1. 17 7月, 2014 1 次提交
    • D
      arch, locking: Ciao arch_mutex_cpu_relax() · 3a6bfbc9
      Davidlohr Bueso 提交于
      The arch_mutex_cpu_relax() function, introduced by 34b133f8, is
      hacky and ugly. It was added a few years ago to address the fact
      that common cpu_relax() calls include yielding on s390, and thus
      impact the optimistic spinning functionality of mutexes. Nowadays
      we use this function well beyond mutexes: rwsem, qrwlock, mcs and
      lockref. Since the macro that defines the call is in the mutex header,
      any users must include mutex.h and the naming is misleading as well.
      
      This patch (i) renames the call to cpu_relax_lowlatency  ("relax, but
      only if you can do it with very low latency") and (ii) defines it in
      each arch's asm/processor.h local header, just like for regular cpu_relax
      functions. On all archs, except s390, cpu_relax_lowlatency is simply cpu_relax,
      and thus we can take it out of mutex.h. While this can seem redundant,
      I believe it is a good choice as it allows us to move out arch specific
      logic from generic locking primitives and enables future(?) archs to
      transparently define it, similarly to System Z.
      Signed-off-by: NDavidlohr Bueso <davidlohr@hp.com>
      Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Anton Blanchard <anton@samba.org>
      Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Bharat Bhushan <r65777@freescale.com>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chen Liqin <liqin.linux@gmail.com>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Christian Borntraeger <borntraeger@de.ibm.com>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: David Howells <dhowells@redhat.com>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
      Cc: Dominik Dingel <dingel@linux.vnet.ibm.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
      Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Hirokazu Takata <takata@linux-m32r.org>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: James E.J. Bottomley <jejb@parisc-linux.org>
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: Jason Wang <jasowang@redhat.com>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Cc: Joe Perches <joe@perches.com>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Joseph Myers <joseph@codesourcery.com>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
      Cc: Lennox Wu <lennox.wu@gmail.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mark Salter <msalter@redhat.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: Max Filippov <jcmvbkbc@gmail.com>
      Cc: Michael Neuling <mikey@neuling.org>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: Nicolas Pitre <nico@linaro.org>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Paul Burton <paul.burton@imgtec.com>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Qais Yousef <qais.yousef@imgtec.com>
      Cc: Qiaowei Ren <qiaowei.ren@intel.com>
      Cc: Rafael Wysocki <rafael.j.wysocki@intel.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Steven Miao <realmz6@gmail.com>
      Cc: Steven Rostedt <srostedt@redhat.com>
      Cc: Stratos Karafotis <stratosk@semaphore.gr>
      Cc: Tim Chen <tim.c.chen@linux.intel.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vasily Kulikov <segoon@openwall.com>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>
      Cc: Waiman Long <Waiman.Long@hp.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Wolfram Sang <wsa@the-dreams.de>
      Cc: adi-buildroot-devel@lists.sourceforge.net
      Cc: linux390@de.ibm.com
      Cc: linux-alpha@vger.kernel.org
      Cc: linux-am33-list@redhat.com
      Cc: linux-arm-kernel@lists.infradead.org
      Cc: linux-c6x-dev@linux-c6x.org
      Cc: linux-cris-kernel@axis.com
      Cc: linux-hexagon@vger.kernel.org
      Cc: linux-ia64@vger.kernel.org
      Cc: linux@lists.openrisc.net
      Cc: linux-m32r-ja@ml.linux-m32r.org
      Cc: linux-m32r@ml.linux-m32r.org
      Cc: linux-m68k@lists.linux-m68k.org
      Cc: linux-metag@vger.kernel.org
      Cc: linux-mips@linux-mips.org
      Cc: linux-parisc@vger.kernel.org
      Cc: linuxppc-dev@lists.ozlabs.org
      Cc: linux-s390@vger.kernel.org
      Cc: linux-sh@vger.kernel.org
      Cc: linux-xtensa@linux-xtensa.org
      Cc: sparclinux@vger.kernel.org
      Link: http://lkml.kernel.org/r/1404079773.2619.4.camel@buesod1.americas.hpqcorp.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
      3a6bfbc9
  2. 09 11月, 2012 1 次提交
  3. 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
  4. 16 11月, 2011 1 次提交
  5. 17 3月, 2011 1 次提交