1. 07 Jun, 2016 5 commits
    • Jyri Sarha's avatar
      drm/omapdrm: Implement gamma_lut atomic crtc properties · 492a426a
      Jyri Sarha authored
      Implement gamma_lut atomic crtc properties, set crtc gamma size to 256
      for all crtcs and use drm_atomic_helper_legacy_gamma_set() as
      gamma_set func. The tv-out crtc has 1024 element gamma table (with
      10bit precision) in HW, but current Xorg server does not accept
      anything else but 256 elements so that is used for all CRTCs. The dss
      dispc API converts table of any length for HW and uses linear
      interpolation in the process. The default gamma table is restored
      if gamma_lut property is deleted.
      Signed-off-by: default avatarJyri Sarha <jsarha@ti.com>
      Signed-off-by: default avatarTomi Valkeinen <tomi.valkeinen@ti.com>
      492a426a
    • Jyri Sarha's avatar
      drm/omapdrm: Workaround for errata i734 (LCD1 Gamma) in DSS dispc · fbff010b
      Jyri Sarha authored
      Workaround for errata i734 in DSS dispc
       - LCD1 Gamma Correction Is Not Working When GFX Pipe Is Disabled
      
      For gamma tables to work on LCD1 the GFX plane has to be used at least
      once after DSS HW has come out of reset. The workaround sets up a
      minimal LCD setup with GFX plane and waits for one vertical sync irq
      before disabling the setup and continuing with the context
      restore. The physical outputs are gated during the operation.
      
      For details see:
      OMAP543x Multimedia Device Silicon Revision 2.0 Silicon Errata
      Literature Number: SWPZ037E
      Or some other relevant errata document for the DSS IP version.
      Signed-off-by: default avatarJyri Sarha <jsarha@ti.com>
      Signed-off-by: default avatarTomi Valkeinen <tomi.valkeinen@ti.com>
      fbff010b
    • Jyri Sarha's avatar
      drm/omapdrm: Add gamma table support to DSS dispc · acc3a231
      Jyri Sarha authored
      Add gamma table support to DSS dispc.
      
      DSS driver initializes the default gamma table at component bind time
      and holds a copy of all gamma tables in its internal data structure.
      
      Each call to dispc_mgr_set_gamma() updates the internal table and
      triggers write to the HW, if it is enabled. The tables are restored to
      HW in PM resume callback. The drivers internal data structure match
      the HW tables in size and in number of significant bits per color
      component. The dispc_mgr_set_gamma() converts the size of any given
      table for the internal data structure using linear interpolation.
      Default gamma table is restored if NULL is given in place of gamma
      lut.
      
      dispc_mgr_gamma_size() gives HW gamma table size for the channel and
      returns 0 if gamma table is not supported by the HW or the DSS driver.
      Signed-off-by: default avatarJyri Sarha <jsarha@ti.com>
      Signed-off-by: default avatarTomi Valkeinen <tomi.valkeinen@ti.com>
      acc3a231
    • Jyri Sarha's avatar
      drm: drm_helper_crtc_enable_color_mgmt() => drm_crtc_enable_color_mgmt() · f8ed34ac
      Jyri Sarha authored
      Add drm_crtc_enable_color_mgmt(), remove drm_helper_crtc_enable_color_mgmt()
      and update drm/i915-driver (the only user of the old function).
      
      The new function is more flexible. It allows driver to enable only the
      features it has without forcing to enable all three color management
      properties: degamma lut, csc matrix (ctm), and gamma lut.
      Suggested-by: default avatarDaniel Vetter <daniel@ffwll.ch>
      Signed-off-by: default avatarJyri Sarha <jsarha@ti.com>
      Signed-off-by: default avatarTomi Valkeinen <tomi.valkeinen@ti.com>
      f8ed34ac
    • Tomi Valkeinen's avatar
      Merge omapdss header refactoring · a1dec226
      Tomi Valkeinen authored
      Merge omapdss public header refactoring, which separates the public
      header into omapdrm and omapfb parts.
      a1dec226
  2. 06 Jun, 2016 15 commits
  3. 05 Jun, 2016 7 commits
    • Linus Torvalds's avatar
      Linux 4.7-rc2 · af8c34ce
      Linus Torvalds authored
      af8c34ce
    • Linus Torvalds's avatar
      Merge branch 'parisc-4.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux · 5975b2c0
      Linus Torvalds authored
      Pull parisc fixes from Helge Deller:
      
       - Fix printk time stamps on SMP systems which got wrong due to a patch
         which was added during the merge window
      
       - Fix two bugs in the stack backtrace code: Races in module unloading
         and possible invalid accesses to memory due to wrong instruction
         decoding (Mikulas Patocka)
      
       - Fix userspace crash when syscalls access invalid unaligned userspace
         addresses.  Those syscalls will now return EFAULT as expected.
         (tagged for stable kernel series)
      
      * 'parisc-4.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
        parisc: Move die_if_kernel() prototype into traps.h header
        parisc: Fix pagefault crash in unaligned __get_user() call
        parisc: Fix printk time during boot
        parisc: Fix backtrace on PA-RISC
      5975b2c0
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security · d834502e
      Linus Torvalds authored
      Pull key handling update from James Morris:
       "This alters a new keyctl function added in the current merge window to
        allow for a future extension planned for the next merge window"
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
        KEYS: Add placeholder for KDF usage with DH
      d834502e
    • Eric W. Biederman's avatar
      devpts: Make each mount of devpts an independent filesystem. · eedf265a
      Eric W. Biederman authored
      The /dev/ptmx device node is changed to lookup the directory entry "pts"
      in the same directory as the /dev/ptmx device node was opened in.  If
      there is a "pts" entry and that entry is a devpts filesystem /dev/ptmx
      uses that filesystem.  Otherwise the open of /dev/ptmx fails.
      
      The DEVPTS_MULTIPLE_INSTANCES configuration option is removed, so that
      userspace can now safely depend on each mount of devpts creating a new
      instance of the filesystem.
      
      Each mount of devpts is now a separate and equal filesystem.
      
      Reserved ttys are now available to all instances of devpts where the
      mounter is in the initial mount namespace.
      
      A new vfs helper path_pts is introduced that finds a directory entry
      named "pts" in the directory of the passed in path, and changes the
      passed in path to point to it.  The helper path_pts uses a function
      path_parent_directory that was factored out of follow_dotdot.
      
      In the implementation of devpts:
       - devpts_mnt is killed as it is no longer meaningful if all mounts of
         devpts are equal.
       - pts_sb_from_inode is replaced by just inode->i_sb as all cached
         inodes in the tty layer are now from the devpts filesystem.
       - devpts_add_ref is rolled into the new function devpts_ptmx.  And the
         unnecessary inode hold is removed.
       - devpts_del_ref is renamed devpts_release and reduced to just a
         deacrivate_super.
       - The newinstance mount option continues to be accepted but is now
         ignored.
      
      In devpts_fs.h definitions for when !CONFIG_UNIX98_PTYS are removed as
      they are never used.
      
      Documentation/filesystems/devices.txt is updated to describe the current
      situation.
      
      This has been verified to work properly on openwrt-15.05, centos5,
      centos6, centos7, debian-6.0.2, debian-7.9, debian-8.2, ubuntu-14.04.3,
      ubuntu-15.10, fedora23, magia-5, mint-17.3, opensuse-42.1,
      slackware-14.1, gentoo-20151225 (13.0?), archlinux-2015-12-01.  With the
      caveat that on centos6 and on slackware-14.1 that there wind up being
      two instances of the devpts filesystem mounted on /dev/pts, the lower
      copy does not end up getting used.
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Cc: Greg KH <greg@kroah.com>
      Cc: Peter Hurley <peter@hurleysoftware.com>
      Cc: Peter Anvin <hpa@zytor.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Serge Hallyn <serge.hallyn@ubuntu.com>
      Cc: Willy Tarreau <w@1wt.eu>
      Cc: Aurelien Jarno <aurelien@aurel32.net>
      Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
      Cc: Jann Horn <jann@thejh.net>
      Cc: Jiri Slaby <jslaby@suse.com>
      Cc: Florian Weimer <fw@deneb.enyo.de>
      Cc: Konstantin Khlebnikov <koct9i@gmail.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      eedf265a
    • Helge Deller's avatar
      58f1c654
    • Helge Deller's avatar
      parisc: Fix pagefault crash in unaligned __get_user() call · 8b78f260
      Helge Deller authored
      One of the debian buildd servers had this crash in the syslog without
      any other information:
      
       Unaligned handler failed, ret = -2
       clock_adjtime (pid 22578): Unaligned data reference (code 28)
       CPU: 1 PID: 22578 Comm: clock_adjtime Tainted: G  E  4.5.0-2-parisc64-smp #1 Debian 4.5.4-1
       task: 000000007d9960f8 ti: 00000001bde7c000 task.ti: 00000001bde7c000
      
            YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
       PSW: 00001000000001001111100000001111 Tainted: G            E
       r00-03  000000ff0804f80f 00000001bde7c2b0 00000000402d2be8 00000001bde7c2b0
       r04-07  00000000409e1fd0 00000000fa6f7fff 00000001bde7c148 00000000fa6f7fff
       r08-11  0000000000000000 00000000ffffffff 00000000fac9bb7b 000000000002b4d4
       r12-15  000000000015241c 000000000015242c 000000000000002d 00000000fac9bb7b
       r16-19  0000000000028800 0000000000000001 0000000000000070 00000001bde7c218
       r20-23  0000000000000000 00000001bde7c210 0000000000000002 0000000000000000
       r24-27  0000000000000000 0000000000000000 00000001bde7c148 00000000409e1fd0
       r28-31  0000000000000001 00000001bde7c320 00000001bde7c350 00000001bde7c218
       sr00-03  0000000001200000 0000000001200000 0000000000000000 0000000001200000
       sr04-07  0000000000000000 0000000000000000 0000000000000000 0000000000000000
      
       IASQ: 0000000000000000 0000000000000000 IAOQ: 00000000402d2e84 00000000402d2e88
        IIR: 0ca0d089    ISR: 0000000001200000  IOR: 00000000fa6f7fff
        CPU:        1   CR30: 00000001bde7c000 CR31: ffffffffffffffff
        ORIG_R28: 00000002369fe628
        IAOQ[0]: compat_get_timex+0x2dc/0x3c0
        IAOQ[1]: compat_get_timex+0x2e0/0x3c0
        RP(r2): compat_get_timex+0x40/0x3c0
       Backtrace:
        [<00000000402d4608>] compat_SyS_clock_adjtime+0x40/0xc0
        [<0000000040205024>] syscall_exit+0x0/0x14
      
      This means the userspace program clock_adjtime called the clock_adjtime()
      syscall and then crashed inside the compat_get_timex() function.
      Syscalls should never crash programs, but instead return EFAULT.
      
      The IIR register contains the executed instruction, which disassebles
      into "ldw 0(sr3,r5),r9".
      This load-word instruction is part of __get_user() which tried to read the word
      at %r5/IOR (0xfa6f7fff). This means the unaligned handler jumped in.  The
      unaligned handler is able to emulate all ldw instructions, but it fails if it
      fails to read the source e.g. because of page fault.
      
      The following program reproduces the problem:
      
      #define _GNU_SOURCE
      #include <unistd.h>
      #include <sys/syscall.h>
      #include <sys/mman.h>
      
      int main(void) {
              /* allocate 8k */
              char *ptr = mmap(NULL, 2*4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
              /* free second half (upper 4k) and make it invalid. */
              munmap(ptr+4096, 4096);
              /* syscall where first int is unaligned and clobbers into invalid memory region */
              /* syscall should return EFAULT */
              return syscall(__NR_clock_adjtime, 0, ptr+4095);
      }
      
      To fix this issue we simply need to check if the faulting instruction address
      is in the exception fixup table when the unaligned handler failed. If it
      is, call the fixup routine instead of crashing.
      
      While looking at the unaligned handler I found another issue as well: The
      target register should not be modified if the handler was unsuccessful.
      Signed-off-by: default avatarHelge Deller <deller@gmx.de>
      Cc: stable@vger.kernel.org
      8b78f260
    • Helge Deller's avatar
      parisc: Fix printk time during boot · 0032c088
      Helge Deller authored
      Avoid showing invalid printk time stamps during boot.
      Signed-off-by: default avatarHelge Deller <deller@gmx.de>
      Reviewed-by: default avatarAaro Koskinen <aaro.koskinen@iki.fi>
      0032c088
  4. 04 Jun, 2016 9 commits
    • Mikulas Patocka's avatar
      parisc: Fix backtrace on PA-RISC · be24a897
      Mikulas Patocka authored
      This patch fixes backtrace on PA-RISC
      
      There were several problems:
      
      1) The code that decodes instructions handles instructions that subtract
      from the stack pointer incorrectly. If the instruction subtracts the
      number X from the stack pointer the code increases the frame size by
      (0x100000000-X).  This results in invalid accesses to memory and
      recursive page faults.
      
      2) Because gcc reorders blocks, handling instructions that subtract from
      the frame pointer is incorrect. For example, this function
      	int f(int a)
      	{
      		if (__builtin_expect(a, 1))
      			return a;
      		g();
      		return a;
      	}
      is compiled in such a way, that the code that decreases the stack
      pointer for the first "return a" is placed before the code for "g" call.
      If we recognize this decrement, we mistakenly believe that the frame
      size for the "g" call is zero.
      
      To fix problems 1) and 2), the patch doesn't recognize instructions that
      decrease the stack pointer at all. To further safeguard the unwind code
      against nonsense values, we don't allow frame size larger than
      Total_frame_size.
      
      3) The backtrace is not locked. If stack dump races with module unload,
      invalid table can be accessed.
      
      This patch adds a spinlock when processing module tables.
      
      Note, that for correct backtrace, you need recent binutils.
      Binutils 2.18 from Debian 5 produce garbage unwind tables.
      Binutils 2.21 work better (it sometimes forgets function frames, but at
      least it doesn't generate garbage).
      Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
      Signed-off-by: default avatarHelge Deller <deller@gmx.de>
      be24a897
    • Linus Torvalds's avatar
      Merge tag 'drm-fixes-for-v4.7-rc2' of git://people.freedesktop.org/~airlied/linux · 049ec1b5
      Linus Torvalds authored
      Pull drm fixes from Dave Airlie:
       "A bunch of ARM drivers got into the fixes vibe this time around, so
        this contains a bunch of fixes for imx, atmel hlcdc, arm hdlcd (only
        so many combos of hlcd), mediatek and omap drm.
      
        Other than that there is one mgag200 fix and a few core drm regression
        fixes"
      
      * tag 'drm-fixes-for-v4.7-rc2' of git://people.freedesktop.org/~airlied/linux: (34 commits)
        drm/omap: fix unused variable warning.
        drm: hdlcd: Add information about the underlying framebuffers in debugfs
        drm: hdlcd: Cleanup the atomic plane operations
        drm/hdlcd: Fix up crtc_state->event handling
        drm: hdlcd: Revamp runtime power management
        drm/mediatek: mtk_dsi: Remove spurious drm_connector_unregister
        drm/mediatek: mtk_dpi: remove invalid error message
        drm: atmel-hlcdc: fix a NULL check
        drm: atmel-hlcdc: fix atmel_hlcdc_crtc_reset() implementation
        drm/mgag200: Black screen fix for G200e rev 4
        drm: Wrap direct calls to driver->gem_free_object from CMA
        drm: fix fb refcount issue with atomic modesetting
        drm: make drm_atomic_set_mode_prop_for_crtc() more reliable
        drm/sti: remove extra mode fixup
        drm: add missing drm_mode_set_crtcinfo call
        drm/omap: include gpio/consumer.h where needed
        drm/omap: include linux/seq_file.h where needed
        Revert "drm/omap: no need to select OMAP2_DSS"
        drm/omap: Remove regulator API abuse
        OMAPDSS: HDMI5: Change DDC timings
        ...
      049ec1b5
    • Linus Torvalds's avatar
      Merge tag 'vfio-v4.7-rc2' of git://github.com/awilliam/linux-vfio · f2c6b9e4
      Linus Torvalds authored
      Pull VFIO fixes from Alex Williamson:
       "Fix irqfd shutdown ordering, build warning, and VPD short read"
      
      * tag 'vfio-v4.7-rc2' of git://github.com/awilliam/linux-vfio:
        vfio/pci: Allow VPD short read
        vfio/type1: Fix build warning
        vfio/pci: Fix ordering of eventfd vs virqfd shutdown
      f2c6b9e4
    • Linus Torvalds's avatar
      Merge tag 'mmc-v4.7-rc1-2' of git://git.linaro.org/people/ulf.hansson/mmc · 95b46aeb
      Linus Torvalds authored
      Pull MMC fixes from Ulf Hansson:
       "MMC core:
         - Fix/restore behaviour when selecting bus width for (e)MMC
      
        MMC host:
         - sunxi: Fix eMMC HS-DDR modes on Allwinner A80"
      
      * tag 'mmc-v4.7-rc1-2' of git://git.linaro.org/people/ulf.hansson/mmc:
        mmc: sunxi: Re-enable eMMC HS-DDR modes on Allwinner A80
        mmc: sunxi: Fix DDR MMC timings for A80
        mmc: fix mmc mode selection for HS-DDR and higher
      95b46aeb
    • Linus Torvalds's avatar
      Merge branch 'for-linus-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs · b2d5ad82
      Linus Torvalds authored
      Pull btrfs fixes from Chris Mason:
       "The important part of this pull is Filipe's set of fixes for btrfs
        device replacement.  Filipe fixed a few issues seen on the list and a
        number he found on his own"
      
      * 'for-linus-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
        Btrfs: deal with duplciates during extent_map insertion in btrfs_get_extent
        Btrfs: fix race between device replace and read repair
        Btrfs: fix race between device replace and discard
        Btrfs: fix race between device replace and chunk allocation
        Btrfs: fix race setting block group back to RW mode during device replace
        Btrfs: fix unprotected assignment of the left cursor for device replace
        Btrfs: fix race setting block group readonly during device replace
        Btrfs: fix race between device replace and block group removal
        Btrfs: fix race between readahead and device replace/removal
      b2d5ad82
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client · a3021a59
      Linus Torvalds authored
      Pull Ceph fixes from Sage Weil:
       "We have a few follow-up fixes for the libceph refactor from Ilya, and
        then some cephfs + fscache fixes from Zheng.
      
        The first two FS-Cache patches are acked by David Howells and deemed
        trivial enough to go through our tree.  The rest fix some issues with
        the ceph fscache handling (disable cache for inodes opened for write,
        and simplify the revalidation logic accordingly, dropping the
        now-unnecessary work queue)"
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
        ceph: use i_version to check validity of fscache
        ceph: improve fscache revalidation
        ceph: disable fscache when inode is opened for write
        ceph: avoid unnecessary fscache invalidation/revlidation
        ceph: call __fscache_uncache_page() if readpages fails
        FS-Cache: make check_consistency callback return int
        FS-Cache: wake write waiter after invalidating writes
        libceph: use %s instead of %pE in dout()s
        libceph: put request only if it's done in handle_reply()
        libceph: change ceph_osdmap_flag() to take osdc
      a3021a59
    • Linus Torvalds's avatar
      Merge tag 'acpi-4.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm · eb10a7b7
      Linus Torvalds authored
      Pull ACPI fixes from Rafael Wysocki:
       "Two fixes for problems introduced recently (ACPICA and the ACPI
        backlight driver) and one fix for an older issue that prevents at
        least one system from booting.
      
        Specifics:
      
         - Fix an incorrect check introduced by recent ACPICA changes which
           causes problems with booting KVM guests to happen, among other
           things (Lv Zheng).
      
         - Fix a backlight issue introduced by recent changes to the ACPI
           video driver (Aaron Lu).
      
         - Fix the ACPI processor initialization which attempts to register an
           IO region without checking if that really is necessary and
           sometimes prevents drivers loaded subsequently from registering
           their resources which leads to boot issues (Rafael Wysocki)"
      
      * tag 'acpi-4.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
        ACPI / processor: Avoid reserving IO regions too early
        ACPICA / Hardware: Fix old register check in acpi_hw_get_access_bit_width()
        ACPI / Thermal / video: fix max_level incorrect value
      eb10a7b7
    • Linus Torvalds's avatar
      Merge tag 'pm-4.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm · 50163203
      Linus Torvalds authored
      Pull power management fixes from Rafael Wysocki:
       "Two fixes for problems introduced recently in the cpufreq core and the
        intel_pstate driver.
      
        Specifics:
      
         - Fix a silly mistake related to the clamp_val() usage in a function
           added by a recent commit (Rafael Wysocki).
      
         - Reduce the log level of an annoying message added to intel_pstate
           during the recent merge window (Srinivas Pandruvada)"
      
      * tag 'pm-4.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
        cpufreq: Fix clamp_val() usage in cpufreq_driver_fast_switch()
        cpufreq: intel_pstate: Downgrade print level for _PPC
      50163203
    • Linus Torvalds's avatar
      Merge branch 'akpm' (patches from Andrew) · d46d0256
      Linus Torvalds authored
      Merge various fixes from Andrew Morton:
       "10 fixes"
      
      * emailed patches from Andrew Morton <akpm@linux-foundation.org>:
        mm, page_alloc: recalculate the preferred zoneref if the context can ignore memory policies
        mm, page_alloc: reset zonelist iterator after resetting fair zone allocation policy
        mm, oom_reaper: do not use siglock in try_oom_reaper()
        mm, page_alloc: prevent infinite loop in buffered_rmqueue()
        checkpatch: reduce git commit description style false positives
        mm/z3fold.c: avoid modifying HEADLESS page and minor cleanup
        memcg: add RCU locking around css_for_each_descendant_pre() in memcg_offline_kmem()
        mm: check the return value of lookup_page_ext for all call sites
        kdump: fix dmesg gdbmacro to work with record based printk
        mm: fix overflow in vm_map_ram()
      d46d0256
  5. 03 Jun, 2016 4 commits
    • Linus Torvalds's avatar
      Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 8c52b6dc
      Linus Torvalds authored
      Pull irq fixes from Thomas Gleixner:
       - a few simple fixes for fallout from the recent gic-v3 changes
       - a workaround for a Cavium thunderX erratum
       - a bugfix for the pic32 irqchip to make external interrupts work proper
       - a missing return value in the generic IPI management code
      
      * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        irqchip/irq-pic32-evic: Fix bug with external interrupts.
        irqchip/gicv3-its: numa: Enable workaround for Cavium thunderx erratum 23144
        irqchip/gic-v3: Fix quiescence check in gic_enable_redist
        irqchip/gic-v3: Fix copy+paste mistakes in defines
        irqchip/gic-v3: Fix ICC_SGI1R_EL1.INTID decoding mask
        genirq: Fix missing return value in irq_destroy_ipi()
      8c52b6dc
    • Mel Gorman's avatar
      mm, page_alloc: recalculate the preferred zoneref if the context can ignore memory policies · e46e7b77
      Mel Gorman authored
      The optimistic fast path may use cpuset_current_mems_allowed instead of
      of a NULL nodemask supplied by the caller for cpuset allocations.  The
      preferred zone is calculated on this basis for statistic purposes and as
      a starting point in the zonelist iterator.
      
      However, if the context can ignore memory policies due to being atomic
      or being able to ignore watermarks then the starting point in the
      zonelist iterator is no longer correct.  This patch resets the zonelist
      iterator in the allocator slowpath if the context can ignore memory
      policies.  This will alter the zone used for statistics but only after
      it is known that it makes sense for that context.  Resetting it before
      entering the slowpath would potentially allow an ALLOC_CPUSET allocation
      to be accounted for against the wrong zone.  Note that while nodemask is
      not explicitly set to the original nodemask, it would only have been
      overwritten if cpuset_enabled() and it was reset before the slowpath was
      entered.
      
      Link: http://lkml.kernel.org/r/20160602103936.GU2527@techsingularity.net
      Fixes: c33d6c06 ("mm, page_alloc: avoid looking up the first zone in a zonelist twice")
      Signed-off-by: default avatarMel Gorman <mgorman@techsingularity.net>
      Reported-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
      Tested-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
      Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e46e7b77
    • Mel Gorman's avatar
      mm, page_alloc: reset zonelist iterator after resetting fair zone allocation policy · 0d0bd894
      Mel Gorman authored
      Geert Uytterhoeven reported the following problem that bisected to
      commit c33d6c06 ("mm, page_alloc: avoid looking up the first zone
      in a zonelist twice") on m68k/ARAnyM
      
          BUG: scheduling while atomic: cron/668/0x10c9a0c0
          Modules linked in:
          CPU: 0 PID: 668 Comm: cron Not tainted 4.6.0-atari-05133-gc33d6c06 #364
          Call Trace: [<0003d7d0>] __schedule_bug+0x40/0x54
            __schedule+0x312/0x388
            __schedule+0x0/0x388
            prepare_to_wait+0x0/0x52
            schedule+0x64/0x82
            schedule_timeout+0xda/0x104
            set_next_entity+0x18/0x40
            pick_next_task_fair+0x78/0xda
            io_schedule_timeout+0x36/0x4a
            bit_wait_io+0x0/0x40
            bit_wait_io+0x12/0x40
            __wait_on_bit+0x46/0x76
            wait_on_page_bit_killable+0x64/0x6c
            bit_wait_io+0x0/0x40
            wake_bit_function+0x0/0x4e
            __lock_page_or_retry+0xde/0x124
            do_scan_async+0x114/0x17c
            lookup_swap_cache+0x24/0x4e
            handle_mm_fault+0x626/0x7de
            find_vma+0x0/0x66
            down_read+0x0/0xe
            wait_on_page_bit_killable_timeout+0x77/0x7c
            find_vma+0x16/0x66
            do_page_fault+0xe6/0x23a
            res_func+0xa3c/0x141a
            buserr_c+0x190/0x6d4
            res_func+0xa3c/0x141a
            buserr+0x20/0x28
            res_func+0xa3c/0x141a
            buserr+0x20/0x28
      
      The relationship is not obvious but it's due to a failure to rescan the
      full zonelist after the fair zone allocation policy exhausts the batch
      count.  While this is a functional problem, it's also a performance
      issue.  A page allocator microbenchmark showed the following
      
                                         4.7.0-rc1                  4.7.0-rc1
                                           vanilla                 reset-v1r2
        Min      alloc-odr0-1     327.00 (  0.00%)           326.00 (  0.31%)
        Min      alloc-odr0-2     235.00 (  0.00%)           235.00 (  0.00%)
        Min      alloc-odr0-4     198.00 (  0.00%)           198.00 (  0.00%)
        Min      alloc-odr0-8     170.00 (  0.00%)           170.00 (  0.00%)
        Min      alloc-odr0-16    156.00 (  0.00%)           156.00 (  0.00%)
        Min      alloc-odr0-32    150.00 (  0.00%)           150.00 (  0.00%)
        Min      alloc-odr0-64    146.00 (  0.00%)           146.00 (  0.00%)
        Min      alloc-odr0-128   145.00 (  0.00%)           145.00 (  0.00%)
        Min      alloc-odr0-256   155.00 (  0.00%)           155.00 (  0.00%)
        Min      alloc-odr0-512   168.00 (  0.00%)           165.00 (  1.79%)
        Min      alloc-odr0-1024  175.00 (  0.00%)           174.00 (  0.57%)
        Min      alloc-odr0-2048  180.00 (  0.00%)           180.00 (  0.00%)
        Min      alloc-odr0-4096  187.00 (  0.00%)           186.00 (  0.53%)
        Min      alloc-odr0-8192  190.00 (  0.00%)           190.00 (  0.00%)
        Min      alloc-odr0-16384 191.00 (  0.00%)           191.00 (  0.00%)
        Min      alloc-odr1-1     736.00 (  0.00%)           445.00 ( 39.54%)
        Min      alloc-odr1-2     343.00 (  0.00%)           335.00 (  2.33%)
        Min      alloc-odr1-4     277.00 (  0.00%)           270.00 (  2.53%)
        Min      alloc-odr1-8     238.00 (  0.00%)           233.00 (  2.10%)
        Min      alloc-odr1-16    224.00 (  0.00%)           218.00 (  2.68%)
        Min      alloc-odr1-32    210.00 (  0.00%)           208.00 (  0.95%)
        Min      alloc-odr1-64    207.00 (  0.00%)           203.00 (  1.93%)
        Min      alloc-odr1-128   276.00 (  0.00%)           202.00 ( 26.81%)
        Min      alloc-odr1-256   206.00 (  0.00%)           202.00 (  1.94%)
        Min      alloc-odr1-512   207.00 (  0.00%)           202.00 (  2.42%)
        Min      alloc-odr1-1024  208.00 (  0.00%)           205.00 (  1.44%)
        Min      alloc-odr1-2048  213.00 (  0.00%)           212.00 (  0.47%)
        Min      alloc-odr1-4096  218.00 (  0.00%)           216.00 (  0.92%)
        Min      alloc-odr1-8192  341.00 (  0.00%)           219.00 ( 35.78%)
      
      Note that order-0 allocations are unaffected but higher orders get a
      small boost from this patch and a large reduction in system CPU usage
      overall as can be seen here:
      
                   4.7.0-rc1   4.7.0-rc1
                     vanilla  reset-v1r2
        User           85.32       86.31
        System       2221.39     2053.36
        Elapsed      2368.89     2202.47
      
      Fixes: c33d6c06 ("mm, page_alloc: avoid looking up the first zone in a zonelist twice")
      Link: http://lkml.kernel.org/r/20160531100848.GR2527@techsingularity.netSigned-off-by: default avatarMel Gorman <mgorman@techsingularity.net>
      Reported-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
      Tested-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
      Tested-by: default avatarMikulas Patocka <mpatocka@redhat.com>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      0d0bd894
    • Michal Hocko's avatar
      mm, oom_reaper: do not use siglock in try_oom_reaper() · cbdcf7f7
      Michal Hocko authored
      Oleg has noted that siglock usage in try_oom_reaper is both pointless
      and dangerous.  signal_group_exit can be checked lockless.  The problem
      is that sighand becomes NULL in __exit_signal so we can crash.
      
      Fixes: 3ef22dff ("oom, oom_reaper: try to reap tasks which skip regular OOM killer path")
      Link: http://lkml.kernel.org/r/1464679423-30218-1-git-send-email-mhocko@kernel.orgSigned-off-by: default avatarMichal Hocko <mhocko@suse.com>
      Suggested-by: default avatarOleg Nesterov <oleg@redhat.com>
      Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
      Cc: David Rientjes <rientjes@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      cbdcf7f7