- 10 2月, 2013 1 次提交
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由 Len Brown 提交于
mwait_idle() is a C1-only idle loop intended to be more efficient than HLT, starting on Pentium-4 HT-enabled processors. But mwait_idle() has been replaced by the more general mwait_idle_with_hints(), which handles both C1 and deeper C-states. ACPI processor_idle and intel_idle use only mwait_idle_with_hints(), and no longer use mwait_idle(). Here we simplify the x86 native idle code by removing mwait_idle(), and the "idle=mwait" bootparam used to invoke it. Since Linux 3.0 there has been a boot-time warning when "idle=mwait" was invoked saying it would be removed in 2012. This removal was also noted in the (now removed:-) feature-removal-schedule.txt. After this change, kernels configured with (CONFIG_ACPI=n && CONFIG_INTEL_IDLE=n) when run on hardware that supports MWAIT will simply use HLT. If MWAIT is desired on those systems, cpuidle and the cpuidle drivers above can be enabled. Signed-off-by: NLen Brown <len.brown@intel.com> Cc: x86@kernel.org
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- 01 12月, 2012 1 次提交
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由 Vincent Palatin 提交于
When a cpu enters S3 state, the FPU state is lost. After resuming for S3, if we try to lazy restore the FPU for a process running on the same CPU, this will result in a corrupted FPU context. Ensure that "fpu_owner_task" is properly invalided when (re-)initializing a CPU, so nobody will try to lazy restore a state which doesn't exist in the hardware. Tested with a 64-bit kernel on a 4-core Ivybridge CPU with eagerfpu=off, by doing thousands of suspend/resume cycles with 4 processes doing FPU operations running. Without the patch, a process is killed after a few hundreds cycles by a SIGFPE. Cc: Duncan Laurie <dlaurie@chromium.org> Cc: Olof Johansson <olofj@chromium.org> Cc: <stable@kernel.org> v3.4+ # for 3.4 need to replace this_cpu_write by percpu_write Signed-off-by: NVincent Palatin <vpalatin@chromium.org> Link: http://lkml.kernel.org/r/1354306532-1014-1-git-send-email-vpalatin@chromium.orgSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
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- 15 11月, 2012 2 次提交
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由 Fenghua Yu 提交于
Instead of waiting for STARTUP after INITs, BSP will execute the BIOS boot-strap code which is not a desired behavior for waking up BSP. To avoid the boot-strap code, wake up CPU0 by NMI instead. This works to wake up soft offlined CPU0 only. If CPU0 is hard offlined (i.e. physically hot removed and then hot added), NMI won't wake it up. We'll change this code in the future to wake up hard offlined CPU0 if real platform and request are available. AP is still waken up as before by INIT, SIPI, SIPI sequence. Signed-off-by: NFenghua Yu <fenghua.yu@intel.com> Link: http://lkml.kernel.org/r/1352896613-25957-1-git-send-email-fenghua.yu@intel.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
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由 Fenghua Yu 提交于
Add smp_store_boot_cpu_info() to store cpu info for BSP during boot time. Now smp_store_cpu_info() stores cpu info for bringing up BSP or AP after it's offline. Continue to online CPU0 in native_cpu_up(). Continue to offline CPU0 in native_cpu_disable(). Signed-off-by: NFenghua Yu <fenghua.yu@intel.com> Link: http://lkml.kernel.org/r/1352835171-3958-5-git-send-email-fenghua.yu@intel.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
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- 14 11月, 2012 1 次提交
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由 Andreas Herrmann 提交于
Introduce cpu_has_topoext to check for AMD's CPUID topology extensions support. It indicates support for CPUID Fn8000_001D_EAX_x[N:0]-CPUID Fn8000_001E_EDX See AMD's CPUID Specification, Publication # 25481 (as of Rev. 2.34 September 2010) Signed-off-by: NAndreas Herrmann <andreas.herrmann3@amd.com> Link: http://lkml.kernel.org/r/20121019085813.GD26718@alberichSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
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- 23 8月, 2012 1 次提交
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由 Rusty Russell 提交于
We still patch SMP instructions to UP variants if we boot with a single CPU, but not at any other time. In particular, not if we unplug CPUs to return to a single cpu. Paul McKenney points out: mean offline overhead is 6251/48=130.2 milliseconds. If I remove the alternatives_smp_switch() from the offline path [...] the mean offline overhead is 550/42=13.1 milliseconds Basically, we're never going to get those 120ms back, and the code is pretty messy. We get rid of: 1) The "smp-alt-once" boot option. It's actually "smp-alt-boot", the documentation is wrong. It's now the default. 2) The skip_smp_alternatives flag used by suspend. 3) arch_disable_nonboot_cpus_begin() and arch_disable_nonboot_cpus_end() which were only used to set this one flag. Signed-off-by: NRusty Russell <rusty@rustcorp.com.au> Cc: Paul McKenney <paul.mckenney@us.ibm.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/87vcgwwive.fsf@rustcorp.com.auSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 14 6月, 2012 1 次提交
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由 Vlad Zolotarov 提交于
Add "read-mostly" qualifier to the following variables in smp.h: - cpu_sibling_map - cpu_core_map - cpu_llc_shared_map - cpu_llc_id - cpu_number - x86_cpu_to_apicid - x86_bios_cpu_apicid - x86_cpu_to_logical_apicid As long as all the variables above are only written during the initialization, this change is meant to prevent the false sharing. More specifically, on vSMP Foundation platform x86_cpu_to_apicid shared the same internode_cache_line with frequently written lapic_events. From the analysis of the first 33 per_cpu variables out of 219 (memories they describe, to be more specific) the 8 have read_mostly nature (tlb_vector_offset, cpu_loops_per_jiffy, xen_debug_irq, etc.) and 25 are frequently written (irq_stack_union, gdt_page, exception_stacks, idt_desc, etc.). Assuming that the spread of the rest of the per_cpu variables is similar, identifying the read mostly memories will make more sense in terms of long-term code maintenance comparing to identifying frequently written memories. Signed-off-by: NVlad Zolotarov <vlad@scalemp.com> Acked-by: NShai Fultheim <shai@scalemp.com> Cc: Shai Fultheim (Shai@ScaleMP.com) <Shai@scalemp.com> Cc: ido@wizery.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1719258.EYKzE4Zbq5@vladSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 13 6月, 2012 1 次提交
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由 Borislav Petkov 提交于
The warning below triggers on AMD MCM packages because physical package IDs on the cores of a _physical_ socket are the same. I.e., this field says which CPUs belong to the same physical package. However, the same two CPUs belong to two different internal, i.e. "logical" nodes in the same physical socket which is reflected in the CPU-to-node map on x86 with NUMA. Which makes this check wrong on the above topologies so circumvent it. [ 0.444413] Booting Node 0, Processors #1 #2 #3 #4 #5 Ok. [ 0.461388] ------------[ cut here ]------------ [ 0.465997] WARNING: at arch/x86/kernel/smpboot.c:310 topology_sane.clone.1+0x6e/0x81() [ 0.473960] Hardware name: Dinar [ 0.477170] sched: CPU #6's mc-sibling CPU #0 is not on the same node! [node: 1 != 0]. Ignoring dependency. [ 0.486860] Booting Node 1, Processors #6 [ 0.491104] Modules linked in: [ 0.494141] Pid: 0, comm: swapper/6 Not tainted 3.4.0+ #1 [ 0.499510] Call Trace: [ 0.501946] [<ffffffff8144bf92>] ? topology_sane.clone.1+0x6e/0x81 [ 0.508185] [<ffffffff8102f1fc>] warn_slowpath_common+0x85/0x9d [ 0.514163] [<ffffffff8102f2b7>] warn_slowpath_fmt+0x46/0x48 [ 0.519881] [<ffffffff8144bf92>] topology_sane.clone.1+0x6e/0x81 [ 0.525943] [<ffffffff8144c234>] set_cpu_sibling_map+0x251/0x371 [ 0.532004] [<ffffffff8144c4ee>] start_secondary+0x19a/0x218 [ 0.537729] ---[ end trace 4eaa2a86a8e2da22 ]--- [ 0.628197] #7 #8 #9 #10 #11 Ok. [ 0.807108] Booting Node 3, Processors #12 #13 #14 #15 #16 #17 Ok. [ 0.897587] Booting Node 2, Processors #18 #19 #20 #21 #22 #23 Ok. [ 0.917443] Brought up 24 CPUs We ran a topology sanity check test we have here on it and it all looks ok... hopefully :). Signed-off-by: NBorislav Petkov <borislav.petkov@amd.com> Cc: Andreas Herrmann <andreas.herrmann3@amd.com> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20120529135442.GE29157@aftab.osrc.amd.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 06 6月, 2012 2 次提交
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由 Kamalesh Babulal 提交于
Commit 316ad248 ("sched/x86: Rewrite set_cpu_sibling_map()") broke the booted_cores accounting. The problem is that the booted_cores accounting needs all the sibling links set up. So restore the second loop and add a comment as to why its needed. On qemu booted with -smp sockets=1,cores=2,threads=2; Before: $ grep cores /proc/cpuinfo cpu cores : 2 cpu cores : 1 cpu cores : 4 cpu cores : 3 With the patch: $ grep cores /proc/cpuinfo cpu cores : 2 cpu cores : 2 cpu cores : 2 cpu cores : 2 Reported-by: NPrarit Bhargava <prarit@redhat.com> Reported-by: NBorislav Petkov <bp@amd64.org> Signed-off-by: NKamalesh Babulal <kamalesh@linux.vnet.ibm.com> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20120531073738.GH7511@linux.vnet.ibm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Joe Perches 提交于
Use a more current logging style: - Bare printks should have a KERN_<LEVEL> for consistency's sake - Add pr_fmt where appropriate - Neaten some macro definitions - Convert some Ok output to OK - Use "%s: ", __func__ in pr_fmt for summit - Convert some printks to pr_<level> Message output is not identical in all cases. Signed-off-by: NJoe Perches <joe@perches.com> Cc: levinsasha928@gmail.com Link: http://lkml.kernel.org/r/1337655007.24226.10.camel@joe2Laptop [ merged two similar patches, tidied up the changelog ] Signed-off-by: NIngo Molnar <mingo@kernel.org>
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- 05 6月, 2012 1 次提交
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由 Yong Zhang 提交于
ipi_call_lock/unlock() lock resp. unlock call_function.lock. This lock protects only the call_function data structure itself, but it's completely unrelated to cpu_online_mask. The mask to which the IPIs are sent is calculated before call_function.lock is taken in smp_call_function_many(), so the locking around set_cpu_online() is pointless and can be removed. [ tglx: Massaged changelog ] Signed-off-by: NYong Zhang <yong.zhang0@gmail.com> Cc: ralf@linux-mips.org Cc: sshtylyov@mvista.com Cc: david.daney@cavium.com Cc: nikunj@linux.vnet.ibm.com Cc: paulmck@linux.vnet.ibm.com Cc: axboe@kernel.dk Cc: peterz@infradead.org Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Link: http://lkml.kernel.org/r/1338275765-3217-7-git-send-email-yong.zhang0@gmail.comAcked-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Acked-by: NPeter Zijlstra <peterz@infradead.org> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 30 5月, 2012 1 次提交
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由 Peter Zijlstra 提交于
Commit commit 8e7fbcbc ("sched: Remove stale power aware scheduling remnants and dysfunctional knobs") made a boo-boo with removing the power aware scheduling muck from the x86 topology bits. We should unconditionally use the llc_shared mask for multi-core. Reported-and-tested-by: NMike Galbraith <efault@gmx.de> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Borislav Petkov <bp@amd64.org> Cc: Andreas Herrmann <andreas.herrmann3@amd.com> Link: http://lkml.kernel.org/n/tip-lsksc2kfyeveb13avh327p0d@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 17 5月, 2012 1 次提交
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由 Peter Zijlstra 提交于
It's been broken forever (i.e. it's not scheduling in a power aware fashion), as reported by Suresh and others sending patches, and nobody cares enough to fix it properly ... so remove it to make space free for something better. There's various problems with the code as it stands today, first and foremost the user interface which is bound to topology levels and has multiple values per level. This results in a state explosion which the administrator or distro needs to master and almost nobody does. Furthermore large configuration state spaces aren't good, it means the thing doesn't just work right because it's either under so many impossibe to meet constraints, or even if there's an achievable state workloads have to be aware of it precisely and can never meet it for dynamic workloads. So pushing this kind of decision to user-space was a bad idea even with a single knob - it's exponentially worse with knobs on every node of the topology. There is a proposal to replace the user interface with a single 3 state knob: sched_balance_policy := { performance, power, auto } where 'auto' would be the preferred default which looks at things like Battery/AC mode and possible cpufreq state or whatever the hw exposes to show us power use expectations - but there's been no progress on it in the past many months. Aside from that, the actual implementation of the various knobs is known to be broken. There have been sporadic attempts at fixing things but these always stop short of reaching a mergable state. Therefore this wholesale removal with the hopes of spurring people who care to come forward once again and work on a coherent replacement. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1326104915.2442.53.camel@twinsSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 14 5月, 2012 1 次提交
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由 Peter Zijlstra 提交于
Commit ad7687dd ("x86/numa: Check for nonsensical topologies on real hw as well") is broken in that the condition can trigger for valid setups but only changes the end result for invalid setups with no real means of discerning between those. Rewrite set_cpu_sibling_map() to make the code clearer and make sure to only warn when the check changes the end result. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-klcwahu3gx467uhfiqjyhdcs@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 09 5月, 2012 5 次提交
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由 Ingo Molnar 提交于
Instead of only checking nonsensical topologies on numa-emu, do it on real hardware as well, and print a warning. Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Tejun Heo <tj@kernel.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: x86@kernel.org Link: http://lkml.kernel.org/n/tip-re15l0jqjtpz709oxozt2zoh@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
When using numa=fake= you can get weird topologies where LLCs can span nodes and other such nonsense. Cure this by hard partitioning these masks on node boundaries. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Tejun Heo <tj@kernel.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: x86@kernel.org Link: http://lkml.kernel.org/n/tip-di5vwjm96q5vrb76opwuflwx@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Jarkko Sakkinen 提交于
Added header for trampoline code that can be used to supply input data to it. This makes interface between real mode code and kernel cleaner and simpler. Replaced two confusing pointers to level4 pgt in trampoline_64.S with a single pointer to the beginning of the page table. Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-21-git-send-email-jarkko.sakkinen@intel.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
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由 Jarkko Sakkinen 提交于
Replaced copying of real_mode_header with a pointer to beginning of RM memory. Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-19-git-send-email-jarkko.sakkinen@intel.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
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由 Jarkko Sakkinen 提交于
Migrated SMP trampoline code to the real mode blob. SMP trampoline code is not yet removed from .x86_trampoline because it is needed by the wakeup code. [ hpa: always enable compiling startup_32_smp in head_32.S... it is only a few instructions which go into .init on UP builds, and it makes the rest of the code less #ifdef ugly. ] Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-6-git-send-email-jarkko.sakkinen@intel.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
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- 26 4月, 2012 2 次提交
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由 Thomas Gleixner 提交于
Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: x86@kernel.org Link: http://lkml.kernel.org/r/20120420124557.246929343@linutronix.de
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由 Thomas Gleixner 提交于
Preparatory patch to use the generic idle thread allocation. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: x86@kernel.org Link: http://lkml.kernel.org/r/20120420124557.176604405@linutronix.de
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- 30 3月, 2012 1 次提交
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由 Boris Ostrovsky 提交于
Currently when a CPU is off-lined it enters either MWAIT-based idle or, if MWAIT is not desired or supported, HLT-based idle (which places the processor in C1 state). This patch allows processors without MWAIT support to stay in states deeper than C1. Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@amd.com> Signed-off-by: NLen Brown <len.brown@intel.com>
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- 27 3月, 2012 1 次提交
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由 Peter Zijlstra 提交于
We should not ever enable IRQs until we're fully set up. This opens up a window where interrupts can hit the cpu and interrupts can do wakeups, wakeups need state that isn't set-up yet, in particular this cpu isn't elegible to run tasks, so if any cpu-affine task that got created in CPU_UP_PREPARE manages to get a wakeup, its affinity mask will get broken and we'll run into lots of 'interesting' problems. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-yaezmlbriluh166tfkgni22m@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 14 3月, 2012 1 次提交
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由 Daniel J Blueman 提交于
Move APIC ID validity check into platform APIC code, so it can be overridden when needed. For NumaChip systems, always trust MADT, as it's constructed with high APIC IDs. Behaviour verifies on standard x86 systems and on NumaChip systems with this, and compile-tested with allyesconfig. Signed-off-by: NDaniel J Blueman <daniel@numascale-asia.com> Reviewed-by: NSteffen Persvold <sp@numascale.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1331709454-27966-1-git-send-email-daniel@numascale-asia.comSigned-off-by: NIngo Molnar <mingo@elte.hu>
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- 13 3月, 2012 1 次提交
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由 Peter Zijlstra 提交于
Stepan found: CPU0 CPUn _cpu_up() __cpu_up() boostrap() notify_cpu_starting() set_cpu_online() while (!cpu_active()) cpu_relax() <PREEMPT-out> smp_call_function(.wait=1) /* we find cpu_online() is true */ arch_send_call_function_ipi_mask() /* wait-forever-more */ <PREEMPT-in> local_irq_enable() cpu_notify(CPU_ONLINE) sched_cpu_active() set_cpu_active() Now the purpose of cpu_active is mostly with bringing down a cpu, where we mark it !active to avoid the load-balancer from moving tasks to it while we tear down the cpu. This is required because we only update the sched_domain tree after we brought the cpu-down. And this is needed so that some tasks can still run while we bring it down, we just don't want new tasks to appear. On cpu-up however the sched_domain tree doesn't yet include the new cpu, so its invisible to the load-balancer, regardless of the active state. So instead of setting the active state after we boot the new cpu (and consequently having to wait for it before enabling interrupts) set the cpu active before we set it online and avoid the whole mess. Reported-by: NStepan Moskovchenko <stepanm@codeaurora.org> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: NThomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1323965362.18942.71.camel@twinsSigned-off-by: NIngo Molnar <mingo@elte.hu>
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- 05 3月, 2012 1 次提交
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由 Igor Mammedov 提交于
When kvm guest uses kvmclock, it may hang on vcpu hot-plug. This is caused by an overflow in pvclock_get_nsec_offset, u64 delta = tsc - shadow->tsc_timestamp; which in turn is caused by an undefined values from percpu hv_clock that hasn't been initialized yet. Uninitialized clock on being booted cpu is accessed from start_secondary -> smp_callin -> smp_store_cpu_info -> identify_secondary_cpu -> mtrr_ap_init -> mtrr_restore -> stop_machine_from_inactive_cpu -> queue_stop_cpus_work ... -> sched_clock -> kvm_clock_read which is well before x86_cpuinit.setup_percpu_clockev call in start_secondary, where percpu clock is initialized. This patch introduces a hook that allows to setup/initialize per_cpu clock early and avoid overflow due to reading - undefined values - old values if cpu was offlined and then onlined again Another possible early user of this clock source is ftrace that accesses it to get timestamps for ring buffer entries. So if mtrr_ap_init is moved from identify_secondary_cpu to past x86_cpuinit.setup_percpu_clockev in start_secondary, ftrace may cause the same overflow/hang on cpu hot-plug anyway. More complete description of the problem: https://lkml.org/lkml/2012/2/2/101 Credits to Marcelo Tosatti <mtosatti@redhat.com> for hook idea. Acked-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NIgor Mammedov <imammedo@redhat.com> Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com> Signed-off-by: NAvi Kivity <avi@redhat.com>
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- 23 2月, 2012 1 次提交
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由 Luck, Tony 提交于
Printing the "start_ip" for every secondary cpu is very noisy on a large system - and doesn't add any value. Drop this message. Console log before: Booting Node 0, Processors #1 smpboot cpu 1: start_ip = 96000 #2 smpboot cpu 2: start_ip = 96000 #3 smpboot cpu 3: start_ip = 96000 #4 smpboot cpu 4: start_ip = 96000 ... #31 smpboot cpu 31: start_ip = 96000 Brought up 32 CPUs Console log after: Booting Node 0, Processors #1 #2 #3 #4 #5 #6 #7 Ok. Booting Node 1, Processors #8 #9 #10 #11 #12 #13 #14 #15 Ok. Booting Node 0, Processors #16 #17 #18 #19 #20 #21 #22 #23 Ok. Booting Node 1, Processors #24 #25 #26 #27 #28 #29 #30 #31 Brought up 32 CPUs Acked-by: NBorislav Petkov <bp@amd64.org> Signed-off-by: NTony Luck <tony.luck@intel.com> Link: http://lkml.kernel.org/r/4f452eb42507460426@agluck-desktop.sc.intel.comSigned-off-by: NH. Peter Anvin <hpa@zytor.com>
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- 13 2月, 2012 1 次提交
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由 Yinghai Lu 提交于
Found out that show_msr=<cpus> is broken, when I asked a user to use it to capture debug info about broken MTRR's whose MTRR settings are probably different between CPUs. Only the first CPUs MSRs are printed, but that is not enough to track down the suspected bug. For years we called print_cpu_msr from print_cpu_info(), but this commit: | commit 2eaad1fd | Author: Mike Travis <travis@sgi.com> | Date: Thu Dec 10 17:19:36 2009 -0800 | | x86: Limit the number of processor bootup messages removed the print_cpu_info() call from all APs. Put it back - it will only print MSRs when the user specifically requests them via show_msr=<cpus>. Signed-off-by: NYinghai Lu <yinghai@kernel.org> Cc: Mike Travis <travis@sgi.com> Link: http://lkml.kernel.org/r/1329069237-11483-1-git-send-email-yinghai@kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>
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- 24 12月, 2011 1 次提交
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由 Suresh Siddha 提交于
If the x2apic mode is disabled for reasons like interrupt-remapping not available etc, then we need to skip the logical cpu bringup of apic-id's >= 255. Otherwise as the platform is in xapic mode, init/startup IPI's will consider only the low 8-bits and there is a possibility of re-sending init/startup IPI's to the logical cpu that is already online. This will avoid potential reboots/unpredictable behavior etc. Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/20111222014632.702932458@sbsiddha-desk.sc.intel.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
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- 06 12月, 2011 1 次提交
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由 Jack Steiner 提交于
Reduce the startup time for slave cpus. Adds hooks for an arch-specific function for clock calibration. These hooks are used on x86. If a newly started cpu has the same phys_proc_id as a core already active, uses the TSC for the delay loop and has a CONSTANT_TSC, use the already-calculated value of loops_per_jiffy. This patch reduces the time required to start slave cpus on a 4096 cpu system from: 465 sec OLD 62 sec NEW This reduces boot time on a 4096p system by almost 7 minutes. Nice... Signed-off-by: NJack Steiner <steiner@sgi.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: John Stultz <john.stultz@linaro.org> [fix CONFIG_SMP=n build] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 05 12月, 2011 1 次提交
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由 Don Zickus 提交于
The previous patch modified the stop cpus path to use NMI instead of IRQ as the way to communicate to the other cpus to shutdown. There were some concerns that various machines may have problems with using an NMI IPI. This patch creates a selftest to check if NMI is working at boot. The idea is to help catch any issues before the machine panics and we learn the hard way. Loosely based on the locking-selftest.c file, this separate file runs a couple of simple tests and reports the results. The output looks like: ... Brought up 4 CPUs ---------------- | NMI testsuite: -------------------- remote IPI: ok | local IPI: ok | -------------------- Good, all 2 testcases passed! | --------------------------------- Total of 4 processors activated (21330.61 BogoMIPS). ... Signed-off-by: NDon Zickus <dzickus@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robert Richter <robert.richter@amd.com> Cc: seiji.aguchi@hds.com Cc: vgoyal@redhat.com Cc: mjg@redhat.com Cc: tony.luck@intel.com Cc: gong.chen@intel.com Cc: satoru.moriya@hds.com Cc: avi@redhat.com Cc: Andi Kleen <andi@firstfloor.org> Link: http://lkml.kernel.org/r/1318533267-18880-3-git-send-email-dzickus@redhat.comSigned-off-by: NIngo Molnar <mingo@elte.hu>
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- 21 7月, 2011 1 次提交
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由 Greg Dietsche 提交于
This array is read-only. Make it explicit by marking as const. Signed-off-by: NGreg Dietsche <Gregory.Dietsche@cuw.edu> Link: http://lkml.kernel.org/r/1309482653-23648-1-git-send-email-Gregory.Dietsche@cuw.eduSigned-off-by: NIngo Molnar <mingo@elte.hu>
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- 08 6月, 2011 1 次提交
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由 Thomas Gleixner 提交于
After a newly plugged CPU sets the cpu_online bit it enables interrupts and goes idle. The cpu which brought up the new cpu waits for the cpu_online bit and when it observes it, it sets the cpu_active bit for this cpu. The cpu_active bit is the relevant one for the scheduler to consider the cpu as a viable target. With forced threaded interrupt handlers which imply forced threaded softirqs we observed the following race: cpu 0 cpu 1 bringup(cpu1); set_cpu_online(smp_processor_id(), true); local_irq_enable(); while (!cpu_online(cpu1)); timer_interrupt() -> wake_up(softirq_thread_cpu1); -> enqueue_on(softirq_thread_cpu1, cpu0); ^^^^ cpu_notify(CPU_ONLINE, cpu1); -> sched_cpu_active(cpu1) -> set_cpu_active((cpu1, true); When an interrupt happens before the cpu_active bit is set by the cpu which brought up the newly onlined cpu, then the scheduler refuses to enqueue the woken thread which is bound to that newly onlined cpu on that newly onlined cpu due to the not yet set cpu_active bit and selects a fallback runqueue. Not really an expected and desirable behaviour. So far this has only been observed with forced hard/softirq threading, but in theory this could happen without forced threaded hard/softirqs as well. It's probably unobservable as it would take a massive interrupt storm on the newly onlined cpu which causes the softirq loop to wake up the softirq thread and an even longer delay of the cpu which waits for the cpu_online bit. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Reviewed-by: NPeter Zijlstra <peterz@infradead.org> Cc: stable@kernel.org # 2.6.39
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- 30 5月, 2011 1 次提交
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由 Avi Kivity 提交于
A logic error in mwait_play_dead() causes the kernel to use mwait even on cpus which don't support it, such as KVM virtual cpus. Introduced by: 349c004e: x86: A fast way to check capabilities of the current cpu Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=36222Reported-by: NTörök Edwin <edwintorok@gmail.com> Signed-off-by: NAvi Kivity <avi@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/1306758237-9327-1-git-send-email-avi@redhat.comSigned-off-by: NIngo Molnar <mingo@elte.hu>
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- 29 5月, 2011 1 次提交
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由 Len Brown 提交于
The workaround for AMD erratum 400 uses the term "c1e" falsely suggesting: 1. Intel C1E is somehow involved 2. All AMD processors with C1E are involved Use the string "amd_c1e" instead of simply "c1e" to clarify that this workaround is specific to AMD's version of C1E. Use the string "e400" to clarify that the workaround is specific to AMD processors with Erratum 400. This patch is text-substitution only, with no functional change. cc: x86@kernel.org Acked-by: NBorislav Petkov <borislav.petkov@amd.com> Signed-off-by: NLen Brown <len.brown@intel.com>
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- 21 4月, 2011 1 次提交
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由 David Rientjes 提交于
Andreas Herrmann reported that 7d6b4670 ("x86, NUMA: Fix fakenuma boot failure") causes certain physical NUMA topologies (for example AMD Magny-Cours) to move sibling cpus to a single node when in reality they are in separate domains. This may result in some nodes being completely void of cpus, which doesn't accurately represent the correct topology. The system will boot, but will have suboptimal NUMA performance. This commit was intended as a fix for NUMA emulation, but should not cause a regression for real NUMA machines as a side effect. ( There will be a separate fix for the numa-debug code, which will not affect physical topologies. ) Reported-by: NAndreas Herrmann <herrmann.der.user@googlemail.com> Signed-off-by: NDavid Rientjes <rientjes@google.com> Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.00.1104201918110.12634@chino.kir.corp.google.comSigned-off-by: NIngo Molnar <mingo@elte.hu>
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- 16 4月, 2011 1 次提交
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由 KOSAKI Motohiro 提交于
Currently, numa=fake boot parameter is broken. If it's used, kernel may panic due to devide by zero error depending on CPU configuration Call Trace: [<ffffffff8104ad4c>] find_busiest_group+0x38c/0xd30 [<ffffffff81086aff>] ? local_clock+0x6f/0x80 [<ffffffff81050533>] load_balance+0xa3/0x600 [<ffffffff81050f53>] idle_balance+0xf3/0x180 [<ffffffff81550092>] schedule+0x722/0x7d0 [<ffffffff81550538>] ? wait_for_common+0x128/0x190 [<ffffffff81550a65>] schedule_timeout+0x265/0x320 [<ffffffff81095815>] ? lock_release_holdtime+0x35/0x1a0 [<ffffffff81550538>] ? wait_for_common+0x128/0x190 [<ffffffff8109bb6c>] ? __lock_release+0x9c/0x1d0 [<ffffffff815534e0>] ? _raw_spin_unlock_irq+0x30/0x40 [<ffffffff815534e0>] ? _raw_spin_unlock_irq+0x30/0x40 [<ffffffff81550540>] wait_for_common+0x130/0x190 [<ffffffff81051920>] ? try_to_wake_up+0x510/0x510 [<ffffffff8155067d>] wait_for_completion+0x1d/0x20 [<ffffffff8107f36c>] kthread_create_on_node+0xac/0x150 [<ffffffff81077bb0>] ? process_scheduled_works+0x40/0x40 [<ffffffff8155045f>] ? wait_for_common+0x4f/0x190 [<ffffffff8107a283>] __alloc_workqueue_key+0x1a3/0x590 [<ffffffff81e0cce2>] cpuset_init_smp+0x6b/0x7b [<ffffffff81df3d07>] kernel_init+0xc3/0x182 [<ffffffff8155d5e4>] kernel_thread_helper+0x4/0x10 [<ffffffff81553cd4>] ? retint_restore_args+0x13/0x13 [<ffffffff81df3c44>] ? start_kernel+0x400/0x400 [<ffffffff8155d5e0>] ? gs_change+0x13/0x13 The divede by zero is caused by the following line, group->cpu_power==0: kernel/sched_fair.c::update_sg_lb_stats() /* Adjust by relative CPU power of the group */ sgs->avg_load = (sgs->group_load * SCHED_LOAD_SCALE) / group->cpu_power; This regression was caused by commit e23bba60 ("x86-64, NUMA: Unify emulated distance mapping") because it changes cpu -> node mapping in the process of dropping fake_physnodes(). old) all cpus are assinged node 0 now) cpus are assigned round robin (the logic is implemented by numa_init_array()) Note: The change in behavior only happens if the system doesn't have neither ACPI SRAT table nor AMD northbridge NUMA information. Round robin assignment doesn't work because init_numa_sched_groups_power() assumes all logical cpus in the same physical cpu share the same node (then it only accounts for group_first_cpu()), and the simple round robin breaks the above assumption. Thus, this patch implements a reassignment of node-ids if buggy firmware or numa emulation makes wrong cpu node map. Tt enforce all logical cpus in the same physical cpu share the same node. Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: NTejun Heo <tj@kernel.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Cc: Shaohui Zheng <shaohui.zheng@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/r/20110415203928.1303.A69D9226@jp.fujitsu.comSigned-off-by: NIngo Molnar <mingo@elte.hu>
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- 29 3月, 2011 1 次提交
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由 Christoph Lameter 提交于
Add this_cpu_has() which determines if the current cpu has a certain ability using a segment prefix and a bit test operation. For that we need to add bit operations to x86s percpu.h. Many uses of cpu_has use a pointer passed to a function to determine the current flags. That is no longer necessary after this patch. However, this patch only converts the straightforward cases where cpu_has is used with this_cpu_ptr. The rest is work for later. -tj: Rolled up patch to add x86_ prefix and use percpu_read() instead of percpu_read_stable(). Signed-off-by: NChristoph Lameter <cl@linux.com> Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NTejun Heo <tj@kernel.org>
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- 23 2月, 2011 1 次提交
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由 Henrik Kretzschmar 提交于
Currently arch_disable_smp_support() on x86 disables only the support for the IOAPIC and is also compiled in if SMP-support is not. Therefore this function is renamed to disable_ioapic_support(), which meets its purpose and is only compiled in the kernel when IOAPIC support is also. A new arch_disable_smp_support() is created in smpboot.c, which calls disable_ioapic_support() and gets only compiled in the kernel when SMP support is also. Signed-off-by: NHenrik Kretzschmar <henne@nachtwindheim.de> LKML-Reference: <1298385487-4708-3-git-send-email-henne@nachtwindheim.de> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 18 2月, 2011 1 次提交
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由 H. Peter Anvin 提交于
Common infrastructure for low memory trampolines. This code installs the trampolines permanently in low memory very early. It also permits multiple pieces of code to be used for this purpose. This code also introduces a standard infrastructure for computing symbol addresses in the trampoline code. The only change to the actual SMP trampolines themselves is that the 64-bit trampoline has been made reusable -- the previous version would overwrite the code with a status variable; this moves the status variable to a separate location. Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com> LKML-Reference: <4D5DFBE4.7090104@intel.com> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Matthieu Castet <castet.matthieu@free.fr> Cc: Stephen Rothwell <sfr@canb.auug.org.au>
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