1. 12 Dec, 2009 1 commit
  2. 11 Dec, 2009 2 commits
  3. 04 Dec, 2009 10 commits
  4. 30 Nov, 2009 8 commits
  5. 26 Nov, 2009 1 commit
    • Ilya Loginov's avatar
      block: add helpers to run flush_dcache_page() against a bio and a request's pages · 2d4dc890
      Ilya Loginov authored
      Mtdblock driver doesn't call flush_dcache_page for pages in request.  So,
      this causes problems on architectures where the icache doesn't fill from
      the dcache or with dcache aliases.  The patch fixes this.
      The ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE symbol was introduced to avoid
      pointless empty cache-thrashing loops on architectures for which
      flush_dcache_page() is a no-op.  Every architecture was provided with this
      flush pages on architectires where ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE is
      equal 1 or do nothing otherwise.
      See "fix mtd_blkdevs problem with caches on some architectures" discussion
      on LKML for more information.
      Signed-off-by: default avatarIlya Loginov <isloginov@gmail.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: David Woodhouse <dwmw2@infradead.org>
      Cc: Peter Horton <phorton@bitbox.co.uk>
      Cc: "Ed L. Cashin" <ecashin@coraid.com>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
  6. 25 Nov, 2009 1 commit
  7. 24 Nov, 2009 5 commits
    • Paul Mundt's avatar
      sh: Apply the sleazy FPU changes for SH-2A FPU as well. · 0f09e197
      Paul Mundt authored
      This plugs in the fpu_counter manipulation for the SH-2A side also.
      Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
    • Stuart Menefy's avatar
      sh: Minor optimisations to FPU handling · d3ea9fa0
      Stuart Menefy authored
      A number of small optimisations to FPU handling, in particular:
       - move the task USEDFPU flag from the thread_info flags field (which
         is accessed asynchronously to the thread) to a new status field,
         which is only accessed by the thread itself. This allows locking to
         be removed in most cases, or can be reduced to a preempt_lock().
         This mimics the i386 behaviour.
       - move the modification of regs->sr and thread_info->status flags out
         of save_fpu() to __unlazy_fpu(). This gives the compiler a better
         chance to optimise things, as well as making save_fpu() symmetrical
         with restore_fpu() and init_fpu().
       - implement prepare_to_copy(), so that when creating a thread, we can
         unlazy the FPU prior to copying the thread data structures.
      Also make sure that the FPU is disabled while in the kernel, in
      particular while booting, and for newly created kernel threads,
      In a very artificial benchmark, the execution time for 2500000
      context switches was reduced from 50 to 45 seconds.
      Signed-off-by: default avatarStuart Menefy <stuart.menefy@st.com>
      Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
    • Stuart Menefy's avatar
      sh: Improve performance of SH4 versions of copy/clear_user_highpage · 39ac11c1
      Stuart Menefy authored
      The previous implementation of clear_user_highpage and copy_user_highpage
      checked to see if there was a D-cache aliasing issue between the user
      and kernel mappings of a page, but if there was they always did a
      flush with writeback on the dirtied kernel alias.
      However as we now have the ability to map a page into kernel space
      with the same cache colour as the user mapping, there is no need to
      write back this data.
      Currently we also invalidate the kernel alias as a precaution, however
      I'm not sure if this is actually required.
      Also correct the definition of FIX_CMAP_END so that the mappings created
      by kmap_coherent() are actually at the correct colour.
      Signed-off-by: default avatarStuart Menefy <stuart.menefy@st.com>
      Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
    • Stuart Menefy's avatar
      sh: Optimised memset for SH4 · dfc34940
      Stuart Menefy authored
      Optimised version of memset for the SH4 which uses movca.l.
      Signed-off-by: default avatarStuart Menefy <stuart.menefy@st.com>
      Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
    • Giuseppe CAVALLARO's avatar
      sh: add sleazy FPU optimization · a0458b07
      Giuseppe CAVALLARO authored
      sh port of the sLeAZY-fpu feature currently implemented for some architectures
      such us i386.
      Right now the SH kernel has a 100% lazy fpu behaviour.
      This is of course great for applications that have very sporadic or no FPU use.
      However for very frequent FPU users...  you take an extra trap every context
      The patch below adds a simple heuristic to this code: after 5 consecutive
      context switches of FPU use, the lazy behavior is disabled and the context
      gets restored every context switch.
      After 256 switches, this is reset and the 100% lazy behavior is returned.
      Tests with LMbench showed no regression.
      I saw a little improvement due to the prefetching (~2%).
      The tests below also show that, with this sLeazy patch, indeed,
      the number of FPU exceptions is reduced.
      To test this. I hacked the lat_ctx LMBench to use the FPU a little more.
         sLeasy implementation
         switch_to calls            |  79326
         sleasy   calls             |  42577
         do_fpu_state_restore  calls|  59232
         restore_fpu   calls        |  59032
         Exceptions:  0x800 (FPU disabled  ): 16604
         100% Leazy (default implementation)
         switch_to  calls            |  79690
         do_fpu_state_restore calls  |  53299
         restore_fpu  calls          |   53101
         Exceptions: 0x800 (FPU disabled  ):  53273
      Signed-off-by: default avatarGiuseppe Cavallaro <peppe.cavallaro@st.com>
      Signed-off-by: default avatarStuart Menefy <stuart.menefy@st.com>
      Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
  8. 18 Nov, 2009 2 commits
  9. 13 Nov, 2009 1 commit
  10. 12 Nov, 2009 5 commits
  11. 11 Nov, 2009 1 commit
  12. 09 Nov, 2009 3 commits