1. 07 Oct, 2015 4 commits
  2. 21 Sep, 2015 10 commits
    • Paul E. McKenney's avatar
      rcu: Make ->cpu_no_qs be a union for aggregate OR · 5b74c458
      Paul E. McKenney authored
      This commit converts the rcu_data structure's ->cpu_no_qs field
      to a union.  The bytewise side of this union allows individual access
      to indications as to whether this CPU needs to find a quiescent state
      for a normal (.norm) and/or expedited (.exp) grace period.  The setwise
      side of the union allows testing whether or not a quiescent state is
      needed at all, for either type of grace period.
      
      For now, only .norm is used.  A later commit will introduce the expedited
      usage.
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      5b74c458
    • Paul E. McKenney's avatar
      rcu: Invert passed_quiesce and rename to cpu_no_qs · 0d43eb34
      Paul E. McKenney authored
      This commit inverts the sense of the rcu_data structure's ->passed_quiesce
      field and renames it to ->cpu_no_qs.  This will allow a later commit to
      use an "aggregate OR" operation to test expedited as well as normal grace
      periods without added overhead.
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      0d43eb34
    • Paul E. McKenney's avatar
      rcu: Rename qs_pending to core_needs_qs · 97c668b8
      Paul E. McKenney authored
      An upcoming commit needs to invert the sense of the ->passed_quiesce
      rcu_data structure field, so this commit is taking this opportunity
      to clarify things a bit by renaming ->qs_pending to ->core_needs_qs.
      
      So if !rdp->core_needs_qs, then this CPU need not concern itself with
      quiescent states, in particular, it need not acquire its leaf rcu_node
      structure's ->lock to check.  Otherwise, it needs to report the next
      quiescent state.
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      97c668b8
    • Paul E. McKenney's avatar
      rcu: Move synchronize_sched_expedited() to combining tree · bce5fa12
      Paul E. McKenney authored
      Currently, synchronize_sched_expedited() uses a single global counter
      to track the number of remaining context switches that the current
      expedited grace period must wait on.  This is problematic on large
      systems, where the resulting memory contention can be pathological.
      This commit therefore makes synchronize_sched_expedited() instead use
      the combining tree in the same manner as synchronize_rcu_expedited(),
      keeping memory contention down to a dull roar.
      
      This commit creates a temporary function sync_sched_exp_select_cpus()
      that is very similar to sync_rcu_exp_select_cpus().  A later commit
      will consolidate these two functions, which becomes possible when
      synchronize_sched_expedited() switches from stop_one_cpu_nowait() to
      smp_call_function_single().
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      bce5fa12
    • Paul E. McKenney's avatar
      rcu: Use single-stage IPI algorithm for RCU expedited grace period · 8203d6d0
      Paul E. McKenney authored
      The current preemptible-RCU expedited grace-period algorithm invokes
      synchronize_sched_expedited() to enqueue all tasks currently running
      in a preemptible-RCU read-side critical section, then waits for all the
      ->blkd_tasks lists to drain.  This works, but results in both an IPI and
      a double context switch even on CPUs that do not happen to be running
      in a preemptible RCU read-side critical section.
      
      This commit implements a new algorithm that causes less OS jitter.
      This new algorithm IPIs all online CPUs that are not idle (from an
      RCU perspective), but refrains from self-IPIs.  If a CPU receiving
      this IPI is not in a preemptible RCU read-side critical section (or
      is just now exiting one), it pushes quiescence up the rcu_node tree,
      otherwise, it sets a flag that will be handled by the upcoming outermost
      rcu_read_unlock(), which will then push quiescence up the tree.
      
      The expedited grace period must of course wait on any pre-existing blocked
      readers, and newly blocked readers must be queued carefully based on
      the state of both the normal and the expedited grace periods.  This
      new queueing approach also avoids the need to update boost state,
      courtesy of the fact that blocked tasks are no longer ever migrated to
      the root rcu_node structure.
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      8203d6d0
    • Paul E. McKenney's avatar
      rcu: Consolidate tree setup for synchronize_rcu_expedited() · b9585e94
      Paul E. McKenney authored
      This commit replaces sync_rcu_preempt_exp_init1(() and
      sync_rcu_preempt_exp_init2() with sync_exp_reset_tree_hotplug()
      and sync_exp_reset_tree(), which will also be used by
      synchronize_sched_expedited(), and sync_rcu_exp_select_nodes(), which
      contains code specific to synchronize_rcu_expedited().
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      b9585e94
    • Paul E. McKenney's avatar
      rcu: Move rcu_report_exp_rnp() to allow consolidation · 7922cd0e
      Paul E. McKenney authored
      This is a nearly pure code-movement commit, moving rcu_report_exp_rnp(),
      sync_rcu_preempt_exp_done(), and rcu_preempted_readers_exp() so
      that later commits can make synchronize_sched_expedited() use them.
      The non-code-movement portion of this commit tags rcu_report_exp_rnp()
      as __maybe_unused to avoid build errors when CONFIG_PREEMPT=n.
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      7922cd0e
    • Paul E. McKenney's avatar
      rcu: Use rsp->expedited_wq instead of sync_rcu_preempt_exp_wq · f4ecea30
      Paul E. McKenney authored
      Now that there is an ->expedited_wq waitqueue in each rcu_state structure,
      there is no need for the sync_rcu_preempt_exp_wq global variable.  This
      commit therefore substitutes ->expedited_wq for sync_rcu_preempt_exp_wq.
      It also initializes ->expedited_wq only once at boot instead of at the
      start of each expedited grace period.
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      f4ecea30
    • Paul E. McKenney's avatar
      rcu: Suppress lockdep false positive for rcp->exp_funnel_mutex · 19a5ecde
      Paul E. McKenney authored
      In kernels built with CONFIG_PREEMPT=y, synchronize_rcu_expedited()
      invokes synchronize_sched_expedited() while holding RCU-preempt's
      root rcu_node structure's ->exp_funnel_mutex, which is acquired after
      the rcu_data structure's ->exp_funnel_mutex.  The first thing that
      synchronize_sched_expedited() will do is acquire RCU-sched's rcu_data
      structure's ->exp_funnel_mutex.   There is no danger of an actual deadlock
      because the locking order is always from RCU-preempt's expedited mutexes
      to those of RCU-sched.  Unfortunately, lockdep considers both rcu_data
      structures' ->exp_funnel_mutex to be in the same lock class and therefore
      reports a deadlock cycle.
      
      This commit silences this false positive by placing RCU-sched's rcu_data
      structures' ->exp_funnel_mutex locks into their own lock class.
      Reported-by: default avatarSasha Levin <sasha.levin@oracle.com>
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      19a5ecde
    • Oleg Nesterov's avatar
      rcu: Change _wait_rcu_gp() to work around GCC bug 67055 · 66e8c57d
      Oleg Nesterov authored
      Code like this in inline functions confuses some recent versions of gcc:
      
      	const int n = const-expr;
      	whatever_t array[n];
      
      For more details, see:
      
      	https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67055#c13
      
      This compiler bug results in the following failure after 114b7fd4b (rcu:
      Create rcu_sync infrastructure):
      
      	In file included from include/linux/rcupdate.h:429:0,
      			  from include/linux/rcu_sync.h:5,
      			  from kernel/rcu/sync.c:1:
      	include/linux/rcutiny.h: In function 'rcu_barrier_sched':
      	include/linux/rcutiny.h:55:20: internal compiler error: Segmentation fault
      	  static inline void rcu_barrier_sched(void)
      
      This commit therefore eliminates the constant local variable in favor of
      direct use of the expression.
      Reported-and-tested-by: default avatarMark Salter <msalter@redhat.com>
      Reported-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      66e8c57d
  3. 20 Sep, 2015 10 commits
    • Linus Torvalds's avatar
      Linux 4.3-rc2 · 1f93e4a9
      Linus Torvalds authored
      1f93e4a9
    • Linus Torvalds's avatar
      Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm · 99bc7215
      Linus Torvalds authored
      Pull ARM fixes from Russell King:
       "Three fixes and a resulting cleanup for -rc2:
      
         - Andre Przywara reported that he was seeing a warning with the new
           cast inside DMA_ERROR_CODE's definition, and fixed the incorrect
           use.
      
         - Doug Anderson noticed that kgdb causes a "scheduling while atomic"
           bug.
      
         - OMAP5 folk noticed that their Thumb-2 compiled X servers crashed
           when enabling support to cover ARMv6 CPUs due to a kernel bug
           leaking some conditional context into the signal handler"
      
      * 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
        ARM: 8425/1: kgdb: Don't try to stop the machine when setting breakpoints
        ARM: 8437/1: dma-mapping: fix build warning with new DMA_ERROR_CODE definition
        ARM: get rid of needless #if in signal handling code
        ARM: fix Thumb2 signal handling when ARMv6 is enabled
      99bc7215
    • Linus Torvalds's avatar
      Merge tag 'linux-kselftest-4.3-rc2' of... · 30ec5682
      Linus Torvalds authored
      Merge tag 'linux-kselftest-4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
      
      Pull kselftest fixes from Shuah Khan:
       "This update contains 7 fixes for problems ranging from build failurs
        to incorrect error reporting"
      
      * tag 'linux-kselftest-4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
        selftests: exec: revert to default emit rule
        selftests: change install command to rsync
        selftests: mqueue: simplify the Makefile
        selftests: mqueue: allow extra cflags
        selftests: rename jump label to static_keys
        selftests/seccomp: add support for s390
        seltests/zram: fix syntax error
      30ec5682
    • Linus Torvalds's avatar
      Merge tag 'pm+acpi-4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm · 009884f3
      Linus Torvalds authored
      Pull power management and ACPI updates from Rafael Wysocki:
       "Included are: a somewhat late devfreq update which however is mostly
        fixes and cleanups with one new thing only (the PPMUv2 support on
        Exynos5433), an ACPI cpufreq driver fixup and two ACPI core cleanups
        related to preprocessor directives.
      
        Specifics:
      
         - Fix a memory allocation size in the devfreq core (Xiaolong Ye).
      
         - Fix a mistake in the exynos-ppmu DT binding (Javier Martinez
           Canillas).
      
         - Add support for PPMUv2 ((Platform Performance Monitoring Unit
           version 2.0) on the Exynos5433 SoCs (Chanwoo Choi).
      
         - Fix a type casting bug in the Exynos PPMU code (MyungJoo Ham).
      
         - Assorted devfreq code cleanups and optimizations (Javi Merino,
           MyungJoo Ham, Viresh Kumar).
      
         - Fix up the ACPI cpufreq driver to use a more lightweight way to get
           to its private data in the ->get() callback (Rafael J Wysocki).
      
         - Fix a CONFIG_ prefix bug in one of the ACPI drivers and make the
           ACPI subsystem use IS_ENABLED() instead of #ifdefs in function
           bodies (Sudeep Holla)"
      
      * tag 'pm+acpi-4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
        cpufreq: acpi-cpufreq: Use cpufreq_cpu_get_raw() in ->get()
        ACPI: Eliminate CONFIG_.*{, _MODULE} #ifdef in favor of IS_ENABLED()
        ACPI: int340x_thermal: add missing CONFIG_ prefix
        PM / devfreq: Fix incorrect type issue.
        PM / devfreq: tegra: Update governor to use devfreq_update_stats()
        PM / devfreq: comments for get_dev_status usage updated
        PM / devfreq: drop comment about thermal setting max_freq
        PM / devfreq: cache the last call to get_dev_status()
        PM / devfreq: Drop unlikely before IS_ERR(_OR_NULL)
        PM / devfreq: exynos-ppmu: bit-wise operation bugfix.
        PM / devfreq: exynos-ppmu: Update documentation to support PPMUv2
        PM / devfreq: exynos-ppmu: Add the support of PPMUv2 for Exynos5433
        PM / devfreq: event: Remove incorrect property in exynos-ppmu DT binding
      009884f3
    • Linus Torvalds's avatar
      Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux · d590b2d4
      Linus Torvalds authored
      Pull clk fixes from Stephen Boyd:
       "A few driver fixes for tegra, rockchip, and st SoCs and a two-liner in
        the framework to avoid oops when get_parent ops return out of range
        values on tegra platforms"
      
      * tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
        drivers: clk: st: Rename st_pll3200c32_407_c0_x into st_pll3200c32_cx_x
        clk: check for invalid parent index of orphans in __clk_init()
        clk: tegra: dfll: Properly protect OPP list
        clk: rockchip: add critical clock for rk3368
      d590b2d4
    • Linus Torvalds's avatar
      Merge tag 'led-fixes-for-v4.3-rc2' of... · e6827baf
      Linus Torvalds authored
      Merge tag 'led-fixes-for-v4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds
      
      Pull LED fixes from Jacek Anaszewski:
       - fix module autoload for six OF platform drivers (aat1290, bcm6328,
         bcm6358, ktd2692, max77693, ns2)
       - aat1290: add missing static modifier
       - ipaq-micro: add missing LEDS_CLASS dependency
       - lp55xx: correct Kconfig dependecy for f/w user helper
      
      * tag 'led-fixes-for-v4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds:
        leds:lp55xx: Correct Kconfig dependency for f/w user helper
        leds: leds-ipaq-micro: Add LEDS_CLASS dependency
        leds: aat1290: add 'static' modifier to init_mm_current_scale
        leds: leds-ns2: Fix module autoload for OF platform driver
        leds: max77693: Fix module autoload for OF platform driver
        leds: ktd2692: Fix module autoload for OF platform driver
        leds: bcm6358: Fix module autoload for OF platform driver
        leds: bcm6328: Fix module autoload for OF platform driver
        leds: aat1290: Fix module autoload for OF platform driver
      e6827baf
    • Linus Torvalds's avatar
      Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma · dc847d5b
      Linus Torvalds authored
      Pull rdma fixes from Doug Ledford:
       "The new hfi1 driver in staging/rdma has had a number of fixup patches
        since being added to the tree.  This is the first batch of those fixes"
      
      * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma:
        IB/hfi: Properly set permissions for user device files
        IB/hfi1: mask vs shift confusion
        IB/hfi1: clean up some defines
        IB/hfi1: info leak in get_ctxt_info()
        IB/hfi1: fix a locking bug
        IB/hfi1: checking for NULL instead of IS_ERR
        IB/hfi1: fix sdma_descq_cnt parameter parsing
        IB/hfi1: fix copy_to/from_user() error handling
        IB/hfi1: fix pstateinfo from returning improperly byteswapped value
      dc847d5b
    • Linus Torvalds's avatar
      Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm · 2673ee56
      Linus Torvalds authored
      Pull libnvdimm fixes from Dan Williams:
      
       - a boot regression (since v4.2) fix for some ARM configurations from
         Tyler
      
       - regression (since v4.1) fixes for mkfs.xfs on a DAX enabled device
         from Jeff.  These are tagged for -stable.
      
       - a pair of locking fixes from Axel that are hidden from lockdep since
         they involve device_lock().  The "btt" one is tagged for -stable, the
         other only applies to the new "pfn" mechanism in v4.3.
      
       - a fix for the pmem ->rw_page() path to use wmb_pmem() from Ross.
      
      * 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
        mm: fix type cast in __pfn_to_phys()
        pmem: add proper fencing to pmem_rw_page()
        libnvdimm: pfn_devs: Fix locking in namespace_store
        libnvdimm: btt_devs: Fix locking in namespace_store
        blockdev: don't set S_DAX for misaligned partitions
        dax: fix O_DIRECT I/O to the last block of a blockdev
      2673ee56
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.dk/linux-block · 133bb595
      Linus Torvalds authored
      Pull block updates from Jens Axboe:
       "This is a bit bigger than it should be, but I could (did) not want to
        send it off last week due to both wanting extra testing, and expecting
        a fix for the bounce regression as well.  In any case, this contains:
      
         - Fix for the blk-merge.c compilation warning on gcc 5.x from me.
      
         - A set of back/front SG gap merge fixes, from me and from Sagi.
           This ensures that we honor SG gapping for integrity payloads as
           well.
      
         - Two small fixes for null_blk from Matias, fixing a leak and a
           capacity propagation issue.
      
         - A blkcg fix from Tejun, fixing a NULL dereference.
      
         - A fast clone optimization from Ming, fixing a performance
           regression since the arbitrarily sized bio's were introduced.
      
         - Also from Ming, a regression fix for bouncing IOs"
      
      * 'for-linus' of git://git.kernel.dk/linux-block:
        block: fix bounce_end_io
        block: blk-merge: fast-clone bio when splitting rw bios
        block: blkg_destroy_all() should clear q->root_blkg and ->root_rl.blkg
        block: Copy a user iovec if it includes gaps
        block: Refuse adding appending a gapped integrity page to a bio
        block: Refuse request/bio merges with gaps in the integrity payload
        block: Check for gaps on front and back merges
        null_blk: fix wrong capacity when bs is not 512 bytes
        null_blk: fix memory leak on cleanup
        block: fix bogus compiler warnings in blk-merge.c
      133bb595
    • Chris Mason's avatar
      fs-writeback: unplug before cond_resched in writeback_sb_inodes · 590dca3a
      Chris Mason authored
      Commit 505a666e ("writeback: plug writeback in wb_writeback() and
      writeback_inodes_wb()") has us holding a plug during writeback_sb_inodes,
      which increases the merge rate when relatively contiguous small files
      are written by the filesystem.  It helps both on flash and spindles.
      
      For an fs_mark workload creating 4K files in parallel across 8 drives,
      this commit improves performance ~9% more by unplugging before calling
      cond_resched().  cond_resched() doesn't trigger an implicit unplug, so
      explicitly getting the IO down to the device before scheduling reduces
      latencies for anyone waiting on clean pages.
      
      It also cuts down on how often we use kblockd to unplug, which means
      less work bouncing from one workqueue to another.
      
      Many more details about how we got here:
      
        https://lkml.org/lkml/2015/9/11/570Signed-off-by: default avatarChris Mason <clm@fb.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      590dca3a
  4. 19 Sep, 2015 1 commit
  5. 18 Sep, 2015 15 commits