1. 15 Oct, 2008 1 commit
  2. 11 Oct, 2008 2 commits
  3. 20 Jul, 2007 1 commit
  4. 06 Mar, 2007 1 commit
  5. 13 Feb, 2007 1 commit
    • Ralf Baechle's avatar
      [MIPS] Improve branch prediction in ll/sc atomic operations. · f65e4fa8
      Ralf Baechle authored
      
      
      Now that finally all supported versions of binutils have functioning
      support for .subsection use .subsection to tweak the branch prediction
      
      I did not modify the R10000 errata variants because it seems unclear if
      this will invalidate the workaround which actually relies on the cheesy
      prediction of branch likely to cause a misspredict if the sc was
      successful.
      Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      f65e4fa8
  6. 04 Dec, 2006 1 commit
  7. 01 Oct, 2006 1 commit
    • Martin Schwidefsky's avatar
      [PATCH] Directed yield: cpu_relax variants for spinlocks and rw-locks · ef6edc97
      Martin Schwidefsky authored
      
      
      On systems running with virtual cpus there is optimization potential in
      regard to spinlocks and rw-locks.  If the virtual cpu that has taken a lock
      is known to a cpu that wants to acquire the same lock it is beneficial to
      yield the timeslice of the virtual cpu in favour of the cpu that has the
      lock (directed yield).
      
      With CONFIG_PREEMPT="n" this can be implemented by the architecture without
      common code changes.  Powerpc already does this.
      
      With CONFIG_PREEMPT="y" the lock loops are coded with _raw_spin_trylock,
      _raw_read_trylock and _raw_write_trylock in kernel/spinlock.c.  If the lock
      could not be taken cpu_relax is called.  A directed yield is not possible
      because cpu_relax doesn't know anything about the lock.  To be able to
      yield the lock in favour of the current lock holder variants of cpu_relax
      for spinlocks and rw-locks are needed.  The new _raw_spin_relax,
      _raw_read_relax and _raw_write_relax primitives differ from cpu_relax
      insofar that they have an argument: a pointer to the lock structure.
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      ef6edc97
  8. 27 Sep, 2006 1 commit
  9. 29 Oct, 2005 3 commits
  10. 10 Sep, 2005 1 commit
    • Ingo Molnar's avatar
      [PATCH] spinlock consolidation · fb1c8f93
      Ingo Molnar authored
      
      
      This patch (written by me and also containing many suggestions of Arjan van
      de Ven) does a major cleanup of the spinlock code.  It does the following
      things:
      
       - consolidates and enhances the spinlock/rwlock debugging code
      
       - simplifies the asm/spinlock.h files
      
       - encapsulates the raw spinlock type and moves generic spinlock
         features (such as ->break_lock) into the generic code.
      
       - cleans up the spinlock code hierarchy to get rid of the spaghetti.
      
      Most notably there's now only a single variant of the debugging code,
      located in lib/spinlock_debug.c.  (previously we had one SMP debugging
      variant per architecture, plus a separate generic one for UP builds)
      
      Also, i've enhanced the rwlock debugging facility, it will now track
      write-owners.  There is new spinlock-owner/CPU-tracking on SMP builds too.
      All locks have lockup detection now, which will work for both soft and hard
      spin/rwlock lockups.
      
      The arch-level include files now only contain the minimally necessary
      subset of the spinlock code - all the rest that can be generalized now
      lives in the generic headers:
      
       include/asm-i386/spinlock_types.h       |   16
       include/asm-x86_64/spinlock_types.h     |   16
      
      I have also split up the various spinlock variants into separate files,
      making it easier to see which does what. The new layout is:
      
         SMP                         |  UP
         ----------------------------|-----------------------------------
         asm/spinlock_types_smp.h    |  linux/spinlock_types_up.h
         linux/spinlock_types.h      |  linux/spinlock_types.h
         asm/spinlock_smp.h          |  linux/spinlock_up.h
         linux/spinlock_api_smp.h    |  linux/spinlock_api_up.h
         linux/spinlock.h            |  linux/spinlock.h
      
      /*
       * here's the role of the various spinlock/rwlock related include files:
       *
       * on SMP builds:
       *
       *  asm/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the
       *                        initializers
       *
       *  linux/spinlock_types.h:
       *                        defines the generic type and initializers
       *
       *  asm/spinlock.h:       contains the __raw_spin_*()/etc. lowlevel
       *                        implementations, mostly inline assembly code
       *
       *   (also included on UP-debug builds:)
       *
       *  linux/spinlock_api_smp.h:
       *                        contains the prototypes for the _spin_*() APIs.
       *
       *  linux/spinlock.h:     builds the final spin_*() APIs.
       *
       * on UP builds:
       *
       *  linux/spinlock_type_up.h:
       *                        contains the generic, simplified UP spinlock type.
       *                        (which is an empty structure on non-debug builds)
       *
       *  linux/spinlock_types.h:
       *                        defines the generic type and initializers
       *
       *  linux/spinlock_up.h:
       *                        contains the __raw_spin_*()/etc. version of UP
       *                        builds. (which are NOPs on non-debug, non-preempt
       *                        builds)
       *
       *   (included on UP-non-debug builds:)
       *
       *  linux/spinlock_api_up.h:
       *                        builds the _spin_*() APIs.
       *
       *  linux/spinlock.h:     builds the final spin_*() APIs.
       */
      
      All SMP and UP architectures are converted by this patch.
      
      arm, i386, ia64, ppc, ppc64, s390/s390x, x64 was build-tested via
      crosscompilers.  m32r, mips, sh, sparc, have not been tested yet, but should
      be mostly fine.
      
      From: Grant Grundler <grundler@parisc-linux.org>
      
        Booted and lightly tested on a500-44 (64-bit, SMP kernel, dual CPU).
        Builds 32-bit SMP kernel (not booted or tested).  I did not try to build
        non-SMP kernels.  That should be trivial to fix up later if necessary.
      
        I converted bit ops atomic_hash lock to raw_spinlock_t.  Doing so avoids
        some ugly nesting of linux/*.h and asm/*.h files.  Those particular locks
        are well tested and contained entirely inside arch specific code.  I do NOT
        expect any new issues to arise with them.
      
       If someone does ever need to use debug/metrics with them, then they will
        need to unravel this hairball between spinlocks, atomic ops, and bit ops
        that exist only because parisc has exactly one atomic instruction: LDCW
        (load and clear word).
      
      From: "Luck, Tony" <tony.luck@intel.com>
      
         ia64 fix
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarArjan van de Ven <arjanv@infradead.org>
      Signed-off-by: default avatarGrant Grundler <grundler@parisc-linux.org>
      Cc: Matthew Wilcox <willy@debian.org>
      Signed-off-by: default avatarHirokazu Takata <takata@linux-m32r.org>
      Signed-off-by: default avatarMikael Pettersson <mikpe@csd.uu.se>
      Signed-off-by: default avatarBenoit Boissinot <benoit.boissinot@ens-lyon.org>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      fb1c8f93
  11. 16 Apr, 2005 1 commit
    • Linus Torvalds's avatar
      Linux-2.6.12-rc2 · 1da177e4
      Linus Torvalds authored
      Initial git repository build. I'm not bothering with the full history,
      even though we have it. We can create a separate "historical" git
      archive of that later if we want to, and in the meantime it's about
      3.2GB when imported into git - space that would just make the early
      git days unnecessarily complicated, when we don't have a lot of good
      infrastructure for it.
      
      Let it rip!
      1da177e4