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* tracing: Do not allow llseek to set_ftrace_filterSteven Rostedt2010-09-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reading the file set_ftrace_filter does three things. 1) shows whether or not filters are set for the function tracer 2) shows what functions are set for the function tracer 3) shows what triggers are set on any functions 3 is independent from 1 and 2. The way this file currently works is that it is a state machine, and as you read it, it may change state. But this assumption breaks when you use lseek() on the file. The state machine gets out of sync and the t_show() may use the wrong pointer and cause a kernel oops. Luckily, this will only kill the app that does the lseek, but the app dies while holding a mutex. This prevents anyone else from using the set_ftrace_filter file (or any other function tracing file for that matter). A real fix for this is to rewrite the code, but that is too much for a -rc release or stable. This patch simply disables llseek on the set_ftrace_filter() file for now, and we can do the proper fix for the next major release. Reported-by: Robert Swiecki <swiecki@google.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Tavis Ormandy <taviso@google.com> Cc: Eugene Teo <eugene@redhat.com> Cc: vendor-sec@lst.de Cc: <stable@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* perf, x86: Try to handle unknown nmis with an enabled PMURobert Richter2010-09-031-13/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the PMU is enabled it is valid to have unhandled nmis, two events could trigger 'simultaneously' raising two back-to-back NMIs. If the first NMI handles both, the latter will be empty and daze the CPU. The solution to avoid an 'unknown nmi' massage in this case was simply to stop the nmi handler chain when the PMU is enabled by stating the nmi was handled. This has the drawback that a) we can not detect unknown nmis anymore, and b) subsequent nmi handlers are not called. This patch addresses this. Now, we check this unknown NMI if it could be a PMU back-to-back NMI. Otherwise we pass it and let the kernel handle the unknown nmi. This is a debug log: cpu #6, nmi #32333, skip_nmi #32330, handled = 1, time = 1934364430 cpu #6, nmi #32334, skip_nmi #32330, handled = 1, time = 1934704616 cpu #6, nmi #32335, skip_nmi #32336, handled = 2, time = 1936032320 cpu #6, nmi #32336, skip_nmi #32336, handled = 0, time = 1936034139 cpu #6, nmi #32337, skip_nmi #32336, handled = 1, time = 1936120100 cpu #6, nmi #32338, skip_nmi #32336, handled = 1, time = 1936404607 cpu #6, nmi #32339, skip_nmi #32336, handled = 1, time = 1937983416 cpu #6, nmi #32340, skip_nmi #32341, handled = 2, time = 1938201032 cpu #6, nmi #32341, skip_nmi #32341, handled = 0, time = 1938202830 cpu #6, nmi #32342, skip_nmi #32341, handled = 1, time = 1938443743 cpu #6, nmi #32343, skip_nmi #32341, handled = 1, time = 1939956552 cpu #6, nmi #32344, skip_nmi #32341, handled = 1, time = 1940073224 cpu #6, nmi #32345, skip_nmi #32341, handled = 1, time = 1940485677 cpu #6, nmi #32346, skip_nmi #32347, handled = 2, time = 1941947772 cpu #6, nmi #32347, skip_nmi #32347, handled = 1, time = 1941949818 cpu #6, nmi #32348, skip_nmi #32347, handled = 0, time = 1941951591 Uhhuh. NMI received for unknown reason 00 on CPU 6. Do you have a strange power saving mode enabled? Dazed and confused, but trying to continue Deltas: nmi #32334 340186 nmi #32335 1327704 nmi #32336 1819 <<<< back-to-back nmi [1] nmi #32337 85961 nmi #32338 284507 nmi #32339 1578809 nmi #32340 217616 nmi #32341 1798 <<<< back-to-back nmi [2] nmi #32342 240913 nmi #32343 1512809 nmi #32344 116672 nmi #32345 412453 nmi #32346 1462095 <<<< 1st nmi (standard) handling 2 counters nmi #32347 2046 <<<< 2nd nmi (back-to-back) handling one counter nmi #32348 1773 <<<< 3rd nmi (back-to-back) handling no counter! [3] For back-to-back nmi detection there are the following rules: The PMU nmi handler was handling more than one counter and no counter was handled in the subsequent nmi (see [1] and [2] above). There is another case if there are two subsequent back-to-back nmis [3]. The 2nd is detected as back-to-back because the first handled more than one counter. If the second handles one counter and the 3rd handles nothing, we drop the 3rd nmi because it could be a back-to-back nmi. Signed-off-by: Robert Richter <robert.richter@amd.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> [ renamed nmi variable to pmu_nmi to avoid clash with .nmi in entry.S ] Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: peterz@infradead.org Cc: gorcunov@gmail.com Cc: fweisbec@gmail.com Cc: ying.huang@intel.com Cc: ming.m.lin@intel.com Cc: eranian@google.com LKML-Reference: <1283454469-1909-3-git-send-email-dzickus@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf, x86: Fix handle_irq return valuesPeter Zijlstra2010-09-032-3/+8
| | | | | | | | | | | | | | | | | Now that we rely on the number of handled overflows, ensure all handle_irq implementations actually return the right number. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: peterz@infradead.org Cc: robert.richter@amd.com Cc: gorcunov@gmail.com Cc: fweisbec@gmail.com Cc: ying.huang@intel.com Cc: ming.m.lin@intel.com Cc: eranian@google.com LKML-Reference: <1283454469-1909-4-git-send-email-dzickus@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf, x86: Fix accidentally ack'ing a second event on intel perf counterDon Zickus2010-09-031-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During testing of a patch to stop having the perf subsytem swallow nmis, it was uncovered that Nehalem boxes were randomly getting unknown nmis when using the perf tool. Moving the ack'ing of the PMI closer to when we get the status allows the hardware to properly re-set the PMU bit signaling another PMI was triggered during the processing of the first PMI. This allows the new logic for dealing with the shortcomings of multiple PMIs to handle the extra NMI by 'eat'ing it later. Now one can wonder why are we getting a second PMI when we disable all the PMUs in the begining of the NMI handler to prevent such a case, for that I do not know. But I know the fix below helps deal with this quirk. Tested on multiple Nehalems where the problem was occuring. With the patch, the code now loops a second time to handle the second PMI (whereas before it was not). Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: peterz@infradead.org Cc: robert.richter@amd.com Cc: gorcunov@gmail.com Cc: fweisbec@gmail.com Cc: ying.huang@intel.com Cc: ming.m.lin@intel.com Cc: eranian@google.com LKML-Reference: <1283454469-1909-2-git-send-email-dzickus@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'urgent' of ↵Ingo Molnar2010-09-013-20/+31
|\ | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile into perf/urgent
| * oprofile, x86: fix init_sysfs() function stubRobert Richter2010-09-011-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The use of the return value of init_sysfs() with commit 10f0412 oprofile, x86: fix init_sysfs error handling discovered the following build error for !CONFIG_PM: .../linux/arch/x86/oprofile/nmi_int.c: In function ‘op_nmi_init’: .../linux/arch/x86/oprofile/nmi_int.c:784: error: expected expression before ‘do’ make[2]: *** [arch/x86/oprofile/nmi_int.o] Error 1 make[1]: *** [arch/x86/oprofile] Error 2 This patch fixes this. Reported-by: Ingo Molnar <mingo@elte.hu> Cc: stable@kernel.org Signed-off-by: Robert Richter <robert.richter@amd.com>
| * oprofile, x86: fix init_sysfs error handlingRobert Richter2010-08-311-3/+13
| | | | | | | | | | | | | | | | | | On failure init_sysfs() might not properly free resources. The error code of the function is not checked. And, when reinitializing the exit function might be called twice. This patch fixes all this. Cc: stable@kernel.org Signed-off-by: Robert Richter <robert.richter@amd.com>
| * oprofile: fix crash when accessing freed task structsRobert Richter2010-08-252-15/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes a crash during shutdown reported below. The crash is caused by accessing already freed task structs. The fix changes the order for registering and unregistering notifier callbacks. All notifiers must be initialized before buffers start working. To stop buffer synchronization we cancel all workqueues, unregister the notifier callback and then flush all buffers. After all of this we finally can free all tasks listed. This should avoid accessing freed tasks. On 22.07.10 01:14:40, Benjamin Herrenschmidt wrote: > So the initial observation is a spinlock bad magic followed by a crash > in the spinlock debug code: > > [ 1541.586531] BUG: spinlock bad magic on CPU#5, events/5/136 > [ 1541.597564] Unable to handle kernel paging request for data at address 0x6b6b6b6b6b6b6d03 > > Backtrace looks like: > > spin_bug+0x74/0xd4 > ._raw_spin_lock+0x48/0x184 > ._spin_lock+0x10/0x24 > .get_task_mm+0x28/0x8c > .sync_buffer+0x1b4/0x598 > .wq_sync_buffer+0xa0/0xdc > .worker_thread+0x1d8/0x2a8 > .kthread+0xa8/0xb4 > .kernel_thread+0x54/0x70 > > So we are accessing a freed task struct in the work queue when > processing the samples. Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: stable@kernel.org Signed-off-by: Robert Richter <robert.richter@amd.com>
* | lockup_detector: Sync touch_*_watchdog back to old semanticsDon Zickus2010-09-011-5/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During my rewrite, the semantics of touch_nmi_watchdog and touch_softlockup_watchdog changed enough to break some drivers (mostly over preemptable regions). These are cases where long delays on one CPU (due to print_delay for example) can cause long delays on other CPUs - so we must 'touch' the nmi_watchdog flag of those other CPUs as well. This change brings those touch_*_watchdog() functions back in line with to how they used to work. Signed-off-by: Don Zickus <dzickus@redhat.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: peterz@infradead.org Cc: fweisbec@gmail.com LKML-Reference: <1283310009-22168-2-git-send-email-dzickus@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | tracing: Fix a race in function profileLi Zefan2010-08-311-4/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While we are reading trace_stat/functionX and someone just disabled function_profile at that time, we can trigger this: divide error: 0000 [#1] PREEMPT SMP ... EIP is at function_stat_show+0x90/0x230 ... This fix just takes the ftrace_profile_lock and checks if rec->counter is 0. If it's 0, we know the profile buffer has been reset. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: stable@kernel.org LKML-Reference: <4C723644.4040708@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | perf_events: Fix time tracking for events with pid != -1 and cpu != -1Stephane Eranian2010-08-301-4/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Per-thread events with a cpu filter, i.e., cpu != -1, were not reporting correct timings when the thread never ran on the monitored cpu. The time enabled was reported as a negative value. This patch fixes the problem by updating tstamp_stopped, tstamp_running in event_sched_out() for events with filters and which are marked as INACTIVE. The function group_sched_out() is modified to systematically call into event_sched_out() to avoid duplicating the timing adjustment code twice. With the patch, I now get: $ task_cpu -i -e unhalted_core_cycles,unhalted_core_cycles noploop 2 noploop for 2 seconds CPU0 0 unhalted_core_cycles (ena=1,991,136,594, run=0) CPU0 0 unhalted_core_cycles (ena=1,991,136,594, run=0) CPU1 0 unhalted_core_cycles (ena=1,991,136,594, run=0) CPU1 0 unhalted_core_cycles (ena=1,991,136,594, run=0) CPU2 0 unhalted_core_cycles (ena=1,991,136,594, run=0) CPU2 0 unhalted_core_cycles (ena=1,991,136,594, run=0) CPU3 4,747,990,931 unhalted_core_cycles (ena=1,991,136,594, run=1,991,136,594) CPU3 4,747,990,931 unhalted_core_cycles (ena=1,991,136,594, run=1,991,136,594) Signed-off-by: Stephane Eranian <eranian@gmail.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: paulus@samba.org Cc: davem@davemloft.net Cc: fweisbec@gmail.com Cc: perfmon2-devel@lists.sf.net Cc: eranian@google.com LKML-Reference: <4c76802d.aae9d80a.115d.70fe@mx.google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | perf: Initialize callchains roots's childen hitsFrederic Weisbecker2010-08-271-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Each histogram entry has a callchain root that stores the callchain samples. However we forgot to initialize the tracking of children hits of these roots, which then got random values on their creation. The root children hits is multiplied by the minimum percentage of hits provided by the user, and the result becomes the minimum hits expected from children branches. If the random value due to the uninitialization is big enough, then this minimum number of hits can be huge and eventually filter every children branches. The end result was invisible callchains. All we need to fix this is to initialize the children hits of the root. Reported-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: 2.6.32.x-2.6.35.y <stable@kernel.org>
* | perf, x86, Pentium4: Clear the P4_CCCR_FORCE_OVF flagLin Ming2010-08-251-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | If on Pentium4 CPUs the FORCE_OVF flag is set then an NMI happens on every event, which can generate a flood of NMIs. Clear it. Reported-by: Vince Weaver <vweaver1@eecs.utk.edu> Signed-off-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | tracing/trace_stack: Fix stack trace on ppc64Anton Blanchard2010-08-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | save_stack_trace() stores the instruction pointer, not the function descriptor. On ppc64 the trace stack code currently dereferences the instruction pointer and shows 8 bytes of instructions in our backtraces: # cat /sys/kernel/debug/tracing/stack_trace Depth Size Location (26 entries) ----- ---- -------- 0) 5424 112 0x6000000048000004 1) 5312 160 0x60000000ebad01b0 2) 5152 160 0x2c23000041c20030 3) 4992 240 0x600000007c781b79 4) 4752 160 0xe84100284800000c 5) 4592 192 0x600000002fa30000 6) 4400 256 0x7f1800347b7407e0 7) 4144 208 0xe89f0108f87f0070 8) 3936 272 0xe84100282fa30000 Since we aren't dealing with function descriptors, use %pS instead of %pF to fix it: # cat /sys/kernel/debug/tracing/stack_trace Depth Size Location (26 entries) ----- ---- -------- 0) 5424 112 ftrace_call+0x4/0x8 1) 5312 160 .current_io_context+0x28/0x74 2) 5152 160 .get_io_context+0x48/0xa0 3) 4992 240 .cfq_set_request+0x94/0x4c4 4) 4752 160 .elv_set_request+0x60/0x84 5) 4592 192 .get_request+0x2d4/0x468 6) 4400 256 .get_request_wait+0x7c/0x258 7) 4144 208 .__make_request+0x49c/0x610 8) 3936 272 .generic_make_request+0x390/0x434 Signed-off-by: Anton Blanchard <anton@samba.org> Cc: rostedt@goodmis.org Cc: fweisbec@gmail.com LKML-Reference: <20100825013238.GE28360@kryten> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds2010-08-242-2/+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: watchdog: Don't throttle the watchdog tracing: Fix timer tracing
| * | watchdog: Don't throttle the watchdogPeter Zijlstra2010-08-231-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Stephane reported that when the machine locks up, the regular ticks, which are responsible to resetting the throttle count, stop too. Hence the NMI watchdog can end up being throttled before it reports on the locked up state, and we end up being sad.. Cure this by having the watchdog overflow reset its own throttle count. Reported-by: Stephane Eranian <eranian@google.com> Tested-by: Stephane Eranian <eranian@google.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1282215916.1926.4696.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | tracing: Fix timer tracingArjan van de Ven2010-08-191-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PowerTOP would like to be able to trace timers. Unfortunately, the current timer tracing is not very useful: the actual timer function is not recorded in the trace at the start of timer execution. Although this is recorded for timer "start" time (when it gets armed), this is not useful; most timers get started early, and a tracer like PowerTOP will never see this event, but will only see the actual running of the timer. This patch just adds the function to the timer tracing; I've verified with PowerTOP that now it can get useful information about timers. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: xiaoguangrong@cn.fujitsu.com Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <stable@kernel.org> # .35.x, .34.x, .33.x LKML-Reference: <4C6C5FA9.3000405@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds2010-08-241-1/+9
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | 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: mutex: Improve the scalability of optimistic spinning
| * | | mutex: Improve the scalability of optimistic spinningTim Chen2010-08-231-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a scalability issue for current implementation of optimistic mutex spin in the kernel. It is found on a 8 node 64 core Nehalem-EX system (HT mode). The intention of the optimistic mutex spin is to busy wait and spin on a mutex if the owner of the mutex is running, in the hope that the mutex will be released soon and be acquired, without the thread trying to acquire mutex going to sleep. However, when we have a large number of threads, contending for the mutex, we could have the mutex grabbed by other thread, and then another ……, and we will keep spinning, wasting cpu cycles and adding to the contention. One possible fix is to quit spinning and put the current thread on wait-list if mutex lock switch to a new owner while we spin, indicating heavy contention (see the patch included). I did some testing on a 8 socket Nehalem-EX system with a total of 64 cores. Using Ingo's test-mutex program that creates/delete files with 256 threads (http://lkml.org/lkml/2006/1/8/50) , I see the following speed up after putting in the mutex spin fix: ./mutex-test V 256 10 Ops/sec 2.6.34 62864 With fix 197200 Repeating the test with Aim7 fserver workload, again there is a speed up with the fix: Jobs/min 2.6.34 91657 With fix 149325 To look at the impact on the distribution of mutex acquisition time, I collected the mutex acquisition time on Aim7 fserver workload with some instrumentation. The average acquisition time is reduced by 48% and number of contentions reduced by 32%. #contentions Time to acquire mutex (cycles) 2.6.34 72973 44765791 With fix 49210 23067129 The histogram of mutex acquisition time is listed below. The acquisition time is in 2^bin cycles. We see that without the fix, the acquisition time is mostly around 2^26 cycles. With the fix, we the distribution get spread out a lot more towards the lower cycles, starting from 2^13. However, there is an increase of the tail distribution with the fix at 2^28 and 2^29 cycles. It seems a small price to pay for the reduced average acquisition time and also getting the cpu to do useful work. Mutex acquisition time distribution (acq time = 2^bin cycles): 2.6.34 With Fix bin #occurrence % #occurrence % 11 2 0.00% 120 0.24% 12 10 0.01% 790 1.61% 13 14 0.02% 2058 4.18% 14 86 0.12% 3378 6.86% 15 393 0.54% 4831 9.82% 16 710 0.97% 4893 9.94% 17 815 1.12% 4667 9.48% 18 790 1.08% 5147 10.46% 19 580 0.80% 6250 12.70% 20 429 0.59% 6870 13.96% 21 311 0.43% 1809 3.68% 22 255 0.35% 2305 4.68% 23 317 0.44% 916 1.86% 24 610 0.84% 233 0.47% 25 3128 4.29% 95 0.19% 26 63902 87.69% 122 0.25% 27 619 0.85% 286 0.58% 28 0 0.00% 3536 7.19% 29 0 0.00% 903 1.83% 30 0 0.00% 0 0.00% I've done similar experiments with 2.6.35 kernel on smaller boxes as well. One is on a dual-socket Westmere box (12 cores total, with HT). Another experiment is on an old dual-socket Core 2 box (4 cores total, no HT) On the 12-core Westmere box, I see a 250% increase for Ingo's mutex-test program with my mutex patch but no significant difference in aim7's fserver workload. On the 4-core Core 2 box, I see the difference with the patch for both mutex-test and aim7 fserver are negligible. So far, it seems like the patch has not caused regression on smaller systems. Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: <stable@kernel.org> # .35.x LKML-Reference: <1282168827.9542.72.camel@schen9-DESK> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | guard page for stacks that grow upwardsLuck, Tony2010-08-243-8/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pa-risc and ia64 have stacks that grow upwards. Check that they do not run into other mappings. By making VM_GROWSUP 0x0 on architectures that do not ever use it, we can avoid some unpleasant #ifdefs in check_stack_guard_page(). Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | drm/i915: fix vblank wait test conditionJesse Barnes2010-08-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When converting this to the new wait_for macro I inverted the wait condition, which causes all sorts of problems. So correct it to fix several failures caused by the bad wait (flickering, bad output detection, tearing, etc.). Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6Linus Torvalds2010-08-249-8/+30
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6: [S390] fix tlb flushing vs. concurrent /proc accesses [S390] s390: fix build error (sys_execve)
| * | | | [S390] fix tlb flushing vs. concurrent /proc accessesMartin Schwidefsky2010-08-248-6/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tlb flushing code uses the mm_users field of the mm_struct to decide if each page table entry needs to be flushed individually with IPTE or if a global flush for the mm_struct is sufficient after all page table updates have been done. The comment for mm_users says "How many users with user space?" but the /proc code increases mm_users after it found the process structure by pid without creating a new user process. Which makes mm_users useless for the decision between the two tlb flusing methods. The current code can be confused to not flush tlb entries by a concurrent access to /proc files if e.g. a fork is in progres. The solution for this problem is to make the tlb flushing logic independent from the mm_users field. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | | | [S390] s390: fix build error (sys_execve)Sebastian Ott2010-08-241-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fix this build error: arch/s390/kernel/process.c:272: error: conflicting types for 'sys_execve' arch/s390/kernel/entry.h:45: error: previous declaration of 'sys_execve' was here make[1]: *** [arch/s390/kernel/process.o] Error 1 make: *** [arch/s390/kernel] Error 2 introduced by d7627467b7a8dd6944885290a03a07ceb28c10eb Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | | | | intel_scu_ipc: fix IPC i2c write bugJianwei Yang2010-08-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We should pass the data to the data register. Signed-off-by: Jianwei Yang <jianwei.yang@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | rar: Fix off by one errorOssama Othman2010-08-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It looks like there is an off-by-one error in one of your changes to drivers/staging/rar_register/rar_register.c: Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | V4L/DVB: mantis: Fix IR_CORE dependencyIngo Molnar2010-08-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This build bug triggers: drivers/built-in.o: In function `mantis_exit': (.text+0x377413): undefined reference to `ir_input_unregister' drivers/built-in.o: In function `mantis_input_init': (.text+0x3774ff): undefined reference to `__ir_input_register' If MANTIS_CORE is enabled but IR_CORE is not. Add the correct dependency. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6Linus Torvalds2010-08-2416-523/+595
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6: sparc64: Get rid of indirect p1275 PROM call buffer. sparc64: Fill a missing delay slot. sparc64: Make lock backoff really a NOP on UP builds. sparc64: simple microoptimizations for atomic functions sparc64: Make rwsems 64-bit. sparc64: Really fix atomic64_t interface types.
| * | | | | sparc64: Get rid of indirect p1275 PROM call buffer.David S. Miller2010-08-237-297/+456
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is based upon a report by Meelis Roos showing that it's possible that we'll try to fetch a property that is 32K in size with some devices. With the current fixed 3K buffer we use for moving data in and out of the firmware during PROM calls, that simply won't work. In fact, it will scramble random kernel data during bootup. The reasoning behind the temporary buffer is entirely historical. It used to be the case that we had problems referencing dynamic kernel memory (including the stack) early in the boot process before we explicitly told the firwmare to switch us over to the kernel trap table. So what we did was always give the firmware buffers that were locked into the main kernel image. But we no longer have problems like that, so get rid of all of this indirect bounce buffering. Besides fixing Meelis's bug, this also makes the kernel data about 3K smaller. It was also discovered during these conversions that the implementation of prom_retain() was completely wrong, so that was fixed here as well. Currently that interface is not in use. Reported-by: Meelis Roos <mroos@linux.ee> Tested-by: Meelis Roos <mroos@linux.ee> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | | sparc64: Fill a missing delay slot.Mikulas Patocka2010-08-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the code were already aligned to 64 bytes, wr instruction would be executed twice --- once in delay slot and once in the jump target. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | | sparc64: Make lock backoff really a NOP on UP builds.David S. Miller2010-08-183-17/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As noticed by Mikulas Patocka, the backoff macros don't completely nop out for UP builds, we still get a branch always and a delay slot nop. Fix this by making the branch to the backoff spin loop selective, then we can nop out the spin loop completely. Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | | sparc64: simple microoptimizations for atomic functionsMikulas Patocka2010-08-181-12/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Simple microoptimizations for sparc64 atomic functions: Save one instruction by using a delay slot. Use %g1 instead of %g7, because %g1 is written earlier. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | | sparc64: Make rwsems 64-bit.David S. Miller2010-08-174-193/+104
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Basically tip-off the powerpc code, use a 64-bit type and atomic64_t interfaces for the implementation. This gets us off of the by-hand asm code I wrote, which frankly I think probably ruins I-cache hit rates. The idea was the keep the call chains less deep, but anything taking the rw-semaphores probably is also calling other stuff and therefore already has allocated a stack-frame. So no real stack frame savings ever. Ben H. has posted patches to make powerpc use 64-bit too and with some abstractions we can probably use a shared header file somewhere. With suggestions from Sam Ravnborg. Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | | sparc64: Really fix atomic64_t interface types.David S. Miller2010-08-171-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linus noticed that some of the interface arguments didn't get "int" --> "long" conversion, as needed. Signed-off-by: David S. Miller <davem@davemloft.net>
* | | | | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpcLinus Torvalds2010-08-2431-118/+219
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (25 commits) powerpc: Fix config dependency problem with MPIC_U3_HT_IRQS via-pmu: Add compat_pmu_ioctl powerpc: Wire up fanotify_init, fanotify_mark, prlimit64 syscalls powerpc/pci: Fix checking for child bridges in PCI code. powerpc: Fix typo in uImage target powerpc: Initialise paca->kstack before early_setup_secondary powerpc: Fix bogus it_blocksize in VIO iommu code powerpc: Inline ppc64_runlatch_off powerpc: Correct smt_enabled=X boot option for > 2 threads per core powerpc: Silence xics_migrate_irqs_away() during cpu offline powerpc: Silence __cpu_up() under normal operation powerpc: Re-enable preemption before cpu_die() powerpc/pci: Drop unnecessary null test powerpc/powermac: Drop unnecessary null test powerpc/powermac: Drop unnecessary of_node_put powerpc/kdump: Stop all other CPUs before running crash handlers powerpc/mm: Fix vsid_scrample typo powerpc: Use is_32bit_task() helper to test 32 bit binary powerpc: Export memstart_addr and kernstart_addr on ppc64 powerpc: Make rwsem use "long" type ...
| * | | | | | powerpc: Fix config dependency problem with MPIC_U3_HT_IRQSAndreas Schwab2010-08-241-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MPIC_U3_HT_IRQS is selected both by PPC_PMAC64 and PPC_MAPLE, but depends on PPC_MAPLE, so a PPC_PMAC64-only config gets this warning: warning: (PPC_PMAC64 && PPC_PMAC && POWER4 || PPC_MAPLE && PPC64 && PPC_BOOK3S) selects MPIC_U3_HT_IRQS which has unmet direct dependencies (PPC_MAPLE) Fix that by removing the dependency on PPC_MAPLE. Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | | | via-pmu: Add compat_pmu_ioctlAndreas Schwab2010-08-241-0/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ioctls are actually compatible, but due to historical mistake the numbers differ between 32bit and 64bit. Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | | | powerpc: Wire up fanotify_init, fanotify_mark, prlimit64 syscallsAndreas Schwab2010-08-243-1/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | | | powerpc/pci: Fix checking for child bridges in PCI code.Grant Likely2010-08-241-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pci_device_to_OF_node() can return null, and list_for_each_entry will never enter the loop when dev is NULL, so it looks like this test is a typo. Reported-by: Julia Lawall <julia@diku.dk> Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | | | powerpc: Fix typo in uImage targetAnatolij Gustschin2010-08-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit e32e78c5ee8aadef020fbaecbe6fb741ed9029fd (powerpc: fix build with make 3.82) introduced a typo in uImage target and broke building uImage: make: *** No rule to make target `uImage'. Stop. Signed-off-by: Anatolij Gustschin <agust@denx.de> Cc: stable <stable@kernel.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | | | powerpc: Initialise paca->kstack before early_setup_secondaryMatt Evans2010-08-241-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As early setup calls down to slb_initialize(), we must have kstack initialised before checking "should we add a bolted SLB entry for our kstack?" Failing to do so means stack access requires an SLB miss exception to refill an entry dynamically, if the stack isn't accessible via SLB(0) (kernel text & static data). It's not always allowable to take such a miss, and intermittent crashes will result. Primary CPUs don't have this issue; an SLB entry is not bolted for their stack anyway (as that lives within SLB(0)). This patch therefore only affects the init of secondaries. Signed-off-by: Matt Evans <matt@ozlabs.org> Cc: stable <stable@kernel.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | | | powerpc: Fix bogus it_blocksize in VIO iommu codeAnton Blanchard2010-08-244-7/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When looking at some issues with the virtual ethernet driver I noticed that TCE allocation was following a very strange pattern: address 00e9000 length 2048 address 0409000 length 2048 <----- address 0429000 length 2048 address 0449000 length 2048 address 0469000 length 2048 address 0489000 length 2048 address 04a9000 length 2048 address 04c9000 length 2048 address 04e9000 length 2048 address 4009000 length 2048 <----- address 4029000 length 2048 Huge unexplained gaps in what should be an empty TCE table. It turns out it_blocksize, the amount we want to align the next allocation to, was c0000000fe903b20. Completely bogus. Initialise it to something reasonable in the VIO IOMMU code, and use kzalloc everywhere to protect against this when we next add a non compulsary field to iommu code and forget to initialise it. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | | | powerpc: Inline ppc64_runlatch_offAnton Blanchard2010-08-242-9/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I'm sick of seeing ppc64_runlatch_off in our profiles, so inline it into the callers. To avoid a mess of circular includes I didn't add it as an inline function. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | | | powerpc: Correct smt_enabled=X boot option for > 2 threads per coreNathan Fontenot2010-08-242-31/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The 'smt_enabled=X' boot option does not handle values of X > 2. For Power 7 processors with smt modes of 0,1,2,3, and 4 this does not work. This patch allows the smt_enabled option to be set to any value limited to a max equal to the number of threads per core. Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | | | powerpc: Silence xics_migrate_irqs_away() during cpu offlineSigned-off-by: Darren Hart2010-08-241-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All IRQs are migrated away from a CPU that is being offlined so the following messages suggest a problem when the system is behaving as designed: IRQ 262 affinity broken off cpu 1 IRQ 17 affinity broken off cpu 0 IRQ 18 affinity broken off cpu 0 IRQ 19 affinity broken off cpu 0 IRQ 256 affinity broken off cpu 0 IRQ 261 affinity broken off cpu 0 IRQ 262 affinity broken off cpu 0 Don't print these messages when the CPU is not online. Signed-off-by: Darren Hart <dvhltc@us.ibm.com> Acked-by: Will Schmidt <will_schmidt@vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nathan Fontenot <nfont@austin.ibm.com> Cc: Robert Jennings <rcj@linux.vnet.ibm.com> Cc: Brian King <brking@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | | | powerpc: Silence __cpu_up() under normal operationSigned-off-by: Darren Hart2010-08-241-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During CPU offline/online tests __cpu_up would flood the logs with the following message: Processor 0 found. This provides no useful information to the user as there is no context provided, and since the operation was a success (to this point) it is expected that the CPU will come back online, providing all the feedback necessary. Change the "Processor found" message to DBG() similar to other such messages in the same function. Also, add an appropriate log level for the "Processor is stuck" message. Signed-off-by: Darren Hart <dvhltc@us.ibm.com> Acked-by: Will Schmidt <will_schmidt@vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nathan Fontenot <nfont@austin.ibm.com> Cc: Robert Jennings <rcj@linux.vnet.ibm.com> Cc: Brian King <brking@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | | | powerpc: Re-enable preemption before cpu_die()Signed-off-by: Darren Hart2010-08-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | start_secondary() is called shortly after _start and also via cpu_idle()->cpu_die()->pseries_mach_cpu_die() start_secondary() expects a preempt_count() of 0. pseries_mach_cpu_die() is called via the cpu_idle() routine with preemption disabled, resulting in the following repeating message during rapid cpu offline/online tests with CONFIG_PREEMPT=y: BUG: scheduling while atomic: swapper/0/0x00000002 Modules linked in: autofs4 binfmt_misc dm_mirror dm_region_hash dm_log [last unloaded: scsi_wait_scan] Call Trace: [c00000010e7079c0] [c0000000000133ec] .show_stack+0xd8/0x218 (unreliable) [c00000010e707aa0] [c0000000006a47f0] .dump_stack+0x28/0x3c [c00000010e707b20] [c00000000006e7a4] .__schedule_bug+0x7c/0x9c [c00000010e707bb0] [c000000000699d9c] .schedule+0x104/0x800 [c00000010e707cd0] [c000000000015b24] .cpu_idle+0x1c4/0x1d8 [c00000010e707d70] [c0000000006aa1b4] .start_secondary+0x398/0x3d4 [c00000010e707e30] [c000000000008278] .start_secondary_resume+0x10/0x14 Move the cpu_die() call inside the existing preemption enabled block of cpu_idle(). This is safe as the idle task is affined to a single CPU so the debug_smp_processor_id() tests (from cpu_should_die()) won't trigger as we are in a "migration disabled" region. Signed-off-by: Darren Hart <dvhltc@us.ibm.com> Acked-by: Will Schmidt <will_schmidt@vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nathan Fontenot <nfont@austin.ibm.com> Cc: Robert Jennings <rcj@linux.vnet.ibm.com> Cc: Brian King <brking@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | | | powerpc/pci: Drop unnecessary null testJulia Lawall2010-08-241-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | list_for_each_entry binds its first argument to a non-null value, and thus any null test on the value of that argument is superfluous. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ iterator I; expression x,E,E1,E2; statement S,S1,S2; @@ I(x,...) { <... - if (x != NULL || ...) S ...> } // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | | | powerpc/powermac: Drop unnecessary null testJulia Lawall2010-08-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | for_each_node_by_name binds its first argument to a non-null value, and thus any null test on the value of that argument is superfluous. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ iterator I; expression x,E; @@ I(x,...) { <... ( - (x != NULL) && E ...> } // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | | | powerpc/powermac: Drop unnecessary of_node_putJulia Lawall2010-08-242-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | for_each_node_by_name only exits when its first argument is NULL, and a subsequent call to of_node_put on that argument is unnecessary. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ iterator name for_each_node_by_name; expression np,E; identifier l; @@ for_each_node_by_name(np,...) { ... when != break; when != goto l; } ... when != np = E - of_node_put(np); // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Reviewed-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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