From: Zhenzhong Duan <zhenzhong.duan@oracle.com>
To: linux-kernel@vger.kernel.org
Cc: vkuznets@redhat.com, linux-hyperv@vger.kernel.org,
kvm@vger.kernel.org, Zhenzhong Duan <zhenzhong.duan@oracle.com>,
Jonathan Corbet <corbet@lwn.net>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Juergen Gross <jgross@suse.com>,
Stefano Stabellini <sstabellini@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>
Subject: [PATCH v3 3/4] xen: Mark "xen_nopvspin" parameter obsolete and map it to "nopvspin"
Date: Mon, 30 Sep 2019 20:44:38 +0800 [thread overview]
Message-ID: <1569847479-13201-4-git-send-email-zhenzhong.duan@oracle.com> (raw)
In-Reply-To: <1569847479-13201-1-git-send-email-zhenzhong.duan@oracle.com>
Fix stale description of "xen_nopvspin" as we use qspinlock now.
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
---
Documentation/admin-guide/kernel-parameters.txt | 7 ++++---
arch/x86/xen/spinlock.c | 13 +++++++------
2 files changed, 11 insertions(+), 9 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 4b956d8..1f0a62f 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -5303,8 +5303,9 @@
never -- do not unplug even if version check succeeds
xen_nopvspin [X86,XEN]
- Disables the ticketlock slowpath using Xen PV
- optimizations.
+ Disables the qspinlock slowpath using Xen PV optimizations.
+ This parameter is obsoleted by "nopvspin" parameter, which
+ has equivalent effect for XEN platform.
xen_nopv [X86]
Disables the PV optimizations forcing the HVM guest to
@@ -5330,7 +5331,7 @@
as generic guest with no PV drivers. Currently support
XEN HVM, KVM, HYPER_V and VMWARE guest.
- nopvspin [X86,KVM] Disables the qspinlock slow path
+ nopvspin [X86,XEN,KVM] Disables the qspinlock slow path
using PV optimizations which allow the hypervisor to
'idle' the guest on lock contention.
diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c
index 6deb490..092a53f 100644
--- a/arch/x86/xen/spinlock.c
+++ b/arch/x86/xen/spinlock.c
@@ -18,7 +18,6 @@
static DEFINE_PER_CPU(int, lock_kicker_irq) = -1;
static DEFINE_PER_CPU(char *, irq_name);
static DEFINE_PER_CPU(atomic_t, xen_qlock_wait_nest);
-static bool xen_pvspin = true;
static void xen_qlock_kick(int cpu)
{
@@ -68,7 +67,7 @@ void xen_init_lock_cpu(int cpu)
int irq;
char *name;
- if (!xen_pvspin)
+ if (!pvspin)
return;
WARN(per_cpu(lock_kicker_irq, cpu) >= 0, "spinlock on CPU%d exists on IRQ%d!\n",
@@ -93,7 +92,7 @@ void xen_init_lock_cpu(int cpu)
void xen_uninit_lock_cpu(int cpu)
{
- if (!xen_pvspin)
+ if (!pvspin)
return;
unbind_from_irqhandler(per_cpu(lock_kicker_irq, cpu), NULL);
@@ -117,9 +116,9 @@ void __init xen_init_spinlocks(void)
/* Don't need to use pvqspinlock code if there is only 1 vCPU. */
if (num_possible_cpus() == 1)
- xen_pvspin = false;
+ pvspin = false;
- if (!xen_pvspin) {
+ if (!pvspin) {
printk(KERN_DEBUG "xen: PV spinlocks disabled\n");
static_branch_disable(&virt_spin_lock_key);
return;
@@ -137,7 +136,9 @@ void __init xen_init_spinlocks(void)
static __init int xen_parse_nopvspin(char *arg)
{
- xen_pvspin = false;
+ pr_notice("\"xen_nopvspin\" is deprecated, please use \"nopvspin\" instead\n");
+ if (xen_domain())
+ pvspin = false;
return 0;
}
early_param("xen_nopvspin", xen_parse_nopvspin);
--
1.8.3.1
next prev parent reply other threads:[~2019-10-01 12:41 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-30 12:44 [PATCH v3 0/4] Add a unified parameter "nopvspin" Zhenzhong Duan
2019-09-30 12:44 ` [PATCH v3 1/4] x86/kvm: Add "nopvspin" parameter to disable PV spinlocks Zhenzhong Duan
2019-10-02 17:10 ` Sean Christopherson
2019-10-03 10:30 ` Zhenzhong Duan
2019-09-30 12:44 ` [PATCH v3 2/4] x86/kvm: Change print code to use pr_*() format Zhenzhong Duan
2019-10-02 17:15 ` Sean Christopherson
2019-10-03 10:32 ` Zhenzhong Duan
2019-09-30 12:44 ` Zhenzhong Duan [this message]
2019-10-02 17:18 ` [PATCH v3 3/4] xen: Mark "xen_nopvspin" parameter obsolete and map it to "nopvspin" Sean Christopherson
2019-10-03 11:21 ` Zhenzhong Duan
2019-09-30 12:44 ` [PATCH v3 4/4] x86/hyperv: Mark "hv_nopvspin" " Zhenzhong Duan
2019-10-02 17:19 ` Sean Christopherson
2019-10-03 11:22 ` Zhenzhong Duan
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