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  1. Jul 16, 2014
    • Peter Zijlstra's avatar
      locking/mutex: Disable optimistic spinning on some architectures · 4badad35
      Peter Zijlstra authored
      
      
      The optimistic spin code assumes regular stores and cmpxchg() play nice;
      this is found to not be true for at least: parisc, sparc32, tile32,
      metag-lock1, arc-!llsc and hexagon.
      
      There is further wreckage, but this in particular seemed easy to
      trigger, so blacklist this.
      
      Opt in for known good archs.
      
      Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
      Reported-by: default avatarMikulas Patocka <mpatocka@redhat.com>
      Cc: David Miller <davem@davemloft.net>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: James Bottomley <James.Bottomley@hansenpartnership.com>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Jason Low <jason.low2@hp.com>
      Cc: Waiman Long <waiman.long@hp.com>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
      Cc: John David Anglin <dave.anglin@bell.net>
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Davidlohr Bueso <davidlohr@hp.com>
      Cc: stable@vger.kernel.org
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: linux-arm-kernel@lists.infradead.org
      Cc: linux-kernel@vger.kernel.org
      Cc: linuxppc-dev@lists.ozlabs.org
      Cc: sparclinux@vger.kernel.org
      Link: http://lkml.kernel.org/r/20140606175316.GV13930@laptop.programming.kicks-ass.net
      
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      4badad35
    • Jason Low's avatar
      locking/rwsem: Reduce the size of struct rw_semaphore · ce069fc9
      Jason Low authored
      
      
      Recent optimistic spinning additions to rwsem provide significant performance
      benefits on many workloads on large machines. The cost of it was increasing
      the size of the rwsem structure by up to 128 bits.
      
      However, now that the previous patches in this series bring the overhead of
      struct optimistic_spin_queue to 32 bits, this patch reorders some fields in
      struct rw_semaphore such that we can reduce the overhead of the rwsem structure
      by 64 bits (on 64 bit systems).
      
      The extra overhead required for rwsem optimistic spinning would now be up
      to 8 additional bytes instead of up to 16 bytes. Additionally, the size of
      rwsem would now be more in line with mutexes.
      
      Signed-off-by: default avatarJason Low <jason.low2@hp.com>
      Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
      Cc: Scott Norton <scott.norton@hp.com>
      Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
      Cc: Dave Chinner <david@fromorbit.com>
      Cc: Waiman Long <waiman.long@hp.com>
      Cc: Davidlohr Bueso <davidlohr@hp.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Tim Chen <tim.c.chen@linux.intel.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Aswin Chandramouleeswaran <aswin@hp.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Chris Mason <clm@fb.com>
      Cc: Josef Bacik <jbacik@fusionio.com>
      Link: http://lkml.kernel.org/r/1405358872-3732-6-git-send-email-jason.low2@hp.com
      
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      ce069fc9
    • Peter Zijlstra's avatar
      locking/rwsem: Rename 'activity' to 'count' · 13b9a962
      Peter Zijlstra authored
      
      
      There are two definitions of struct rw_semaphore, one in linux/rwsem.h
      and one in linux/rwsem-spinlock.h.
      
      For some reason they have different names for the initial field. This
      makes it impossible to use C99 named initialization for
      __RWSEM_INITIALIZER() -- or we have to duplicate that entire thing
      along with the structure definitions.
      
      The simpler patch is renaming the rwsem-spinlock variant to match the
      regular rwsem.
      
      This allows us to switch to C99 named initialization.
      
      Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Link: http://lkml.kernel.org/n/tip-bmrZolsbGmautmzrerog27io@git.kernel.org
      
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      13b9a962
    • Jason Low's avatar
      locking/spinlocks/mcs: Micro-optimize osq_unlock() · 33ecd208
      Jason Low authored
      
      
      In the unlock function of the cancellable MCS spinlock, the first
      thing we do is to retrive the current CPU's osq node. However, due to
      the changes made in the previous patch, in the common case where the
      lock is not contended, we wouldn't need to access the current CPU's
      osq node anymore.
      
      This patch optimizes this by only retriving this CPU's osq node
      after we attempt the initial cmpxchg to unlock the osq and found
      that its contended.
      
      Signed-off-by: default avatarJason Low <jason.low2@hp.com>
      Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
      Cc: Scott Norton <scott.norton@hp.com>
      Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
      Cc: Dave Chinner <david@fromorbit.com>
      Cc: Waiman Long <waiman.long@hp.com>
      Cc: Davidlohr Bueso <davidlohr@hp.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Tim Chen <tim.c.chen@linux.intel.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Aswin Chandramouleeswaran <aswin@hp.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Link: http://lkml.kernel.org/r/1405358872-3732-5-git-send-email-jason.low2@hp.com
      
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      33ecd208
    • Jason Low's avatar
      locking/spinlocks/mcs: Introduce and use init macro and function for osq locks · 4d9d951e
      Jason Low authored
      
      
      Currently, we initialize the osq lock by directly setting the lock's values. It
      would be preferable if we use an init macro to do the initialization like we do
      with other locks.
      
      This patch introduces and uses a macro and function for initializing the osq lock.
      
      Signed-off-by: default avatarJason Low <jason.low2@hp.com>
      Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
      Cc: Scott Norton <scott.norton@hp.com>
      Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
      Cc: Dave Chinner <david@fromorbit.com>
      Cc: Waiman Long <waiman.long@hp.com>
      Cc: Davidlohr Bueso <davidlohr@hp.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Tim Chen <tim.c.chen@linux.intel.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Aswin Chandramouleeswaran <aswin@hp.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Chris Mason <clm@fb.com>
      Cc: Josef Bacik <jbacik@fusionio.com>
      Link: http://lkml.kernel.org/r/1405358872-3732-4-git-send-email-jason.low2@hp.com
      
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      4d9d951e
    • Jason Low's avatar
      locking/spinlocks/mcs: Convert osq lock to atomic_t to reduce overhead · 90631822
      Jason Low authored
      
      
      The cancellable MCS spinlock is currently used to queue threads that are
      doing optimistic spinning. It uses per-cpu nodes, where a thread obtaining
      the lock would access and queue the local node corresponding to the CPU that
      it's running on. Currently, the cancellable MCS lock is implemented by using
      pointers to these nodes.
      
      In this patch, instead of operating on pointers to the per-cpu nodes, we
      store the CPU numbers in which the per-cpu nodes correspond to in atomic_t.
      A similar concept is used with the qspinlock.
      
      By operating on the CPU # of the nodes using atomic_t instead of pointers
      to those nodes, this can reduce the overhead of the cancellable MCS spinlock
      by 32 bits (on 64 bit systems).
      
      Signed-off-by: default avatarJason Low <jason.low2@hp.com>
      Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
      Cc: Scott Norton <scott.norton@hp.com>
      Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
      Cc: Dave Chinner <david@fromorbit.com>
      Cc: Waiman Long <waiman.long@hp.com>
      Cc: Davidlohr Bueso <davidlohr@hp.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Tim Chen <tim.c.chen@linux.intel.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Aswin Chandramouleeswaran <aswin@hp.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Chris Mason <clm@fb.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Josef Bacik <jbacik@fusionio.com>
      Link: http://lkml.kernel.org/r/1405358872-3732-3-git-send-email-jason.low2@hp.com
      
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      90631822
    • Jason Low's avatar
      locking/spinlocks/mcs: Rename optimistic_spin_queue() to optimistic_spin_node() · 046a619d
      Jason Low authored
      
      
      Currently, the per-cpu nodes structure for the cancellable MCS spinlock is
      named "optimistic_spin_queue". However, in a follow up patch in the series
      we will be introducing a new structure that serves as the new "handle" for
      the lock. It would make more sense if that structure is named
      "optimistic_spin_queue". Additionally, since the current use of the
      "optimistic_spin_queue" structure are  "nodes", it might be better if we
      rename them to "node" anyway.
      
      This preparatory patch renames all current "optimistic_spin_queue"
      to "optimistic_spin_node".
      
      Signed-off-by: default avatarJason Low <jason.low2@hp.com>
      Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
      Cc: Scott Norton <scott.norton@hp.com>
      Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
      Cc: Dave Chinner <david@fromorbit.com>
      Cc: Waiman Long <waiman.long@hp.com>
      Cc: Davidlohr Bueso <davidlohr@hp.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Tim Chen <tim.c.chen@linux.intel.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Aswin Chandramouleeswaran <aswin@hp.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Chris Mason <clm@fb.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Josef Bacik <jbacik@fusionio.com>
      Link: http://lkml.kernel.org/r/1405358872-3732-2-git-send-email-jason.low2@hp.com
      
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      046a619d
    • Jason Low's avatar
      locking/rwsem: Allow conservative optimistic spinning when readers have lock · 37e95624
      Jason Low authored
      Commit 4fc828e2
      
       ("locking/rwsem: Support optimistic spinning")
      introduced a major performance regression for workloads such as
      xfs_repair which mix read and write locking of the mmap_sem across
      many threads. The result was xfs_repair ran 5x slower on 3.16-rc2
      than on 3.15 and using 20x more system CPU time.
      
      Perf profiles indicate in some workloads that significant time can
      be spent spinning on !owner. This is because we don't set the lock
      owner when readers(s) obtain the rwsem.
      
      In this patch, we'll modify rwsem_can_spin_on_owner() such that we'll
      return false if there is no lock owner. The rationale is that if we
      just entered the slowpath, yet there is no lock owner, then there is
      a possibility that a reader has the lock. To be conservative, we'll
      avoid spinning in these situations.
      
      This patch reduced the total run time of the xfs_repair workload from
      about 4 minutes 24 seconds down to approximately 1 minute 26 seconds,
      back to close to the same performance as on 3.15.
      
      Retesting of AIM7, which were some of the workloads used to test the
      original optimistic spinning code, confirmed that we still get big
      performance gains with optimistic spinning, even with this additional
      regression fix. Davidlohr found that while the 'custom' workload took
      a performance hit of ~-14% to throughput for >300 users with this
      additional patch, the overall gain with optimistic spinning is
      still ~+45%. The 'disk' workload even improved by ~+15% at >1000 users.
      
      Tested-by: default avatarDave Chinner <dchinner@redhat.com>
      Acked-by: default avatarDavidlohr Bueso <davidlohr@hp.com>
      Signed-off-by: default avatarJason Low <jason.low2@hp.com>
      Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
      Cc: Tim Chen <tim.c.chen@linux.intel.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Link: http://lkml.kernel.org/r/1404532172.2572.30.camel@j-VirtualBox
      
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      37e95624
  2. Jul 14, 2014
    • Linus Torvalds's avatar
      Linux 3.16-rc5 · 1795cd9b
      Linus Torvalds authored
      1795cd9b
    • Linus Torvalds's avatar
      Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 · 18b34d9a
      Linus Torvalds authored
      Pull ext4 bugfixes from Ted Ts'o:
       "More bug fixes for ext4 -- most importantly, a fix for a bug
        introduced in 3.15 that can end up triggering a file system corruption
        error after a journal replay.
      
        It shouldn't lead to any actual data corruption, but it is scary and
        can force file systems to be remounted read-only, etc"
      
      * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
        ext4: fix potential null pointer dereference in ext4_free_inode
        ext4: fix a potential deadlock in __ext4_es_shrink()
        ext4: revert commit which was causing fs corruption after journal replays
        ext4: disable synchronous transaction batching if max_batch_time==0
        ext4: clarify ext4_error message in ext4_mb_generate_buddy_error()
        ext4: clarify error count warning messages
        ext4: fix unjournalled bg descriptor while initializing inode bitmap
      18b34d9a
    • Linus Torvalds's avatar
      Merge tag 'clk-fixes-for-linus' of git://git.linaro.org/people/mike.turquette/linux · 502fde1a
      Linus Torvalds authored
      Pull clock driver fixes from Mike Turquette:
       "This batch of fixes is for a handful of clock drivers from Allwinner,
        Samsung, ST & TI.  Most of them are of the "this hardware won't work
        without this fix" variety, including patches that fix platforms that
        did not boot under certain configurations.  Other fixes are the result
        of changes to the clock core introduced in 3.15 that had subtle
        impacts on the clock drivers.
      
        There are no fixes to the clock framework core in this pull request"
      
      * tag 'clk-fixes-for-linus' of git://git.linaro.org/people/mike.turquette/linux:
        clk: spear3xx: Set proper clock parent of uart1/2
        clk: spear3xx: Use proper control register offset
        clk: qcom: HDMI source sel is 3 not 2
        clk: sunxi: fix devm_ioremap_resource error detection code
        clk: s2mps11: Fix double free corruption during driver unbind
        clk: ti: am43x: Fix boot with CONFIG_SOC_AM33XX disabled
        clk: exynos5420: Remove aclk66_peric from the clock tree description
        clk/exynos5250: fix bit number for tv sysmmu clock
        clk: s3c64xx: Hookup SPI clocks correctly
        clk: samsung: exynos4: Remove SRC_MASK_ISP gates
        clk: samsung: add more aliases for s3c24xx
        clk: samsung: fix several typos to fix boot on s3c2410
        clk: ti: set CLK_SET_RATE_NO_REPARENT for ti,mux-clock
        clk: ti: am43x: Fix boot with CONFIG_SOC_AM33XX disabled
        clk: ti: dra7: return error code in failure case
        clk: ti: apll: not allocating enough data
      502fde1a
    • Linus Torvalds's avatar
      Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc · 2f3870e9
      Linus Torvalds authored
      Pull ARM SoC fixes from Olof Johansson:
       "This week's arm-soc fixes:
      
         - Another set of OMAP fixes
           * Clock fixes
           * Restart handling
           * PHY regulators
           * SATA hwmod data for DRA7
           + Some trivial fixes and removal of a bit of dead code
         - Exynos fixes
           * A bunch of clock fixes
           * Some SMP fixes
           * Exynos multi-core timer: register as clocksource and fix ftrace.
           + a few other minor fixes
      
        There's also a couple more patches, and at91 fix for USB caused by
        common clock conversion, and more MAINTAINERS entries for shmobile.
      
        We're definitely switching to only regression fixes from here on out,
        we've been a little less strict than usual up until now"
      
      * tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (26 commits)
        ARM: at91: at91sam9x5: add clocks for usb device
        ARM: EXYNOS: Register cpuidle device only on exynos4210 and 5250
        ARM: dts: Add clock property for mfc_pd in exynos5420
        clk: exynos5420: Add IDs for clocks used in PD mfc
        ARM: EXYNOS: Add support for clock handling in power domain
        ARM: OMAP2+: Remove non working OMAP HDMI audio initialization
        ARM: imx: fix shared gate clock
        ARM: dts: Update the parent for Audss clocks in Exynos5420
        ARM: EXYNOS: Update secondary boot addr for secure mode
        ARM: dts: Fix TI CPSW Phy mode selection on IGEP COM AQUILA.
        ARM: dts: am335x-evmsk: Enable the McASP FIFO for audio
        ARM: dts: am335x-evm: Enable the McASP FIFO for audio
        ARM: OMAP2+: Make GPMC skip disabled devices
        ARM: OMAP2+: create dsp device only on OMAP3 SoCs
        ARM: dts: dra7-evm: Make VDDA_1V8_PHY supply always on
        ARM: DRA7/AM43XX: fix header definition for omap44xx_restart
        ARM: OMAP2+: clock/dpll: fix _dpll_test_fint arithmetics overflow
        ARM: DRA7: hwmod: Add SYSCONFIG for usb_otg_ss
        ARM: DRA7: hwmod: Fixup SATA hwmod
        ARM: OMAP3: PRM/CM: Add back macros used by TI DSP/Bridge driver
        ...
      2f3870e9
    • Linus Torvalds's avatar
      Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm · 5fa77b54
      Linus Torvalds authored
      Pull ARM fixes from Russell King:
       "Another round of fixes for ARM:
         - a set of kprobes fixes from Jon Medhurst
         - fix the revision checking for the L2 cache which wasn't noticed to
           have been broken"
      
      * 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
        ARM: l2c: fix revision checking
        ARM: kprobes: Fix test code compilation errors for ARMv4 targets
        ARM: kprobes: Disallow instructions with PC and register specified shift
        ARM: kprobes: Prevent known test failures stopping other tests running
      5fa77b54
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k · 33fe3aee
      Linus Torvalds authored
      Pull m68k fixes from Geert Uytterhoeven:
       "Summary:
        - Fix for a boot regression introduced in v3.16-rc1,
        - Fix for a build issue in -next"
      
      Christoph Hellwig questioned why mach_random_get_entropy should be
      exported to modules, and Geert explains that random_get_entropy() is
      called by at least the crypto layer and ends up using it on m68k.  On
      most other architectures it just uses get_cycles() (which is typically
      inlined and doesn't need exporting),
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
        m68k: Export mach_random_get_entropy to modules
        m68k: Fix boot regression on machines with RAM at non-zero
      33fe3aee
    • Linus Torvalds's avatar
      Merge branch 'parisc-3.16-5' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux · 54f8c2aa
      Linus Torvalds authored
      Pull parisc fixes from Helge Deller:
       "The major patch in here is one which fixes the fanotify_mark() syscall
        in the compat layer of the 64bit parisc kernel.  It went unnoticed so
        long, because the calling syntax when using a 64bit parameter in a
        32bit syscall is quite complex and even worse, it may be even
        different if you call syscall() or the glibc wrapper.  This patch
        makes the kernel accept the calling convention when called by the
        glibc wrapper.
      
        The other two patches are trivial and remove unused headers, #includes
        and adds the serial ports of the fastest C8000 workstation to the
        parisc-kernel internal hardware database"
      
      * 'parisc-3.16-5' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
        parisc: drop unused defines and header includes
        parisc: fix fanotify_mark() syscall on 32bit compat kernel
        parisc: add serial ports of C8000/1GHz machine to hardware database
      54f8c2aa
  3. Jul 13, 2014
  4. Jul 12, 2014