• Waiman Long's avatar
    locking/qspinlock: Extract out code snippets for the next patch · 6403bd7d
    Waiman Long authored
    
    
    This is a preparatory patch that extracts out the following 2 code
    snippets to prepare for the next performance optimization patch.
    
     1) the logic for the exchange of new and previous tail code words
        into a new xchg_tail() function.
     2) the logic for clearing the pending bit and setting the locked bit
        into a new clear_pending_set_locked() function.
    
    This patch also simplifies the trylock operation before queuing by
    calling queued_spin_trylock() directly.
    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/1429901803-29771-5-git-send-email-Waiman.Long@hp.com
    
    Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
    6403bd7d
qspinlock.c 8.02 KB