1. 21 Dec, 2018 1 commit
  2. 02 Nov, 2017 1 commit
    • Greg Kroah-Hartman's avatar
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman authored
      Many source files in the tree are missing licensing information, which
      makes it harder for compliance tools to determine the correct license.
      
      By default all files without license information are under the default
      license of the kernel, which is GPL version 2.
      
      Update the files which contain no license information with the 'GPL-2.0'
      SPDX license identifier.  The SPDX identifier is a legally binding
      shorthand, which can be used instead of the full boiler plate text.
      
      This patch is based on work done by Thomas Gleixner and Kate Stewart and
      Philippe Ombredanne.
      
      How this work was done:
      
      Patches were generated and checked against linux-4.14-rc6 for a subset of
      the use cases:
       - file had no licensing information it it.
       - file was a */uapi/* one with no licensing information in it,
       - file was a */uapi/* one with existing licensing information,
      
      Further patches will be generated in subsequent months to fix up cases
      where non-standard...
      b2441318
  3. 21 Feb, 2017 1 commit
  4. 22 Nov, 2016 1 commit
    • Peter Zijlstra's avatar
      x86/paravirt: Optimize native pv_lock_ops.vcpu_is_preempted() · 3cded417
      Peter Zijlstra authored
      
      
      Avoid the pointless function call to pv_lock_ops.vcpu_is_preempted()
      when a paravirt spinlock enabled kernel is ran on native hardware.
      
      Do this by patching out the CALL instruction with "XOR %RAX,%RAX"
      which has the same effect (0 return value).
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: David.Laight@ACULAB.COM
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: benh@kernel.crashing.org
      Cc: boqun.feng@gmail.com
      Cc: borntraeger@de.ibm.com
      Cc: bsingharora@gmail.com
      Cc: dave@stgolabs.net
      Cc: jgross@suse.com
      Cc: kernellwp@gmail.com
      Cc: konrad.wilk@oracle.com
      Cc: mpe@ellerman.id.au
      Cc: paulmck@linux.vnet.ibm.com
      Cc: paulus@samba.org
      Cc: pbonzini@redhat.com
      Cc: rkrcmar@redhat.com
      Cc: will.deacon@arm.com
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      3cded417
  5. 11 Sep, 2015 2 commits
  6. 08 May, 2015 3 commits
    • Peter Zijlstra (Intel)'s avatar
      locking/pvqspinlock, x86: Implement the paravirt qspinlock call patching · f233f7f1
      Peter Zijlstra (Intel) authored
      
      
      We use the regular paravirt call patching to switch between:
      
        native_queued_spin_lock_slowpath()	__pv_queued_spin_lock_slowpath()
        native_queued_spin_unlock()		__pv_queued_spin_unlock()
      
      We use a callee saved call for the unlock function which reduces the
      i-cache footprint and allows 'inlining' of SPIN_UNLOCK functions
      again.
      
      We further optimize the unlock path by patching the direct call with a
      "movb $0,%arg1" if we are indeed using the native unlock code. This
      makes the unlock code almost as fast as the !PARAVIRT case.
      
      This significantly lowers the overhead of having
      CONFIG_PARAVIRT_SPINLOCKS enabled, even for native code.
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Signed-off-by: default avatarWaiman Long <Waiman.Long@hp.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Daniel J Blueman <daniel@numascale.com>
      Cc: David Vrabel <david.vrabel@citrix.com>
      Cc: Douglas Hatch <doug.hatch@hp.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Paolo Bonzini <paolo.bonzini@gmail.com>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Scott J Norton <scott.norton@hp.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: virtualization@lists.linux-foundation.org
      Cc: xen-devel@lists.xenproject.org
      Link: http://lkml.kernel.org/r/1429901803-29771-10-git-send-email-Waiman.Long@hp.com
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      f233f7f1
    • Peter Zijlstra (Intel)'s avatar
      locking/qspinlock: Revert to test-and-set on hypervisors · 2aa79af6
      Peter Zijlstra (Intel) authored
      
      
      When we detect a hypervisor (!paravirt, see qspinlock paravirt support
      patches), revert to a simple test-and-set lock to avoid the horrors
      of queue preemption.
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Signed-off-by: default avatarWaiman Long <Waiman.Long@hp.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Daniel J Blueman <daniel@numascale.com>
      Cc: David Vrabel <david.vrabel@citrix.com>
      Cc: Douglas Hatch <doug.hatch@hp.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Paolo Bonzini <paolo.bonzini@gmail.com>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Scott J Norton <scott.norton@hp.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: virtualization@lists.linux-foundation.org
      Cc: xen-devel@lists.xenproject.org
      Link: http://lkml.kernel.org/r/1429901803-29771-8-git-send-email-Waiman.Long@hp.com
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      2aa79af6
    • Waiman Long's avatar
      locking/qspinlock, x86: Enable x86-64 to use queued spinlocks · d73a3397
      Waiman Long authored
      
      
      This patch makes the necessary changes at the x86 architecture
      specific layer to enable the use of queued spinlocks for x86-64. As
      x86-32 machines are typically not multi-socket. The benefit of queue
      spinlock may not be apparent. So queued spinlocks are not enabled.
      
      Currently, there is some incompatibilities between the para-virtualized
      spinlock code (which hard-codes the use of ticket spinlock) and the
      queued spinlocks. Therefore, the use of queued spinlocks is disabled
      when the para-virtualized spinlock is enabled.
      
      The arch/x86/include/asm/qspinlock.h header file includes some x86
      specific optimization which will make the queueds spinlock code
      perform better than the generic implementation.
      Signed-off-by: default avatarWaiman Long <Waiman.Long@hp.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Daniel J Blueman <daniel@numascale.com>
      Cc: David Vrabel <david.vrabel@citrix.com>
      Cc: Douglas Hatch <doug.hatch@hp.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Paolo Bonzini <paolo.bonzini@gmail.com>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Scott J Norton <scott.norton@hp.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: virtualization@lists.linux-foundation.org
      Cc: xen-devel@lists.xenproject.org
      Link: http://lkml.kernel.org/r/1429901803-29771-3-git-send-email-Waiman.Long@hp.com
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      d73a3397