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Groups > linux.kernel > #1505123
| From | Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v5 8/9] s390/spinlock: Provide vcpu_is_preempted |
| Date | 2016-10-20 19:40 +0200 |
| Message-ID | <suptT-2bV-15@gated-at.bofh.it> (permalink) |
| References | <suptT-2bV-1@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
From: Christian Borntraeger <borntraeger@de.ibm.com>
this implements the s390 backend for commit
"kernel/sched: introduce vcpu preempted check interface"
by reworking the existing smp_vcpu_scheduled into
arch_vcpu_is_preempted. We can then also get rid of the
local cpu_is_preempted function by moving the
CIF_ENABLED_WAIT test into arch_vcpu_is_preempted.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
---
arch/s390/include/asm/spinlock.h | 8 ++++++++
arch/s390/kernel/smp.c | 9 +++++++--
arch/s390/lib/spinlock.c | 25 ++++++++-----------------
3 files changed, 23 insertions(+), 19 deletions(-)
diff --git a/arch/s390/include/asm/spinlock.h b/arch/s390/include/asm/spinlock.h
index 7e9e09f..7ecd890 100644
--- a/arch/s390/include/asm/spinlock.h
+++ b/arch/s390/include/asm/spinlock.h
@@ -23,6 +23,14 @@ _raw_compare_and_swap(unsigned int *lock, unsigned int old, unsigned int new)
return __sync_bool_compare_and_swap(lock, old, new);
}
+#ifndef CONFIG_SMP
+static inline bool arch_vcpu_is_preempted(int cpu) { return false; }
+#else
+bool arch_vcpu_is_preempted(int cpu);
+#endif
+
+#define vcpu_is_preempted arch_vcpu_is_preempted
+
/*
* Simple spin lock operations. There are two variants, one clears IRQ's
* on the local processor, one does not.
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 35531fe..b988ed1 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -368,10 +368,15 @@ int smp_find_processor_id(u16 address)
return -1;
}
-int smp_vcpu_scheduled(int cpu)
+bool arch_vcpu_is_preempted(int cpu)
{
- return pcpu_running(pcpu_devices + cpu);
+ if (test_cpu_flag_of(CIF_ENABLED_WAIT, cpu))
+ return false;
+ if (pcpu_running(pcpu_devices + cpu))
+ return false;
+ return true;
}
+EXPORT_SYMBOL(arch_vcpu_is_preempted);
void smp_yield_cpu(int cpu)
{
diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c
index e5f50a7..e48a48e 100644
--- a/arch/s390/lib/spinlock.c
+++ b/arch/s390/lib/spinlock.c
@@ -37,15 +37,6 @@ static inline void _raw_compare_and_delay(unsigned int *lock, unsigned int old)
asm(".insn rsy,0xeb0000000022,%0,0,%1" : : "d" (old), "Q" (*lock));
}
-static inline int cpu_is_preempted(int cpu)
-{
- if (test_cpu_flag_of(CIF_ENABLED_WAIT, cpu))
- return 0;
- if (smp_vcpu_scheduled(cpu))
- return 0;
- return 1;
-}
-
void arch_spin_lock_wait(arch_spinlock_t *lp)
{
unsigned int cpu = SPINLOCK_LOCKVAL;
@@ -62,7 +53,7 @@ void arch_spin_lock_wait(arch_spinlock_t *lp)
continue;
}
/* First iteration: check if the lock owner is running. */
- if (first_diag && cpu_is_preempted(~owner)) {
+ if (first_diag && arch_vcpu_is_preempted(~owner)) {
smp_yield_cpu(~owner);
first_diag = 0;
continue;
@@ -81,7 +72,7 @@ void arch_spin_lock_wait(arch_spinlock_t *lp)
* yield the CPU unconditionally. For LPAR rely on the
* sense running status.
*/
- if (!MACHINE_IS_LPAR || cpu_is_preempted(~owner)) {
+ if (!MACHINE_IS_LPAR || arch_vcpu_is_preempted(~owner)) {
smp_yield_cpu(~owner);
first_diag = 0;
}
@@ -108,7 +99,7 @@ void arch_spin_lock_wait_flags(arch_spinlock_t *lp, unsigned long flags)
continue;
}
/* Check if the lock owner is running. */
- if (first_diag && cpu_is_preempted(~owner)) {
+ if (first_diag && arch_vcpu_is_preempted(~owner)) {
smp_yield_cpu(~owner);
first_diag = 0;
continue;
@@ -127,7 +118,7 @@ void arch_spin_lock_wait_flags(arch_spinlock_t *lp, unsigned long flags)
* yield the CPU unconditionally. For LPAR rely on the
* sense running status.
*/
- if (!MACHINE_IS_LPAR || cpu_is_preempted(~owner)) {
+ if (!MACHINE_IS_LPAR || arch_vcpu_is_preempted(~owner)) {
smp_yield_cpu(~owner);
first_diag = 0;
}
@@ -165,7 +156,7 @@ void _raw_read_lock_wait(arch_rwlock_t *rw)
owner = 0;
while (1) {
if (count-- <= 0) {
- if (owner && cpu_is_preempted(~owner))
+ if (owner && arch_vcpu_is_preempted(~owner))
smp_yield_cpu(~owner);
count = spin_retry;
}
@@ -211,7 +202,7 @@ void _raw_write_lock_wait(arch_rwlock_t *rw, unsigned int prev)
owner = 0;
while (1) {
if (count-- <= 0) {
- if (owner && cpu_is_preempted(~owner))
+ if (owner && arch_vcpu_is_preempted(~owner))
smp_yield_cpu(~owner);
count = spin_retry;
}
@@ -241,7 +232,7 @@ void _raw_write_lock_wait(arch_rwlock_t *rw)
owner = 0;
while (1) {
if (count-- <= 0) {
- if (owner && cpu_is_preempted(~owner))
+ if (owner && arch_vcpu_is_preempted(~owner))
smp_yield_cpu(~owner);
count = spin_retry;
}
@@ -285,7 +276,7 @@ void arch_lock_relax(unsigned int cpu)
{
if (!cpu)
return;
- if (MACHINE_IS_LPAR && !cpu_is_preempted(~cpu))
+ if (MACHINE_IS_LPAR && !arch_vcpu_is_preempted(~cpu))
return;
smp_yield_cpu(~cpu);
}
--
2.4.11
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH v5 0/9] implement vcpu preempted check Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> - 2016-10-20 19:40 +0200
[PATCH v5 2/9] locking/osq: Drop the overload of osq_lock() Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> - 2016-10-20 19:40 +0200
[PATCH v5 8/9] s390/spinlock: Provide vcpu_is_preempted Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> - 2016-10-20 19:40 +0200
[PATCH v5 3/9] kernel/locking: Drop the overload of {mutex,rwsem}_spin_on_owner Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> - 2016-10-20 19:40 +0200
[PATCH v5 1/9] kernel/sched: introduce vcpu preempted check interface Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> - 2016-10-20 19:40 +0200
[PATCH v5 7/9] x86, xen: support vcpu preempted check Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> - 2016-10-20 19:40 +0200
Re: [PATCH v5 7/9] x86, xen: support vcpu preempted check Juergen Gross <jgross@suse.com> - 2016-10-21 07:10 +0200
[PATCH v5 5/9] x86, paravirt: Add interface to support kvm/xen vcpu preempted check Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> - 2016-10-20 19:40 +0200
[PATCH v5 9/9] Documentation: virtual: kvm: Support vcpu preempted check Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> - 2016-10-20 19:40 +0200
Re: [PATCH v5 9/9] Documentation: virtual: kvm: Support vcpu preempted check Boqun Feng <boqun.feng@gmail.com> - 2016-10-21 03:30 +0200
RE: [PATCH v5 9/9] Documentation: virtual: kvm: Support vcpu preempted check David Laight <David.Laight@ACULAB.COM> - 2016-10-21 13:40 +0200
Re: [PATCH v5 9/9] Documentation: virtual: kvm: Support vcpu preempted check "rkrcmar@redhat.com" <rkrcmar@redhat.com> - 2016-10-21 20:50 +0200
Re: [PATCH v5 9/9] Documentation: virtual: kvm: Support vcpu preempted check xinhui <xinhui.pan@linux.vnet.ibm.com> - 2016-10-24 04:50 +0200
Re: [PATCH v5 9/9] Documentation: virtual: kvm: Support vcpu preempted check Paolo Bonzini <pbonzini@redhat.com> - 2016-10-24 16:50 +0200
Re: [PATCH v5 9/9] Documentation: virtual: kvm: Support vcpu preempted check "rkrcmar@redhat.com" <rkrcmar@redhat.com> - 2016-10-24 17:10 +0200
Re: [PATCH v5 9/9] Documentation: virtual: kvm: Support vcpu preempted check xinhui <xinhui.pan@linux.vnet.ibm.com> - 2016-10-24 04:50 +0200
Re: [PATCH v5 9/9] Documentation: virtual: kvm: Support vcpu preempted check xinhui <xinhui.pan@linux.vnet.ibm.com> - 2016-10-24 10:20 +0200
[PATCH v5 4/9] powerpc/spinlock: support vcpu preempted check Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> - 2016-10-20 19:40 +0200
[PATCH v5 6/9] x86, kvm: support vcpu preempted check Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> - 2016-10-20 19:40 +0200
Re: [PATCH v5 6/9] x86, kvm: support vcpu preempted check xinhui <xinhui.pan@linux.vnet.ibm.com> - 2016-10-24 10:10 +0200
Re: [PATCH v5 0/9] implement vcpu preempted check Peter Zijlstra <peterz@infradead.org> - 2016-10-21 07:50 +0200
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