1. 10 Apr, 2013 5 commits
  2. 08 Apr, 2013 1 commit
  3. 18 Mar, 2013 2 commits
  4. 14 Mar, 2013 1 commit
  5. 13 Mar, 2013 2 commits
    • Frederic Weisbecker's avatar
      sched: Lower chances of cputime scaling overflow · d9a3c982
      Frederic Weisbecker authored
      Some users have reported that after running a process with
      hundreds of threads on intensive CPU-bound loads, the cputime
      of the group started to freeze after a few days.
      
      This is due to how we scale the tick-based cputime against
      the scheduler precise execution time value.
      
      We add the values of all threads in the group and we multiply
      that against the sum of the scheduler exec runtime of the whole
      group.
      
      This easily overflows after a few days/weeks of execution.
      
      A proposed solution to solve this was to compute that multiplication
      on stime instead of utime:
         62188451
         ("cputime: Avoid multiplication overflow on utime scaling")
      
      The rationale behind that was that it's easy for a thread to
      spend most of its time in userspace under intensive CPU-bound workload
      but it's much harder to do CPU-bound intensive long run in the kernel.
      
      This postulate got defeated when a user recently reported he was still
      seeing cputime freezes after the above patch. The workload that
      triggers this issue relates to intensive networking workloads where
      most of the cputime is consumed in the kernel.
      
      To reduce much more the opportunities for multiplication overflow,
      lets reduce the multiplication factors to the remainders of the division
      between sched exec runtime and cputime. Assuming the difference between
      these shouldn't ever be that large, it could work on many situations.
      
      This gets the same results as in the upstream scaling code except for
      a small difference: the upstream code always rounds the results to
      the nearest integer not greater to what would be the precise result.
      The new code rounds to the nearest integer either greater or not
      greater. In practice this difference probably shouldn't matter but
      it's worth mentioning.
      
      If this solution appears not to be enough in the end, we'll
      need to partly revert back to the behaviour prior to commit
           0cf55e1e
           ("sched, cputime: Introduce thread_group_times()")
      
      Back then, the scaling was done on exit() time before adding the cputime
      of an exiting thread to the signal struct. And then we'll need to
      scale one-by-one the live threads cputime in thread_group_cputime(). The
      drawback may be a slightly slower code on exit time.
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Stanislaw Gruszka <sgruszka@redhat.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      d9a3c982
    • Frederic Weisbecker's avatar
      math64: New div64_u64_rem helper · f7926850
      Frederic Weisbecker authored
      Provide an extended version of div64_u64() that
      also returns the remainder of the division.
      
      We are going to need this to refine the cputime
      scaling code.
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Stanislaw Gruszka <sgruszka@redhat.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      f7926850
  6. 11 Mar, 2013 2 commits
  7. 08 Mar, 2013 1 commit
  8. 07 Mar, 2013 5 commits
    • Frederic Weisbecker's avatar
      context_tracking: Enable probes by default for selftesting · 8b438766
      Frederic Weisbecker authored
      Until we provide the nohz_mask boot parameter, keeping
      the context tracking probes disabled by default is pointless
      since what we want is to runtime test this code anyway.
      
      It's furthermore confusing for the users which don't expect
      the probes to be off when they select RCU user mode or full
      dynticks cputime accounting.
      
      Let's enable these probes selftests by default for now.
      
      Suggested: Steven Rostedt <rostedt@goodmis.org>
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Li Zhong <zhong@linux.vnet.ibm.com>
      Cc: Kevin Hilman <khilman@linaro.org>
      Cc: Mats Liljegren <mats.liljegren@enea.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Namhyung Kim <namhyung.kim@lge.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      8b438766
    • Frederic Weisbecker's avatar
      cputime: Dynamically scale cputime for full dynticks accounting · 9fbc42ea
      Frederic Weisbecker authored
      The full dynticks cputime accounting is able to account either
      using the tick or the context tracking subsystem. This way
      the housekeeping CPU can keep the low overhead tick based
      solution.
      
      This latter mode has a low jiffies resolution granularity and
      need to be scaled against CFS precise runtime accounting to
      improve its result. We are doing this for CONFIG_TICK_CPU_ACCOUNTING,
      now we also need to expand it to full dynticks accounting dynamic
      off-case as well.
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Li Zhong <zhong@linux.vnet.ibm.com>
      Cc: Kevin Hilman <khilman@linaro.org>
      Cc: Mats Liljegren <mats.liljegren@enea.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Namhyung Kim <namhyung.kim@lge.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      9fbc42ea
    • Frederic Weisbecker's avatar
      context_tracking: Restore preempted context state after preempt_schedule_irq() · b22366cd
      Frederic Weisbecker authored
      From the context tracking POV, preempt_schedule_irq() behaves pretty much
      like an exception: It can be called anytime and schedule another task.
      
      But currently it doesn't restore the context tracking state of the preempted
      code on preempt_schedule_irq() return.
      
      As a result, if preempt_schedule_irq() is called in the tiny frame between
      user_enter() and the actual return to userspace, we resume userspace with
      the wrong context tracking state.
      
      Fix this by using exception_enter/exit() which are a perfect fit for this
      kind of issue.
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Li Zhong <zhong@linux.vnet.ibm.com>
      Cc: Kevin Hilman <khilman@linaro.org>
      Cc: Mats Liljegren <mats.liljegren@enea.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Namhyung Kim <namhyung.kim@lge.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      b22366cd
    • Frederic Weisbecker's avatar
      context_tracking: Restore correct previous context state on exception exit · 6c1e0256
      Frederic Weisbecker authored
      On exception exit, we restore the previous context tracking state based on
      the regs of the interrupted frame. Iff that frame is in user mode as
      stated by user_mode() helper, we restore the context tracking user mode.
      
      However there is a tiny chunck of low level arch code after we pass through
      user_enter() and until the CPU eventually resumes userspace.
      If an exception happens in this tiny area, exception_enter() correctly
      exits the context tracking user mode but exception_exit() won't restore
      it because of the value returned by user_mode(regs).
      
      As a result we may return to userspace with the wrong context tracking
      state.
      
      To fix this, change exception_enter() to return the context tracking state
      prior to its call and pass this saved state to exception_exit(). This restores
      the real context tracking state of the interrupted frame.
      
      (May be this patch was suggested to me, I don't recall exactly. If so,
      sorry for the missing credit).
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Li Zhong <zhong@linux.vnet.ibm.com>
      Cc: Kevin Hilman <khilman@linaro.org>
      Cc: Mats Liljegren <mats.liljegren@enea.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Namhyung Kim <namhyung.kim@lge.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      6c1e0256
    • Frederic Weisbecker's avatar
      context_tracking: Move exception handling to generic code · 56dd9470
      Frederic Weisbecker authored
      Exceptions handling on context tracking should share common
      treatment: on entry we exit user mode if the exception triggered
      in that context. Then on exception exit we return to that previous
      context.
      
      Generalize this to avoid duplication across archs.
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Li Zhong <zhong@linux.vnet.ibm.com>
      Cc: Kevin Hilman <khilman@linaro.org>
      Cc: Mats Liljegren <mats.liljegren@enea.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Namhyung Kim <namhyung.kim@lge.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      56dd9470
  9. 06 Mar, 2013 9 commits
  10. 03 Mar, 2013 12 commits
    • Linus Torvalds's avatar
      Linux 3.9-rc1 · 6dbe51c2
      Linus Torvalds authored
      6dbe51c2
    • Linus Torvalds's avatar
      Merge tag 'disintegrate-fbdev-20121220' of git://git.infradead.org/users/dhowells/linux-headers · ea882c2e
      Linus Torvalds authored
      Pull fbdev UAPI disintegration from David Howells:
       "You'll be glad to here that the end is nigh for the UAPI patches.
        Only the fbdev/framebuffer piece remains now that the SCSI stuff has
        gone in.
      
        Here are the UAPI disintegration bits for the fbdev drivers.  It
        appears that Florian hasn't had time to deal with my patch, but back
        in December he did say he didn't mind if I pushed it forward."
      
      Yay.  No more uapi movement.  And hopefully no more big header file
      cleanups coming up either, it just tends to be very painful.
      
      * tag 'disintegrate-fbdev-20121220' of git://git.infradead.org/users/dhowells/linux-headers:
        UAPI: (Scripted) Disintegrate include/video
      ea882c2e
    • Linus Torvalds's avatar
      Merge tag 'stable/for-linus-3.9-rc1-tag' of... · 8e8b180a
      Linus Torvalds authored
      Merge tag 'stable/for-linus-3.9-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
      
      Pull Xen bug-fixes from Konrad Rzeszutek Wilk:
       - Update the Xen ACPI memory and CPU hotplug locking mechanism.
       - Fix PAT issues wherein various applications would not start
       - Fix handling of multiple MSI as AHCI now does it.
       - Fix ARM compile failures.
      
      * tag 'stable/for-linus-3.9-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
        xenbus: fix compile failure on ARM with Xen enabled
        xen/pci: We don't do multiple MSI's.
        xen/pat: Disable PAT using pat_enabled value.
        xen/acpi: xen cpu hotplug minor updates
        xen/acpi: xen memory hotplug minor updates
      8e8b180a
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs · 56a79b7b
      Linus Torvalds authored
      Pull  more VFS bits from Al Viro:
       "Unfortunately, it looks like xattr series will have to wait until the
        next cycle ;-/
      
        This pile contains 9p cleanups and fixes (races in v9fs_fid_add()
        etc), fixup for nommu breakage in shmem.c, several cleanups and a bit
        more file_inode() work"
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
        constify path_get/path_put and fs_struct.c stuff
        fix nommu breakage in shmem.c
        cache the value of file_inode() in struct file
        9p: if v9fs_fid_lookup() gets to asking server, it'd better have hashed dentry
        9p: make sure ->lookup() adds fid to the right dentry
        9p: untangle ->lookup() a bit
        9p: double iput() in ->lookup() if d_materialise_unique() fails
        9p: v9fs_fid_add() can't fail now
        v9fs: get rid of v9fs_dentry
        9p: turn fid->dlist into hlist
        9p: don't bother with private lock in ->d_fsdata; dentry->d_lock will do just fine
        more file_inode() open-coded instances
        selinux: opened file can't have NULL or negative ->f_path.dentry
      
      (In the meantime, the hlist traversal macros have changed, so this
      required a semantic conflict fixup for the newly hlistified fid->dlist)
      56a79b7b
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs · 1c82315a
      Linus Torvalds authored
      Pull btrfs fixup from Chris Mason:
       "Geert and James both sent this one in, sorry guys"
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
        btrfs/raid56: Add missing #include <linux/vmalloc.h>
      1c82315a
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux · 530ede14
      Linus Torvalds authored
      Pull second set of s390 patches from Martin Schwidefsky:
       "The main part of this merge are Heikos uaccess patches.  Together with
        commit 09884964 ("mm: do not grow the stack vma just because of an
        overrun on preceding vma") the user string access is hopefully fixed
        for good.
      
        In addition some bug fixes and two cleanup patches."
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
        s390/module: fix compile warning
        qdio: remove unused parameters
        s390/uaccess: fix kernel ds access for page table walk
        s390/uaccess: fix strncpy_from_user string length check
        input: disable i8042 PC Keyboard controller for s390
        s390/dis: Fix invalid array size
        s390/uaccess: remove pointless access_ok() checks
        s390/uaccess: fix strncpy_from_user/strnlen_user zero maxlen case
        s390/uaccess: shorten strncpy_from_user/strnlen_user
        s390/dasd: fix unresponsive device after all channel paths were lost
        s390/mm: ignore change bit for vmemmap
        s390/page table dumper: add support for change-recording override bit
      530ede14
    • Linus Torvalds's avatar
      Merge branch 'fixes-for-3.9-latest' of... · 6977c6fc
      Linus Torvalds authored
      Merge branch 'fixes-for-3.9-latest' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
      
      Pull second round of PARISC updates from Helge Deller:
       "The most important fix in this branch is the switch of io_setup,
        io_getevents and io_submit syscalls to use the available compat
        syscalls when running 32bit userspace on 64bit kernel.  Other than
        that it's mostly removal of compile warnings."
      
      * 'fixes-for-3.9-latest' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
        parisc: fix redefinition of SET_PERSONALITY
        parisc: do not install modules when installing kernel
        parisc: fix compile warnings triggered by atomic_sub(sizeof(),v)
        parisc: check return value of down_interruptible() in hp_sdc_rtc.c
        parisc: avoid unitialized variable warning in pa_memcpy()
        parisc: remove unused variable 'compat_val'
        parisc: switch to compat_functions of io_setup, io_getevents and io_submit
        parisc: select ARCH_WANT_FRAME_POINTERS
      6977c6fc
    • Linus Torvalds's avatar
      Merge tag 'metag-v3.9-rc1-v4' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag · 8fd5e7a2
      Linus Torvalds authored
      Pull new ImgTec Meta architecture from James Hogan:
       "This adds core architecture support for Imagination's Meta processor
        cores, followed by some later miscellaneous arch/metag cleanups and
        fixes which I kept separate to ease review:
      
         - Support for basic Meta 1 (ATP) and Meta 2 (HTP) core architecture
         - A few fixes all over, particularly for symbol prefixes
         - A few privilege protection fixes
         - Several cleanups (setup.c includes, split out a lot of
           metag_ksyms.c)
         - Fix some missing exports
         - Convert hugetlb to use vm_unmapped_area()
         - Copy device tree to non-init memory
         - Provide dma_get_sgtable()"
      
      * tag 'metag-v3.9-rc1-v4' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag: (61 commits)
        metag: Provide dma_get_sgtable()
        metag: prom.h: remove declaration of metag_dt_memblock_reserve()
        metag: copy devicetree to non-init memory
        metag: cleanup metag_ksyms.c includes
        metag: move mm/init.c exports out of metag_ksyms.c
        metag: move usercopy.c exports out of metag_ksyms.c
        metag: move setup.c exports out of metag_ksyms.c
        metag: move kick.c exports out of metag_ksyms.c
        metag: move traps.c exports out of metag_ksyms.c
        metag: move irq enable out of irqflags.h on SMP
        genksyms: fix metag symbol prefix on crc symbols
        metag: hugetlb: convert to vm_unmapped_area()
        metag: export clear_page and copy_page
        metag: export metag_code_cache_flush_all
        metag: protect more non-MMU memory regions
        metag: make TXPRIVEXT bits explicit
        metag: kernel/setup.c: sort includes
        perf: Enable building perf tools for Meta
        metag: add boot time LNKGET/LNKSET check
        metag: add __init to metag_cache_probe()
        ...
      8fd5e7a2
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm · 529e5fbc
      Linus Torvalds authored
      Pull late ARM updates from Russell King:
       "Here is the late set of ARM updates for this merge window; in here is:
      
         - The ARM parts of the broadcast timer support, core parts merged
           through tglx's tree.  This was left over from the previous merge to
           allow the dependency on tglx's tree to be resolved.
      
         - A fix to the VFP code which shows up on Raspberry Pi's, as well as
           fixing the fallout from a previous commit in this area.
      
         - A number of smaller fixes scattered throughout the ARM tree"
      
      * 'for-linus' of git://git.linaro.org/people/rmk/linux-arm:
        ARM: Fix broken commit 0cc41e4a corrupting kernel messages
        ARM: fix scheduling while atomic warning in alignment handling code
        ARM: VFP: fix emulation of second VFP instruction
        ARM: 7656/1: uImage: Error out on build of multiplatform without LOADADDR
        ARM: 7640/1: memory: tegra_ahb_enable_smmu() depends on TEGRA_IOMMU_SMMU
        ARM: 7654/1: Preserve L_PTE_VALID in pte_modify()
        ARM: 7653/2: do not scale loops_per_jiffy when using a constant delay clock
        ARM: 7651/1: remove unused smp_timer_broadcast #define
      529e5fbc
    • Linus Torvalds's avatar
      Merge tag 'char-misc-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc · 686c0940
      Linus Torvalds authored
      Pull char/misc patch from Greg Kroah-Hartman:
       "Here is one remaining patch for 3.9-rc1.  It is for the hyper-v
        drivers, and had to wait until some other patches went in through the
        x86 tree."
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      
      * tag 'char-misc-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
        Drivers: hv: vmbus: Use the new infrastructure for delivering VMBUS interrupts
      686c0940
    • Linus Torvalds's avatar
      Merge tag 'usb-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb · bc2e4a90
      Linus Torvalds authored
      Pull USB patch revert from Greg Kroah-Hartman:
       "Here is one remaining USB patch for 3.9-rc1, it reverts a 3.8 patch
        that has caused a lot of regressions for some VIA EHCI controllers."
      
      * tag 'usb-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
        USB: EHCI: revert "remove ASS/PSS polling timeout"
      bc2e4a90
    • Linus Torvalds's avatar
      Merge git://www.linux-watchdog.org/linux-watchdog · 68b86a25
      Linus Torvalds authored
      Pull watchdog updates from Wim Van Sebroeck:
       "This contains:
         - fixes and improvements
         - devicetree bindings
         - conversion to watchdog generic framework of the following drivers:
              - booke_wdt
              - bcm47xx_wdt.c
              - at91sam9_wdt
         - Removal of old STMP3xxx driver
         - Addition of following new drivers:
              - new driver for STMP3xxx and i.MX23/28
              - Retu watchdog driver"
      
      * git://www.linux-watchdog.org/linux-watchdog: (30 commits)
        watchdog: sp805_wdt depends on ARM
        watchdog: davinci_wdt: update to devm_* API
        watchdog: davinci_wdt: use devm managed clk get
        watchdog: at91rm9200: add DT support
        watchdog: add timeout-sec property binding
        watchdog: at91sam9_wdt: Convert to use the watchdog framework
        watchdog: omap_wdt: Add option nowayout
        watchdog: core: dt: add support for the timeout-sec dt property
        watchdog: bcm47xx_wdt.c: add hard timer
        watchdog: bcm47xx_wdt.c: rename wdt_time to timeout
        watchdog: bcm47xx_wdt.c: rename ops methods
        watchdog: bcm47xx_wdt.c: use platform device
        watchdog: bcm47xx_wdt.c: convert to watchdog core api
        watchdog: Convert BookE watchdog driver to watchdog infrastructure
        watchdog: s3c2410_wdt: Use devm_* functions
        watchdog: remove old STMP3xxx driver
        watchdog: add new driver for STMP3xxx and i.MX23/28
        rtc: stmp3xxx: add wdt-accessor function
        watchdog: introduce retu_wdt driver
        watchdog: intel_scu_watchdog: fix Kconfig dependency
        ...
      68b86a25