1. 11 9月, 2015 21 次提交
    • C
      dma-mapping: consolidate dma_set_mask · 452e06af
      Christoph Hellwig 提交于
      Almost everyone implements dma_set_mask the same way, although some time
      that's hidden in ->set_dma_mask methods.
      
      This patch consolidates those into a common implementation that either
      calls ->set_dma_mask if present or otherwise uses the default
      implementation.  Some architectures used to only call ->set_dma_mask
      after the initial checks, and those instance have been fixed to do the
      full work.  h8300 implemented dma_set_mask bogusly as a no-ops and has
      been fixed.
      
      Unfortunately some architectures overload unrelated semantics like changing
      the dma_ops into it so we still need to allow for an architecture override
      for now.
      
      [jcmvbkbc@gmail.com: fix xtensa]
      Signed-off-by: NChristoph Hellwig <hch@lst.de>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
      Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      452e06af
    • C
      dma-mapping: consolidate dma_supported · ee196371
      Christoph Hellwig 提交于
      Most architectures just call into ->dma_supported, but some also return 1
      if the method is not present, or 0 if no dma ops are present (although
      that should never happeb). Consolidate this more broad version into
      common code.
      
      Also fix h8300 which inorrectly always returned 0, which would have been
      a problem if it's dma_set_mask implementation wasn't a similarly buggy
      noop.
      
      As a few architectures have much more elaborate implementations, we
      still allow for arch overrides.
      
      [jcmvbkbc@gmail.com: fix xtensa]
      Signed-off-by: NChristoph Hellwig <hch@lst.de>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
      Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ee196371
    • C
      dma-mapping: cosolidate dma_mapping_error · efa21e43
      Christoph Hellwig 提交于
      Currently there are three valid implementations of dma_mapping_error:
      
       (1) call ->mapping_error
       (2) check for a hardcoded error code
       (3) always return 0
      
      This patch provides a common implementation that calls ->mapping_error
      if present, then checks for DMA_ERROR_CODE if defined or otherwise
      returns 0.
      
      [jcmvbkbc@gmail.com: fix xtensa]
      Signed-off-by: NChristoph Hellwig <hch@lst.de>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
      Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      efa21e43
    • C
      dma-mapping: consolidate dma_{alloc,free}_noncoherent · 1e893752
      Christoph Hellwig 提交于
      Most architectures do not support non-coherent allocations and either
      define dma_{alloc,free}_noncoherent to their coherent versions or stub
      them out.
      
      Openrisc uses dma_{alloc,free}_attrs to implement them, and only Mips
      implements them directly.
      
      This patch moves the Openrisc version to common code, and handles the
      DMA_ATTR_NON_CONSISTENT case in the mips dma_map_ops instance.
      
      Note that actual non-coherent allocations require a dma_cache_sync
      implementation, so if non-coherent allocations didn't work on
      an architecture before this patch they still won't work after it.
      
      [jcmvbkbc@gmail.com: fix xtensa]
      Signed-off-by: NChristoph Hellwig <hch@lst.de>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
      Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1e893752
    • C
      dma-mapping: consolidate dma_{alloc,free}_{attrs,coherent} · 6894258e
      Christoph Hellwig 提交于
      Since 2009 we have a nice asm-generic header implementing lots of DMA API
      functions for architectures using struct dma_map_ops, but unfortunately
      it's still missing a lot of APIs that all architectures still have to
      duplicate.
      
      This series consolidates the remaining functions, although we still need
      arch opt outs for two of them as a few architectures have very
      non-standard implementations.
      
      This patch (of 5):
      
      The coherent DMA allocator works the same over all architectures supporting
      dma_map operations.
      
      This patch consolidates them and converges the minor differences:
      
       - the debug_dma helpers are now called from all architectures, including
         those that were previously missing them
       - dma_alloc_from_coherent and dma_release_from_coherent are now always
         called from the generic alloc/free routines instead of the ops
         dma-mapping-common.h always includes dma-coherent.h to get the defintions
         for them, or the stubs if the architecture doesn't support this feature
       - checks for ->alloc / ->free presence are removed.  There is only one
         magic instead of dma_map_ops without them (mic_dma_ops) and that one
         is x86 only anyway.
      
      Besides that only x86 needs special treatment to replace a default devices
      if none is passed and tweak the gfp_flags.  An optional arch hook is provided
      for that.
      
      [linux@roeck-us.net: fix build]
      [jcmvbkbc@gmail.com: fix xtensa]
      Signed-off-by: NChristoph Hellwig <hch@lst.de>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
      Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
      Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      6894258e
    • O
      mm, mpx: add "vm_flags_t vm_flags" arg to do_mmap_pgoff() · 1fcfd8db
      Oleg Nesterov 提交于
      Add the additional "vm_flags_t vm_flags" argument to do_mmap_pgoff(),
      rename it to do_mmap(), and re-introduce do_mmap_pgoff() as a simple
      wrapper on top of do_mmap().  Perhaps we should update the callers of
      do_mmap_pgoff() and kill it later.
      
      This way mpx_mmap() can simply call do_mmap(vm_flags => VM_MPX) and do not
      play with vm internals.
      
      After this change mmap_region() has a single user outside of mmap.c,
      arch/tile/mm/elf.c:arch_setup_additional_pages().  It would be nice to
      change arch/tile/ and unexport mmap_region().
      
      [kirill@shutemov.name: fix build]
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: NOleg Nesterov <oleg@redhat.com>
      Acked-by: NDave Hansen <dave.hansen@linux.intel.com>
      Tested-by: NDave Hansen <dave.hansen@linux.intel.com>
      Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1fcfd8db
    • D
      kexec: split kexec_load syscall from kexec core code · 2965faa5
      Dave Young 提交于
      There are two kexec load syscalls, kexec_load another and kexec_file_load.
       kexec_file_load has been splited as kernel/kexec_file.c.  In this patch I
      split kexec_load syscall code to kernel/kexec.c.
      
      And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and
      use kexec_file_load only, or vice verse.
      
      The original requirement is from Ted Ts'o, he want kexec kernel signature
      being checked with CONFIG_KEXEC_VERIFY_SIG enabled.  But kexec-tools use
      kexec_load syscall can bypass the checking.
      
      Vivek Goyal proposed to create a common kconfig option so user can compile
      in only one syscall for loading kexec kernel.  KEXEC/KEXEC_FILE selects
      KEXEC_CORE so that old config files still work.
      
      Because there's general code need CONFIG_KEXEC_CORE, so I updated all the
      architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects
      KEXEC_CORE in arch Kconfig.  Also updated general kernel code with to
      kexec_load syscall.
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: NDave Young <dyoung@redhat.com>
      Cc: Eric W. Biederman <ebiederm@xmission.com>
      Cc: Vivek Goyal <vgoyal@redhat.com>
      Cc: Petr Tesarik <ptesarik@suse.cz>
      Cc: Theodore Ts'o <tytso@mit.edu>
      Cc: Josh Boyer <jwboyer@fedoraproject.org>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2965faa5
    • D
      kexec: split kexec_file syscall code to kexec_file.c · a43cac0d
      Dave Young 提交于
      Split kexec_file syscall related code to another file kernel/kexec_file.c
      so that the #ifdef CONFIG_KEXEC_FILE in kexec.c can be dropped.
      
      Sharing variables and functions are moved to kernel/kexec_internal.h per
      suggestion from Vivek and Petr.
      
      [akpm@linux-foundation.org: fix bisectability]
      [akpm@linux-foundation.org: declare the various arch_kexec functions]
      [akpm@linux-foundation.org: fix build]
      Signed-off-by: NDave Young <dyoung@redhat.com>
      Cc: Eric W. Biederman <ebiederm@xmission.com>
      Cc: Vivek Goyal <vgoyal@redhat.com>
      Cc: Petr Tesarik <ptesarik@suse.cz>
      Cc: Theodore Ts'o <tytso@mit.edu>
      Cc: Josh Boyer <jwboyer@fedoraproject.org>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a43cac0d
    • A
      seq_file: provide an analogue of print_hex_dump() · 37607102
      Andy Shevchenko 提交于
      This introduces a new helper and switches current users to use it.  All
      patches are compiled tested. kmemleak is tested via its own test suite.
      
      This patch (of 6):
      
      The new seq_hex_dump() is a complete analogue of print_hex_dump().
      
      We have few users of this functionality already. It allows to reduce their
      codebase.
      Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: Joe Perches <joe@perches.com>
      Cc: Tadeusz Struk <tadeusz.struk@intel.com>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Ingo Tuchscherer <ingo.tuchscherer@de.ibm.com>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      37607102
    • F
      kmod: use system_unbound_wq instead of khelper · 90f02303
      Frederic Weisbecker 提交于
      We need to launch the usermodehelper kernel threads with the widest
      affinity and this is partly why we use khelper.  This workqueue has
      unbound properties and thus a wide affinity inherited by all its children.
      
      Now khelper also has special properties that we aren't much interested in:
      ordered and singlethread.  There is really no need about ordering as all
      we do is creating kernel threads.  This can be done concurrently.  And
      singlethread is a useless limitation as well.
      
      The workqueue engine already proposes generic unbound workqueues that
      don't share these useless properties and handle well parallel jobs.
      
      The only worrysome specific is their affinity to the node of the current
      CPU.  It's fine for creating the usermodehelper kernel threads but those
      inherit this affinity for longer jobs such as requesting modules.
      
      This patch proposes to use these node affine unbound workqueues assuming
      that a node is sufficient to handle several parallel usermodehelper
      requests.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Rik van Riel <riel@redhat.com>
      Reviewed-by: NOleg Nesterov <oleg@redhat.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      90f02303
    • K
      lib/string_helpers: rename "esc" arg to "only" · b40bdb7f
      Kees Cook 提交于
      To further clarify the purpose of the "esc" argument, rename it to "only"
      to reflect that it is a limit, not a list of additional characters to
      escape.
      Signed-off-by: NKees Cook <keescook@chromium.org>
      Suggested-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b40bdb7f
    • L
      hexdump: do not print debug dumps for !CONFIG_DEBUG · cdf17449
      Linus Walleij 提交于
      print_hex_dump_debug() is likely supposed to be analogous to pr_debug() or
      dev_dbg() & friends.  Currently it will adhere to dynamic debug, but will
      not stub out prints if CONFIG_DEBUG is not set.  Let's make it do the
      right thing, because I am tired of having my dmesg buffer full of hex
      dumps on production systems.
      Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      cdf17449
    • J
      include/linux/printk.h: include pr_fmt in pr_debug_ratelimited · 515a9adc
      Jason A. Donenfeld 提交于
      The other two implementations of pr_debug_ratelimited include pr_fmt,
      along with every other pr_* function.  But pr_debug_ratelimited forgot to
      add it with the CONFIG_DYNAMIC_DEBUG implementation.
      
      This patch unifies the behavior.
      Signed-off-by: NJason A. Donenfeld <Jason@zx2c4.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      515a9adc
    • V
      include/linux/poison.h: remove not-used poison pointer macros · 8b839635
      Vasily Kulikov 提交于
      Signed-off-by: NVasily Kulikov <segoon@openwall.com>
      Cc: Solar Designer <solar@openwall.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8b839635
    • V
      include/linux/poison.h: fix LIST_POISON{1,2} offset · 8a5e5e02
      Vasily Kulikov 提交于
      Poison pointer values should be small enough to find a room in
      non-mmap'able/hardly-mmap'able space.  E.g.  on x86 "poison pointer space"
      is located starting from 0x0.  Given unprivileged users cannot mmap
      anything below mmap_min_addr, it should be safe to use poison pointers
      lower than mmap_min_addr.
      
      The current poison pointer values of LIST_POISON{1,2} might be too big for
      mmap_min_addr values equal or less than 1 MB (common case, e.g.  Ubuntu
      uses only 0x10000).  There is little point to use such a big value given
      the "poison pointer space" below 1 MB is not yet exhausted.  Changing it
      to a smaller value solves the problem for small mmap_min_addr setups.
      
      The values are suggested by Solar Designer:
      http://www.openwall.com/lists/oss-security/2015/05/02/6Signed-off-by: NVasily Kulikov <segoon@openwall.com>
      Cc: Solar Designer <solar@openwall.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8a5e5e02
    • V
      proc: export idle flag via kpageflags · f074a8f4
      Vladimir Davydov 提交于
      As noted by Minchan, a benefit of reading idle flag from /proc/kpageflags
      is that one can easily filter dirty and/or unevictable pages while
      estimating the size of unused memory.
      
      Note that idle flag read from /proc/kpageflags may be stale in case the
      page was accessed via a PTE, because it would be too costly to iterate
      over all page mappings on each /proc/kpageflags read to provide an
      up-to-date value.  To make sure the flag is up-to-date one has to read
      /sys/kernel/mm/page_idle/bitmap first.
      Signed-off-by: NVladimir Davydov <vdavydov@parallels.com>
      Reviewed-by: NAndres Lagar-Cavilla <andreslc@google.com>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Greg Thelen <gthelen@google.com>
      Cc: Michel Lespinasse <walken@google.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Pavel Emelyanov <xemul@parallels.com>
      Cc: Cyrill Gorcunov <gorcunov@openvz.org>
      Cc: Jonathan Corbet <corbet@lwn.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f074a8f4
    • V
      mm: introduce idle page tracking · 33c3fc71
      Vladimir Davydov 提交于
      Knowing the portion of memory that is not used by a certain application or
      memory cgroup (idle memory) can be useful for partitioning the system
      efficiently, e.g.  by setting memory cgroup limits appropriately.
      Currently, the only means to estimate the amount of idle memory provided
      by the kernel is /proc/PID/{clear_refs,smaps}: the user can clear the
      access bit for all pages mapped to a particular process by writing 1 to
      clear_refs, wait for some time, and then count smaps:Referenced.  However,
      this method has two serious shortcomings:
      
       - it does not count unmapped file pages
       - it affects the reclaimer logic
      
      To overcome these drawbacks, this patch introduces two new page flags,
      Idle and Young, and a new sysfs file, /sys/kernel/mm/page_idle/bitmap.
      A page's Idle flag can only be set from userspace by setting bit in
      /sys/kernel/mm/page_idle/bitmap at the offset corresponding to the page,
      and it is cleared whenever the page is accessed either through page tables
      (it is cleared in page_referenced() in this case) or using the read(2)
      system call (mark_page_accessed()). Thus by setting the Idle flag for
      pages of a particular workload, which can be found e.g.  by reading
      /proc/PID/pagemap, waiting for some time to let the workload access its
      working set, and then reading the bitmap file, one can estimate the amount
      of pages that are not used by the workload.
      
      The Young page flag is used to avoid interference with the memory
      reclaimer.  A page's Young flag is set whenever the Access bit of a page
      table entry pointing to the page is cleared by writing to the bitmap file.
      If page_referenced() is called on a Young page, it will add 1 to its
      return value, therefore concealing the fact that the Access bit was
      cleared.
      
      Note, since there is no room for extra page flags on 32 bit, this feature
      uses extended page flags when compiled on 32 bit.
      
      [akpm@linux-foundation.org: fix build]
      [akpm@linux-foundation.org: kpageidle requires an MMU]
      [akpm@linux-foundation.org: decouple from page-flags rework]
      Signed-off-by: NVladimir Davydov <vdavydov@parallels.com>
      Reviewed-by: NAndres Lagar-Cavilla <andreslc@google.com>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Greg Thelen <gthelen@google.com>
      Cc: Michel Lespinasse <walken@google.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Pavel Emelyanov <xemul@parallels.com>
      Cc: Cyrill Gorcunov <gorcunov@openvz.org>
      Cc: Jonathan Corbet <corbet@lwn.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      33c3fc71
    • V
      mmu-notifier: add clear_young callback · 1d7715c6
      Vladimir Davydov 提交于
      In the scope of the idle memory tracking feature, which is introduced by
      the following patch, we need to clear the referenced/accessed bit not only
      in primary, but also in secondary ptes.  The latter is required in order
      to estimate wss of KVM VMs.  At the same time we want to avoid flushing
      tlb, because it is quite expensive and it won't really affect the final
      result.
      
      Currently, there is no function for clearing pte young bit that would meet
      our requirements, so this patch introduces one.  To achieve that we have
      to add a new mmu-notifier callback, clear_young, since there is no method
      for testing-and-clearing a secondary pte w/o flushing tlb.  The new method
      is not mandatory and currently only implemented by KVM.
      Signed-off-by: NVladimir Davydov <vdavydov@parallels.com>
      Reviewed-by: NAndres Lagar-Cavilla <andreslc@google.com>
      Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Greg Thelen <gthelen@google.com>
      Cc: Michel Lespinasse <walken@google.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Pavel Emelyanov <xemul@parallels.com>
      Cc: Cyrill Gorcunov <gorcunov@openvz.org>
      Cc: Jonathan Corbet <corbet@lwn.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1d7715c6
    • V
      memcg: zap try_get_mem_cgroup_from_page · e993d905
      Vladimir Davydov 提交于
      It is only used in mem_cgroup_try_charge, so fold it in and zap it.
      Signed-off-by: NVladimir Davydov <vdavydov@parallels.com>
      Reviewed-by: NAndres Lagar-Cavilla <andreslc@google.com>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Greg Thelen <gthelen@google.com>
      Cc: Michel Lespinasse <walken@google.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Pavel Emelyanov <xemul@parallels.com>
      Cc: Cyrill Gorcunov <gorcunov@openvz.org>
      Cc: Jonathan Corbet <corbet@lwn.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      e993d905
    • V
      memcg: add page_cgroup_ino helper · 2fc04524
      Vladimir Davydov 提交于
      This patchset introduces a new user API for tracking user memory pages
      that have not been used for a given period of time.  The purpose of this
      is to provide the userspace with the means of tracking a workload's
      working set, i.e.  the set of pages that are actively used by the
      workload.  Knowing the working set size can be useful for partitioning the
      system more efficiently, e.g.  by tuning memory cgroup limits
      appropriately, or for job placement within a compute cluster.
      
      ==== USE CASES ====
      
      The unified cgroup hierarchy has memory.low and memory.high knobs, which
      are defined as the low and high boundaries for the workload working set
      size.  However, the working set size of a workload may be unknown or
      change in time.  With this patch set, one can periodically estimate the
      amount of memory unused by each cgroup and tune their memory.low and
      memory.high parameters accordingly, therefore optimizing the overall
      memory utilization.
      
      Another use case is balancing workloads within a compute cluster.  Knowing
      how much memory is not really used by a workload unit may help take a more
      optimal decision when considering migrating the unit to another node
      within the cluster.
      
      Also, as noted by Minchan, this would be useful for per-process reclaim
      (https://lwn.net/Articles/545668/). With idle tracking, we could reclaim idle
      pages only by smart user memory manager.
      
      ==== USER API ====
      
      The user API consists of two new files:
      
       * /sys/kernel/mm/page_idle/bitmap.  This file implements a bitmap where each
         bit corresponds to a page, indexed by PFN. When the bit is set, the
         corresponding page is idle. A page is considered idle if it has not been
         accessed since it was marked idle. To mark a page idle one should set the
         bit corresponding to the page by writing to the file. A value written to the
         file is OR-ed with the current bitmap value. Only user memory pages can be
         marked idle, for other page types input is silently ignored. Writing to this
         file beyond max PFN results in the ENXIO error. Only available when
         CONFIG_IDLE_PAGE_TRACKING is set.
      
         This file can be used to estimate the amount of pages that are not
         used by a particular workload as follows:
      
         1. mark all pages of interest idle by setting corresponding bits in the
            /sys/kernel/mm/page_idle/bitmap
         2. wait until the workload accesses its working set
         3. read /sys/kernel/mm/page_idle/bitmap and count the number of bits set
      
       * /proc/kpagecgroup.  This file contains a 64-bit inode number of the
         memory cgroup each page is charged to, indexed by PFN. Only available when
         CONFIG_MEMCG is set.
      
         This file can be used to find all pages (including unmapped file pages)
         accounted to a particular cgroup. Using /sys/kernel/mm/page_idle/bitmap, one
         can then estimate the cgroup working set size.
      
      For an example of using these files for estimating the amount of unused
      memory pages per each memory cgroup, please see the script attached
      below.
      
      ==== REASONING ====
      
      The reason to introduce the new user API instead of using
      /proc/PID/{clear_refs,smaps} is that the latter has two serious
      drawbacks:
      
       - it does not count unmapped file pages
       - it affects the reclaimer logic
      
      The new API attempts to overcome them both. For more details on how it
      is achieved, please see the comment to patch 6.
      
      ==== PATCHSET STRUCTURE ====
      
      The patch set is organized as follows:
      
       - patch 1 adds page_cgroup_ino() helper for the sake of
         /proc/kpagecgroup and patches 2-3 do related cleanup
       - patch 4 adds /proc/kpagecgroup, which reports cgroup ino each page is
         charged to
       - patch 5 introduces a new mmu notifier callback, clear_young, which is
         a lightweight version of clear_flush_young; it is used in patch 6
       - patch 6 implements the idle page tracking feature, including the
         userspace API, /sys/kernel/mm/page_idle/bitmap
       - patch 7 exports idle flag via /proc/kpageflags
      
      ==== SIMILAR WORKS ====
      
      Originally, the patch for tracking idle memory was proposed back in 2011
      by Michel Lespinasse (see http://lwn.net/Articles/459269/).  The main
      difference between Michel's patch and this one is that Michel implemented
      a kernel space daemon for estimating idle memory size per cgroup while
      this patch only provides the userspace with the minimal API for doing the
      job, leaving the rest up to the userspace.  However, they both share the
      same idea of Idle/Young page flags to avoid affecting the reclaimer logic.
      
      ==== PERFORMANCE EVALUATION ====
      
      SPECjvm2008 (https://www.spec.org/jvm2008/) was used to evaluate the
      performance impact introduced by this patch set.  Three runs were carried
      out:
      
       - base: kernel without the patch
       - patched: patched kernel, the feature is not used
       - patched-active: patched kernel, 1 minute-period daemon is used for
         tracking idle memory
      
      For tracking idle memory, idlememstat utility was used:
      https://github.com/locker/idlememstat
      
      testcase            base            patched        patched-active
      
      compiler       537.40 ( 0.00)%   532.26 (-0.96)%   538.31 ( 0.17)%
      compress       305.47 ( 0.00)%   301.08 (-1.44)%   300.71 (-1.56)%
      crypto         284.32 ( 0.00)%   282.21 (-0.74)%   284.87 ( 0.19)%
      derby          411.05 ( 0.00)%   413.44 ( 0.58)%   412.07 ( 0.25)%
      mpegaudio      189.96 ( 0.00)%   190.87 ( 0.48)%   189.42 (-0.28)%
      scimark.large   46.85 ( 0.00)%    46.41 (-0.94)%    47.83 ( 2.09)%
      scimark.small  412.91 ( 0.00)%   415.41 ( 0.61)%   421.17 ( 2.00)%
      serial         204.23 ( 0.00)%   213.46 ( 4.52)%   203.17 (-0.52)%
      startup         36.76 ( 0.00)%    35.49 (-3.45)%    35.64 (-3.05)%
      sunflow        115.34 ( 0.00)%   115.08 (-0.23)%   117.37 ( 1.76)%
      xml            620.55 ( 0.00)%   619.95 (-0.10)%   620.39 (-0.03)%
      
      composite      211.50 ( 0.00)%   211.15 (-0.17)%   211.67 ( 0.08)%
      
      time idlememstat:
      
      17.20user 65.16system 2:15:23elapsed 1%CPU (0avgtext+0avgdata 8476maxresident)k
      448inputs+40outputs (1major+36052minor)pagefaults 0swaps
      
      ==== SCRIPT FOR COUNTING IDLE PAGES PER CGROUP ====
      #! /usr/bin/python
      #
      
      import os
      import stat
      import errno
      import struct
      
      CGROUP_MOUNT = "/sys/fs/cgroup/memory"
      BUFSIZE = 8 * 1024  # must be multiple of 8
      
      def get_hugepage_size():
          with open("/proc/meminfo", "r") as f:
              for s in f:
                  k, v = s.split(":")
                  if k == "Hugepagesize":
                      return int(v.split()[0]) * 1024
      
      PAGE_SIZE = os.sysconf("SC_PAGE_SIZE")
      HUGEPAGE_SIZE = get_hugepage_size()
      
      def set_idle():
          f = open("/sys/kernel/mm/page_idle/bitmap", "wb", BUFSIZE)
          while True:
              try:
                  f.write(struct.pack("Q", pow(2, 64) - 1))
              except IOError as err:
                  if err.errno == errno.ENXIO:
                      break
                  raise
          f.close()
      
      def count_idle():
          f_flags = open("/proc/kpageflags", "rb", BUFSIZE)
          f_cgroup = open("/proc/kpagecgroup", "rb", BUFSIZE)
      
          with open("/sys/kernel/mm/page_idle/bitmap", "rb", BUFSIZE) as f:
              while f.read(BUFSIZE): pass  # update idle flag
      
          idlememsz = {}
          while True:
              s1, s2 = f_flags.read(8), f_cgroup.read(8)
              if not s1 or not s2:
                  break
      
              flags, = struct.unpack('Q', s1)
              cgino, = struct.unpack('Q', s2)
      
              unevictable = (flags >> 18) & 1
              huge = (flags >> 22) & 1
              idle = (flags >> 25) & 1
      
              if idle and not unevictable:
                  idlememsz[cgino] = idlememsz.get(cgino, 0) + \
                      (HUGEPAGE_SIZE if huge else PAGE_SIZE)
      
          f_flags.close()
          f_cgroup.close()
          return idlememsz
      
      if __name__ == "__main__":
          print "Setting the idle flag for each page..."
          set_idle()
      
          raw_input("Wait until the workload accesses its working set, "
                    "then press Enter")
      
          print "Counting idle pages..."
          idlememsz = count_idle()
      
          for dir, subdirs, files in os.walk(CGROUP_MOUNT):
              ino = os.stat(dir)[stat.ST_INO]
              print dir + ": " + str(idlememsz.get(ino, 0) / 1024) + " kB"
      ==== END SCRIPT ====
      
      This patch (of 8):
      
      Add page_cgroup_ino() helper to memcg.
      
      This function returns the inode number of the closest online ancestor of
      the memory cgroup a page is charged to.  It is required for exporting
      information about which page is charged to which cgroup to userspace,
      which will be introduced by a following patch.
      Signed-off-by: NVladimir Davydov <vdavydov@parallels.com>
      Reviewed-by: NAndres Lagar-Cavilla <andreslc@google.com>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Greg Thelen <gthelen@google.com>
      Cc: Michel Lespinasse <walken@google.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Pavel Emelyanov <xemul@parallels.com>
      Cc: Cyrill Gorcunov <gorcunov@openvz.org>
      Cc: Jonathan Corbet <corbet@lwn.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2fc04524
    • D
      zpool: add zpool_has_pool() · 3f0e1312
      Dan Streetman 提交于
      This series makes creation of the zpool and compressor dynamic, so that
      they can be changed at runtime.  This makes using/configuring zswap
      easier, as before this zswap had to be configured at boot time, using boot
      params.
      
      This uses a single list to track both the zpool and compressor together,
      although Seth had mentioned an alternative which is to track the zpools
      and compressors using separate lists.  In the most common case, only a
      single zpool and single compressor, using one list is slightly simpler
      than using two lists, and for the uncommon case of multiple zpools and/or
      compressors, using one list is slightly less simple (and uses slightly
      more memory, probably) than using two lists.
      
      This patch (of 4):
      
      Add zpool_has_pool() function, indicating if the specified type of zpool
      is available (i.e.  zsmalloc or zbud).  This allows checking if a pool is
      available, without actually trying to allocate it, similar to
      crypto_has_alg().
      
      This is used by a following patch to zswap that enables the dynamic
      runtime creation of zswap zpools.
      Signed-off-by: NDan Streetman <ddstreet@ieee.org>
      Acked-by: NSeth Jennings <sjennings@variantweb.net>
      Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      3f0e1312
  2. 10 9月, 2015 5 次提交
    • H
      ether: add IEEE 1722 ethertype - TSN · 1ab1e895
      Henrik Austad 提交于
      IEEE 1722 describes AVB (later renamed to TSN - Time Sensitive
      Networking), a protocol, encapsualtion and synchronization to utilize
      standard networks for audio/video (and later other time-sensitive)
      streams.
      
      This standard uses ethertype 0x22F0.
      
      http://standards.ieee.org/develop/regauth/ethertype/eth.txt
      
      This is a respin of a previous patch ("ether: add AVB frame type
      ETH_P_AVB")
      
      CC: "David S. Miller" <davem@davemloft.net>
      CC: netdev@vger.kernel.org
      CC: linux-api@vger.kernel.org
      CC: linux-kernel@vger.kernel.org
      Signed-off-by: NHenrik Austad <henrik@austad.us>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      1ab1e895
    • M
      elf-em.h: move EM_MICROBLAZE to the common header · b1413279
      Mike Frysinger 提交于
      The linux/audit.h header uses EM_MICROBLAZE in order to define
      AUDIT_ARCH_MICROBLAZE, but it's only available in the microblaze
      asm headers.  Move it to the common elf-em.h header so that the
      define can be used on non-microblaze systems.  Otherwise we get
      build errors that EM_MICROBLAZE isn't defined when we try to use
      the AUDIT_ARCH_MICROBLAZE symbol.
      Signed-off-by: NMike Frysinger <vapier@gentoo.org>
      Signed-off-by: NMichal Simek <michal.simek@xilinx.com>
      b1413279
    • D
      netlink, mmap: fix edge-case leakages in nf queue zero-copy · 6bb0fef4
      Daniel Borkmann 提交于
      When netlink mmap on receive side is the consumer of nf queue data,
      it can happen that in some edge cases, we write skb shared info into
      the user space mmap buffer:
      
      Assume a possible rx ring frame size of only 4096, and the network skb,
      which is being zero-copied into the netlink skb, contains page frags
      with an overall skb->len larger than the linear part of the netlink
      skb.
      
      skb_zerocopy(), which is generic and thus not aware of the fact that
      shared info cannot be accessed for such skbs then tries to write and
      fill frags, thus leaking kernel data/pointers and in some corner cases
      possibly writing out of bounds of the mmap area (when filling the
      last slot in the ring buffer this way).
      
      I.e. the ring buffer slot is then of status NL_MMAP_STATUS_VALID, has
      an advertised length larger than 4096, where the linear part is visible
      at the slot beginning, and the leaked sizeof(struct skb_shared_info)
      has been written to the beginning of the next slot (also corrupting
      the struct nl_mmap_hdr slot header incl. status etc), since skb->end
      points to skb->data + ring->frame_size - NL_MMAP_HDRLEN.
      
      The fix adds and lets __netlink_alloc_skb() take the actual needed
      linear room for the network skb + meta data into account. It's completely
      irrelevant for non-mmaped netlink sockets, but in case mmap sockets
      are used, it can be decided whether the available skb_tailroom() is
      really large enough for the buffer, or whether it needs to internally
      fallback to a normal alloc_skb().
      
      >From nf queue side, the information whether the destination port is
      an mmap RX ring is not really available without extra port-to-socket
      lookup, thus it can only be determined in lower layers i.e. when
      __netlink_alloc_skb() is called that checks internally for this. I
      chose to add the extra ldiff parameter as mmap will then still work:
      We have data_len and hlen in nfqnl_build_packet_message(), data_len
      is the full length (capped at queue->copy_range) for skb_zerocopy()
      and hlen some possible part of data_len that needs to be copied; the
      rem_len variable indicates the needed remaining linear mmap space.
      
      The only other workaround in nf queue internally would be after
      allocation time by f.e. cap'ing the data_len to the skb_tailroom()
      iff we deal with an mmap skb, but that would 1) expose the fact that
      we use a mmap skb to upper layers, and 2) trim the skb where we
      otherwise could just have moved the full skb into the normal receive
      queue.
      
      After the patch, in my test case the ring slot doesn't fit and therefore
      shows NL_MMAP_STATUS_COPY, where a full skb carries all the data and
      thus needs to be picked up via recv().
      
      Fixes: 3ab1f683 ("nfnetlink: add support for memory mapped netlink")
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      6bb0fef4
    • W
      add microchip LAN88xx phy driver · 792aec47
      Woojung.Huh@microchip.com 提交于
      Add Microchip LAN88XX phy driver for phylib.
      Signed-off-by: NWoojung Huh <woojung.huh@microchip.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      792aec47
    • P
      net: ipv6: use common fib_default_rule_pref · f53de1e9
      Phil Sutter 提交于
      This switches IPv6 policy routing to use the shared
      fib_default_rule_pref() function of IPv4 and DECnet. It is also used in
      multicast routing for IPv4 as well as IPv6.
      
      The motivation for this patch is a complaint about iproute2 behaving
      inconsistent between IPv4 and IPv6 when adding policy rules: Formerly,
      IPv6 rules were assigned a fixed priority of 0x3FFF whereas for IPv4 the
      assigned priority value was decreased with each rule added.
      
      Since then all users of the default_pref field have been converted to
      assign the generic function fib_default_rule_pref(), fib_nl_newrule()
      may just use it directly instead. Therefore get rid of the function
      pointer altogether and make fib_default_rule_pref() static, as it's not
      used outside fib_rules.c anymore.
      Signed-off-by: NPhil Sutter <phil@nwl.cc>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f53de1e9
  3. 09 9月, 2015 14 次提交
    • K
      mm: zbud: constify the zbud_ops · c83db4f4
      Krzysztof Kozlowski 提交于
      The structure zbud_ops is not modified so make the pointer to it a
      pointer to const.
      Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
      Acked-by: NDan Streetman <ddstreet@ieee.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c83db4f4
    • K
      mm: zpool: constify the zpool_ops · 78672779
      Krzysztof Kozlowski 提交于
      The structure zpool_ops is not modified so make the pointer to it a
      pointer to const.
      Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
      Acked-by: NDan Streetman <ddstreet@ieee.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      78672779
    • D
      mm: swap: zswap: maybe_preload & refactoring · 5b999aad
      Dmitry Safonov 提交于
      zswap_get_swap_cache_page and read_swap_cache_async have pretty much the
      same code with only significant difference in return value and usage of
      swap_readpage.
      
      I a helper __read_swap_cache_async() with the common code.  Behavior
      change: now zswap_get_swap_cache_page will use radix_tree_maybe_preload
      instead radix_tree_preload.  Looks like, this wasn't changed only by the
      reason of code duplication.
      Signed-off-by: NDmitry Safonov <0x7f454c46@gmail.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Vladimir Davydov <vdavydov@parallels.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Jens Axboe <axboe@fb.com>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: David Herrmann <dh.herrmann@gmail.com>
      Cc: Seth Jennings <sjennings@variantweb.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      5b999aad
    • S
      zsmalloc: account the number of compacted pages · 860c707d
      Sergey Senozhatsky 提交于
      Compaction returns back to zram the number of migrated objects, which is
      quite uninformative -- we have objects of different sizes so user space
      cannot obtain any valuable data from that number.  Change compaction to
      operate in terms of pages and return back to compaction issuer the
      number of pages that were freed during compaction.  So from now on we
      will export more meaningful value in zram<id>/mm_stat -- the number of
      freed (compacted) pages.
      
      This requires:
       (a) a rename of `num_migrated' to 'pages_compacted'
       (b) a internal API change -- return first_page's fullness_group from
           putback_zspage(), so we know when putback_zspage() did
           free_zspage().  It helps us to account compaction stats correctly.
      Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
      Acked-by: NMinchan Kim <minchan@kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      860c707d
    • S
      zsmalloc/zram: introduce zs_pool_stats api · 7d3f3938
      Sergey Senozhatsky 提交于
      `zs_compact_control' accounts the number of migrated objects but it has
      a limited lifespan -- we lose it as soon as zs_compaction() returns back
      to zram.  It worked fine, because (a) zram had it's own counter of
      migrated objects and (b) only zram could trigger compaction.  However,
      this does not work for automatic pool compaction (not issued by zram).
      To account objects migrated during auto-compaction (issued by the
      shrinker) we need to store this number in zs_pool.
      
      Define a new `struct zs_pool_stats' structure to keep zs_pool's stats
      there.  It provides only `num_migrated', as of this writing, but it
      surely can be extended.
      
      A new zsmalloc zs_pool_stats() symbol exports zs_pool's stats back to
      caller.
      
      Use zs_pool_stats() in zram and remove `num_migrated' from zram_stats.
      Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
      Suggested-by: NMinchan Kim <minchan@kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      7d3f3938
    • V
      mm: use numa_mem_id() in alloc_pages_node() · 82c1fc71
      Vlastimil Babka 提交于
      alloc_pages_node() might fail when called with NUMA_NO_NODE and
      __GFP_THISNODE on a CPU belonging to a memoryless node.  To make the
      local-node fallback more robust and prevent such situations, use
      numa_mem_id(), which was introduced for similar scenarios in the slab
      context.
      Suggested-by: NChristoph Lameter <cl@linux.com>
      Signed-off-by: NVlastimil Babka <vbabka@suse.cz>
      Acked-by: NDavid Rientjes <rientjes@google.com>
      Acked-by: NMel Gorman <mgorman@techsingularity.net>
      Acked-by: NChristoph Lameter <cl@linux.com>
      Cc: Michal Hocko <mhocko@suse.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      82c1fc71
    • V
      mm: unify checks in alloc_pages_node() and __alloc_pages_node() · 0bc35a97
      Vlastimil Babka 提交于
      Perform the same debug checks in alloc_pages_node() as are done in
      __alloc_pages_node(), by making the former function a wrapper of the
      latter one.
      
      In addition to better diagnostics in DEBUG_VM builds for situations
      which have been already fatal (e.g.  out-of-bounds node id), there are
      two visible changes for potential existing buggy callers of
      alloc_pages_node():
      
      - calling alloc_pages_node() with any negative nid (e.g. due to arithmetic
        overflow) was treated as passing NUMA_NO_NODE and fallback to local node was
        applied. This will now be fatal.
      - calling alloc_pages_node() with an offline node will now be checked for
        DEBUG_VM builds. Since it's not fatal if the node has been previously online,
        and this patch may expose some existing buggy callers, change the VM_BUG_ON
        in __alloc_pages_node() to VM_WARN_ON.
      Signed-off-by: NVlastimil Babka <vbabka@suse.cz>
      Acked-by: NDavid Rientjes <rientjes@google.com>
      Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
      Acked-by: NChristoph Lameter <cl@linux.com>
      Acked-by: NMichal Hocko <mhocko@suse.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0bc35a97
    • V
      mm: rename alloc_pages_exact_node() to __alloc_pages_node() · 96db800f
      Vlastimil Babka 提交于
      alloc_pages_exact_node() was introduced in commit 6484eb3e ("page
      allocator: do not check NUMA node ID when the caller knows the node is
      valid") as an optimized variant of alloc_pages_node(), that doesn't
      fallback to current node for nid == NUMA_NO_NODE.  Unfortunately the
      name of the function can easily suggest that the allocation is
      restricted to the given node and fails otherwise.  In truth, the node is
      only preferred, unless __GFP_THISNODE is passed among the gfp flags.
      
      The misleading name has lead to mistakes in the past, see for example
      commits 5265047a ("mm, thp: really limit transparent hugepage
      allocation to local node") and b360edb4 ("mm, mempolicy:
      migrate_to_node should only migrate to node").
      
      Another issue with the name is that there's a family of
      alloc_pages_exact*() functions where 'exact' means exact size (instead
      of page order), which leads to more confusion.
      
      To prevent further mistakes, this patch effectively renames
      alloc_pages_exact_node() to __alloc_pages_node() to better convey that
      it's an optimized variant of alloc_pages_node() not intended for general
      usage.  Both functions get described in comments.
      
      It has been also considered to really provide a convenience function for
      allocations restricted to a node, but the major opinion seems to be that
      __GFP_THISNODE already provides that functionality and we shouldn't
      duplicate the API needlessly.  The number of users would be small
      anyway.
      
      Existing callers of alloc_pages_exact_node() are simply converted to
      call __alloc_pages_node(), with the exception of sba_alloc_coherent()
      which open-codes the check for NUMA_NO_NODE, so it is converted to use
      alloc_pages_node() instead.  This means it no longer performs some
      VM_BUG_ON checks, and since the current check for nid in
      alloc_pages_node() uses a 'nid < 0' comparison (which includes
      NUMA_NO_NODE), it may hide wrong values which would be previously
      exposed.
      
      Both differences will be rectified by the next patch.
      
      To sum up, this patch makes no functional changes, except temporarily
      hiding potentially buggy callers.  Restricting the checks in
      alloc_pages_node() is left for the next patch which can in turn expose
      more existing buggy callers.
      Signed-off-by: NVlastimil Babka <vbabka@suse.cz>
      Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
      Acked-by: NRobin Holt <robinmholt@gmail.com>
      Acked-by: NMichal Hocko <mhocko@suse.com>
      Acked-by: NChristoph Lameter <cl@linux.com>
      Acked-by: NMichael Ellerman <mpe@ellerman.id.au>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Greg Thelen <gthelen@google.com>
      Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Gleb Natapov <gleb@kernel.org>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Cliff Whickman <cpw@sgi.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      96db800f
    • W
      mm/hwpoison: fix race between soft_offline_page and unpoison_memory · da1b13cc
      Wanpeng Li 提交于
      Wanpeng Li reported a race between soft_offline_page() and
      unpoison_memory(), which causes the following kernel panic:
      
         BUG: Bad page state in process bash  pfn:97000
         page:ffffea00025c0000 count:0 mapcount:1 mapping:          (null) index:0x7f4fdbe00
         flags: 0x1fffff80080048(uptodate|active|swapbacked)
         page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
         bad because of flags:
         flags: 0x40(active)
         Modules linked in: snd_hda_codec_hdmi i915 rpcsec_gss_krb5 nfsv4 dns_resolver bnep rfcomm nfsd bluetooth auth_rpcgss nfs_acl nfs rfkill lockd grace sunrpc i2c_algo_bit drm_kms_helper snd_hda_codec_realtek snd_hda_codec_generic drm snd_hda_intel fscache snd_hda_codec x86_pkg_temp_thermal coretemp kvm_intel snd_hda_core snd_hwdep kvm snd_pcm snd_seq_dummy snd_seq_oss crct10dif_pclmul snd_seq_midi crc32_pclmul snd_seq_midi_event ghash_clmulni_intel snd_rawmidi aesni_intel lrw gf128mul snd_seq glue_helper ablk_helper snd_seq_device cryptd fuse snd_timer dcdbas serio_raw mei_me parport_pc snd mei ppdev i2c_core video lp soundcore parport lpc_ich shpchp mfd_core ext4 mbcache jbd2 sd_mod e1000e ahci ptp libahci crc32c_intel libata pps_core
         CPU: 3 PID: 2211 Comm: bash Not tainted 4.2.0-rc5-mm1+ #45
         Hardware name: Dell Inc. OptiPlex 7020/0F5C5X, BIOS A03 01/08/2015
         Call Trace:
           dump_stack+0x48/0x5c
           bad_page+0xe6/0x140
           free_pages_prepare+0x2f9/0x320
           ? uncharge_list+0xdd/0x100
           free_hot_cold_page+0x40/0x170
           __put_single_page+0x20/0x30
           put_page+0x25/0x40
           unmap_and_move+0x1a6/0x1f0
           migrate_pages+0x100/0x1d0
           ? kill_procs+0x100/0x100
           ? unlock_page+0x6f/0x90
           __soft_offline_page+0x127/0x2a0
           soft_offline_page+0xa6/0x200
      
      This race is explained like below:
      
        CPU0                    CPU1
      
        soft_offline_page
        __soft_offline_page
        TestSetPageHWPoison
                              unpoison_memory
                              PageHWPoison check (true)
                              TestClearPageHWPoison
                              put_page    -> release refcount held by get_hwpoison_page in unpoison_memory
                              put_page    -> release refcount held by isolate_lru_page in __soft_offline_page
        migrate_pages
      
      The second put_page() releases refcount held by isolate_lru_page() which
      will lead to unmap_and_move() releases the last refcount of page and w/
      mapcount still 1 since try_to_unmap() is not called if there is only one
      user map the page.  Anyway, the page refcount and mapcount will still
      mess if the page is mapped by multiple users.
      
      This race was introduced by commit 4491f712 ("mm/memory-failure: set
      PageHWPoison before migrate_pages()"), which focuses on preventing the
      reuse of successfully migrated page.  Before this commit we prevent the
      reuse by changing the migratetype to MIGRATE_ISOLATE during soft
      offlining, which has the following problems, so simply reverting the
      commit is not a best option:
      
        1) it doesn't eliminate the reuse completely, because
           set_migratetype_isolate() can fail to set MIGRATE_ISOLATE to the
           target page if the pageblock of the page contains one or more
           unmovable pages (i.e.  has_unmovable_pages() returns true).
      
        2) the original code changes migratetype to MIGRATE_ISOLATE
           forcibly, and sets it to MIGRATE_MOVABLE forcibly after soft offline,
           regardless of the original migratetype state, which could impact
           other subsystems like memory hotplug or compaction.
      
      This patch moves PageSetHWPoison just after put_page() in
      unmap_and_move(), which closes up the reported race window and minimizes
      another race window b/w SetPageHWPoison and reallocation (which causes
      the reuse of soft-offlined page.) The latter race window still exists
      but it's acceptable, because it's rare and effectively the same as
      ordinary "containment failure" case even if it happens, so keep the
      window open is acceptable.
      
      Fixes: 4491f712 ("mm/memory-failure: set PageHWPoison before migrate_pages()")
      Signed-off-by: NWanpeng Li <wanpeng.li@hotmail.com>
      Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Reported-by: NWanpeng Li <wanpeng.li@hotmail.com>
      Tested-by: NWanpeng Li <wanpeng.li@hotmail.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      da1b13cc
    • N
      mm/hwpoison: introduce num_poisoned_pages wrappers · 8e30456b
      Naoya Horiguchi 提交于
      num_poisoned_pages counter will be changed outside mm/memory-failure.c
      by a subsequent patch, so this patch prepares wrappers to manipulate it.
      Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Tested-by: NWanpeng Li <wanpeng.li@hotmail.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8e30456b
    • W
      mm/hwpoison: introduce put_hwpoison_page to put refcount for memory error handling · 94bf4ec8
      Wanpeng Li 提交于
      Introduce put_hwpoison_page to put refcount for memory error handling.
      Signed-off-by: NWanpeng Li <wanpeng.li@hotmail.com>
      Suggested-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Acked-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      94bf4ec8
    • M
      mm: add utility for early copy from unmapped ram · 6b0f68e3
      Mark Salter 提交于
      When booting an arm64 kernel w/initrd using UEFI/grub, use of mem= will
      likely cut off part or all of the initrd.  This leaves it outside the
      kernel linear map which leads to failure when unpacking.  The x86 code
      has a similar need to relocate an initrd outside of mapped memory in
      some cases.
      
      The current x86 code uses early_memremap() to copy the original initrd
      from unmapped to mapped RAM.  This patchset creates a generic
      copy_from_early_mem() utility based on that x86 code and has arm64 and
      x86 share it in their respective initrd relocation code.
      
      This patch (of 3):
      
      In some early boot circumstances, it may be necessary to copy from RAM
      outside the kernel linear mapping to mapped RAM.  The need to relocate
      an initrd is one example in the x86 code.  This patch creates a helper
      function based on current x86 code.
      Signed-off-by: NMark Salter <msalter@redhat.com>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      6b0f68e3
    • S
      pci: mm: add pci_pool_zalloc() call · 01a7fd33
      Sean O. Stalley 提交于
      Add a wrapper function for pci_pool_alloc() to get zeroed memory.
      Signed-off-by: NSean O. Stalley <sean.stalley@intel.com>
      Cc: Vinod Koul <vinod.koul@intel.com>
      Cc: Bjorn Helgaas <bhelgaas@google.com>
      Cc: Gilles Muller <Gilles.Muller@lip6.fr>
      Cc: Nicolas Palix <nicolas.palix@imag.fr>
      Cc: Michal Marek <mmarek@suse.cz>
      Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
      Cc: Jonathan Corbet <corbet@lwn.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      01a7fd33
    • S
      mm: add dma_pool_zalloc() call to DMA API · ad82362b
      Sean O. Stalley 提交于
      Add a wrapper function for dma_pool_alloc() to get zeroed memory.
      Signed-off-by: NSean O. Stalley <sean.stalley@intel.com>
      Cc: Vinod Koul <vinod.koul@intel.com>
      Cc: Bjorn Helgaas <bhelgaas@google.com>
      Cc: Gilles Muller <Gilles.Muller@lip6.fr>
      Cc: Nicolas Palix <nicolas.palix@imag.fr>
      Cc: Michal Marek <mmarek@suse.cz>
      Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
      Cc: Jonathan Corbet <corbet@lwn.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ad82362b
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