| Message ID | 1477642287-24104-11-git-send-email-xinhui.pan@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
On Fri, Oct 28, 2016 at 04:11:26AM -0400, Pan Xinhui wrote: > From: Juergen Gross <jgross@suse.com> > > Support the vcpu_is_preempted() functionality under Xen. This will > enhance lock performance on overcommitted hosts (more runnable vcpus > than physical cpus in the system) as doing busy waits for preempted > vcpus will hurt system performance far worse than early yielding. > > A quick test (4 vcpus on 1 physical cpu doing a parallel build job > with "make -j 8") reduced system time by about 5% with this patch. > > Signed-off-by: Juergen Gross <jgross@suse.com> > Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> > --- > arch/x86/xen/spinlock.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c > index 3d6e006..74756bb 100644 > --- a/arch/x86/xen/spinlock.c > +++ b/arch/x86/xen/spinlock.c > @@ -114,7 +114,6 @@ void xen_uninit_lock_cpu(int cpu) > per_cpu(irq_name, cpu) = NULL; > } > > - Spurious change. > /* > * Our init of PV spinlocks is split in two init functions due to us > * using paravirt patching and jump labels patching and having to do > @@ -137,6 +136,8 @@ void __init xen_init_spinlocks(void) > pv_lock_ops.queued_spin_unlock = PV_CALLEE_SAVE(__pv_queued_spin_unlock); > pv_lock_ops.wait = xen_qlock_wait; > pv_lock_ops.kick = xen_qlock_kick; > + > + pv_lock_ops.vcpu_is_preempted = xen_vcpu_stolen; > } > > /* > -- > 2.4.11 > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > https://lists.xen.org/xen-devel
在 2016/10/29 03:43, Konrad Rzeszutek Wilk 写道: > On Fri, Oct 28, 2016 at 04:11:26AM -0400, Pan Xinhui wrote: >> From: Juergen Gross <jgross@suse.com> >> >> Support the vcpu_is_preempted() functionality under Xen. This will >> enhance lock performance on overcommitted hosts (more runnable vcpus >> than physical cpus in the system) as doing busy waits for preempted >> vcpus will hurt system performance far worse than early yielding. >> >> A quick test (4 vcpus on 1 physical cpu doing a parallel build job >> with "make -j 8") reduced system time by about 5% with this patch. >> >> Signed-off-by: Juergen Gross <jgross@suse.com> >> Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> >> --- >> arch/x86/xen/spinlock.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c >> index 3d6e006..74756bb 100644 >> --- a/arch/x86/xen/spinlock.c >> +++ b/arch/x86/xen/spinlock.c >> @@ -114,7 +114,6 @@ void xen_uninit_lock_cpu(int cpu) >> per_cpu(irq_name, cpu) = NULL; >> } >> >> - > > Spurious change. well, just remove one unnecessary blank line while at it. >> /* >> * Our init of PV spinlocks is split in two init functions due to us >> * using paravirt patching and jump labels patching and having to do >> @@ -137,6 +136,8 @@ void __init xen_init_spinlocks(void) >> pv_lock_ops.queued_spin_unlock = PV_CALLEE_SAVE(__pv_queued_spin_unlock); >> pv_lock_ops.wait = xen_qlock_wait; >> pv_lock_ops.kick = xen_qlock_kick; >> + >> + pv_lock_ops.vcpu_is_preempted = xen_vcpu_stolen; >> } >> >> /* >> -- >> 2.4.11 >> >> >> _______________________________________________ >> Xen-devel mailing list >> Xen-devel@lists.xen.org >> https://lists.xen.org/xen-devel >
diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c index 3d6e006..74756bb 100644 --- a/arch/x86/xen/spinlock.c +++ b/arch/x86/xen/spinlock.c @@ -114,7 +114,6 @@ void xen_uninit_lock_cpu(int cpu) per_cpu(irq_name, cpu) = NULL; } - /* * Our init of PV spinlocks is split in two init functions due to us * using paravirt patching and jump labels patching and having to do @@ -137,6 +136,8 @@ void __init xen_init_spinlocks(void) pv_lock_ops.queued_spin_unlock = PV_CALLEE_SAVE(__pv_queued_spin_unlock); pv_lock_ops.wait = xen_qlock_wait; pv_lock_ops.kick = xen_qlock_kick; + + pv_lock_ops.vcpu_is_preempted = xen_vcpu_stolen; } /*