446f3dc8cc
Optimize spinlock and mutex busy-loops by providing a vcpu_is_preempted(cpu) function on KVM and Xen platforms. Extend the pv_lock_ops interface accordingly and implement the callbacks on KVM and Xen. Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> [ Translated to English. ] Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: David.Laight@ACULAB.COM Cc: Linus Torvalds <torvalds@linux-foundation.org> 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: linuxppc-dev@lists.ozlabs.org Cc: mpe@ellerman.id.au Cc: paulmck@linux.vnet.ibm.com Cc: paulus@samba.org Cc: rkrcmar@redhat.com Cc: virtualization@lists.linux-foundation.org Cc: will.deacon@arm.com Cc: xen-devel-request@lists.xenproject.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1478077718-37424-7-git-send-email-xinhui.pan@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
42 lines
1.0 KiB
C
42 lines
1.0 KiB
C
/*
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* Split spinlock implementation out into its own file, so it can be
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* compiled in a FTRACE-compatible way.
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*/
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#include <linux/spinlock.h>
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#include <linux/export.h>
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#include <linux/jump_label.h>
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#include <asm/paravirt.h>
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__visible void __native_queued_spin_unlock(struct qspinlock *lock)
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{
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native_queued_spin_unlock(lock);
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}
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PV_CALLEE_SAVE_REGS_THUNK(__native_queued_spin_unlock);
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bool pv_is_native_spin_unlock(void)
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{
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return pv_lock_ops.queued_spin_unlock.func ==
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__raw_callee_save___native_queued_spin_unlock;
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}
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static bool native_vcpu_is_preempted(int cpu)
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{
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return 0;
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}
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struct pv_lock_ops pv_lock_ops = {
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#ifdef CONFIG_SMP
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.queued_spin_lock_slowpath = native_queued_spin_lock_slowpath,
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.queued_spin_unlock = PV_CALLEE_SAVE(__native_queued_spin_unlock),
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.wait = paravirt_nop,
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.kick = paravirt_nop,
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.vcpu_is_preempted = native_vcpu_is_preempted,
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#endif /* SMP */
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};
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EXPORT_SYMBOL(pv_lock_ops);
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struct static_key paravirt_ticketlocks_enabled = STATIC_KEY_INIT_FALSE;
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EXPORT_SYMBOL(paravirt_ticketlocks_enabled);
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