkml.org/lkml/2009/9/23/293). o Forward ported to put it into the 2.6.33 stream. o Added lockdep support. o Make lightweight rcu_barrier. Changes from v5 (http://lkml.org/lkml/2009/6/23/12). o Ported to latest pre-2.6.32 merge window kernel. - Renamed rcu_qsctr_inc() to rcu_sched_qs(). - Renamed rcu_bh_qsctr_inc() to rcu_bh_qs(). - Provided trivial rcu_cpu_notify(). - Provided trivial exit_rcu(). - Provided trivial rcu_needs_cpu(). - Fixed up the rcu_*_enter/exit() functions in linux/hardirq.h. o Removed the dependence on EMBEDDED, with a view to making TINY_RCU default for !SMP at some time in the future. o Added (trivial) support for expedited grace periods. Changes from v4 (http://lkml.org/lkml/2009/5/2/91) include: o Squeeze the size down a bit further by removing the ->completed field from struct rcu_ctrlblk. o This permits synchronize_rcu() to become the empty function. Previous concerns about rcutorture were unfounded, as rcutorture correctly handles a constant value from rcu_batches_completed() and rcu_batches_completed_bh(). Changes from v3 (http://lkml.org/lkml/2009/3/29/221) include: o Changed rcu_batches_completed(), rcu_batches_completed_bh() rcu_enter_nohz(), rcu_exit_nohz(), rcu_nmi_enter(), and rcu_nmi_exit(), to be static inlines, as suggested by David Howells. Doing this saves about 100 bytes from rcutiny.o. (The numbers between v3 and this v4 of the patch are not directly comparable, since they are against different versions of Linux.) Changes from v2 (http://lkml.org/lkml/2009/2/3/333) include: o Fix whitespace issues. o Change short-circuit "||" operator to instead be "+" in order to fix performance bug noted by "kraai" on LWN. (http://lwn.net/Articles/324348/) Changes from v1 (http://lkml.org/lkml/2009/1/13/440) include: o This version depends on EMBEDDED as well as !SMP, as suggested by Ingo. o Updated rcu_needs_cpu() to unconditionally return zero, permitting the CPU to enter dynticks-idle mode at any time. This works because callbacks can be invoked upon entry to dynticks-idle mode. o Paul is now OK with this being included, based on a poll at the Kernel Miniconf at linux.conf.au, where about ten people said that they cared about saving 900 bytes on single-CPU systems. o Applies to both mainline and tip/core/rcu. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: David Howells <dhowells@redhat.com> Acked-by: Josh Triplett <josh@joshtriplett.org> Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: avi@redhat.com Cc: mtosatti@redhat.com LKML-Reference: <12565226351355-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-15rcu: Add rnp->blocked_tasks to tracingPaul E. McKenney1-2/+6
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com Cc: npiggin@suse.de Cc: jens.axboe@oracle.com Cc: Josh Triplett <josh@joshtriplett.org> LKML-Reference: <20091014233638.GE6763@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> kernel/rcutree_trace.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
2009-10-15rcu: Stopgap fix for synchronize_rcu_expedited() for TREE_PREEMPT_RCUPaul E. McKenney1-0/+21
For the short term, map synchronize_rcu_expedited() to synchronize_rcu() for TREE_PREEMPT_RCU and to synchronize_sched_expedited() for TREE_RCU. Longer term, there needs to be a real expedited grace period for TREE_PREEMPT_RCU, but candidate patches to date are considerably more complex and intrusive. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com Cc: npiggin@suse.de Cc: jens.axboe@oracle.com LKML-Reference: <12555405592331-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-15rcu: Prevent RCU IPI storms in presence of high call_rcu() loadPaul E. McKenney2-5/+28
As the number of callbacks on a given CPU rises, invoke force_quiescent_state() only every blimit number of callbacks (defaults to 10,000), and even then only if no other CPU has invoked force_quiescent_state() in the meantime. This should fix the performance regression reported by Nick. Reported-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com Cc: jens.axboe@oracle.com LKML-Reference: <12555405592133-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-14futex: Check for NULL keys in match_futexDarren Hart1-1/+2
If userspace tries to perform a requeue_pi on a non-requeue_pi waiter, it will find the futex_q->requeue_pi_key to be NULL and OOPS. Check for NULL in match_futex() instead of doing explicit NULL pointer checks on all call sites. While match_futex(NULL, NULL) returning false is a little odd, it's still correct as we expect valid key references. Signed-off-by: Darren Hart <dvhltc@us.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> CC: Eric Dumazet <eric.dumazet@gmail.com> CC: Dinakar Guniguntala <dino@in.ibm.com> CC: John Stultz <johnstul@us.ibm.com> Cc: stable@kernel.org LKML-Reference: <4AD60687.10306@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-10-13futex: Handle spurious wake upThomas Gleixner1-3/+15
The futex code does not handle spurious wake up in futex_wait and futex_wait_requeue_pi. The code assumes that any wake up which was not caused by futex_wake / requeue or by a timeout was caused by a signal wake up and returns one of the syscall restart error codes. In case of a spurious wake up the signal delivery code which deals with the restart error codes is not invoked and we return that error code to user space. That causes applications which actually check the return codes to fail. Blaise reported that on preempt-rt a python test program run into a exception trap. -rt exposed that due to a built in spurious wake up accelerator :) Solve this by checking signal_pending(current) in the wake up path and handle the spurious wake up case w/o returning to user space. Reported-by: Blaise Gassend <blaise@willowgarage.com> Debugged-by: Darren Hart <dvhltc@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@kernel.org LKML-Reference: <new-submission>
2009-10-09lockdep: Use cpu_clock() for lockstatPeter Zijlstra1-8/+12
Some tracepoint magic (TRACE_EVENT(lock_acquired)) relies on the fact that lock hold times are positive and uses div64 on that. That triggered a build warning on MIPS, and probably causes bad output in certain circumstances as well. Make it truly positive. Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1254818502.21044.112.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-08Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds10-299/+386
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: futex: fix requeue_pi key imbalance futex: Fix typo in FUTEX_WAIT/WAKE_BITSET_PRIVATE definitions rcu: Place root rcu_node structure in separate lockdep class rcu: Make hot-unplugged CPU relinquish its own RCU callbacks rcu: Move rcu_barrier() to rcutree futex: Move exit_pi_state() call to release_mm() futex: Nullify robust lists after cleanup futex: Fix locking imbalance panic: Fix panic message visibility by calling bust_spinlocks(0) before dying rcu: Replace the rcu_barrier enum with pointer to call_rcu*() function rcu: Clean up code based on review feedback from Josh Triplett, part 4 rcu: Clean up code based on review feedback from Josh Triplett, part 3 rcu: Fix rcu_lock_map build failure on CONFIG_PROVE_LOCKING=y rcu: Clean up code to address Ingo's checkpatch feedback rcu: Clean up code based on review feedback from Josh Triplett, part 2 rcu: Clean up code based on review feedback from Josh Triplett
2009-10-08Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds1-11/+9
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: Set correct normal_prio and prio values in sched_fork()
2009-10-08Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds5-35/+37
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: tracing: user local buffer variable for trace branch tracer tracing: fix warning on kernel/trace/trace_branch.c andtrace_hw_branches.c ftrace: check for failure for all conversions tracing: correct module boundaries for ftrace_release tracing: fix transposed numbers of lock_depth and preempt_count trace: Fix missing assignment in trace_ctxwake_* tracing: Use free_percpu instead of kfree tracing: Check total refcount before releasing bufs in profile_enable failure
2009-10-08Merge branch 'sparc-perf-events-fixes-for-linus' of ↵Linus Torvalds1-62/+186
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sparc-perf-events-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: mm, perf_event: Make vmalloc_user() align base kernel virtual address to SHMLBA perf_event: Provide vmalloc() based mmap() backing
2009-10-08Merge branch 'perf-fixes-for-linus-2' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf_events: Make ABI definitions available to userspace perf tools: elf_sym__is_function() should accept "zero" sized functions tracing/syscalls: Use long for syscall ret format and field definitions perf trace: Update eval_flag() flags array to match interrupt.h perf trace: Remove unused code in builtin-trace.c perf: Propagate term signal to child
2009-10-07tracing: user local buffer variable for trace branch tracerSteven Rostedt1-3/+5
Just using the tr->buffer for the API to trace_buffer_lock_reserve is not good enough. This is because the tr->buffer may change, and we do not want to commit with a different buffer that we reserved from. This patch uses a local variable to hold the buffer that was used to reserve and commit with. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-10-07tracing: fix warning on kernel/trace/trace_branch.c andtrace_hw_branches.cZhenwen Xu2-4/+6
fix warnings that caused the API change of trace_buffer_lock_reserve() change files: kernel/trace/trace_hw_branch.c kernel/trace/trace_branch.c Signed-off-by: Zhenwen Xu <helight.xu@gmail.com> LKML-Reference: <20091008012146.GA4170@helight> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-10-07ftrace: check for failure for all conversionsSteven Rostedt1-8/+3
Due to legacy code from back when the dynamic tracer used a daemon, only core kernel code was checking for failures. This is no longer the case. We must check for failures any time we perform text modifications. Cc: stable@kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-10-07tracing: correct module boundaries for ftrace_releasejolsa@redhat.com1-8/+4
When the module is about the unload we release its call records. The ftrace_release function was given wrong values representing the module core boundaries, thus not releasing its call records. Plus making ftrace_release function module specific. Signed-off-by: Jiri Olsa <jolsa@redhat.com> LKML-Reference: <1254934835-363-3-git-send-email-jolsa@redhat.com> Cc: stable@kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-10-07futex: fix requeue_pi key imbalanceDarren Hart1-1/+0
If futex_wait_requeue_pi() wakes prior to requeue, we drop the reference to the source futex_key twice, once in handle_early_requeue_pi_wakeup() and once on our way out. Remove the drop from the handle_early_requeue_pi_wakeup() and keep the get/drops together in futex_wait_requeue_pi(). Reported-by: Helge Bahmann <hcb@chaoticmind.net> Signed-off-by: Darren Hart <dvhltc@us.ibm.com> Cc: Helge Bahmann <hcb@chaoticmind.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Dinakar Guniguntala <dino@in.ibm.com> Cc: John Stultz <johnstul@us.ibm.com> Cc: stable-2.6.31 <stable@kernel.org> LKML-Reference: <4ACCE21E.5030805@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-10-07tracing: fix transposed numbers of lock_depth and preempt_countSteven Rostedt1-6/+8
The lock_depth and preempt_count numbers in the latency format is transposed. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-10-07NOHZ: update idle state also when NOHZ is inactiveEero Nurkkala1-2/+7
Commit f2e21c9610991e95621a81407cdbab881226419b had unfortunate side effects with cpufreq governors on some systems. If the system did not switch into NOHZ mode ts->inidle is not set when tick_nohz_stop_sched_tick() is called from the idle routine. Therefor all subsequent calls from irq_exit() to tick_nohz_stop_sched_tick() fail to call tick_nohz_start_idle(). This results in bogus idle accounting information which is passed to cpufreq governors. Set the inidle flag unconditionally of the NOHZ active state to keep the idle time accounting correct in any case. [ tglx: Added comment and tweaked the changelog ] Reported-by: Steven Noonan <steven@uplinklabs.net> Signed-off-by: Eero Nurkkala <ext-eero.nurkkala@nokia.com> Cc: Rik van Riel <riel@redhat.com> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: Greg KH <greg@kroah.com> Cc: Steven Noonan <steven@uplinklabs.net> Cc: stable@kernel.org LKML-Reference: <1254907901.30157.93.camel@eenurkka-desktop> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-10-07rcu: Place root rcu_node structure in separate lockdep classPaul E. McKenney1-1/+3
Before this patch, all of the rcu_node structures were in the same lockdep class, so that lockdep would complain when rcu_preempt_offline_tasks() acquired the root rcu_node structure's lock while holding one of the leaf rcu_nodes' locks. This patch changes rcu_init_one() to use a separate spin_lock_init() for the root rcu_node structure's lock than is used for that of all of the rest of the rcu_node structures, which puts the root rcu_node structure's lock in its own lockdep class. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <12548908983277-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-07rcu: Make hot-unplugged CPU relinquish its own RCU callbacksPaul E. McKenney4-75/+125
The current interaction between RCU and CPU hotplug requires that RCU block in CPU notifiers waiting for callbacks to drain. This can be greatly simplified by having each CPU relinquish its own callbacks, and for both _rcu_barrier() and CPU_DEAD notifiers to adopt all callbacks that were previously relinquished. This change also eliminates the possibility of certain types of hangs due to the previous practice of waiting for callbacks to be invoked from within CPU notifiers. If you don't every wait, you cannot hang. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <1254890898456-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-07rcu: Move rcu_barrier() to rcutreePaul E. McKenney2-119/+120
Move the existing rcu_barrier() implementation to rcutree.c, consistent with the fact that the rcu_barrier() implementation is tied quite tightly to the RCU implementation. This opens the way to simplify and fix rcutree.c's rcu_barrier() implementation in a later patch. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <12548908982563-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-06futex: Move exit_pi_state() call to release_mm()Thomas Gleixner2-2/+2
exit_pi_state() is called from do_exit() but not from do_execve(). Move it to release_mm() so it gets called from do_execve() as well. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <new-submission> Cc: stable@kernel.org Cc: Anirban Sinha <ani@anirban.org> Cc: Peter Zijlstra <peterz@infradead.org>
2009-10-06futex: Nullify robust lists after cleanupPeter Zijlstra1-2/+6
The robust list pointers of user space held futexes are kept intact over an exec() call. When the exec'ed task exits exit_robust_list() is called with the stale pointer. The risk of corruption is minimal, but still it is incorrect to keep the pointers valid. Actually glibc should uninstall the robust list before calling exec() but we have to deal with it anyway. Nullify the pointers after [compat_]exit_robust_list() has been called. Reported-by: Anirban Sinha <ani@anirban.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <new-submission> Cc: stable@kernel.org
2009-10-06trace: Fix missing assignment in trace_ctxwake_*Hiroshi Shimamoto1-2/+2
The state char variable S should be reassigned, if S == 0. We are missing the state of the task that is going to sleep for the context switch events (in the raw mode). Fortunately the problem arises with the sched_switch/wake_up tracers, not the sched trace events. The formers are legacy now. But still, that was buggy. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Cc: Steven Rostedt <srostedt@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <4AC43118.6050409@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-06perf_event: Provide vmalloc() based mmap() backingPeter Zijlstra1-62/+186
Some architectures such as Sparc, ARM and MIPS (basically everything with flush_dcache_page()) need to deal with dcache aliases by carefully placing pages in both kernel and user maps. These architectures typically have to use vmalloc_user() for this. However, on other architectures, vmalloc() is not needed and has the downsides of being more restricted and slower than regular allocations. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: David Miller <davem@davemloft.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1254830228.21044.272.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-06tracing/syscalls: Use long for syscall ret format and field definitionsTom Zanussi1-2/+2
The syscall event definitions use long for the syscall exit ret value, but unsigned long for the same thing in the format and field definitions. Change them all to long. Signed-off-by: Tom Zanussi <tzanussi@gmail.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: rostedt@goodmis.org Cc: lizf@cn.fujitsu.com Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <1254808849-7829-4-git-send-email-tzanussi@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-05futex: Fix locking imbalanceThomas Gleixner1-1/+1
Rich reported a lock imbalance in the futex code: http://bugzilla.kernel.org/show_bug.cgi?id=14288 It's caused by the displacement of the retry_private label in futex_wake_op(). The code unlocks the hash bucket locks in the error handling path and retries without locking them again which makes the next unlock fail. Move retry_private so we lock the hash bucket locks when we retry. Reported-by: Rich Ercolany <rercola@acm.jhu.edu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Darren Hart <dvhltc@us.ibm.com> Cc: stable-2.6.31 <stable@kernel.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-05panic: Fix panic message visibility by calling bust_spinlocks(0) before dyingAaro Koskinen1-1/+2
Commit ffd71da4e3f ("panic: decrease oops_in_progress only after having done the panic") moved bust_spinlocks(0) to the end of the function, which in practice is never reached. As a result console_unblank() is not called, and on some systems the user may not see the panic message. Move it back up to before the unblanking. Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com> Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <1254483680-25578-1-git-send-email-aaro.koskinen@nokia.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-05Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds1-25/+9
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 tools: Run generate-cmdlist.sh properly perf_event: Clean up perf_event_init_task() perf_event: Fix event group handling in __perf_event_sched_*() perf timechart: Add a power-only mode perf top: Add poll_idle to the skip list
2009-10-05Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds1-2/+0
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: hrtimer: Remove overly verbose "switch to high res mode" message
2009-10-05Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds2-1/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: kmemtrace: Fix up tracer registration tracing: Fix infinite recursion in ftrace_update_pid_func()
2009-10-05rcu: Replace the rcu_barrier enum with pointer to call_rcu*() functionPaul E. McKenney1-22/+10
The rcu_barrier enum causes several problems: (1) you have to define the enum somewhere, and there is no convenient place, (2) the difference between TREE_RCU and TREE_PREEMPT_RCU causes problems when you need to map from rcu_barrier enum to struct rcu_state, (3) the switch statement are large, and (4) TINY_RCU really needs a different rcu_barrier() than do the treercu implementations. So replace it with a functionally equivalent but cleaner function pointer abstraction. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <12541998232366-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-05rcu: Clean up code based on review feedback from Josh Triplett, part 4Paul E. McKenney3-29/+40
These issues identified during an old-fashioned face-to-face code review extending over many hours. This group improves an existing abstraction and introduces two new ones. It also fixes an RCU stall-warning bug found while making the other changes. o Make RCU_INIT_FLAVOR() declare its own variables, removing the need to declare them at each call site. o Create an rcu_for_each_leaf() macro that scans the leaf nodes of the rcu_node tree. o Create an rcu_for_each_node_breadth_first() macro that does a breadth-first traversal of the rcu_node tree, AKA stepping through the array in index-number order. o If all CPUs corresponding to a given leaf rcu_node structure go offline, then any tasks queued on that leaf will be moved to the root rcu_node structure. Therefore, the stall-warning code must dump out tasks queued on the root rcu_node structure as well as those queued on the leaf rcu_node structures. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <12541491934126-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-05rcu: Clean up code based on review feedback from Josh Triplett, part 3Paul E. McKenney1-5/+5
Whitespace fixes, updated comments, and trivial code movement. o Fix whitespace error in RCU_HEAD_INIT() o Move "So where is rcu_write_lock()" comment so that it does not come between the rcu_read_unlock() header comment and the rcu_read_unlock() definition. o Move the module_param statements for blimit, qhimark, and qlowmark to immediately follow the corresponding definitions. o In __rcu_offline_cpu(), move the assignment to rdp_me inside the "if" statement, given that rdp_me is not used outside of that "if" statement. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <12541491931164-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-05rcu: Fix rcu_lock_map build failure on CONFIG_PROVE_LOCKING=yPaul E. McKenney2-7/+7
Move the rcu_lock_map definition from rcutree.c to rcupdate.c so that TINY_RCU can use lockdep. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-05sched: Set correct normal_prio and prio values in sched_fork()Peter Williams1-11/+9
normal_prio should be updated if policy changes from RT to SCHED_MORMAL or if static_prio/nice is changed. Some paths through sched_fork() ignore this requirement and may result in normal_prio having an invalid value. Fixing this issue allows the call to effective_prio() in wake_up_new_task() to be removed. Signed-off-by: Peter Williams <pwil3058@bigpond.net.au> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <f8f46736fd4e7f090ac0.1253774830@mudlark.pw.nest> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-05tracing: Use free_percpu instead of kfreeFrederic Weisbecker1-2/+2
In the event->profile_enable() failure path, we release the per cpu buffers using kfree which is wrong because they are per cpu pointers. Although free_percpu only wraps kfree for now, that may change in the future so lets use the correct way. Reported-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Li Zefan <lizf@cn.fujitsu.com>
2009-10-05tracing: Check total refcount before releasing bufs in profile_enable failureFrederic Weisbecker1-5/+10
When we call the profile_enable() callback of an event, we release the shared perf event tracing buffers unconditionnaly in the failure path. This is wrong because there may be other users of these. Then check the total refcount before doing this. Reported-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Li Zefan <lizf@cn.fujitsu.com>
2009-10-04Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds1-0/+39
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: (41 commits) Revert "Seperate read and write statistics of in_flight requests" cfq-iosched: don't delay async queue if it hasn't dispatched at all block: Topology ioctls cfq-iosched: use assigned slice sync value, not default cfq-iosched: rename 'desktop' sysfs entry to 'low_latency' cfq-iosched: implement slower async initiate and queue ramp up cfq-iosched: delay async IO dispatch, if sync IO was just done cfq-iosched: add a knob for desktop interactiveness Add a tracepoint for block request remapping block: allow large discard requests block: use normal I/O path for discard requests swapfile: avoid NULL pointer dereference in swapon when s_bdev is NULL fs/bio.c: move EXPORT* macros to line after function Add missing blk_trace_remove_sysfs to be in pair with blk_trace_init_sysfs cciss: fix build when !PROC_FS block: Do not clamp max_hw_sectors for stacking devices block: Set max_sectors correctly for stacking devices cciss: cciss_host_attr_groups should be const cciss: Dynamically allocate the drive_info_struct for each logical drive. cciss: Add usage_count attribute to each logical drive in /sys ...
2009-10-01memcg: some modification to softlimit under hierarchical memory reclaim.KAMEZAWA Hiroyuki1-16/+2
This patch clean up/fixes for memcg's uncharge soft limit path. Problems: Now, res_counter_charge()/uncharge() handles softlimit information at charge/uncharge and softlimit-check is done when event counter per memcg goes over limit. Now, event counter per memcg is updated only when memory usage is over soft limit. Here, considering hierarchical memcg management, ancesotors should be taken care of. Now, ancerstors(hierarchy) are handled in charge() but not in uncharge(). This is not good. Prolems: 1. memcg's event counter incremented only when softlimit hits. That's bad. It makes event counter hard to be reused for other purpose. 2. At uncharge, only the lowest level rescounter is handled. This is bug. Because ancesotor's event counter is not incremented, children should take care of them. 3. res_counter_uncharge()'s 3rd argument is NULL in most case. ops under res_counter->lock should be small. No "if" sentense is better. Fixes: * Removed soft_limit_xx poitner and checks in charge and uncharge. Do-check-only-when-necessary scheme works enough well without them. * make event-counter of memcg incremented at every charge/uncharge. (per-cpu area will be accessed soon anyway) * All ancestors are checked at soft-limit-check. This is necessary because ancesotor's event counter may never be modified. Then, they should be checked at the same time. Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01cgroup: catch bad css refcnt at css_putKAMEZAWA Hiroyuki1-1/+4
__css_put() doesn't check a bug as refcnt goes to minus. I think it should be caught. This patch adds a check for it. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01const: constify remaining file_operationsAlexey Dobriyan6-15/+15
[akpm@linux-foundation.org: fix KVM] Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01module: fix up CONFIG_KALLSYMS=n build.Paul Mundt1-3/+4
Starting from commit 4a4962263f07d14660849ec134ee42b63e95ea9a "reduce symbol table for loaded modules (v2)", the kernel/module.c build is broken with CONFIG_KALLSYMS disabled. CC kernel/module.o kernel/module.c:1995: warning: type defaults to 'int' in declaration of 'Elf_Hdr' kernel/module.c:1995: error: expected ';', ',' or ')' before '*' token kernel/module.c: In function 'load_module': kernel/module.c:2203: error: 'strmap' undeclared (first use in this function) kernel/module.c:2203: error: (Each undeclared identifier is reported only once kernel/module.c:2203: error: for each function it appears in.) kernel/module.c:2239: error: 'symoffs' undeclared (first use in this function) kernel/module.c:2239: error: implicit declaration of function 'layout_symtab' kernel/module.c:2240: error: 'stroffs' undeclared (first use in this function) make[1]: *** [kernel/module.o] Error 1 make: *** [kernel/module.o] Error 2 There are three different issues: - layout_symtab() takes a const Elf_Ehdr - layout_symtab() needs to return a value - symoffs/stroffs/strmap are referenced by the load_module() code despite being ifdefed out, which seems unnecessary given the noop behaviour of layout_symtab()/add_kallsyms() in the case of CONFIG_KALLSYMS=n. Signed-off-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Jan Beulich <jbeulich@novell.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01Add a tracepoint for block request remappingJun'ichi Nomura1-0/+34
Since 2.6.31 now has request-based device-mapper, it's useful to have a tracepoint for request-remapping as well as bio-remapping. This patch adds a tracepoint for request-remapping, trace_block_rq_remap(). Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: Alasdair G Kergon <agk@redhat.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-10-01Add missing blk_trace_remove_sysfs to be in pair with blk_trace_init_sysfsZdenek Kabelac1-0/+5
Add missing blk_trace_remove_sysfs to be in pair with blk_trace_init_sysfs introduced in commit 1d54ad6da9192fed5dd3b60224d9f2dfea0dcd82. Release kobject also in case the request_fn is NULL. Problem was noticed via kmemleak backtrace when some sysfs entries were note properly destroyed during device removal: unreferenced object 0xffff88001aa76640 (size 80): comm "lvcreate", pid 2120, jiffies 4294885144 hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 f0 65 a7 1a 00 88 ff ff .........e...... 90 66 a7 1a 00 88 ff ff 86 1d 53 81 ff ff ff ff .f........S..... backtrace: [<ffffffff813f9cc6>] kmemleak_alloc+0x26/0x60 [<ffffffff8111d693>] kmem_cache_alloc+0x133/0x1c0 [<ffffffff81195891>] sysfs_new_dirent+0x41/0x120 [<ffffffff81194b0c>] sysfs_add_file_mode+0x3c/0xb0 [<ffffffff81197c81>] internal_create_group+0xc1/0x1a0 [<ffffffff81197d93>] sysfs_create_group+0x13/0x20 [<ffffffff810d8004>] blk_trace_init_sysfs+0x14/0x20 [<ffffffff8123f45c>] blk_register_queue+0x3c/0xf0 [<ffffffff812447e4>] add_disk+0x94/0x160 [<ffffffffa00d8b08>] dm_create+0x598/0x6e0 [dm_mod] [<ffffffffa00de951>] dev_create+0x51/0x350 [dm_mod] [<ffffffffa00de823>] ctl_ioctl+0x1a3/0x240 [dm_mod] [<ffffffffa00de8f2>] dm_compat_ctl_ioctl+0x12/0x20 [dm_mod] [<ffffffff81177bfd>] compat_sys_ioctl+0xcd/0x4f0 [<ffffffff81036ed8>] sysenter_dispatch+0x7/0x2c [<ffffffffffffffff>] 0xffffffffffffffff Signed-off-by: Zdenek Kabelac <zkabelac@redhat.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-10-01kmemtrace: Fix up tracer registrationPaul Mundt1-1/+1
Commit ddc1637af217dbd8bc51f30e6d24e84476a869a6 ("kmemtrace: Print binary output only if 'bin' option is set") ended up inverting the error detection logic. register_tracer() returns 0 on success, which this change caused to treat as an error, resulting in: [ 0.132000] Warning: could not register the kmem tracer as well as bailing out of the initcall with an error value. This restores the old logic. Signed-off-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <20090928075540.GD6668@linux-sh.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>