1. 17 3月, 2010 1 次提交
  2. 17 2月, 2010 2 次提交
    • A
      powerpc: Use lwarx/ldarx hint in bit locks · 864b9e6f
      Anton Blanchard 提交于
      This patch implements the lwarx/ldarx hint bit for bit locks.
      Signed-off-by: NAnton Blanchard <anton@samba.org>
      Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      864b9e6f
    • A
      powerpc: Use lwarx hint in spinlocks · 4e14a4d1
      Anton Blanchard 提交于
      Recent versions of the PowerPC architecture added a hint bit to the larx
      instructions to differentiate between an atomic operation and a lock operation:
      
      > 0 Other programs might attempt to modify the word in storage addressed by EA
      > even if the subsequent Store Conditional succeeds.
      >
      > 1 Other programs will not attempt to modify the word in storage addressed by
      > EA until the program that has acquired the lock performs a subsequent store
      > releasing the lock.
      
      To avoid a binutils dependency this patch create macros for the extended lwarx
      format and uses it in the spinlock code. To test this change I used a simple
      test case that acquires and releases a global pthread mutex:
      
      	pthread_mutex_lock(&mutex);
      	pthread_mutex_unlock(&mutex);
      
      On a 32 core POWER6, running 32 test threads we spend almost all our time in
      the futex spinlock code:
      
          94.37%     perf  [kernel]                     [k] ._raw_spin_lock
                     |
                     |--99.95%-- ._raw_spin_lock
                     |          |
                     |          |--63.29%-- .futex_wake
                     |          |
                     |          |--36.64%-- .futex_wait_setup
      
      Which is a good test for this patch. The results (in lock/unlock operations per
      second) are:
      
      before: 1538203 ops/sec
      after:  2189219 ops/sec
      
      An improvement of 42%
      
      A 32 core POWER7 improves even more:
      
      before: 1279529 ops/sec
      after:  2282076 ops/sec
      
      An improvement of 78%
      Signed-off-by: NAnton Blanchard <anton@samba.org>
      Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      4e14a4d1
  3. 20 8月, 2009 1 次提交
  4. 21 5月, 2009 3 次提交
  5. 23 4月, 2009 1 次提交
  6. 07 4月, 2009 2 次提交
  7. 23 2月, 2009 1 次提交
    • K
      powerpc: Unify opcode definitions and support · 16c57b36
      Kumar Gala 提交于
      Create a new header that becomes a single location for defining PowerPC
      opcodes used by code that is either generationg instructions
      at runtime (fixups, debug, etc.), emulating instructions, or just
      compiling instructions old assemblers don't know about.
      
      We currently don't handle the floating point emulation or alignment decode
      as both are better handled by the specific decode support they already
      have.
      
      Added support for the new dcbzl, dcbal, msgsnd, tlbilx, & wait instructions
      since older assemblers don't know about them.
      Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
      Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      16c57b36