1. 23 Sep, 2013 4 commits
    • Christoph Lameter's avatar
      rcu: Replace __get_cpu_var() uses · c9d4b0af
      Christoph Lameter authored
      __get_cpu_var() is used for multiple purposes in the kernel source. One
      of them is address calculation via the form &__get_cpu_var(x). This
      calculates the address for the instance of the percpu variable of the
      current processor based on an offset.
      
      Other use cases are for storing and retrieving data from the current
      processors percpu area.  __get_cpu_var() can be used as an lvalue when
      writing data or on the right side of an assignment.
      
      __get_cpu_var() is defined as :
      
      __get_cpu_var() always only does an address determination. However,
      store and retrieve operations could use a segment prefix (or global
      register on other platforms) to avoid the address calculation.
      
      this_cpu_write() and this_cpu_read() can directly take an offset into
      a percpu area and use optimized assembly code to read and write per
      cpu variables.
      
      This patch converts __get_cpu_var into either an explicit address
      calculation using this_cpu_ptr() or into a use of this_cpu operations
      that use the offset. Thereby address calcualtions are avoided and less
      registers are used when code is generated.
      
      At the end of the patchset all uses of __get_cpu_var have been removed
      so the macro is removed too.
      
      The patchset includes passes over all arches as well. Once these
      operations are used throughout then specialized macros can be defined in
      non -x86 arches as well in order to optimize per cpu access by f.e. using
      a global register that may be set to the per cpu base.
      
      Transformations done to __get_cpu_var()
      
      1. Determine the address of the percpu instance of the current processor.
      
      	DEFINE_PER_CPU(int, y);
      	int *x = &__get_cpu_var(y);
      
          Converts to
      
      	int *x = this_cpu_ptr(&y);
      
      2. Same as #1 but this time an array structure is involved.
      
      	DEFINE_PER_CPU(int, y[20]);
      	int *x = __get_cpu_var(y);
      
          Converts to
      
      	int *x = this_cpu_ptr(y);
      
      3. Retrieve the content of the current processors instance of a per cpu
         variable.
      
      	DEFINE_PER_CPU(int, u);
      	int x = __get_cpu_var(y)
      
         Converts to
      
      	int x = __this_cpu_read(y);
      
      4. Retrieve the content of a percpu struct
      
      	DEFINE_PER_CPU(struct mystruct, y);
      	struct mystruct x = __get_cpu_var(y);
      
         Converts to
      
      	memcpy(this_cpu_ptr(&x), y, sizeof(x));
      
      5. Assignment to a per cpu variable
      
      	DEFINE_PER_CPU(int, y)
      	__get_cpu_var(y) = x;
      
         Converts to
      
      	this_cpu_write(y, x);
      
      6. Increment/Decrement etc of a per cpu variable
      
      	DEFINE_PER_CPU(int, y);
      	__get_cpu_var(y)++
      
         Converts to
      
      	this_cpu_inc(y)
      Signed-off-by: default avatarChristoph Lameter <cl@linux.com>
      [ paulmck: Address conflicts. ]
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      c9d4b0af
    • Paul E. McKenney's avatar
      rcu: Make list_splice_init_rcu() account for RCU readers · 2a855b64
      Paul E. McKenney authored
      The list_splice_init_rcu() function allows a list visible to RCU readers
      to be spliced into another list visible to RCU readers.  This is OK,
      except for the use of INIT_LIST_HEAD(), which does pointer updates
      without doing anything to make those updates safe for concurrent readers.
      
      Of course, most of the time INIT_LIST_HEAD() is being used in reader-free
      contexts, such as initialization or cleanup, so it is OK for it to update
      pointers in an unsafe-for-RCU-readers manner.  This commit therefore
      creates an INIT_LIST_HEAD_RCU() that uses ACCESS_ONCE() to make the updates
      reader-safe.  The reason that we can use ACCESS_ONCE() instead of the more
      typical rcu_assign_pointer() is that list_splice_init_rcu() is updating the
      pointers to reference something that is already visible to readers, so
      that there is no problem with pre-initialized values.
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      2a855b64
    • Paul E. McKenney's avatar
      rcu: Fix dubious "if" condition in __call_rcu_nocb_enqueue() · 829511d8
      Paul E. McKenney authored
      This commit replaces an incorrect (but fortunately functional)
      bitwise OR ("|") operator with the correct logical OR ("||").
      Reported-by: default avatarkbuild test robot <fengguang.wu@intel.com>
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      829511d8
    • Paul E. McKenney's avatar
      rcu: Convert local functions to static · 01896f7e
      Paul E. McKenney authored
      The rcu_cpu_stall_timeout kernel parameter, the rcu_dynticks per-CPU
      variable, and the rcu_gp_fqs() function are used only locally.  This
      commit therefore marks them as static.
      Reported-by: default avatarkbuild test robot <fengguang.wu@intel.com>
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      01896f7e
  2. 20 Sep, 2013 2 commits
    • Paul E. McKenney's avatar
      rcu: Use proper cpp macro for ->gp_flags · b3f2d025
      Paul E. McKenney authored
      One of the ->gp_flags assignments used a raw number rather than the
      cpp macro that was intended for this purpose, which this commit fixes.
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      b3f2d025
    • Paul E. McKenney's avatar
      mm: Place preemption point in do_mlockall() loop · 5c889690
      Paul E. McKenney authored
      There is a loop in do_mlockall() that lacks a preemption point, which
      means that the following can happen on non-preemptible builds of the
      kernel:
      
      > My fuzz tester keeps hitting this. Every instance shows the non-irq stack
      > came in from mlockall.  I'm only seeing this on one box, but that has more
      > ram (8gb) than my other machines, which might explain it.
      >
      > 	Dave
      >
      > INFO: rcu_preempt self-detected stall on CPU { 3}  (t=6500 jiffies g=470344 c=470343 q=0)
      > sending NMI to all CPUs:
      > NMI backtrace for cpu 3
      > CPU: 3 PID: 29664 Comm: trinity-child2 Not tainted 3.11.0-rc1+ #32
      > task: ffff88023e743fc0 ti: ffff88022f6f2000 task.ti: ffff88022f6f2000
      > RIP: 0010:[<ffffffff810bf7d1>]  [<ffffffff810bf7d1>] trace_hardirqs_off_caller+0x21/0xb0
      > RSP: 0018:ffff880244e03c30  EFLAGS: 00000046
      > RAX: ffff88023e743fc0 RBX: 0000000000000001 RCX: 000000000000003c
      > RDX: 000000000000000f RSI: 0000000000000004 RDI: ffffffff81033cab
      > RBP: ffff880244e03c38 R08: ffff880243288a80 R09: 0000000000000001
      > R10: 0000000000000000 R11: 0000000000000001 R12: ffff880243288a80
      > R13: ffff8802437eda40 R14: 0000000000080000 R15: 000000000000d010
      > FS:  00007f50ae33b740(0000) GS:ffff880244e00000(0000) knlGS:0000000000000000
      > CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      > CR2: 000000000097f000 CR3: 0000000240fa0000 CR4: 00000000001407e0
      > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
      > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
      > Stack:
      >  ffffffff810bf86d ffff880244e03c98 ffffffff81033cab 0000000000000096
      >  000000000000d008 0000000300000002 0000000000000004 0000000000000003
      >  0000000000002710 ffffffff81c50d00 ffffffff81c50d00 ffff880244fcde00
      > Call Trace:
      >  <IRQ>
      >  [<ffffffff810bf86d>] ? trace_hardirqs_off+0xd/0x10
      >  [<ffffffff81033cab>] __x2apic_send_IPI_mask+0x1ab/0x1c0
      >  [<ffffffff81033cdc>] x2apic_send_IPI_all+0x1c/0x20
      >  [<ffffffff81030115>] arch_trigger_all_cpu_backtrace+0x65/0xa0
      >  [<ffffffff811144b1>] rcu_check_callbacks+0x331/0x8e0
      >  [<ffffffff8108bfa0>] ? hrtimer_run_queues+0x20/0x180
      >  [<ffffffff8109e905>] ? sched_clock_cpu+0xb5/0x100
      >  [<ffffffff81069557>] update_process_times+0x47/0x80
      >  [<ffffffff810bd115>] tick_sched_handle.isra.16+0x25/0x60
      >  [<ffffffff810bd231>] tick_sched_timer+0x41/0x60
      >  [<ffffffff8108ace1>] __run_hrtimer+0x81/0x4e0
      >  [<ffffffff810bd1f0>] ? tick_sched_do_timer+0x60/0x60
      >  [<ffffffff8108b93f>] hrtimer_interrupt+0xff/0x240
      >  [<ffffffff8102de84>] local_apic_timer_interrupt+0x34/0x60
      >  [<ffffffff81718c5f>] smp_apic_timer_interrupt+0x3f/0x60
      >  [<ffffffff817178ef>] apic_timer_interrupt+0x6f/0x80
      >  [<ffffffff8170e8e0>] ? retint_restore_args+0xe/0xe
      >  [<ffffffff8105f101>] ? __do_softirq+0xb1/0x440
      >  [<ffffffff8105f64d>] irq_exit+0xcd/0xe0
      >  [<ffffffff81718c65>] smp_apic_timer_interrupt+0x45/0x60
      >  [<ffffffff817178ef>] apic_timer_interrupt+0x6f/0x80
      >  <EOI>
      >  [<ffffffff8170e8e0>] ? retint_restore_args+0xe/0xe
      >  [<ffffffff8170b830>] ? wait_for_completion_killable+0x170/0x170
      >  [<ffffffff8170c853>] ? preempt_schedule_irq+0x53/0x90
      >  [<ffffffff8170e9f6>] retint_kernel+0x26/0x30
      >  [<ffffffff8107a523>] ? queue_work_on+0x43/0x90
      >  [<ffffffff8107c369>] schedule_on_each_cpu+0xc9/0x1a0
      >  [<ffffffff81167770>] ? lru_add_drain+0x50/0x50
      >  [<ffffffff811677c5>] lru_add_drain_all+0x15/0x20
      >  [<ffffffff81186965>] SyS_mlockall+0xa5/0x1a0
      >  [<ffffffff81716e94>] tracesys+0xdd/0xe2
      
      This commit addresses this problem by inserting the required preemption
      point.
      Reported-by: default avatarDave Jones <davej@redhat.com>
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
      Cc: Michel Lespinasse <walken@google.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      5c889690
  3. 16 Sep, 2013 5 commits
  4. 15 Sep, 2013 7 commits
    • Linus Torvalds's avatar
      Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus · d8efd82e
      Linus Torvalds authored
      Pull MIPS fixes from Ralf Baechle:
       "These are four patches for three construction sites:
      
         - Fix register decoding for the combination of multi-core processors
           and multi-threading.
      
         - Two more fixes that are part of the ongoing DECstation resurrection
           work.  One of these touches a DECstation-only network driver.
      
         - Finally Markos' trivial build fix for the AP/SP support.
      
        (With this applied now all MIPS defconfigs are building again)"
      
      * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
        MIPS: kernel: vpe: Make vpe_attrs an array of pointers.
        MIPS: Fix SMP core calculations when using MT support.
        MIPS: DECstation I/O ASIC DMA interrupt handling fix
        MIPS: DECstation HRT initialization rearrangement
      d8efd82e
    • Linus Torvalds's avatar
      Merge branch 'for_linus' of git://cavan.codon.org.uk/platform-drivers-x86 · cd619e21
      Linus Torvalds authored
      Pull x86 platform updates from Matthew Garrett:
       "Nothing amazing here, almost entirely cleanups and minor bugfixes and
        one bit of hardware enablement in the amilo-rfkill driver"
      
      * 'for_linus' of git://cavan.codon.org.uk/platform-drivers-x86:
        platform/x86: panasonic-laptop: reuse module_acpi_driver
        samsung-laptop: fix config build error
        platform: x86: remove unnecessary platform_set_drvdata()
        amilo-rfkill: Enable using amilo-rfkill with the FSC Amilo L1310.
        wmi: parse_wdg() should return kernel error codes
        hp_wmi: Fix unregister order in hp_wmi_rfkill_setup()
        platform: replace strict_strto*() with kstrto*()
        x86: irst: use module_acpi_driver to simplify the code
        x86: smartconnect: use module_acpi_driver to simplify the code
        platform samsung-q10: use ACPI instead of direct EC calls
        thinkpad_acpi: add the ability setting TPACPI_LED_NONE by quirk
        thinkpad_acpi: return -NODEV while operating uninitialized LEDs
      cd619e21
    • Linus Torvalds's avatar
      Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi · 0375ec58
      Linus Torvalds authored
      Pull misc SCSI driver updates from James Bottomley:
       "This patch set is a set of driver updates (megaraid_sas, fnic, lpfc,
        ufs, hpsa) we also have a couple of bug fixes (sd out of bounds and
        ibmvfc error handling) and the first round of esas2r checker fixes and
        finally the much anticipated big endian additions for megaraid_sas"
      
      * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (47 commits)
        [SCSI] fnic: fnic Driver Tuneables Exposed through CLI
        [SCSI] fnic: Kernel panic while running sh/nosh with max lun cfg
        [SCSI] fnic: Hitting BUG_ON(io_req->abts_done) in fnic_rport_exch_reset
        [SCSI] fnic: Remove QUEUE_FULL handling code
        [SCSI] fnic: On system with >1.1TB RAM, VIC fails multipath after boot up
        [SCSI] fnic: FC stat param seconds_since_last_reset not getting updated
        [SCSI] sd: Fix potential out-of-bounds access
        [SCSI] lpfc 8.3.42: Update lpfc version to driver version 8.3.42
        [SCSI] lpfc 8.3.42: Fixed issue of task management commands having a fixed timeout
        [SCSI] lpfc 8.3.42: Fixed inconsistent spin lock usage.
        [SCSI] lpfc 8.3.42: Fix driver's abort loop functionality to skip IOs already getting aborted
        [SCSI] lpfc 8.3.42: Fixed failure to allocate SCSI buffer on PPC64 platform for SLI4 devices
        [SCSI] lpfc 8.3.42: Fix WARN_ON when driver unloads
        [SCSI] lpfc 8.3.42: Avoided making pci bar ioremap call during dual-chute WQ/RQ pci bar selection
        [SCSI] lpfc 8.3.42: Fixed driver iocbq structure's iocb_flag field running out of space
        [SCSI] lpfc 8.3.42: Fix crash on driver load due to cpu affinity logic
        [SCSI] lpfc 8.3.42: Fixed logging format of setting driver sysfs attributes hard to interpret
        [SCSI] lpfc 8.3.42: Fixed back to back RSCNs discovery failure.
        [SCSI] lpfc 8.3.42: Fixed race condition between BSG I/O dispatch and timeout handling
        [SCSI] lpfc 8.3.42: Fixed function mode field defined too small for not recognizing dual-chute mode
        ...
      0375ec58
    • Linus Torvalds's avatar
      Merge branch 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux · bff157b3
      Linus Torvalds authored
      Pull SLAB update from Pekka Enberg:
       "Nothing terribly exciting here apart from Christoph's kmalloc
        unification patches that brings sl[aou]b implementations closer to
        each other"
      
      * 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux:
        slab: Use correct GFP_DMA constant
        slub: remove verify_mem_not_deleted()
        mm/sl[aou]b: Move kmallocXXX functions to common code
        mm, slab_common: add 'unlikely' to size check of kmalloc_slab()
        mm/slub.c: beautify code for removing redundancy 'break' statement.
        slub: Remove unnecessary page NULL check
        slub: don't use cpu partial pages on UP
        mm/slub: beautify code for 80 column limitation and tab alignment
        mm/slub: remove 'per_cpu' which is useless variable
      bff157b3
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input · 8bf5e36d
      Linus Torvalds authored
      Pull input update from Dmitry Torokhov:
       "The only change is David Hermann's new EVIOCREVOKE evdev ioctl that
        allows safely passing file descriptors to input devices to session
        processes and later being able to stop delivery of events through
        these fds so that inactive sessions will no longer receive user input
        that does not belong to them"
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
        Input: evdev - add EVIOCREVOKE ioctl
      8bf5e36d
    • Linus Torvalds's avatar
      vfs: fix typo in comment in recent dentry work · 05a8252b
      Linus Torvalds authored
      Sedat points out that I transposed some letters in "LRU" and wrote "RLU"
      instead in one of the new comments explaining the flow.  Let's just fix
      it.
      Reported-by: default avatarSedat Dilek <sedat.dilek@jpberlin.de>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      05a8252b
    • Davidlohr Bueso's avatar
      partitions/efi: loosen check fot pmbr size in lba · 6b02fa59
      Davidlohr Bueso authored
      Matt found that commit 27a7c642 ("partitions/efi: account for pmbr
      size in lba") caused his GPT formatted eMMC device not to boot.  The
      reason is that this commit enforced Linux to always check the lesser of
      the whole disk or 2Tib for the pMBR size in LBA.  While most disk
      partitioning tools out there create a pMBR with these characteristics,
      Microsoft does not, as it always sets the entry to the maximum 32-bit
      limitation - even though a drive may be smaller than that[1].
      
      Loosen this check and only verify that the size is either the whole disk
      or 0xFFFFFFFF.  No tool in its right mind would set it to any value
      other than these.
      
      [1] http://thestarman.pcministry.com/asm/mbr/GPT.htm#GPTPTReported-and-tested-by: default avatarMatt Porter <matt.porter@linaro.org>
      Signed-off-by: default avatarDavidlohr Bueso <davidlohr@hp.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      6b02fa59
  5. 14 Sep, 2013 2 commits
  6. 13 Sep, 2013 20 commits