1. 24 9月, 2014 1 次提交
    • W
      sched: Fix unreleased llc_shared_mask bit during CPU hotplug · 03bd4e1f
      Wanpeng Li 提交于
      The following bug can be triggered by hot adding and removing a large number of
      xen domain0's vcpus repeatedly:
      
      	BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 IP: [..] find_busiest_group
      	PGD 5a9d5067 PUD 13067 PMD 0
      	Oops: 0000 [#3] SMP
      	[...]
      	Call Trace:
      	load_balance
      	? _raw_spin_unlock_irqrestore
      	idle_balance
      	__schedule
      	schedule
      	schedule_timeout
      	? lock_timer_base
      	schedule_timeout_uninterruptible
      	msleep
      	lock_device_hotplug_sysfs
      	online_store
      	dev_attr_store
      	sysfs_write_file
      	vfs_write
      	SyS_write
      	system_call_fastpath
      
      Last level cache shared mask is built during CPU up and the
      build_sched_domain() routine takes advantage of it to setup
      the sched domain CPU topology.
      
      However, llc_shared_mask is not released during CPU disable,
      which leads to an invalid sched domainCPU topology.
      
      This patch fix it by releasing the llc_shared_mask correctly
      during CPU disable.
      
      Yasuaki also reported that this can happen on real hardware:
      
        https://lkml.org/lkml/2014/7/22/1018
      
      His case is here:
      
      	==
      	Here is an example on my system.
      	My system has 4 sockets and each socket has 15 cores and HT is
      	enabled. In this case, each core of sockes is numbered as
      	follows:
      
      		 | CPU#
      	Socket#0 | 0-14 , 60-74
      	Socket#1 | 15-29, 75-89
      	Socket#2 | 30-44, 90-104
      	Socket#3 | 45-59, 105-119
      
      	Then llc_shared_mask of CPU#30 has 0x3fff80000001fffc0000000.
      
      	It means that last level cache of Socket#2 is shared with
      	CPU#30-44 and 90-104.
      
      	When hot-removing socket#2 and #3, each core of sockets is
      	numbered as follows:
      
      		 | CPU#
      	Socket#0 | 0-14 , 60-74
      	Socket#1 | 15-29, 75-89
      
      	But llc_shared_mask is not cleared. So llc_shared_mask of CPU#30
      	remains having 0x3fff80000001fffc0000000.
      
      	After that, when hot-adding socket#2 and #3, each core of
      	sockets is numbered as follows:
      
      		 | CPU#
      	Socket#0 | 0-14 , 60-74
      	Socket#1 | 15-29, 75-89
      	Socket#2 | 30-59
      	Socket#3 | 90-119
      
      	Then llc_shared_mask of CPU#30 becomes
      	0x3fff8000fffffffc0000000. It means that last level cache of
      	Socket#2 is shared with CPU#30-59 and 90-104. So the mask has
      	the wrong value.
      Signed-off-by: NWanpeng Li <wanpeng.li@linux.intel.com>
      Tested-by: NLinn Crosetto <linn@hp.com>
      Reviewed-by: NBorislav Petkov <bp@suse.de>
      Reviewed-by: NToshi Kani <toshi.kani@hp.com>
      Reviewed-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Cc: <stable@vger.kernel.org>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Steven Rostedt <srostedt@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1411547885-48165-1-git-send-email-wanpeng.li@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      03bd4e1f
  2. 31 7月, 2014 2 次提交
  3. 09 6月, 2014 1 次提交
  4. 05 6月, 2014 3 次提交
    • I
      x86/smpboot: Initialize secondary CPU only if master CPU will wait for it · 3e1a878b
      Igor Mammedov 提交于
      Hang is observed on virtual machines during CPU hotplug,
      especially in big guests with many CPUs. (It reproducible
      more often if host is over-committed).
      
      It happens because master CPU gives up waiting on
      secondary CPU and allows it to run wild. As result
      AP causes locking or crashing system. For example
      as described here:
      
         https://lkml.org/lkml/2014/3/6/257
      
      If master CPU have sent STARTUP IPI successfully,
      and AP signalled to master CPU that it's ready
      to start initialization, make master CPU wait
      indefinitely till AP is onlined.
      To ensure that AP won't ever run wild, make it
      wait at early startup till master CPU confirms its
      intention to wait for AP. If AP doesn't respond in 10
      seconds, the master CPU will timeout and cancel
      AP onlining.
      Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
      Acked-by: NToshi Kani <toshi.kani@hp.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/1401975765-22328-4-git-send-email-imammedo@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      3e1a878b
    • I
      x86/smpboot: Log error on secondary CPU wakeup failure at ERR level · feef1e8e
      Igor Mammedov 提交于
      If system is running without debug level logging,
      it will not log error if do_boot_cpu() failed to
      wakeup AP. It may lead to silent AP bringup
      failures at boot time.
      Change message level to KERN_ERR to make error
      visible to user as it's done on other architectures.
      Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
      Acked-by: NToshi Kani <toshi.kani@hp.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/1401975765-22328-3-git-send-email-imammedo@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      feef1e8e
    • I
      x86: Fix list/memory corruption on CPU hotplug · 89f898c1
      Igor Mammedov 提交于
      currently if AP wake up is failed, master CPU marks AP as not
      present in do_boot_cpu() by calling set_cpu_present(cpu, false).
      That leads to following list corruption on the next physical CPU
      hotplug:
      
      [  418.107336] WARNING: CPU: 1 PID: 45 at lib/list_debug.c:33 __list_add+0xbe/0xd0()
      [  418.115268] list_add corruption. prev->next should be next (ffff88003dc57600), but was ffff88003e20c3a0. (prev=ffff88003e20c3a0).
      [  418.123693] Modules linked in: nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_MASQUERADE ip6t_REJECT ipt_REJECT cfg80211 xt_conntrack rfkill ee
      [  418.138979] CPU: 1 PID: 45 Comm: kworker/u10:1 Not tainted 3.14.0-rc6+ #387
      [  418.149989] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2007
      [  418.165750] Workqueue: kacpi_hotplug acpi_hotplug_work_fn
      [  418.166433]  0000000000000021 ffff880038ca7988 ffffffff8159b22d 0000000000000021
      [  418.176460]  ffff880038ca79d8 ffff880038ca79c8 ffffffff8106942c ffff880038ca79e8
      [  418.177453]  ffff88003e20c3a0 ffff88003dc57600 ffff88003e20c3a0 00000000ffffffea
      [  418.178445] Call Trace:
      [  418.185811]  [<ffffffff8159b22d>] dump_stack+0x49/0x5c
      [  418.186440]  [<ffffffff8106942c>] warn_slowpath_common+0x8c/0xc0
      [  418.187192]  [<ffffffff81069516>] warn_slowpath_fmt+0x46/0x50
      [  418.191231]  [<ffffffff8136ef51>] ? acpi_ns_get_node+0xb7/0xc7
      [  418.193889]  [<ffffffff812f796e>] __list_add+0xbe/0xd0
      [  418.196649]  [<ffffffff812e2aa9>] kobject_add_internal+0x79/0x200
      [  418.208610]  [<ffffffff812e2e18>] kobject_add_varg+0x38/0x60
      [  418.213831]  [<ffffffff812e2ef4>] kobject_add+0x44/0x70
      [  418.229961]  [<ffffffff813e2c60>] device_add+0xd0/0x550
      [  418.234991]  [<ffffffff813f0e95>] ? pm_runtime_init+0xe5/0xf0
      [  418.250226]  [<ffffffff813e32be>] device_register+0x1e/0x30
      [  418.255296]  [<ffffffff813e82a3>] register_cpu+0xe3/0x130
      [  418.266539]  [<ffffffff81592be5>] arch_register_cpu+0x65/0x150
      [  418.285845]  [<ffffffff81355c0d>] acpi_processor_hotadd_init+0x5a/0x9b
      ...
      Which is caused by the fact that generic_processor_info() allocates
      logical CPU id by calling:
      
       cpu = cpumask_next_zero(-1, cpu_present_mask);
      
      which returns id of previously failed to wake up CPU, since its
      bit is cleared by do_boot_cpu() and as result register_cpu()
      tries to register another CPU with the same id as already
      present but failed to be onlined CPU.
      
      Taking in account that AP will not do anything if master CPU
      failed to wake it up, there is no reason to mark that AP as not
      present and break next cpu hotplug attempts. As a side effect of
      not marking AP as not present, user would be allowed to online
      it again later.
      
      Also fix memory corruption in acpi_unmap_lsapic()
      
      if during CPU hotplug master CPU failed to wake up AP
      it set percpu x86_cpu_to_apicid to BAD_APICID=0xFFFF for AP.
      
      However following attempt to unplug that CPU will lead to
      out of bound write access to __apicid_to_node[] which is
      32768 items long on x86_64 kernel.
      
      So with above fix of cpu_present_mask make sure that a present
      CPU has a valid APIC ID by not setting x86_cpu_to_apicid
      to BAD_APICID in do_boot_cpu() on failure and allow
      acpi_processor_remove()->acpi_unmap_lsapic() cleanly remove CPU.
      Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
      Acked-by: NToshi Kani <toshi.kani@hp.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/1401975765-22328-2-git-send-email-imammedo@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      89f898c1
  5. 05 5月, 2014 1 次提交
  6. 01 5月, 2014 1 次提交
    • H
      x86-64, espfix: Don't leak bits 31:16 of %esp returning to 16-bit stack · 3891a04a
      H. Peter Anvin 提交于
      The IRET instruction, when returning to a 16-bit segment, only
      restores the bottom 16 bits of the user space stack pointer.  This
      causes some 16-bit software to break, but it also leaks kernel state
      to user space.  We have a software workaround for that ("espfix") for
      the 32-bit kernel, but it relies on a nonzero stack segment base which
      is not available in 64-bit mode.
      
      In checkin:
      
          b3b42ac2 x86-64, modify_ldt: Ban 16-bit segments on 64-bit kernels
      
      we "solved" this by forbidding 16-bit segments on 64-bit kernels, with
      the logic that 16-bit support is crippled on 64-bit kernels anyway (no
      V86 support), but it turns out that people are doing stuff like
      running old Win16 binaries under Wine and expect it to work.
      
      This works around this by creating percpu "ministacks", each of which
      is mapped 2^16 times 64K apart.  When we detect that the return SS is
      on the LDT, we copy the IRET frame to the ministack and use the
      relevant alias to return to userspace.  The ministacks are mapped
      readonly, so if IRET faults we promote #GP to #DF which is an IST
      vector and thus has its own stack; we then do the fixup in the #DF
      handler.
      
      (Making #GP an IST exception would make the msr_safe functions unsafe
      in NMI/MC context, and quite possibly have other effects.)
      
      Special thanks to:
      
      - Andy Lutomirski, for the suggestion of using very small stack slots
        and copy (as opposed to map) the IRET frame there, and for the
        suggestion to mark them readonly and let the fault promote to #DF.
      - Konrad Wilk for paravirt fixup and testing.
      - Borislav Petkov for testing help and useful comments.
      Reported-by: NBrian Gerst <brgerst@gmail.com>
      Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      Link: http://lkml.kernel.org/r/1398816946-3351-1-git-send-email-hpa@linux.intel.com
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Andrew Lutomriski <amluto@gmail.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Dirk Hohndel <dirk@hohndel.org>
      Cc: Arjan van de Ven <arjan.van.de.ven@intel.com>
      Cc: comex <comexk@gmail.com>
      Cc: Alexander van Heukelum <heukelum@fastmail.fm>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: <stable@vger.kernel.org> # consider after upstream merge
      3891a04a
  7. 11 3月, 2014 1 次提交
  8. 07 3月, 2014 1 次提交
    • S
      x86: Keep thread_info on thread stack in x86_32 · 198d208d
      Steven Rostedt 提交于
      x86_64 uses a per_cpu variable kernel_stack to always point to
      the thread stack of current. This is where the thread_info is stored
      and is accessed from this location even when the irq or exception stack
      is in use. This removes the complexity of having to maintain the
      thread info on the stack when interrupts are running and having to
      copy the preempt_count and other fields to the interrupt stack.
      
      x86_32 uses the old method of copying the thread_info from the thread
      stack to the exception stack just before executing the exception.
      
      Having the two different requires #ifdefs and also the x86_32 way
      is a bit of a pain to maintain. By converting x86_32 to the same
      method of x86_64, we can remove #ifdefs, clean up the x86_32 code
      a little, and remove the overhead of the copy.
      
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Brian Gerst <brgerst@gmail.com>
      Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      Link: http://lkml.kernel.org/r/20110806012354.263834829@goodmis.org
      Link: http://lkml.kernel.org/r/20140206144321.852942014@goodmis.orgSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      198d208d
  9. 28 2月, 2014 1 次提交
  10. 09 2月, 2014 1 次提交
  11. 16 1月, 2014 1 次提交
    • P
      x86: Add check for number of available vectors before CPU down · da6139e4
      Prarit Bhargava 提交于
      Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=64791
      
      When a cpu is downed on a system, the irqs on the cpu are assigned to
      other cpus.  It is possible, however, that when a cpu is downed there
      aren't enough free vectors on the remaining cpus to account for the
      vectors from the cpu that is being downed.
      
      This results in an interesting "overflow" condition where irqs are
      "assigned" to a CPU but are not handled.
      
      For example, when downing cpus on a 1-64 logical processor system:
      
      <snip>
      [  232.021745] smpboot: CPU 61 is now offline
      [  238.480275] smpboot: CPU 62 is now offline
      [  245.991080] ------------[ cut here ]------------
      [  245.996270] WARNING: CPU: 0 PID: 0 at net/sched/sch_generic.c:264 dev_watchdog+0x246/0x250()
      [  246.005688] NETDEV WATCHDOG: p786p1 (ixgbe): transmit queue 0 timed out
      [  246.013070] Modules linked in: lockd sunrpc iTCO_wdt iTCO_vendor_support sb_edac ixgbe microcode e1000e pcspkr joydev edac_core lpc_ich ioatdma ptp mdio mfd_core i2c_i801 dca pps_core i2c_core wmi acpi_cpufreq isci libsas scsi_transport_sas
      [  246.037633] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.12.0+ #14
      [  246.044451] Hardware name: Intel Corporation S4600LH ........../SVRBD-ROW_T, BIOS SE5C600.86B.01.08.0003.022620131521 02/26/2013
      [  246.057371]  0000000000000009 ffff88081fa03d40 ffffffff8164fbf6 ffff88081fa0ee48
      [  246.065728]  ffff88081fa03d90 ffff88081fa03d80 ffffffff81054ecc ffff88081fa13040
      [  246.074073]  0000000000000000 ffff88200cce0000 0000000000000040 0000000000000000
      [  246.082430] Call Trace:
      [  246.085174]  <IRQ>  [<ffffffff8164fbf6>] dump_stack+0x46/0x58
      [  246.091633]  [<ffffffff81054ecc>] warn_slowpath_common+0x8c/0xc0
      [  246.098352]  [<ffffffff81054fb6>] warn_slowpath_fmt+0x46/0x50
      [  246.104786]  [<ffffffff815710d6>] dev_watchdog+0x246/0x250
      [  246.110923]  [<ffffffff81570e90>] ? dev_deactivate_queue.constprop.31+0x80/0x80
      [  246.119097]  [<ffffffff8106092a>] call_timer_fn+0x3a/0x110
      [  246.125224]  [<ffffffff8106280f>] ? update_process_times+0x6f/0x80
      [  246.132137]  [<ffffffff81570e90>] ? dev_deactivate_queue.constprop.31+0x80/0x80
      [  246.140308]  [<ffffffff81061db0>] run_timer_softirq+0x1f0/0x2a0
      [  246.146933]  [<ffffffff81059a80>] __do_softirq+0xe0/0x220
      [  246.152976]  [<ffffffff8165fedc>] call_softirq+0x1c/0x30
      [  246.158920]  [<ffffffff810045f5>] do_softirq+0x55/0x90
      [  246.164670]  [<ffffffff81059d35>] irq_exit+0xa5/0xb0
      [  246.170227]  [<ffffffff8166062a>] smp_apic_timer_interrupt+0x4a/0x60
      [  246.177324]  [<ffffffff8165f40a>] apic_timer_interrupt+0x6a/0x70
      [  246.184041]  <EOI>  [<ffffffff81505a1b>] ? cpuidle_enter_state+0x5b/0xe0
      [  246.191559]  [<ffffffff81505a17>] ? cpuidle_enter_state+0x57/0xe0
      [  246.198374]  [<ffffffff81505b5d>] cpuidle_idle_call+0xbd/0x200
      [  246.204900]  [<ffffffff8100b7ae>] arch_cpu_idle+0xe/0x30
      [  246.210846]  [<ffffffff810a47b0>] cpu_startup_entry+0xd0/0x250
      [  246.217371]  [<ffffffff81646b47>] rest_init+0x77/0x80
      [  246.223028]  [<ffffffff81d09e8e>] start_kernel+0x3ee/0x3fb
      [  246.229165]  [<ffffffff81d0989f>] ? repair_env_string+0x5e/0x5e
      [  246.235787]  [<ffffffff81d095a5>] x86_64_start_reservations+0x2a/0x2c
      [  246.242990]  [<ffffffff81d0969f>] x86_64_start_kernel+0xf8/0xfc
      [  246.249610] ---[ end trace fb74fdef54d79039 ]---
      [  246.254807] ixgbe 0000:c2:00.0 p786p1: initiating reset due to tx timeout
      [  246.262489] ixgbe 0000:c2:00.0 p786p1: Reset adapter
      Last login: Mon Nov 11 08:35:14 from 10.18.17.119
      [root@(none) ~]# [  246.792676] ixgbe 0000:c2:00.0 p786p1: detected SFP+: 5
      [  249.231598] ixgbe 0000:c2:00.0 p786p1: NIC Link is Up 10 Gbps, Flow Control: RX/TX
      [  246.792676] ixgbe 0000:c2:00.0 p786p1: detected SFP+: 5
      [  249.231598] ixgbe 0000:c2:00.0 p786p1: NIC Link is Up 10 Gbps, Flow Control: RX/TX
      
      (last lines keep repeating.  ixgbe driver is dead until module reload.)
      
      If the downed cpu has more vectors than are free on the remaining cpus on the
      system, it is possible that some vectors are "orphaned" even though they are
      assigned to a cpu.  In this case, since the ixgbe driver had a watchdog, the
      watchdog fired and notified that something was wrong.
      
      This patch adds a function, check_vectors(), to compare the number of vectors
      on the CPU going down and compares it to the number of vectors available on
      the system.  If there aren't enough vectors for the CPU to go down, an
      error is returned and propogated back to userspace.
      
      v2: Do not need to look at percpu irqs
      v3: Need to check affinity to prevent counting of MSIs in IOAPIC Lowest
          Priority Mode
      v4: Additional changes suggested by Gong Chen.
      v5/v6/v7/v8: Updated comment text
      Signed-off-by: NPrarit Bhargava <prarit@redhat.com>
      Link: http://lkml.kernel.org/r/1389613861-3853-1-git-send-email-prarit@redhat.comReviewed-by: NGong Chen <gong.chen@linux.intel.com>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: Michel Lespinasse <walken@google.com>
      Cc: Seiji Aguchi <seiji.aguchi@hds.com>
      Cc: Yang Zhang <yang.z.zhang@Intel.com>
      Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
      Cc: Janet Morgan <janet.morgan@intel.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Ruiv Wang <ruiv.wang@gmail.com>
      Cc: Gong Chen <gong.chen@linux.intel.com>
      Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      Cc: <stable@vger.kernel.org>
      da6139e4
  12. 20 12月, 2013 1 次提交
  13. 01 10月, 2013 1 次提交
    • B
      x86/boot: Further compress CPUs bootup message · a17bce4d
      Borislav Petkov 提交于
      Turn it into (for example):
      
      [    0.073380] x86: Booting SMP configuration:
      [    0.074005] .... node   #0, CPUs:          #1   #2   #3   #4   #5   #6   #7
      [    0.603005] .... node   #1, CPUs:     #8   #9  #10  #11  #12  #13  #14  #15
      [    1.200005] .... node   #2, CPUs:    #16  #17  #18  #19  #20  #21  #22  #23
      [    1.796005] .... node   #3, CPUs:    #24  #25  #26  #27  #28  #29  #30  #31
      [    2.393005] .... node   #4, CPUs:    #32  #33  #34  #35  #36  #37  #38  #39
      [    2.996005] .... node   #5, CPUs:    #40  #41  #42  #43  #44  #45  #46  #47
      [    3.600005] .... node   #6, CPUs:    #48  #49  #50  #51  #52  #53  #54  #55
      [    4.202005] .... node   #7, CPUs:    #56  #57  #58  #59  #60  #61  #62  #63
      [    4.811005] .... node   #8, CPUs:    #64  #65  #66  #67  #68  #69  #70  #71
      [    5.421006] .... node   #9, CPUs:    #72  #73  #74  #75  #76  #77  #78  #79
      [    6.032005] .... node  #10, CPUs:    #80  #81  #82  #83  #84  #85  #86  #87
      [    6.648006] .... node  #11, CPUs:    #88  #89  #90  #91  #92  #93  #94  #95
      [    7.262005] .... node  #12, CPUs:    #96  #97  #98  #99 #100 #101 #102 #103
      [    7.865005] .... node  #13, CPUs:   #104 #105 #106 #107 #108 #109 #110 #111
      [    8.466005] .... node  #14, CPUs:   #112 #113 #114 #115 #116 #117 #118 #119
      [    9.073006] .... node  #15, CPUs:   #120 #121 #122 #123 #124 #125 #126 #127
      [    9.679901] x86: Booted up 16 nodes, 128 CPUs
      
      and drop useless elements.
      
      Change num_digits() to hpa's division-avoiding, cell-phone-typed
      version which he went at great lengths and pains to submit on a
      Saturday evening.
      Signed-off-by: NBorislav Petkov <bp@suse.de>
      Cc: huawei.libin@huawei.com
      Cc: wangyijing@huawei.com
      Cc: fenghua.yu@intel.com
      Cc: guohanjun@huawei.com
      Cc: paul.gortmaker@windriver.com
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/20130930095624.GB16383@pd.tnicSigned-off-by: NIngo Molnar <mingo@kernel.org>
      a17bce4d
  14. 28 9月, 2013 1 次提交
    • B
      x86: Improve the printout of the SMP bootup CPU table · 646e29a1
      Borislav Petkov 提交于
      As the new x86 CPU bootup printout format code maintainer, I am
      taking immediate action to improve and clean (and thus indulge
      my OCD) the reporting of the cores when coming up online.
      
      Fix padding to a right-hand alignment, cleanup code and bind
      reporting width to the max number of supported CPUs on the
      system, like this:
      
       [    0.074509] smpboot: Booting Node   0, Processors:      #1  #2  #3  #4  #5  #6  #7 OK
       [    0.644008] smpboot: Booting Node   1, Processors:  #8  #9 #10 #11 #12 #13 #14 #15 OK
       [    1.245006] smpboot: Booting Node   2, Processors: #16 #17 #18 #19 #20 #21 #22 #23 OK
       [    1.864005] smpboot: Booting Node   3, Processors: #24 #25 #26 #27 #28 #29 #30 #31 OK
       [    2.489005] smpboot: Booting Node   4, Processors: #32 #33 #34 #35 #36 #37 #38 #39 OK
       [    3.093005] smpboot: Booting Node   5, Processors: #40 #41 #42 #43 #44 #45 #46 #47 OK
       [    3.698005] smpboot: Booting Node   6, Processors: #48 #49 #50 #51 #52 #53 #54 #55 OK
       [    4.304005] smpboot: Booting Node   7, Processors: #56 #57 #58 #59 #60 #61 #62 #63 OK
       [    4.961413] Brought up 64 CPUs
      
      and this:
      
       [    0.072367] smpboot: Booting Node   0, Processors:    #1 #2 #3 #4 #5 #6 #7 OK
       [    0.686329] Brought up 8 CPUs
      Signed-off-by: NBorislav Petkov <bp@suse.de>
      Cc: Libin <huawei.libin@huawei.com>
      Cc: wangyijing@huawei.com
      Cc: fenghua.yu@intel.com
      Cc: guohanjun@huawei.com
      Cc: paul.gortmaker@windriver.com
      Link: http://lkml.kernel.org/r/20130927143554.GF4422@pd.tnicSigned-off-by: NIngo Molnar <mingo@kernel.org>
      646e29a1
  15. 25 9月, 2013 1 次提交
  16. 05 9月, 2013 1 次提交
  17. 15 7月, 2013 1 次提交
    • P
      x86: delete __cpuinit usage from all x86 files · 148f9bb8
      Paul Gortmaker 提交于
      The __cpuinit type of throwaway sections might have made sense
      some time ago when RAM was more constrained, but now the savings
      do not offset the cost and complications.  For example, the fix in
      commit 5e427ec2 ("x86: Fix bit corruption at CPU resume time")
      is a good example of the nasty type of bugs that can be created
      with improper use of the various __init prefixes.
      
      After a discussion on LKML[1] it was decided that cpuinit should go
      the way of devinit and be phased out.  Once all the users are gone,
      we can then finally remove the macros themselves from linux/init.h.
      
      Note that some harmless section mismatch warnings may result, since
      notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
      are flagged as __cpuinit  -- so if we remove the __cpuinit from
      arch specific callers, we will also get section mismatch warnings.
      As an intermediate step, we intend to turn the linux/init.h cpuinit
      content into no-ops as early as possible, since that will get rid
      of these warnings.  In any case, they are temporary and harmless.
      
      This removes all the arch/x86 uses of the __cpuinit macros from
      all C files.  x86 only had the one __CPUINIT used in assembly files,
      and it wasn't paired off with a .previous or a __FINIT, so we can
      delete it directly w/o any corresponding additional change there.
      
      [1] https://lkml.org/lkml/2013/5/20/589
      
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: x86@kernel.org
      Acked-by: NIngo Molnar <mingo@kernel.org>
      Acked-by: NThomas Gleixner <tglx@linutronix.de>
      Acked-by: NH. Peter Anvin <hpa@linux.intel.com>
      Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
      148f9bb8
  18. 31 5月, 2013 1 次提交
    • A
      sched/x86: Construct all sibling maps if smt · b0bc225d
      Andrew Jones 提交于
      Commit 316ad248 ("sched/x86: Rewrite
      set_cpu_sibling_map()") broke the construction of sibling maps,
      which also broke the booted_cores accounting.
      
      Before the rewrite, if smt was present, then each map was
      updated for each smt sibling. After the rewrite only
      cpu_sibling_mask gets updated, as the llc and core maps depend
      on 'has_mc = x86_max_cores > 1' instead. This leads to problems
      with topologies like the following
      
      (qemu -smp sockets=2,cores=1,threads=2)
      
        processor       : 0
        physical id     : 0
        siblings        : 1    <= should be 2
        core id         : 0
        cpu cores       : 1
      
        processor       : 1
        physical id     : 0
        siblings        : 1    <= should be 2
        core id         : 0
        cpu cores       : 0    <= should be 1
      
        processor       : 2
        physical id     : 1
        siblings        : 1    <= should be 2
        core id         : 0
        cpu cores       : 1
      
        processor       : 3
        physical id     : 1
        siblings        : 1    <= should be 2
        core id         : 0
        cpu cores       : 0    <= should be 1
      
      This patch restores the former construction by defining has_mc
      as (has_smt || x86_max_cores > 1). This should be fine as there
      were no (has_smt && !has_mc) conditions in the context.
      
      Aso rename has_mc to has_mp now that it's not just for cores.
      Signed-off-by: NAndrew Jones <drjones@redhat.com>
      Acked-by: NPeter Zijlstra <peterz@infradead.org>
      Cc: a.p.zijlstra@chello.nl
      Cc: fenghua.yu@intel.com
      Link: http://lkml.kernel.org/r/1369831695-11970-1-git-send-email-drjones@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      b0bc225d
  19. 08 4月, 2013 1 次提交
  20. 06 3月, 2013 1 次提交
  21. 10 2月, 2013 1 次提交
    • L
      x86 idle: remove mwait_idle() and "idle=mwait" cmdline param · 69fb3676
      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
      69fb3676
  22. 01 12月, 2012 1 次提交
    • V
      x86, fpu: Avoid FPU lazy restore after suspend · 644c1541
      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>
      644c1541
  23. 15 11月, 2012 2 次提交
  24. 14 11月, 2012 1 次提交
  25. 23 8月, 2012 1 次提交
    • R
      x86/smp: Don't ever patch back to UP if we unplug cpus · 816afe4f
      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>
      816afe4f
  26. 14 6月, 2012 1 次提交
    • V
      x86: Add read_mostly declaration/definition to variables from smp.h · 0816b0f0
      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>
      0816b0f0
  27. 13 6月, 2012 1 次提交
    • B
      x86/smp: Fix topology checks on AMD MCM CPUs · 161270fc
      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>
      161270fc
  28. 06 6月, 2012 2 次提交
  29. 05 6月, 2012 1 次提交
  30. 30 5月, 2012 1 次提交
  31. 17 5月, 2012 1 次提交
    • P
      sched: Remove stale power aware scheduling remnants and dysfunctional knobs · 8e7fbcbc
      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>
      8e7fbcbc
  32. 14 5月, 2012 1 次提交
  33. 09 5月, 2012 3 次提交