1. 17 Feb, 2016 3 commits
    • Andy Lutomirski's avatar
      x86/signal/64: Re-add support for SS in the 64-bit signal context · 6c25da5a
      Andy Lutomirski authored
      This is a second attempt to make the improvements from c6f20629
      ("x86/signal/64: Fix SS handling for signals delivered to 64-bit
      programs"), which was reverted by 51adbfbba5c6 ("x86/signal/64: Add
      support for SS in the 64-bit signal context").
      
      This adds two new uc_flags flags.  UC_SIGCONTEXT_SS will be set for
      all 64-bit signals (including x32).  It indicates that the saved SS
      field is valid and that the kernel supports the new behavior.
      
      The goal is to fix a problems with signal handling in 64-bit tasks:
      SS wasn't saved in the 64-bit signal context, making it awkward to
      determine what SS was at the time of signal delivery and making it
      impossible to return to a non-flat SS (as calling sigreturn clobbers
      SS).
      
      This also made it extremely difficult for 64-bit tasks to return to
      fully-defined 16-bit contexts, because only the kernel can easily do
      espfix64, but sigreturn was unable to set a non-flag SS:ESP.
      (DOSEMU has a monstrous hack to partially work around this
      limitation.)
      
      If we could go back in time, the correct fix would be to make 64-bit
      signals work just like 32-bit signals with respect to SS: save it
      in signal context, reset it when delivering a signal, and restore
      it in sigreturn.
      
      Unfortunately, doing that (as I tried originally) breaks DOSEMU:
      DOSEMU wouldn't reset the signal context's SS when clearing the LDT
      and changing the saved CS to 64-bit mode, since it predates the SS
      context field existing in the first place.
      
      This patch is a bit more complicated, and it tries to balance a
      bunch of goals.  It makes most cases of changing ucontext->ss during
      signal handling work as expected.
      
      I do this by special-casing the interesting case.  On sigreturn,
      ucontext->ss will be honored by default, unless the ucontext was
      created from scratch by an old program and had a 64-bit CS
      (unfortunately, CRIU can do this) or was the result of changing a
      32-bit signal context to 64-bit without resetting SS (as DOSEMU
      does).
      
      For the benefit of new 64-bit software that uses segmentation (new
      versions of DOSEMU might), the new behavior can be detected with a
      new ucontext flag UC_SIGCONTEXT_SS.
      
      To avoid compilation issues, __pad0 is left as an alias for ss in
      ucontext.
      
      The nitty-gritty details are documented in the header file.
      
      This patch also re-enables the sigreturn_64 and ldt_gdt_64 selftests,
      as the kernel change allows both of them to pass.
      Tested-by: default avatarStas Sergeev <stsp@list.ru>
      Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
      Acked-by: default avatarBorislav Petkov <bp@alien8.de>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Cyrill Gorcunov <gorcunov@gmail.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Pavel Emelyanov <xemul@parallels.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/749149cbfc3e75cd7fcdad69a854b399d792cc6f.1455664054.git.luto@kernel.org
      [ Small readability edit. ]
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      6c25da5a
    • Andy Lutomirski's avatar
      x86/signal/64: Fix SS if needed when delivering a 64-bit signal · 8ff5bd2e
      Andy Lutomirski authored
      Signals are always delivered to 64-bit tasks with CS set to a long
      mode segment.  In long mode, SS doesn't matter as long as it's a
      present writable segment.
      
      If SS starts out invalid (this can happen if the signal was caused
      by an IRET fault or was delivered on the way out of set_thread_area
      or modify_ldt), then IRET to the signal handler can fail, eventually
      killing the task.
      
      The straightforward fix would be to simply reset SS when delivering
      a signal.  That breaks DOSEMU, though: 64-bit builds of DOSEMU rely
      on SS being set to the faulting SS when signals are delivered.
      
      As a compromise, this patch leaves SS alone so long as it's valid.
      
      The net effect should be that the behavior of successfully delivered
      signals is unchanged.  Some signals that would previously have
      failed to be delivered will now be delivered successfully.
      
      This has no effect for x32 or 32-bit tasks: their signal handlers
      were already called with SS == __USER_DS.
      
      (On Xen, there's a slight hole: if a task sets SS to a writable
       *kernel* data segment, then we will fail to identify it as invalid
       and we'll still kill the task.  If anyone cares, this could be fixed
       with a new paravirt hook.)
      Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
      Acked-by: default avatarBorislav Petkov <bp@alien8.de>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Cyrill Gorcunov <gorcunov@gmail.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Pavel Emelyanov <xemul@parallels.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stas Sergeev <stsp@list.ru>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/163c6e1eacde41388f3ff4d2fe6769be651d7b6e.1455664054.git.luto@kernel.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      8ff5bd2e
    • Andy Lutomirski's avatar
      x86/signal/64: Add a comment about sigcontext->fs and gs · e54fdcca
      Andy Lutomirski authored
      These fields have a strange history.  This tries to document it.
      
      This borrows from 9a036b93 ("x86/signal/64: Remove 'fs' and 'gs'
      from sigcontext"), which was reverted by ed596cde ("Revert x86
      sigcontext cleanups").
      Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
      Acked-by: default avatarBorislav Petkov <bp@alien8.de>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Cyrill Gorcunov <gorcunov@gmail.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Pavel Emelyanov <xemul@parallels.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stas Sergeev <stsp@list.ru>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/baa78f3c84106fa5acbc319377b1850602f5deec.1455664054.git.luto@kernel.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      e54fdcca
  2. 16 Feb, 2016 1 commit
    • Borislav Petkov's avatar
      x86/cpufeature: Speed up cpu_feature_enabled() · f2cc8e07
      Borislav Petkov authored
      When GCC cannot do constant folding for this macro, it falls back to
      cpu_has(). But static_cpu_has() is optimal and it works at all times
      now. So use it and speedup the fallback case.
      
      Before we had this:
      
        mov    0x99d674(%rip),%rdx        # ffffffff81b0d9f4 <boot_cpu_data+0x34>
        shr    $0x2e,%rdx
        and    $0x1,%edx
        jne    ffffffff811704e9 <do_munmap+0x3f9>
      
      After alternatives patching, it turns into:
      
      		  jmp    0xffffffff81170390
      		  nopl   (%rax)
      		  ...
      		  callq  ffffffff81056e00 <mpx_notify_unmap>
      ffffffff81170390: mov    0x170(%r12),%rdi
      Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
      Cc: Joerg Roedel <joro@8bytes.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/1455578358-28347-1-git-send-email-bp@alien8.deSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      f2cc8e07
  3. 09 Feb, 2016 2 commits
    • Matthew Wilcox's avatar
      x86/mm: Honour passed pgprot in track_pfn_insert() and track_pfn_remap() · dd7b6847
      Matthew Wilcox authored
      track_pfn_insert() overwrites the pgprot that is passed in with a value
      based on the VMA's page_prot.  This is a problem for people trying to
      do clever things with the new vm_insert_pfn_prot() as it will simply
      overwrite the passed protection flags.  If we use the current value of
      the pgprot as the base, then it will behave as people are expecting.
      
      Also fix track_pfn_remap() in the same way.
      Signed-off-by: default avatarMatthew Wilcox <willy@linux.intel.com>
      Acked-by: default avatarAndy Lutomirski <luto@kernel.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-mm@kvack.org
      Link: http://lkml.kernel.org/r/1453742717-10326-2-git-send-email-matthew.r.wilcox@intel.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      dd7b6847
    • Denys Vlasenko's avatar
      x86/asm/bitops: Force inlining of test_and_set_bit and friends · 8dd5032d
      Denys Vlasenko authored
      Sometimes GCC mysteriously doesn't inline very small functions
      we expect to be inlined, see:
      
        https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66122
      
      Arguably, GCC should do better, but GCC people aren't willing
      to invest time into it and are asking to use __always_inline
      instead.
      
      With this .config:
      
        http://busybox.net/~vda/kernel_config_OPTIMIZE_INLINING_and_Os
      
      here's an example of functions getting deinlined many times:
      
        test_and_set_bit (166 copies, ~1260 calls)
               55                      push   %rbp
               48 89 e5                mov    %rsp,%rbp
               f0 48 0f ab 3e          lock bts %rdi,(%rsi)
               72 04                   jb     <test_and_set_bit+0xf>
               31 c0                   xor    %eax,%eax
               eb 05                   jmp    <test_and_set_bit+0x14>
               b8 01 00 00 00          mov    $0x1,%eax
               5d                      pop    %rbp
               c3                      retq
      
        test_and_clear_bit (124 copies, ~1000 calls)
               55                      push   %rbp
               48 89 e5                mov    %rsp,%rbp
               f0 48 0f b3 3e          lock btr %rdi,(%rsi)
               72 04                   jb     <test_and_clear_bit+0xf>
               31 c0                   xor    %eax,%eax
               eb 05                   jmp    <test_and_clear_bit+0x14>
               b8 01 00 00 00          mov    $0x1,%eax
               5d                      pop    %rbp
               c3                      retq
      
        change_bit (3 copies, 8 calls)
               55                      push   %rbp
               48 89 e5                mov    %rsp,%rbp
               f0 48 0f bb 3e          lock btc %rdi,(%rsi)
               5d                      pop    %rbp
               c3                      retq
      
        clear_bit_unlock (2 copies, 11 calls)
               55                      push   %rbp
               48 89 e5                mov    %rsp,%rbp
               f0 48 0f b3 3e          lock btr %rdi,(%rsi)
               5d                      pop    %rbp
               c3                      retq
      
      This patch works it around via s/inline/__always_inline/.
      
      Code size decrease by ~13.5k after the patch:
      
            text     data      bss       dec    filename
        92110727 20826144 36417536 149354407    vmlinux.before
        92097234 20826176 36417536 149340946    vmlinux.after
      Signed-off-by: default avatarDenys Vlasenko <dvlasenk@redhat.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Thomas Graf <tgraf@suug.ch>
      Link: http://lkml.kernel.org/r/1454881887-1367-1-git-send-email-dvlasenk@redhat.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      8dd5032d
  4. 01 Feb, 2016 4 commits
  5. 30 Jan, 2016 7 commits
  6. 29 Jan, 2016 11 commits
  7. 27 Jan, 2016 1 commit
  8. 24 Jan, 2016 11 commits
    • Linus Torvalds's avatar
      Linux 4.5-rc1 · 92e963f5
      Linus Torvalds authored
      92e963f5
    • Linus Torvalds's avatar
      Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus · e2464688
      Linus Torvalds authored
      Pull MIPS updates from Ralf Baechle:
       "This is the main pull request for MIPS for 4.5 plus some 4.4 fixes.
      
        The executive summary:
      
         - ATH79 platform improvments, use DT bindings for the ATH79 USB PHY.
         - Avoid useless rebuilds for zboot.
         - jz4780: Add NEMC, BCH and NAND device tree nodes
         - Initial support for the MicroChip's DT platform.  As all the device
           drivers are missing this is still of limited use.
         - Some Loongson3 cleanups.
         - The unavoidable whitespace polishing.
         - Reduce clock skew when synchronizing the CPU cycle counters on CPU
           startup.
         - Add MIPS R6 fixes.
         - Lots of cleanups across arch/mips as fallout from KVM.
         - Lots of minor fixes and changes for IEEE 754-2008 support to the
           FPU emulator / fp-assist software.
         - Minor Ralink, BCM47xx and bcm963xx platform support improvments.
         - Support SMP on BCM63168"
      
      * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (84 commits)
        MIPS: zboot: Add support for serial debug using the PROM
        MIPS: zboot: Avoid useless rebuilds
        MIPS: BMIPS: Enable ARCH_WANT_OPTIONAL_GPIOLIB
        MIPS: bcm63xx: nvram: Remove unused bcm63xx_nvram_get_psi_size() function
        MIPS: bcm963xx: Update bcm_tag field image_sequence
        MIPS: bcm963xx: Move extended flash address to bcm_tag header file
        MIPS: bcm963xx: Move Broadcom BCM963xx image tag data structure
        MIPS: bcm63xx: nvram: Use nvram structure definition from header file
        MIPS: bcm963xx: Add Broadcom BCM963xx board nvram data structure
        MAINTAINERS: Add KVM for MIPS entry
        MIPS: KVM: Add missing newline to kvm_err()
        MIPS: Move KVM specific opcodes into asm/inst.h
        MIPS: KVM: Use cacheops.h definitions
        MIPS: Break down cacheops.h definitions
        MIPS: Use EXCCODE_ constants with set_except_vector()
        MIPS: Update trap codes
        MIPS: Move Cause.ExcCode trap codes to mipsregs.h
        MIPS: KVM: Make kvm_mips_{init,exit}() static
        MIPS: KVM: Refactor added offsetof()s
        MIPS: KVM: Convert EXPORT_SYMBOL to _GPL
        ...
      e2464688
    • Linus Torvalds's avatar
      Merge tag 'platform-drivers-x86-v4.5-2' of... · e1c10879
      Linus Torvalds authored
      Merge tag 'platform-drivers-x86-v4.5-2' of git://git.infradead.org/users/dvhart/linux-platform-drivers-x86
      
      Pull x86 platform driver updates from Darren Hart:
       "Emergency travel prevented me from completing my final testing on this
        until today.  Nothing here that couldn't wait until RC1 fixes, but I
        thought it best to get it out sooner rather than later as it does
        contain a build warning fix.
      
        Summary:
      
        A build warning fix, MAINTAINERS cleanup, and a new DMI quirk:
      
        ideapad-laptop:
         - Add Lenovo Yoga 700 to no_hw_rfkill dmi list
      
        MAINTAINERS:
         - Combine multiple telemetry entries
      
        intel_telemetry_debugfs:
         - Fix unused warnings in telemetry debugfs"
      
      * tag 'platform-drivers-x86-v4.5-2' of git://git.infradead.org/users/dvhart/linux-platform-drivers-x86:
        ideapad-laptop: Add Lenovo Yoga 700 to no_hw_rfkill dmi list
        MAINTAINERS: Combine multiple telemetry entries
        intel_telemetry_debugfs: Fix unused warnings in telemetry debugfs
      e1c10879
    • Linus Torvalds's avatar
      Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux · 81f05fee
      Linus Torvalds authored
      Pull thermal management updates from Zhang Rui:
       "The top merge commit was re-generated yesterday because two topic
        branches were dropped from this pull request in the last minute due to
        some unaddressed comments.  All the other material has been in
        linux-next for quite a while.
      
        Specifics:
      
         - Enhance thermal core to handle unexpected device cooling states
           after fresh boot and system resume.  From Zhang Rui and Chen Yu.
      
         - Several fixes and cleanups on Rockchip and RCAR thermal drivers.
           From Caesar Wang and Kuninori Morimoto.
      
         - Add Broxton support for Intel processor thermal reporting device
           driver.  From Amy Wiles"
      
      * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
        thermal: trip_point_temp_store() calls thermal_zone_device_update()
        thermal: rcar: rcar_thermal_get_temp() return error if strange temp
        thermal: rcar: check irq possibility in rcar_thermal_irq_xxx()
        thermal: rcar: check every rcar_thermal_update_temp() return value
        thermal: rcar: move rcar_thermal_dt_ids to upside
        thermal: rockchip: Support the RK3399 SoCs in thermal driver
        thermal: rockchip: Support the RK3228 SoCs in thermal driver
        dt-bindings: rockchip-thermal: Support the RK3228/RK3399 SoCs compatible
        thermal: rockchip: fix a trivial typo
        Thermal: Enable Broxton SoC thermal reporting device
        thermal: constify pch_dev_ops structure
        Thermal: do thermal zone update after a cooling device registered
        Thermal: handle thermal zone device properly during system sleep
        Thermal: initialize thermal zone device correctly
      81f05fee
    • Linus Torvalds's avatar
      Merge tag 'for-linus-4.5-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs · c52cb431
      Linus Torvalds authored
      Pull 9p updates from Eric Van Hensbergen:
       "Sorry for the last minute pull request, there's was a change that
        didn't get pulled into for-next until two weeks ago and I wanted to
        give it some bake time.
      
        Summary:
      
        Rework and error handling fixes, primarily in the fscatch and fd
        transports"
      
      * tag 'for-linus-4.5-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
        fs/9p: use fscache mutex rather than spinlock
        9p: trans_fd, bail out if recv fcall if missing
        9p: trans_fd, read rework to use p9_parse_header
        net/9p: Add device name details on error
      c52cb431
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client · 00e3f5cc
      Linus Torvalds authored
      Pull Ceph updates from Sage Weil:
       "The two main changes are aio support in CephFS, and a series that
        fixes several issues in the authentication key timeout/renewal code.
      
        On top of that are a variety of cleanups and minor bug fixes"
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
        libceph: remove outdated comment
        libceph: kill off ceph_x_ticket_handler::validity
        libceph: invalidate AUTH in addition to a service ticket
        libceph: fix authorizer invalidation, take 2
        libceph: clear messenger auth_retry flag if we fault
        libceph: fix ceph_msg_revoke()
        libceph: use list_for_each_entry_safe
        ceph: use i_size_{read,write} to get/set i_size
        ceph: re-send AIO write request when getting -EOLDSNAP error
        ceph: Asynchronous IO support
        ceph: Avoid to propagate the invalid page point
        ceph: fix double page_unlock() in page_mkwrite()
        rbd: delete an unnecessary check before rbd_dev_destroy()
        libceph: use list_next_entry instead of list_entry_next
        ceph: ceph_frag_contains_value can be boolean
        ceph: remove unused functions in ceph_frag.h
      00e3f5cc
    • Linus Torvalds's avatar
      Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6 · 772950ed
      Linus Torvalds authored
      Pull SMB3 fixes from Steve French:
       "A collection of CIFS/SMB3 fixes.
      
        It includes a couple bug fixes, a few for improved debugging of
        cifs.ko and some improvements to the way cifs does key generation.
      
        I do have some additional bug fixes I expect in the next week or two
        (to address a problem found by xfstest, and some fixes for SMB3.11
        dialect, and a couple patches that just came in yesterday that I am
        reviewing)"
      
      * 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
        cifs_dbg() outputs an uninitialized buffer in cifs_readdir()
        cifs: fix race between call_async() and reconnect()
        Prepare for encryption support (first part). Add decryption and encryption key generation. Thanks to Metze for helping with this.
        cifs: Allow using O_DIRECT with cache=loose
        cifs: Make echo interval tunable
        cifs: Check uniqueid for SMB2+ and return -ESTALE if necessary
        Print IP address of unresponsive server
        cifs: Ratelimit kernel log messages
      772950ed
    • Josh Boyer's avatar
      ideapad-laptop: Add Lenovo Yoga 700 to no_hw_rfkill dmi list · 6b31de3e
      Josh Boyer authored
      Like the Yoga 900 models the Lenovo Yoga 700 does not have a
      hw rfkill switch, and trying to read the hw rfkill switch through the
      ideapad module causes it to always reported blocking breaking wifi.
      
      This commit adds the Lenovo Yoga 700 to the no_hw_rfkill dmi list, fixing
      the wifi breakage.
      
      BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1295272
      Tested-by: <dinyar.rabady+spam@gmail.com>
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarJosh Boyer <jwboyer@fedoraproject.org>
      Signed-off-by: default avatarDarren Hart <dvhart@linux.intel.com>
      6b31de3e
    • Souvik Kumar Chakravarty's avatar
      MAINTAINERS: Combine multiple telemetry entries · f1fc3cd8
      Souvik Kumar Chakravarty authored
      This patch combines all the telemetry file entries in MAINTAINERS via
      wildcard.
      Signed-off-by: default avatarSouvik Kumar Chakravarty <souvik.k.chakravarty@intel.com>
      Signed-off-by: default avatarDarren Hart <dvhart@linux.intel.com>
      f1fc3cd8
    • Souvik Kumar Chakravarty's avatar
      intel_telemetry_debugfs: Fix unused warnings in telemetry debugfs · 7885f2f9
      Souvik Kumar Chakravarty authored
      This patch fixes compile time warnings when CONFIG_PM_SLEEP
      is undefined. In this case sleep related counters are unused.
      Signed-off-by: default avatarSouvik Kumar Chakravarty <souvik.k.chakravarty@intel.com>
      Signed-off-by: default avatarDarren Hart <dvhart@linux.intel.com>
      7885f2f9
    • Christoph Lameter's avatar
      vmstat: Remove BUG_ON from vmstat_update · 587198ba
      Christoph Lameter authored
      If we detect that there is nothing to do just set the flag and do not
      check if it was already set before.  Races really do not matter.  If the
      flag is set by any code then the shepherd will start dealing with the
      situation and reenable the vmstat workers when necessary again.
      
      Since commit 0eb77e98 ("vmstat: make vmstat_updater deferrable again
      and shut down on idle") quiet_vmstat might update cpu_stat_off and mark
      a particular cpu to be handled by vmstat_shepherd.  This might trigger a
      VM_BUG_ON in vmstat_update because the work item might have been
      sleeping during the idle period and see the cpu_stat_off updated after
      the wake up.  The VM_BUG_ON is therefore misleading and no more
      appropriate.  Moreover it doesn't really suite any protection from real
      bugs because vmstat_shepherd will simply reschedule the vmstat_work
      anytime it sees a particular cpu set or vmstat_update would do the same
      from the worker context directly.  Even when the two would race the
      result wouldn't be incorrect as the counters update is fully idempotent.
      Reported-by: default avatarSasha Levin <sasha.levin@oracle.com>
      Signed-off-by: default avatarChristoph Lameter <cl@linux.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      587198ba