1. 29 3月, 2011 13 次提交
  2. 24 3月, 2011 1 次提交
    • O
      crash_dump: export is_kdump_kernel to modules, consolidate elfcorehdr_addr,... · 93a72052
      Olaf Hering 提交于
      crash_dump: export is_kdump_kernel to modules, consolidate elfcorehdr_addr, setup_elfcorehdr and saved_max_pfn
      
      The Xen PV drivers in a crashed HVM guest can not connect to the dom0
      backend drivers because both frontend and backend drivers are still in
      connected state.  To run the connection reset function only in case of a
      crashdump, the is_kdump_kernel() function needs to be available for the PV
      driver modules.
      
      Consolidate elfcorehdr_addr, setup_elfcorehdr and saved_max_pfn into
      kernel/crash_dump.c Also export elfcorehdr_addr to make is_kdump_kernel()
      usable for modules.
      
      Leave 'elfcorehdr' as early_param().  This changes powerpc from __setup()
      to early_param().  It adds an address range check from x86 also on ia64
      and powerpc.
      
      [akpm@linux-foundation.org: additional #includes]
      [akpm@linux-foundation.org: remove elfcorehdr_addr export]
      [akpm@linux-foundation.org: fix for Tejun's mm/nobootmem.c changes]
      Signed-off-by: NOlaf Hering <olaf@aepfle.de>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      93a72052
  3. 23 3月, 2011 1 次提交
  4. 03 3月, 2011 2 次提交
  5. 25 2月, 2011 3 次提交
  6. 31 1月, 2011 1 次提交
    • T
      ia64: Switch do_timer() to xtime_update() · 1aabd67d
      Torben Hohn 提交于
      local_cpu_data->itm_next = new_itm; does not need to be protected by
      xtime_lock. xtime_update() takes the lock itself.
      Signed-off-by: NTorben Hohn <torbenh@gmx.de>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: johnstul@us.ibm.com
      Cc: hch@infradead.org
      Cc: yong.zhang0@gmail.com
      LKML-Reference: <20110127145956.23248.49107.stgit@localhost>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      1aabd67d
  7. 25 1月, 2011 1 次提交
    • T
      percpu: align percpu readmostly subsection to cacheline · 19df0c2f
      Tejun Heo 提交于
      Currently percpu readmostly subsection may share cachelines with other
      percpu subsections which may result in unnecessary cacheline bounce
      and performance degradation.
      
      This patch adds @cacheline parameter to PERCPU() and PERCPU_VADDR()
      linker macros, makes each arch linker scripts specify its cacheline
      size and use it to align percpu subsections.
      
      This is based on Shaohua's x86 only patch.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Cc: Shaohua Li <shaohua.li@intel.com>
      19df0c2f
  8. 14 1月, 2011 1 次提交
  9. 13 1月, 2011 3 次提交
    • A
      pass default dentry_operations to mount_pseudo() · c74a1cbb
      Al Viro 提交于
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      c74a1cbb
    • T
      [IA64] Fix format warning in arch/ia64/kernel/acpi.c · dff0092b
      Tony Luck 提交于
      arch/ia64/kernel/acpi.c:481: warning: format ‘%d’ expects type ‘int’, but argument 2 has type ‘long unsigned int’
      
      Introduced by commit 05f2f274
          [IA64] Avoid array overflow if there are too many cpus in SRAT table
      Signed-off-by: NTony Luck <tony.luck@intel.com>
      dff0092b
    • T
      ACPI, intel_idle: Cleanup idle= internal variables · d1896049
      Thomas Renninger 提交于
      Having four variables for the same thing:
        idle_halt, idle_nomwait, force_mwait and boot_option_idle_overrides
      is rather confusing and unnecessary complex.
      
      if idle= boot param is passed, only set up one variable:
      boot_option_idle_overrides
      
      Introduces following functional changes/fixes:
        - intel_idle driver does not register if any idle=xy
          boot param is passed.
        - processor_idle.c will also not register a cpuidle driver
          and get active if idle=halt is passed.
          Before a cpuidle driver with one (C1, halt) state got registered
          Now the default_idle function will be used which finally uses
          the same idle call to enter sleep state (safe_halt()), but
          without registering a whole cpuidle driver.
      
      That means idle= param will always avoid cpuidle drivers to register
      with one exception (same behavior as before):
      idle=nomwait
      may still register acpi_idle cpuidle driver, but C1 will not use
      mwait, but hlt. This can be a workaround for IO based deeper sleep
      states where C1 mwait causes problems.
      Signed-off-by: NThomas Renninger <trenn@suse.de>
      cc: x86@kernel.org
      Signed-off-by: NLen Brown <len.brown@intel.com>
      d1896049
  10. 08 1月, 2011 1 次提交
  11. 07 1月, 2011 3 次提交
    • N
      fs: scale mntget/mntput · b3e19d92
      Nick Piggin 提交于
      The problem that this patch aims to fix is vfsmount refcounting scalability.
      We need to take a reference on the vfsmount for every successful path lookup,
      which often go to the same mount point.
      
      The fundamental difficulty is that a "simple" reference count can never be made
      scalable, because any time a reference is dropped, we must check whether that
      was the last reference. To do that requires communication with all other CPUs
      that may have taken a reference count.
      
      We can make refcounts more scalable in a couple of ways, involving keeping
      distributed counters, and checking for the global-zero condition less
      frequently.
      
      - check the global sum once every interval (this will delay zero detection
        for some interval, so it's probably a showstopper for vfsmounts).
      
      - keep a local count and only taking the global sum when local reaches 0 (this
        is difficult for vfsmounts, because we can't hold preempt off for the life of
        a reference, so a counter would need to be per-thread or tied strongly to a
        particular CPU which requires more locking).
      
      - keep a local difference of increments and decrements, which allows us to sum
        the total difference and hence find the refcount when summing all CPUs. Then,
        keep a single integer "long" refcount for slow and long lasting references,
        and only take the global sum of local counters when the long refcount is 0.
      
      This last scheme is what I implemented here. Attached mounts and process root
      and working directory references are "long" references, and everything else is
      a short reference.
      
      This allows scalable vfsmount references during path walking over mounted
      subtrees and unattached (lazy umounted) mounts with processes still running
      in them.
      
      This results in one fewer atomic op in the fastpath: mntget is now just a
      per-CPU inc, rather than an atomic inc; and mntput just requires a spinlock
      and non-atomic decrement in the common case. However code is otherwise bigger
      and heavier, so single threaded performance is basically a wash.
      Signed-off-by: NNick Piggin <npiggin@kernel.dk>
      b3e19d92
    • N
      fs: dcache reduce branches in lookup path · fb045adb
      Nick Piggin 提交于
      Reduce some branches and memory accesses in dcache lookup by adding dentry
      flags to indicate common d_ops are set, rather than having to check them.
      This saves a pointer memory access (dentry->d_op) in common path lookup
      situations, and saves another pointer load and branch in cases where we
      have d_op but not the particular operation.
      
      Patched with:
      
      git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i
      Signed-off-by: NNick Piggin <npiggin@kernel.dk>
      fb045adb
    • N
      fs: change d_delete semantics · fe15ce44
      Nick Piggin 提交于
      Change d_delete from a dentry deletion notification to a dentry caching
      advise, more like ->drop_inode. Require it to be constant and idempotent,
      and not take d_lock. This is how all existing filesystems use the callback
      anyway.
      
      This makes fine grained dentry locking of dput and dentry lru scanning
      much simpler.
      Signed-off-by: NNick Piggin <npiggin@kernel.dk>
      fe15ce44
  12. 29 12月, 2010 4 次提交
  13. 29 10月, 2010 1 次提交
  14. 28 10月, 2010 1 次提交
  15. 15 10月, 2010 1 次提交
    • A
      llseek: automatically add .llseek fop · 6038f373
      Arnd Bergmann 提交于
      All file_operations should get a .llseek operation so we can make
      nonseekable_open the default for future file operations without a
      .llseek pointer.
      
      The three cases that we can automatically detect are no_llseek, seq_lseek
      and default_llseek. For cases where we can we can automatically prove that
      the file offset is always ignored, we use noop_llseek, which maintains
      the current behavior of not returning an error from a seek.
      
      New drivers should normally not use noop_llseek but instead use no_llseek
      and call nonseekable_open at open time.  Existing drivers can be converted
      to do the same when the maintainer knows for certain that no user code
      relies on calling seek on the device file.
      
      The generated code is often incorrectly indented and right now contains
      comments that clarify for each added line why a specific variant was
      chosen. In the version that gets submitted upstream, the comments will
      be gone and I will manually fix the indentation, because there does not
      seem to be a way to do that using coccinelle.
      
      Some amount of new code is currently sitting in linux-next that should get
      the same modifications, which I will do at the end of the merge window.
      
      Many thanks to Julia Lawall for helping me learn to write a semantic
      patch that does all this.
      
      ===== begin semantic patch =====
      // This adds an llseek= method to all file operations,
      // as a preparation for making no_llseek the default.
      //
      // The rules are
      // - use no_llseek explicitly if we do nonseekable_open
      // - use seq_lseek for sequential files
      // - use default_llseek if we know we access f_pos
      // - use noop_llseek if we know we don't access f_pos,
      //   but we still want to allow users to call lseek
      //
      @ open1 exists @
      identifier nested_open;
      @@
      nested_open(...)
      {
      <+...
      nonseekable_open(...)
      ...+>
      }
      
      @ open exists@
      identifier open_f;
      identifier i, f;
      identifier open1.nested_open;
      @@
      int open_f(struct inode *i, struct file *f)
      {
      <+...
      (
      nonseekable_open(...)
      |
      nested_open(...)
      )
      ...+>
      }
      
      @ read disable optional_qualifier exists @
      identifier read_f;
      identifier f, p, s, off;
      type ssize_t, size_t, loff_t;
      expression E;
      identifier func;
      @@
      ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
      {
      <+...
      (
         *off = E
      |
         *off += E
      |
         func(..., off, ...)
      |
         E = *off
      )
      ...+>
      }
      
      @ read_no_fpos disable optional_qualifier exists @
      identifier read_f;
      identifier f, p, s, off;
      type ssize_t, size_t, loff_t;
      @@
      ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
      {
      ... when != off
      }
      
      @ write @
      identifier write_f;
      identifier f, p, s, off;
      type ssize_t, size_t, loff_t;
      expression E;
      identifier func;
      @@
      ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
      {
      <+...
      (
        *off = E
      |
        *off += E
      |
        func(..., off, ...)
      |
        E = *off
      )
      ...+>
      }
      
      @ write_no_fpos @
      identifier write_f;
      identifier f, p, s, off;
      type ssize_t, size_t, loff_t;
      @@
      ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
      {
      ... when != off
      }
      
      @ fops0 @
      identifier fops;
      @@
      struct file_operations fops = {
       ...
      };
      
      @ has_llseek depends on fops0 @
      identifier fops0.fops;
      identifier llseek_f;
      @@
      struct file_operations fops = {
      ...
       .llseek = llseek_f,
      ...
      };
      
      @ has_read depends on fops0 @
      identifier fops0.fops;
      identifier read_f;
      @@
      struct file_operations fops = {
      ...
       .read = read_f,
      ...
      };
      
      @ has_write depends on fops0 @
      identifier fops0.fops;
      identifier write_f;
      @@
      struct file_operations fops = {
      ...
       .write = write_f,
      ...
      };
      
      @ has_open depends on fops0 @
      identifier fops0.fops;
      identifier open_f;
      @@
      struct file_operations fops = {
      ...
       .open = open_f,
      ...
      };
      
      // use no_llseek if we call nonseekable_open
      ////////////////////////////////////////////
      @ nonseekable1 depends on !has_llseek && has_open @
      identifier fops0.fops;
      identifier nso ~= "nonseekable_open";
      @@
      struct file_operations fops = {
      ...  .open = nso, ...
      +.llseek = no_llseek, /* nonseekable */
      };
      
      @ nonseekable2 depends on !has_llseek @
      identifier fops0.fops;
      identifier open.open_f;
      @@
      struct file_operations fops = {
      ...  .open = open_f, ...
      +.llseek = no_llseek, /* open uses nonseekable */
      };
      
      // use seq_lseek for sequential files
      /////////////////////////////////////
      @ seq depends on !has_llseek @
      identifier fops0.fops;
      identifier sr ~= "seq_read";
      @@
      struct file_operations fops = {
      ...  .read = sr, ...
      +.llseek = seq_lseek, /* we have seq_read */
      };
      
      // use default_llseek if there is a readdir
      ///////////////////////////////////////////
      @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier readdir_e;
      @@
      // any other fop is used that changes pos
      struct file_operations fops = {
      ... .readdir = readdir_e, ...
      +.llseek = default_llseek, /* readdir is present */
      };
      
      // use default_llseek if at least one of read/write touches f_pos
      /////////////////////////////////////////////////////////////////
      @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier read.read_f;
      @@
      // read fops use offset
      struct file_operations fops = {
      ... .read = read_f, ...
      +.llseek = default_llseek, /* read accesses f_pos */
      };
      
      @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier write.write_f;
      @@
      // write fops use offset
      struct file_operations fops = {
      ... .write = write_f, ...
      +	.llseek = default_llseek, /* write accesses f_pos */
      };
      
      // Use noop_llseek if neither read nor write accesses f_pos
      ///////////////////////////////////////////////////////////
      
      @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier read_no_fpos.read_f;
      identifier write_no_fpos.write_f;
      @@
      // write fops use offset
      struct file_operations fops = {
      ...
       .write = write_f,
       .read = read_f,
      ...
      +.llseek = noop_llseek, /* read and write both use no f_pos */
      };
      
      @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier write_no_fpos.write_f;
      @@
      struct file_operations fops = {
      ... .write = write_f, ...
      +.llseek = noop_llseek, /* write uses no f_pos */
      };
      
      @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier read_no_fpos.read_f;
      @@
      struct file_operations fops = {
      ... .read = read_f, ...
      +.llseek = noop_llseek, /* read uses no f_pos */
      };
      
      @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      @@
      struct file_operations fops = {
      ...
      +.llseek = noop_llseek, /* no read or write fn */
      };
      ===== End semantic patch =====
      Signed-off-by: NArnd Bergmann <arnd@arndb.de>
      Cc: Julia Lawall <julia@diku.dk>
      Cc: Christoph Hellwig <hch@infradead.org>
      6038f373
  16. 12 10月, 2010 2 次提交
  17. 08 10月, 2010 1 次提交