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. 16 7月, 2014 1 次提交
    • P
      locking/mutex: Disable optimistic spinning on some architectures · 4badad35
      Peter Zijlstra 提交于
      The optimistic spin code assumes regular stores and cmpxchg() play nice;
      this is found to not be true for at least: parisc, sparc32, tile32,
      metag-lock1, arc-!llsc and hexagon.
      
      There is further wreckage, but this in particular seemed easy to
      trigger, so blacklist this.
      
      Opt in for known good archs.
      Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
      Reported-by: NMikulas Patocka <mpatocka@redhat.com>
      Cc: David Miller <davem@davemloft.net>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: James Bottomley <James.Bottomley@hansenpartnership.com>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Jason Low <jason.low2@hp.com>
      Cc: Waiman Long <waiman.long@hp.com>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
      Cc: John David Anglin <dave.anglin@bell.net>
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Davidlohr Bueso <davidlohr@hp.com>
      Cc: stable@vger.kernel.org
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: linux-arm-kernel@lists.infradead.org
      Cc: linux-kernel@vger.kernel.org
      Cc: linuxppc-dev@lists.ozlabs.org
      Cc: sparclinux@vger.kernel.org
      Link: http://lkml.kernel.org/r/20140606175316.GV13930@laptop.programming.kicks-ass.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
      4badad35
  3. 13 7月, 2014 4 次提交
  4. 11 7月, 2014 14 次提交
  5. 10 7月, 2014 1 次提交
  6. 09 7月, 2014 2 次提交
  7. 08 7月, 2014 5 次提交
  8. 07 7月, 2014 11 次提交
  9. 05 7月, 2014 1 次提交