1. 20 6月, 2014 4 次提交
  2. 28 5月, 2014 1 次提交
  3. 08 4月, 2014 1 次提交
    • D
      mm: per-thread vma caching · 615d6e87
      Davidlohr Bueso 提交于
      This patch is a continuation of efforts trying to optimize find_vma(),
      avoiding potentially expensive rbtree walks to locate a vma upon faults.
      The original approach (https://lkml.org/lkml/2013/11/1/410), where the
      largest vma was also cached, ended up being too specific and random,
      thus further comparison with other approaches were needed.  There are
      two things to consider when dealing with this, the cache hit rate and
      the latency of find_vma().  Improving the hit-rate does not necessarily
      translate in finding the vma any faster, as the overhead of any fancy
      caching schemes can be too high to consider.
      
      We currently cache the last used vma for the whole address space, which
      provides a nice optimization, reducing the total cycles in find_vma() by
      up to 250%, for workloads with good locality.  On the other hand, this
      simple scheme is pretty much useless for workloads with poor locality.
      Analyzing ebizzy runs shows that, no matter how many threads are
      running, the mmap_cache hit rate is less than 2%, and in many situations
      below 1%.
      
      The proposed approach is to replace this scheme with a small per-thread
      cache, maximizing hit rates at a very low maintenance cost.
      Invalidations are performed by simply bumping up a 32-bit sequence
      number.  The only expensive operation is in the rare case of a seq
      number overflow, where all caches that share the same address space are
      flushed.  Upon a miss, the proposed replacement policy is based on the
      page number that contains the virtual address in question.  Concretely,
      the following results are seen on an 80 core, 8 socket x86-64 box:
      
      1) System bootup: Most programs are single threaded, so the per-thread
         scheme does improve ~50% hit rate by just adding a few more slots to
         the cache.
      
      +----------------+----------+------------------+
      | caching scheme | hit-rate | cycles (billion) |
      +----------------+----------+------------------+
      | baseline       | 50.61%   | 19.90            |
      | patched        | 73.45%   | 13.58            |
      +----------------+----------+------------------+
      
      2) Kernel build: This one is already pretty good with the current
         approach as we're dealing with good locality.
      
      +----------------+----------+------------------+
      | caching scheme | hit-rate | cycles (billion) |
      +----------------+----------+------------------+
      | baseline       | 75.28%   | 11.03            |
      | patched        | 88.09%   | 9.31             |
      +----------------+----------+------------------+
      
      3) Oracle 11g Data Mining (4k pages): Similar to the kernel build workload.
      
      +----------------+----------+------------------+
      | caching scheme | hit-rate | cycles (billion) |
      +----------------+----------+------------------+
      | baseline       | 70.66%   | 17.14            |
      | patched        | 91.15%   | 12.57            |
      +----------------+----------+------------------+
      
      4) Ebizzy: There's a fair amount of variation from run to run, but this
         approach always shows nearly perfect hit rates, while baseline is just
         about non-existent.  The amounts of cycles can fluctuate between
         anywhere from ~60 to ~116 for the baseline scheme, but this approach
         reduces it considerably.  For instance, with 80 threads:
      
      +----------------+----------+------------------+
      | caching scheme | hit-rate | cycles (billion) |
      +----------------+----------+------------------+
      | baseline       | 1.06%    | 91.54            |
      | patched        | 99.97%   | 14.18            |
      +----------------+----------+------------------+
      
      [akpm@linux-foundation.org: fix nommu build, per Davidlohr]
      [akpm@linux-foundation.org: document vmacache_valid() logic]
      [akpm@linux-foundation.org: attempt to untangle header files]
      [akpm@linux-foundation.org: add vmacache_find() BUG_ON]
      [hughd@google.com: add vmacache_valid_mm() (from Oleg)]
      [akpm@linux-foundation.org: coding-style fixes]
      [akpm@linux-foundation.org: adjust and enhance comments]
      Signed-off-by: NDavidlohr Bueso <davidlohr@hp.com>
      Reviewed-by: NRik van Riel <riel@redhat.com>
      Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
      Reviewed-by: NMichel Lespinasse <walken@google.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Tested-by: NHugh Dickins <hughd@google.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      615d6e87
  4. 10 2月, 2014 2 次提交
    • T
      locking/mcs: Allow architecture specific asm files to be used for contended case · ddf1d169
      Tim Chen 提交于
      This patch allows each architecture to add its specific assembly optimized
      arch_mcs_spin_lock_contended and arch_mcs_spinlock_uncontended for
      MCS lock and unlock functions.
      Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
      Cc: Scott J Norton <scott.norton@hp.com>
      Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
      Cc: AswinChandramouleeswaran <aswin@hp.com>
      Cc: George Spelvin <linux@horizon.com>
      Cc: Rik vanRiel <riel@redhat.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: MichelLespinasse <walken@google.com>
      Cc: Peter Hurley <peter@hurleysoftware.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: Alex Shi <alex.shi@linaro.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Tim Chen <tim.c.chen@linux.intel.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: "Figo.zhang" <figo1802@gmail.com>
      Cc: "Paul E.McKenney" <paulmck@linux.vnet.ibm.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
      Cc: Waiman Long <waiman.long@hp.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Matthew R Wilcox <matthew.r.wilcox@intel.com>
      Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1390347382.3138.67.camel@schen9-DESKSigned-off-by: NIngo Molnar <mingo@kernel.org>
      ddf1d169
    • T
      locking/mcs: Order the header files in Kbuild of each architecture in alphabetical order · b119fa61
      Tim Chen 提交于
      We perform a clean up of the Kbuid files in each architecture.
      We order the files in each Kbuild in alphabetical order
      by running the below script.
      
      for i in arch/*/include/asm/Kbuild
      do
              cat $i | gawk '/^generic-y/ {
                      i = 3;
                      do {
                              for (; i <= NF; i++) {
                                      if ($i == "\\") {
                                              getline;
                                              i = 1;
                                              continue;
                                      }
                                      if ($i != "")
                                              hdr[$i] = $i;
                              }
                              break;
                      } while (1);
                      next;
              }
              // {
                      print $0;
              }
              END {
                      n = asort(hdr);
                      for (i = 1; i <= n; i++)
                              print "generic-y += " hdr[i];
              }' > ${i}.sorted;
              mv ${i}.sorted $i;
      done
      Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Matthew R Wilcox <matthew.r.wilcox@intel.com>
      Cc: AswinChandramouleeswaran <aswin@hp.com>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: "Paul E.McKenney" <paulmck@linux.vnet.ibm.com>
      Cc: Scott J Norton <scott.norton@hp.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: "Figo.zhang" <figo1802@gmail.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Waiman Long <waiman.long@hp.com>
      Cc: Peter Hurley <peter@hurleysoftware.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Tim Chen <tim.c.chen@linux.intel.com>
      Cc: Alex Shi <alex.shi@linaro.org>
      Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: George Spelvin <linux@horizon.com>
      Cc: MichelLespinasse <walken@google.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
      [ Fixed build bug. ]
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      b119fa61
  5. 12 1月, 2014 1 次提交
  6. 18 12月, 2013 1 次提交
  7. 15 11月, 2013 1 次提交
  8. 14 11月, 2013 1 次提交
  9. 25 9月, 2013 1 次提交
  10. 04 7月, 2013 1 次提交
  11. 29 6月, 2013 1 次提交
  12. 20 12月, 2012 1 次提交
  13. 14 11月, 2012 1 次提交
  14. 09 11月, 2012 4 次提交
  15. 04 10月, 2012 2 次提交
    • D
      UAPI: Fix the guards on various asm/unistd.h files · 89013952
      David Howells 提交于
      asm-generic/unistd.h and a number of asm/unistd.h files have been given
      reinclusion guards that allow the guard to be overridden if __SYSCALL is
      defined.  Unfortunately, these files define __SYSCALL and don't undefine it
      when they've finished with it, thus rendering the guard ineffective.
      
      The reason for this override is to allow the file to be #included multiple
      times with different settings on __SYSCALL for purposes like generating syscall
      tables.
      
      The following guards are problematic:
      
      arch/arm64/include/asm/unistd.h:#if !defined(__ASM_UNISTD_H) || defined(__SYSCALL)
      arch/arm64/include/asm/unistd32.h:#if !defined(__ASM_UNISTD32_H) || defined(__SYSCALL)
      arch/c6x/include/asm/unistd.h:#if !defined(_ASM_C6X_UNISTD_H) || defined(__SYSCALL)
      arch/hexagon/include/asm/unistd.h:#if !defined(_ASM_HEXAGON_UNISTD_H) || defined(__SYSCALL)
      arch/openrisc/include/asm/unistd.h:#if !defined(__ASM_OPENRISC_UNISTD_H) || defined(__SYSCALL)
      arch/score/include/asm/unistd.h:#if !defined(_ASM_SCORE_UNISTD_H) || defined(__SYSCALL)
      arch/tile/include/asm/unistd.h:#if !defined(_ASM_TILE_UNISTD_H) || defined(__SYSCALL)
      arch/unicore32/include/asm/unistd.h:#if !defined(__UNICORE_UNISTD_H__) || defined(__SYSCALL)
      include/asm-generic/unistd.h:#if !defined(_ASM_GENERIC_UNISTD_H) || defined(__SYSCALL)
      
      On the assumption that the guards' ineffectiveness has passed unnoticed, just
      remove these guards entirely.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Acked-by: NArnd Bergmann <arnd@arndb.de>
      Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
      89013952
    • M
      asm-generic: Add default clkdev.h · e7a570ff
      Mark Brown 提交于
      Ease the deployment of clkdev by providing a default asm/clkdev.h for
      use if the arch does not have an include/asm/clkdev.h.
      
      Due to limitations in Kbuild we manually add clkdev.h to all
      architectures that don't have one rather than having the header appear
      by default.
      Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
      Reviewed-by: NStephen Rothwell <sfr@canb.auug.org.au>
      Signed-off-by: NArnd Bergmann <arnd@arndb.de>
      e7a570ff
  16. 01 10月, 2012 2 次提交
  17. 20 9月, 2012 1 次提交
  18. 17 5月, 2012 1 次提交
    • S
      fork: move the real prepare_to_copy() users to arch_dup_task_struct() · 55ccf3fe
      Suresh Siddha 提交于
      Historical prepare_to_copy() is mostly a no-op, duplicated for majority of
      the architectures and the rest following the x86 model of flushing the extended
      register state like fpu there.
      
      Remove it and use the arch_dup_task_struct() instead.
      Suggested-by: NOleg Nesterov <oleg@redhat.com>
      Suggested-by: NLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
      Link: http://lkml.kernel.org/r/1336692811-30576-1-git-send-email-suresh.b.siddha@intel.comAcked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
      Cc: Mike Frysinger <vapier@gentoo.org>
      Cc: Mark Salter <msalter@redhat.com>
      Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: James E.J. Bottomley <jejb@parisc-linux.org>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Chen Liqin <liqin.chen@sunplusct.com>
      Cc: Lennox Wu <lennox.wu@gmail.com>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      55ccf3fe
  19. 08 4月, 2012 1 次提交
  20. 29 3月, 2012 2 次提交
  21. 28 3月, 2012 1 次提交
  22. 21 3月, 2012 1 次提交
  23. 10 1月, 2012 2 次提交
  24. 07 1月, 2012 1 次提交
    • M
      PCI: UniCore: convert pcibios_set_master() to a non-inlined function · b73224fd
      Myron Stowe 提交于
      This patch converts UniCore's architecture-specific
      'pcibios_set_master()' routine to a non-inlined function.  This will
      allow follow on patches to create a generic 'pcibios_set_master()'
      function using the '__weak' attribute which can be used by all
      architectures as a default which, if necessary, can then be over-
      ridden by architecture-specific code.
      
      Converting 'pci_bios_set_master()' to a non-inlined function will
      allow UniCore's 'pcibios_set_master()' implementation to remain
      architecture-specific after the generic version is introduced and
      thus, not change current behavior.
      
      No functional change.
      Signed-off-by: NMyron Stowe <myron.stowe@redhat.com>
      Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
      b73224fd
  25. 22 11月, 2011 1 次提交
  26. 16 11月, 2011 1 次提交
  27. 15 11月, 2011 1 次提交
  28. 28 9月, 2011 1 次提交
    • P
      doc: fix broken references · 395cf969
      Paul Bolle 提交于
      There are numerous broken references to Documentation files (in other
      Documentation files, in comments, etc.). These broken references are
      caused by typo's in the references, and by renames or removals of the
      Documentation files. Some broken references are simply odd.
      
      Fix these broken references, sometimes by dropping the irrelevant text
      they were part of.
      Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
      Signed-off-by: NJiri Kosina <jkosina@suse.cz>
      395cf969
  29. 09 6月, 2011 1 次提交