- 15 2月, 2014 1 次提交
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由 Viresh Kumar 提交于
When a timer is enqueued or modified on a remote target, the latter is expected to see and handle this timer on its next tick. However if the target is idle and CONFIG_NO_HZ_IDLE=y, the CPU may be sleeping tickless and the timer may be ignored. wake_up_nohz_cpu() takes care of that by setting TIF_NEED_RESCHED and sending an IPI to idle targets so that the tick is reevaluated on the idle loop through the tick_nohz_idle_*() APIs. Now this is all performed regardless of the power properties of the timer. If the timer is deferrable, idle targets don't need to be woken up. Only the next buzy tick needs to care about it, and no IPI kick is needed for that to happen. So lets spare the IPI on idle targets when the timer is deferrable. Meanwhile we keep the current behaviour on full dynticks targets. We can spare IPIs on idle full dynticks targets as well but some tricky races against idle_cpu() must be dealt all along to make sure that the timer is well handled after idle exit. We can deal with that later since NO_HZ_FULL already has more important powersaving issues. Reported-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/CAKohpomMZ0TAN2e6N76_g4ZRzxd5vZ1XfuZfxrP7GMxfTNiLVw@mail.gmail.comSigned-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
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- 09 2月, 2014 1 次提交
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由 Preeti U Murthy 提交于
The hrtimer mode of broadcast is supported only when GENERIC_CLOCKEVENTS_BROADCAST and TICK_ONESHOT config options are enabled. Hence compile in the functions for hrtimer mode of broadcast only when these options are selected. Also fix max_delta_ticks value for the pseudo clock device. Reported-by: NFengguang Wu <fengguang.wu@intel.com> Reported-by: NIngo Molnar <mingo@kernel.org> Signed-off-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/52F719EE.9010304@linux.vnet.ibm.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 07 2月, 2014 6 次提交
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由 Thomas Gleixner 提交于
Make the stub function static inline instead of static and move the clockevents related function into the proper ifdeffed section. Reported-by: NFengguang Wu <fengguang.wu@intel.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Cc: Soren Brinkmann <soren.brinkmann@xilinx.com> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
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由 Preeti U Murthy 提交于
On some architectures, in certain CPU deep idle states the local timers stop. An external clock device is used to wakeup these CPUs. The kernel support for the wakeup of these CPUs is provided by the tick broadcast framework by using the external clock device as the wakeup source. However not all implementations of architectures provide such an external clock device. This patch includes support in the broadcast framework to handle the wakeup of the CPUs in deep idle states on such systems by queuing a hrtimer on one of the CPUs, which is meant to handle the wakeup of CPUs in deep idle states. This patchset introduces a pseudo clock device which can be registered by the archs as tick_broadcast_device in the absence of a real external clock device. Once registered, the broadcast framework will work as is for these architectures as long as the archs take care of the BROADCAST_ENTER notification failing for one of the CPUs. This CPU is made the stand by CPU to handle wakeup of the CPUs in deep idle and it *must not enter deep idle states*. The CPU with the earliest wakeup is chosen to be this CPU. Hence this way the stand by CPU dynamically moves around and so does the hrtimer which is queued to trigger at the next earliest wakeup time. This is consistent with the case where an external clock device is present. The smp affinity of this clock device is set to the CPU with the earliest wakeup. This patchset handles the hotplug of the stand by CPU as well by moving the hrtimer on to the CPU handling the CPU_DEAD notification. Originally-from: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com> Cc: deepthi@linux.vnet.ibm.com Cc: paulmck@linux.vnet.ibm.com Cc: fweisbec@gmail.com Cc: paulus@samba.org Cc: srivatsa.bhat@linux.vnet.ibm.com Cc: svaidy@linux.vnet.ibm.com Cc: peterz@infradead.org Cc: benh@kernel.crashing.org Cc: rafael.j.wysocki@intel.com Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/20140207080632.17187.80532.stgit@preeti.in.ibm.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Preeti U Murthy 提交于
The broadcast framework can potentially be made use of by archs which do not have an external clock device as well. Then, it is required that one of the CPUs need to handle the broadcasting of wakeup IPIs to the CPUs in deep idle. As a result its local timers should remain functional all the time. For such a CPU, the BROADCAST_ENTER notification has to fail indicating that its clock device cannot be shutdown. To make way for this support, change the return type of tick_broadcast_oneshot_control() and hence clockevents_notify() to indicate such scenarios. Signed-off-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com> Cc: deepthi@linux.vnet.ibm.com Cc: paulmck@linux.vnet.ibm.com Cc: fweisbec@gmail.com Cc: paulus@samba.org Cc: srivatsa.bhat@linux.vnet.ibm.com Cc: svaidy@linux.vnet.ibm.com Cc: peterz@infradead.org Cc: benh@kernel.crashing.org Cc: rafael.j.wysocki@intel.com Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/20140207080606.17187.78306.stgit@preeti.in.ibm.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Soren Brinkmann 提交于
clockevent devices in periodic mode are not updated when the frequency of the device changes. Issue a dev->set_mode() callback which forces the device to reevaluate the timer settings. Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com> Cc: linux-arm-kernel@lists.infradead.org Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Michal Simek <michal.simek@xilinx.com> Link: http://lkml.kernel.org/r/1391466877-28908-3-git-send-email-soren.brinkmann@xilinx.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Thomas Gleixner 提交于
We can identify the broadcast device in the core and serialize all callers including interrupts on a different CPU against the update. Also, disabling interrupts is moved into the core allowing callers to leave interrutps enabled when calling clockevents_update_freq(). Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com> Cc: linux-arm-kernel@lists.infradead.org Cc: Soeren Brinkmann <soren.brinkmann@xilinx.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Michal Simek <michal.simek@xilinx.com> Link: http://lkml.kernel.org/r/1391466877-28908-2-git-send-email-soren.brinkmann@xilinx.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Shaibal Dutta 提交于
For better use of CPU idle time, allow the scheduler to select the CPU on which the CMOS clock sync work would be scheduled. This improves idle residency time and conserver power. This functionality is enabled when CONFIG_WQ_POWER_EFFICIENT is selected. Signed-off-by: NShaibal Dutta <shaibal.dutta@broadcom.com> [zoran.markovic@linaro.org: Added commit message. Aligned code.] Signed-off-by: NZoran Markovic <zoran.markovic@linaro.org> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/1391195904-12497-1-git-send-email-zoran.markovic@linaro.orgSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 31 1月, 2014 2 次提交
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由 Roman Gushchin 提交于
After commit 9a46ad6d ("smp: make smp_call_function_many() use logic similar to smp_call_function_single()"), cfd->cpumask is accessed only in smp_call_function_many(). So there is no more need to copy it into cfd->cpumask_ipi before putting csd into the list. The cpumask_ipi field is obsolete and can be removed. Signed-off-by: NRoman Gushchin <klamm@yandex-team.ru> Cc: Ingo Molnar <mingo@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Wang YanQing <udknight@gmail.com> Cc: Xie XiuQi <xiexiuqi@huawei.com> Cc: Shaohua Li <shli@fusionio.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Christoph Hellwig 提交于
Make smp_call_function_single and friends more efficient by using a lockless list. Signed-off-by: NChristoph Hellwig <hch@lst.de> Reviewed-by: NJan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 28 1月, 2014 6 次提交
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由 Peter Zijlstra 提交于
Not all classes implement (or can implement) a useful get_rr_interval() function, default to a 0 time-slice for them. This fixes a crash reported by Tommi Rantala. Reported-by: NTommi Rantala <tt.rantala@gmail.com> Cc: Dave Jones <davej@redhat.com> Cc: Tommi Rantala <tt.rantala@gmail.com> Signed-off-by: NPeter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140127105413.GC11314@laptop.programming.kicks-ass.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Dario Faggioli 提交于
Add in Documentation/scheduler/ some hints about the design choices, the usage and the future possible developments of the sched_dl scheduling class and of the SCHED_DEADLINE policy. Reviewed-by: NHenrik Austad <henrik@austad.us> Signed-off-by: NDario Faggioli <raistlin@linux.it> Signed-off-by: NJuri Lelli <juri.lelli@gmail.com> [ Re-wrote sections 2 and 3. ] Signed-off-by: NLuca Abeni <luca.abeni@unitn.it> Signed-off-by: NPeter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1390821615-23247-1-git-send-email-juri.lelli@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Joe Perches 提交于
Reduce data size a little. Reduce checkpatch noise. $ size kernel/softirq.o* text data bss dec hex filename 11554 6013 4008 21575 5447 kernel/softirq.o.new 11474 6093 4008 21575 5447 kernel/softirq.o.old Signed-off-by: NJoe Perches <joe@perches.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Joe Perches 提交于
Use a more current logging style. Signed-off-by: NJoe Perches <joe@perches.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Joe Perches 提交于
Possible speed improvement of __do_softirq() by using ffs() instead of using a while loop with an & 1 test then single bit shift. Signed-off-by: NJoe Perches <joe@perches.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Chen Gang 提交于
vsnprintf() may let 'r' larger than sizeof(buf), in this case, if 'r' is also less than "vmcoreinfo_max_size - vmcoreinfo_size" (left size of destination buffer), next memcpy() will read the unexpected addresses. Signed-off-by: NChen Gang <gang.chen@asianux.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 25 1月, 2014 4 次提交
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由 Aaron Tomlin 提交于
When khungtaskd detects hung tasks, it prints out backtraces from a number of those tasks. Limiting the number of backtraces being printed out can result in the user not seeing the information necessary to debug the issue. The hung_task_warnings sysctl controls this feature. This patch makes it possible for hung_task_warnings to accept a special value to print an unlimited number of backtraces when khungtaskd detects hung tasks. The special value is -1. To use this value it is necessary to change types from ulong to int. Signed-off-by: NAaron Tomlin <atomlin@redhat.com> Reviewed-by: NRik van Riel <riel@redhat.com> Acked-by: NDavid Rientjes <rientjes@google.com> Cc: oleg@redhat.com Link: http://lkml.kernel.org/r/1390239253-24030-3-git-send-email-atomlin@redhat.com [ Build warning fix. ] Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Oleg Nesterov 提交于
rcu_dereference_check_fdtable() looks very wrong, 1. rcu_my_thread_group_empty() was added by 844b9a87 "vfs: fix RCU-lockdep false positive due to /proc" but it doesn't really fix the problem. A CLONE_THREAD (without CLONE_FILES) task can hit the same race with get_files_struct(). And otoh rcu_my_thread_group_empty() can suppress the correct warning if the caller is the CLONE_FILES (without CLONE_THREAD) task. 2. files->count == 1 check is not really right too. Even if this files_struct is not shared it is not safe to access it lockless unless the caller is the owner. Otoh, this check is sub-optimal. files->count == 0 always means it is safe to use it lockless even if files != current->files, but put_files_struct() has to take rcu_read_lock(). See the next patch. This patch removes the buggy checks and turns fcheck_files() into __fcheck_files() which uses rcu_dereference_raw(), the "unshared" callers, fget_light() and fget_raw_light(), can use it to avoid the warning from RCU-lockdep. fcheck_files() is trivially reimplemented as rcu_lockdep_assert() plus __fcheck_files(). Signed-off-by: NOleg Nesterov <oleg@redhat.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Aaron Tomlin 提交于
Add neg_one to the list of standard constraints - will be used by the next patch. Signed-off-by: NAaron Tomlin <atomlin@redhat.com> Acked-by: NRik van Riel <riel@redhat.com> Acked-by: NDavid Rientjes <rientjes@google.com> Cc: oleg@redhat.com Link: http://lkml.kernel.org/r/1390239253-24030-2-git-send-email-atomlin@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Mike Travis 提交于
Some code added to the debug_core module had KDB dependencies that it shouldn't have. Move the KDB dependent REASON back to the caller to remove the dependency in the debug core code. Update the call from the UV NMI handler to conform to the new interface. Signed-off-by: NMike Travis <travis@sgi.com> Reviewed-by: NHedi Berriche <hedi@sgi.com> Cc: Russ Anderson <rja@sgi.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Link: http://lkml.kernel.org/r/20140114162551.318251993@asylum.americas.sgi.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 24 1月, 2014 11 次提交
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由 Vivek Goyal 提交于
Right now we seem to be exporting the max data size contained inside vmcoreinfo note. But this does not include the size of meta data around vmcore info data. Like name of the note and starting and ending elf_note. I think user space expects total size and that size is put in PT_NOTE elf header. Things seem to be fine so far because we are not using vmcoreinfo note to the maximum capacity. But as it starts filling up, to capacity, at some point of time, problem will be visible. I don't think user space will be broken with this change. So there is no need to introduce vmcoreinfo2. This change is safe and backward compatible. More explanation on why this change is safe is below. vmcoreinfo contains information about kernel which user space needs to know to do things like filtering. For example, various kernel config options or information about size or offset of some data structures etc. All this information is commmunicated to user space with an ELF note present in ELF /proc/vmcore file. Currently vmcoreinfo data size is 4096. With some elf note meta data around it, actual size is 4132 bytes. But we are using barely 25% of that size. Rest is empty. So even if we tell user space that size of ELf note is 4096 and not 4132, nothing will be broken becase after around 1000 bytes, everything is zero anyway. But once we start filling up the note to the capacity, and not report the full size of note, bad things will start happening. Either some data will be lost or tools will be confused that they did not fine the zero note at the end. So I think this change is safe and should not break existing tools. Signed-off-by: NVivek Goyal <vgoyal@redhat.com> Cc: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp> Cc: Dan Aloni <da-x@monatomic.org> Cc: Greg KH <greg@kroah.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Kees Cook 提交于
For general-purpose (i.e. distro) kernel builds it makes sense to build with CONFIG_KEXEC to allow end users to choose what kind of things they want to do with kexec. However, in the face of trying to lock down a system with such a kernel, there needs to be a way to disable kexec_load (much like module loading can be disabled). Without this, it is too easy for the root user to modify kernel memory even when CONFIG_STRICT_DEVMEM and modules_disabled are set. With this change, it is still possible to load an image for use later, then disable kexec_load so the image (or lack of image) can't be altered. The intention is for using this in environments where "perfect" enforcement is hard. Without a verified boot, along with verified modules, and along with verified kexec, this is trying to give a system a better chance to defend itself (or at least grow the window of discoverability) against attack in the face of a privilege escalation. In my mind, I consider several boot scenarios: 1) Verified boot of read-only verified root fs loading fd-based verification of kexec images. 2) Secure boot of writable root fs loading signed kexec images. 3) Regular boot loading kexec (e.g. kcrash) image early and locking it. 4) Regular boot with no control of kexec image at all. 1 and 2 don't exist yet, but will soon once the verified kexec series has landed. 4 is the state of things now. The gap between 2 and 4 is too large, so this change creates scenario 3, a middle-ground above 4 when 2 and 1 are not possible for a system. Signed-off-by: NKees Cook <keescook@chromium.org> Acked-by: NRik van Riel <riel@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Oleg Nesterov 提交于
Change do_signal_stop() and do_sigaction() to avoid next_thread() and use while_each_thread() instead. Signed-off-by: NOleg Nesterov <oleg@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Kees Cook <keescook@chromium.org> Reviewed-by: NSameer Nanda <snanda@chromium.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Oleg Nesterov 提交于
Change k_getrusage() to use while_each_thread(), no changes in the compiled code. Signed-off-by: NOleg Nesterov <oleg@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Kees Cook <keescook@chromium.org> Reviewed-by: NSameer Nanda <snanda@chromium.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Oleg Nesterov 提交于
We can kill either task->did_exec or PF_FORKNOEXEC, they are mutually exclusive. The patch kills ->did_exec because it has a single user. Signed-off-by: NOleg Nesterov <oleg@redhat.com> Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Daeseok Youn 提交于
current->mm doesn't need a NULL check in dup_mm(). Becasue dup_mm() is used only in copy_mm() and current->mm is checked whether it is NULL or not in copy_mm() before calling dup_mm(). Signed-off-by: NDaeseok Youn <daeseok.youn@gmail.com> Acked-by: NOleg Nesterov <oleg@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Daeseok Youn 提交于
Fix errors reported by checkpatch.pl. One error is parentheses, the other is a whitespace issue. Signed-off-by: NDaeseok Youn <daeseok.youn@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 DaeSeok Youn 提交于
dup_mm() is used only in kernel/fork.c Signed-off-by: NDaeseok Youn <daeseok.youn@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Arun KS 提交于
An earlier newline was missing and current print is from different task. In this scenario flush the continuation line and store this line seperatly. This patch fix the below scenario of timestamp interleaving, [ 28.154370 ] read_word_reg : reg[0x 3], reg[0x 4] data [0x 642] [ 28.155428 ] uart disconnect [ 31.947341 ] dvfs[cpufreq.c<275>]:plug-in cpu<1> done [ 28.155445 ] UART detached : send switch state 201 [ 32.014112 ] read_reg : reg[0x 3] data[0x21] [akpm@linux-foundation.org: simplify and condense the code] Signed-off-by: NArun KS <getarunks@gmail.com> Signed-off-by: NArun KS <arun.ks@broadcom.com> Cc: Joe Perches <joe@perches.com> Cc: Tejun Heo <tj@kernel.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Kay Sievers <kay@vrfy.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andi Kleen 提交于
Add a working sysctl to enable/disable automatic numa memory balancing at runtime. This allows us to track down performance problems with this feature and is generally a good idea. This was possible earlier through debugfs, but only with special debugging options set. Also fix the boot message. [akpm@linux-foundation.org: s/sched_numa_balancing/sysctl_numa_balancing/] Signed-off-by: NAndi Kleen <ak@linux.intel.com> Acked-by: NMel Gorman <mgorman@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Steven Rostedt (Red Hat) 提交于
If trace_puts() is used very early in boot up, it can crash the machine if it is called before the ring buffer is allocated. If a trace_printk() is used with no arguments, then it will be converted into a trace_puts() and suffer the same fate. Cc: stable@vger.kernel.org # 3.10+ Fixes: 09ae7234 "tracing: Add trace_puts() for even faster trace_printk() tracing" Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 23 1月, 2014 4 次提交
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由 Peter Zijlstra 提交于
The code would assume sched_clock_stable() and switch to !stable later, this switch brings a discontinuity in time. The discontinuity on switching from stable to unstable was always present, but previously we would set stable/unstable before initializing TSC and usually stick to the one we start out with. So the static_key bits brought an extra switch where there previously wasn't one. Things are further complicated by the fact that we cannot use static_key as early as we usually call set_sched_clock_stable(). Fix things by tracking the stable state in a regular variable and only set the static_key to the right state on sched_clock_init(), which is ran right after late_time_init->tsc_init(). Before this we would not be using the TSC anyway. Reported-and-Tested-by: NSasha Levin <sasha.levin@oracle.com> Reported-by: dyoung@redhat.com Fixes: 35af99e6 ("sched/clock, x86: Use a static_key for sched_clock_stable") Cc: jacob.jun.pan@linux.intel.com Cc: Mike Galbraith <bitbucket@online.de> Cc: hpa@zytor.com Cc: paulmck@linux.vnet.ibm.com Cc: John Stultz <john.stultz@linaro.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: lenb@kernel.org Cc: rjw@rjwysocki.net Cc: Eliezer Tamir <eliezer.tamir@linux.intel.com> Cc: rui.zhang@intel.com Signed-off-by: NPeter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140122115918.GG3694@twins.programming.kicks-ass.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Vincent Guittot 提交于
This reverts commit 282cf499. With the current implementation, the load average statistics of a sched entity change according to other activity on the CPU even if this activity is done between the running window of the sched entity and have no influence on the running duration of the task. When a task wakes up on the same CPU, we currently update last_runnable_update with the return of __synchronize_entity_decay without updating the runnable_avg_sum and runnable_avg_period accordingly. In fact, we have to sync the load_contrib of the se with the rq's blocked_load_contrib before removing it from the latter (with __synchronize_entity_decay) but we must keep last_runnable_update unchanged for updating runnable_avg_sum/period during the next update_entity_load_avg. Signed-off-by: NVincent Guittot <vincent.guittot@linaro.org> Signed-off-by: NPeter Zijlstra <peterz@infradead.org> Reviewed-by: NBen Segall <bsegall@google.com> Cc: pjt@google.com Cc: alex.shi@linaro.org Link: http://lkml.kernel.org/r/1390376734-6800-1-git-send-email-vincent.guittot@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Steven Rostedt (Red Hat) 提交于
Fix the formatting of the README file in the trace debugfs to fit in an 80 character window. Also add a comment about the event trigger counter with regards to traceon and traceoff. Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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由 Tom Zanussi 提交于
It would be useful to have a cheat-sheet for everything under tracing/events/ alongside the existing text describing the other files in the tracing/ dir. Add short descriptions of the directories and files under events/ along with examples, similar to the existing text for the other files in tracing/. Also clean up a few minor alignment problems noticed when adding the new text. Link: http://lkml.kernel.org/r/1389993104.3040.445.camel@empanadaSigned-off-by: NTom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 22 1月, 2014 5 次提交
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由 Mel Gorman 提交于
This patch adds three tracepoints o trace_sched_move_numa when a task is moved to a node o trace_sched_swap_numa when a task is swapped with another task o trace_sched_stick_numa when a numa-related migration fails The tracepoints allow the NUMA scheduler activity to be monitored and the following high-level metrics can be calculated o NUMA migrated stuck nr trace_sched_stick_numa o NUMA migrated idle nr trace_sched_move_numa o NUMA migrated swapped nr trace_sched_swap_numa o NUMA local swapped trace_sched_swap_numa src_nid == dst_nid (should never happen) o NUMA remote swapped trace_sched_swap_numa src_nid != dst_nid (should == NUMA migrated swapped) o NUMA group swapped trace_sched_swap_numa src_ngid == dst_ngid Maybe a small number of these are acceptable but a high number would be a major surprise. It would be even worse if bounces are frequent. o NUMA avg task migs. Average number of migrations for tasks o NUMA stddev task mig Self-explanatory o NUMA max task migs. Maximum number of migrations for a single task In general the intent of the tracepoints is to help diagnose problems where automatic NUMA balancing appears to be doing an excessive amount of useless work. [akpm@linux-foundation.org: remove semicolon-after-if, repair coding-style] Signed-off-by: NMel Gorman <mgorman@suse.de> Reviewed-by: NRik van Riel <riel@redhat.com> Cc: Alex Thorlton <athorlton@sgi.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Santosh Shilimkar 提交于
Switch to memblock interfaces for early memory allocator instead of bootmem allocator. No functional change in beahvior than what it is in current code from bootmem users points of view. Archs already converted to NO_BOOTMEM now directly use memblock interfaces instead of bootmem wrappers build on top of memblock. And the archs which still uses bootmem, these new apis just fallback to exiting bootmem APIs. Acked-by: N"Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Paul Walmsley <paul@pwsan.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Russell King <linux@arm.linux.org.uk> Cc: Tejun Heo <tj@kernel.org> Cc: Tony Lindgren <tony@atomide.com> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Santosh Shilimkar 提交于
Switch to memblock interfaces for early memory allocator instead of bootmem allocator. No functional change in beahvior than what it is in current code from bootmem users points of view. Archs already converted to NO_BOOTMEM now directly use memblock interfaces instead of bootmem wrappers build on top of memblock. And the archs which still uses bootmem, these new apis just fallback to exiting bootmem APIs. Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Paul Walmsley <paul@pwsan.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Russell King <linux@arm.linux.org.uk> Cc: Tony Lindgren <tony@atomide.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Oleg Nesterov 提交于
while_each_thread() and next_thread() should die, almost every lockless usage is wrong. 1. Unless g == current, the lockless while_each_thread() is not safe. while_each_thread(g, t) can loop forever if g exits, next_thread() can't reach the unhashed thread in this case. Note that this can happen even if g is the group leader, it can exec. 2. Even if while_each_thread() itself was correct, people often use it wrongly. It was never safe to just take rcu_read_lock() and loop unless you verify that pid_alive(g) == T, even the first next_thread() can point to the already freed/reused memory. This patch adds signal_struct->thread_head and task->thread_node to create the normal rcu-safe list with the stable head. The new for_each_thread(g, t) helper is always safe under rcu_read_lock() as long as this task_struct can't go away. Note: of course it is ugly to have both task_struct->thread_node and the old task_struct->thread_group, we will kill it later, after we change the users of while_each_thread() to use for_each_thread(). Perhaps we can kill it even before we convert all users, we can reimplement next_thread(t) using the new thread_head/thread_node. But we can't do this right now because this will lead to subtle behavioural changes. For example, do/while_each_thread() always sees at least one task, while for_each_thread() can do nothing if the whole thread group has died. Or thread_group_empty(), currently its semantics is not clear unless thread_group_leader(p) and we need to audit the callers before we can change it. So this patch adds the new interface which has to coexist with the old one for some time, hopefully the next changes will be more or less straightforward and the old one will go away soon. Signed-off-by: NOleg Nesterov <oleg@redhat.com> Reviewed-by: NSergey Dyasly <dserrg@gmail.com> Tested-by: NSergey Dyasly <dserrg@gmail.com> Reviewed-by: NSameer Nanda <snanda@chromium.org> Acked-by: NDavid Rientjes <rientjes@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mandeep Singh Baines <msb@chromium.org> Cc: "Ma, Xindong" <xindong.ma@intel.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: "Tu, Xiaobing" <xiaobing.tu@intel.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Jerome Marchand 提交于
Some applications that run on HPC clusters are designed around the availability of RAM and the overcommit ratio is fine tuned to get the maximum usage of memory without swapping. With growing memory, the 1%-of-all-RAM grain provided by overcommit_ratio has become too coarse for these workload (on a 2TB machine it represents no less than 20GB). This patch adds the new overcommit_kbytes sysctl variable that allow a much finer grain. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix nommu build] Signed-off-by: NJerome Marchand <jmarchan@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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