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Groups > linux.kernel > #1321772 > unrolled thread
| Started by | Daniel Wagner <daniel.wagner@bmw-carit.de> |
|---|---|
| First post | 2016-01-29 15:10 +0100 |
| Last post | 2016-01-29 15:10 +0100 |
| Articles | 5 — 1 participant |
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[PATCH tip v7 0/7] Simple wait queue support Daniel Wagner <daniel.wagner@bmw-carit.de> - 2016-01-29 15:10 +0100
[PATCH tip v7 1/7] video: Use bool instead int pointer for get_opt_bool() argument Daniel Wagner <daniel.wagner@bmw-carit.de> - 2016-01-29 15:10 +0100
[PATCH tip v7 5/7] KVM: use simple waitqueue for vcpu->wq Daniel Wagner <daniel.wagner@bmw-carit.de> - 2016-01-29 15:10 +0100
[PATCH tip v7 2/7] MIPS: Differentiate between 32 and 64 bit ELF header Daniel Wagner <daniel.wagner@bmw-carit.de> - 2016-01-29 15:10 +0100
[PATCH tip v7 7/7] rcu: use simple wait queues where possible in rcutree Daniel Wagner <daniel.wagner@bmw-carit.de> - 2016-01-29 15:10 +0100
| From | Daniel Wagner <daniel.wagner@bmw-carit.de> |
|---|---|
| Date | 2016-01-29 15:10 +0100 |
| Subject | [PATCH tip v7 0/7] Simple wait queue support |
| Message-ID | <qWhUm-4fz-3@gated-at.bofh.it> |
Hi, As it turns out I missed a few incompatible-pointer-types errors. Furthermore I even missed to update one calling side on wait in the ARM KVM code base. Luckily the kbuild test robot found them all. These patches are against tip/sched/core 0905f04eb21fc1c2e690bed5d0418a061d56c225 also available as git tree: git://git.kernel.org/pub/scm/linux/kernel/git/wagi/linux.git tip-swait cheers, daniel changes since v6: - fixed a couple of incompatible-pointer-types errors - fixed a missing KVM ARM wait -> swait update changes since v5: - unconditionally add -Werror=incompatible-pointer-types - updated KVM statistics in commit message - rebased on tip/sched/core - added ack-by PeterZ changes since v4: - replaced patch #2 which tried to force to compiler to exit with an error by using compile time assertion type check macros. Instead use -Werror=incompatible-pointer-types to tell the compiler to barf loudly. - fixed wrong API usage in patch 4 as reported by Boqun. changes since v3 - rebased it on tip/sched/core (KVM bits have changed slightly) - added compile time type check assertion - added non lazy version of swake_up_locked() changes since v2 - rebased again on tip/master. The patches apply cleanly on v4.3-rc6 too. - fixed up mips - reordered patches to avoid lockdep warning when doing bissect. - remove unnecessary initialization of rsp->rda in rcu_init_one(). changes since v1 (PATCH v0) - rebased and fixed some typos found by cross building for S390, ARM and powerpc. For some unknown reason didn't catch them last time. - dropped completion patches because it is not clear yet how to handle complete_all() calls hard-irq/atomic contexts and swake_up_all. changes since v0 (RFC v0) - promoted the series to PATCH state instead of RFC - fixed a few fallouts with build all and some cross compilers such ARM, PowerPC, S390. - Added the simple waitqueue transformation for KVM from -rt including some numbers requested by Paolo. - Added a commit message to PeterZ's patch. Hope he likes it. [I got the numbering wrong in v1, so instead 'PATCH v1' you find it as 'PATCH v0' series] v6: https://lkml.org/lkml/2016/1/28/462 v5: https://lkml.org/lkml/2015/11/30/318 v4: https://lwn.net/Articles/665655/ v3: https://lwn.net/Articles/661415/ v2: https://lwn.net/Articles/660628/ v1: https://lwn.net/Articles/656942/ v0: https://lwn.net/Articles/653586/ Daniel Wagner (4): video: Use bool instead int pointer for get_opt_bool() argument MIPS: Differentiate between 32 and 64 bit ELF header kbuild: Add option to turn incompatible pointer check into error rcu: Do not call rcu_nocb_gp_cleanup() while holding rnp->lock Marcelo Tosatti (1): KVM: use simple waitqueue for vcpu->wq Paul Gortmaker (1): rcu: use simple wait queues where possible in rcutree Peter Zijlstra (Intel) (1): wait.[ch]: Introduce the simple waitqueue (swait) implementation Makefile | 3 + arch/arm/kvm/arm.c | 8 +- arch/arm/kvm/psci.c | 4 +- arch/mips/include/asm/elf.h | 68 ++++++------ arch/mips/kvm/mips.c | 8 +- arch/powerpc/include/asm/kvm_host.h | 4 +- arch/powerpc/kvm/book3s_hv.c | 23 ++--- arch/s390/include/asm/kvm_host.h | 2 +- arch/s390/kvm/interrupt.c | 4 +- arch/x86/kvm/lapic.c | 6 +- drivers/video/fbdev/intelfb/intelfbdrv.c | 2 +- include/linux/kvm_host.h | 5 +- include/linux/swait.h | 172 +++++++++++++++++++++++++++++++ kernel/rcu/tree.c | 24 +++-- kernel/rcu/tree.h | 12 ++- kernel/rcu/tree_plugin.h | 32 ++++-- kernel/sched/Makefile | 2 +- kernel/sched/swait.c | 123 ++++++++++++++++++++++ virt/kvm/async_pf.c | 4 +- virt/kvm/kvm_main.c | 17 ++- 20 files changed, 420 insertions(+), 103 deletions(-) create mode 100644 include/linux/swait.h create mode 100644 kernel/sched/swait.c -- 2.5.0
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| From | Daniel Wagner <daniel.wagner@bmw-carit.de> |
|---|---|
| Date | 2016-01-29 15:10 +0100 |
| Subject | [PATCH tip v7 1/7] video: Use bool instead int pointer for get_opt_bool() argument |
| Message-ID | <qWhUp-4fz-55@gated-at.bofh.it> |
| In reply to | #1321772 |
As the function name already indicates that get_opt_bool() parses
for a bool. It is not a surprise that compiler is complaining
about it when -Werror=incompatible-pointer-types is used:
drivers/video/fbdev/intelfb/intelfbdrv.c: In function ‘intelfb_setup’:
drivers/video/fbdev/intelfb/intelfbdrv.c:353:39: error: passing argument 3 of ‘get_opt_bool’ from incompatible pointer type [-Werror=incompatible-pointer-types]
if (get_opt_bool(this_opt, "accel", &accel))
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
---
drivers/video/fbdev/intelfb/intelfbdrv.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/video/fbdev/intelfb/intelfbdrv.c b/drivers/video/fbdev/intelfb/intelfbdrv.c
index bbec737..bf20744 100644
--- a/drivers/video/fbdev/intelfb/intelfbdrv.c
+++ b/drivers/video/fbdev/intelfb/intelfbdrv.c
@@ -302,7 +302,7 @@ static __inline__ int get_opt_int(const char *this_opt, const char *name,
}
static __inline__ int get_opt_bool(const char *this_opt, const char *name,
- int *ret)
+ bool *ret)
{
if (!ret)
return 0;
--
2.5.0
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| From | Daniel Wagner <daniel.wagner@bmw-carit.de> |
|---|---|
| Date | 2016-01-29 15:10 +0100 |
| Subject | [PATCH tip v7 5/7] KVM: use simple waitqueue for vcpu->wq |
| Message-ID | <qWhUp-4fz-71@gated-at.bofh.it> |
| In reply to | #1321772 |
From: Marcelo Tosatti <mtosatti@redhat.com>
The problem:
On -rt, an emulated LAPIC timer instances has the following path:
1) hard interrupt
2) ksoftirqd is scheduled
3) ksoftirqd wakes up vcpu thread
4) vcpu thread is scheduled
This extra context switch introduces unnecessary latency in the
LAPIC path for a KVM guest.
The solution:
Allow waking up vcpu thread from hardirq context,
thus avoiding the need for ksoftirqd to be scheduled.
Normal waitqueues make use of spinlocks, which on -RT
are sleepable locks. Therefore, waking up a waitqueue
waiter involves locking a sleeping lock, which
is not allowed from hard interrupt context.
cyclictest command line:
This patch reduces the average latency in my tests from 14us to 11us.
Daniel writes:
Paolo asked for numbers from kvm-unit-tests/tscdeadline_latency
benchmark on mainline. The test was run 1000 times on
tip/sched/core 4.4.0-rc8-01134-g0905f04:
./x86-run x86/tscdeadline_latency.flat -cpu host
with idle=poll.
The test seems not to deliver really stable numbers though most of
them are smaller. Paolo write:
"Anything above ~10000 cycles means that the host went to C1 or
lower---the number means more or less nothing in that case.
The mean shows an improvement indeed."
Before:
min max mean std
count 1000.000000 1000.000000 1000.000000 1000.000000
mean 5162.596000 2019270.084000 5824.491541 20681.645558
std 75.431231 622607.723969 89.575700 6492.272062
min 4466.000000 23928.000000 5537.926500 585.864966
25% 5163.000000 1613252.750000 5790.132275 16683.745433
50% 5175.000000 2281919.000000 5834.654000 23151.990026
75% 5190.000000 2382865.750000 5861.412950 24148.206168
max 5228.000000 4175158.000000 6254.827300 46481.048691
After
min max mean std
count 1000.000000 1000.00000 1000.000000 1000.000000
mean 5143.511000 2076886.10300 5813.312474 21207.357565
std 77.668322 610413.09583 86.541500 6331.915127
min 4427.000000 25103.00000 5529.756600 559.187707
25% 5148.000000 1691272.75000 5784.889825 17473.518244
50% 5160.000000 2308328.50000 5832.025000 23464.837068
75% 5172.000000 2393037.75000 5853.177675 24223.969976
max 5222.000000 3922458.00000 6186.720500 42520.379830
[Patch was originaly based on the swait implementation found in the -rt
tree. Daniel ported it to mainline's version and gathered the
benchmark numbers for tscdeadline_latency test.]
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
---
arch/arm/kvm/arm.c | 8 ++++----
arch/arm/kvm/psci.c | 4 ++--
arch/mips/kvm/mips.c | 8 ++++----
arch/powerpc/include/asm/kvm_host.h | 4 ++--
arch/powerpc/kvm/book3s_hv.c | 23 +++++++++++------------
arch/s390/include/asm/kvm_host.h | 2 +-
arch/s390/kvm/interrupt.c | 4 ++--
arch/x86/kvm/lapic.c | 6 +++---
include/linux/kvm_host.h | 5 +++--
virt/kvm/async_pf.c | 4 ++--
virt/kvm/kvm_main.c | 17 ++++++++---------
11 files changed, 42 insertions(+), 43 deletions(-)
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index e06fd29..f7e3235 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -498,18 +498,18 @@ static void kvm_arm_resume_guest(struct kvm *kvm)
struct kvm_vcpu *vcpu;
kvm_for_each_vcpu(i, vcpu, kvm) {
- wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
+ struct swait_queue_head *wq = kvm_arch_vcpu_wq(vcpu);
vcpu->arch.pause = false;
- wake_up_interruptible(wq);
+ swake_up(wq);
}
}
static void vcpu_sleep(struct kvm_vcpu *vcpu)
{
- wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
+ struct swait_queue_head *wq = kvm_arch_vcpu_wq(vcpu);
- wait_event_interruptible(*wq, ((!vcpu->arch.power_off) &&
+ swait_event_interruptible(*wq, ((!vcpu->arch.power_off) &&
(!vcpu->arch.pause)));
}
diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
index a9b3b90..c2b1315 100644
--- a/arch/arm/kvm/psci.c
+++ b/arch/arm/kvm/psci.c
@@ -70,7 +70,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
{
struct kvm *kvm = source_vcpu->kvm;
struct kvm_vcpu *vcpu = NULL;
- wait_queue_head_t *wq;
+ struct swait_queue_head *wq;
unsigned long cpu_id;
unsigned long context_id;
phys_addr_t target_pc;
@@ -119,7 +119,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
smp_mb(); /* Make sure the above is visible */
wq = kvm_arch_vcpu_wq(vcpu);
- wake_up_interruptible(wq);
+ swake_up(wq);
return PSCI_RET_SUCCESS;
}
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index b9b803f..28e9acb 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -445,8 +445,8 @@ int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu,
dvcpu->arch.wait = 0;
- if (waitqueue_active(&dvcpu->wq))
- wake_up_interruptible(&dvcpu->wq);
+ if (swait_active(&dvcpu->wq))
+ swake_up(&dvcpu->wq);
return 0;
}
@@ -1174,8 +1174,8 @@ static void kvm_mips_comparecount_func(unsigned long data)
kvm_mips_callbacks->queue_timer_int(vcpu);
vcpu->arch.wait = 0;
- if (waitqueue_active(&vcpu->wq))
- wake_up_interruptible(&vcpu->wq);
+ if (swait_active(&vcpu->wq))
+ swake_up(&vcpu->wq);
}
/* low level hrtimer wake routine */
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index cfa758c..f8673ff 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -286,7 +286,7 @@ struct kvmppc_vcore {
struct list_head runnable_threads;
struct list_head preempt_list;
spinlock_t lock;
- wait_queue_head_t wq;
+ struct swait_queue_head wq;
spinlock_t stoltb_lock; /* protects stolen_tb and preempt_tb */
u64 stolen_tb;
u64 preempt_tb;
@@ -626,7 +626,7 @@ struct kvm_vcpu_arch {
u8 prodded;
u32 last_inst;
- wait_queue_head_t *wqp;
+ struct swait_queue_head *wqp;
struct kvmppc_vcore *vcore;
int ret;
int trap;
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index a7352b5..df34a64 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -114,11 +114,11 @@ static bool kvmppc_ipi_thread(int cpu)
static void kvmppc_fast_vcpu_kick_hv(struct kvm_vcpu *vcpu)
{
int cpu;
- wait_queue_head_t *wqp;
+ struct swait_queue_head *wqp;
wqp = kvm_arch_vcpu_wq(vcpu);
- if (waitqueue_active(wqp)) {
- wake_up_interruptible(wqp);
+ if (swait_active(wqp)) {
+ swake_up(wqp);
++vcpu->stat.halt_wakeup;
}
@@ -707,8 +707,8 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
tvcpu->arch.prodded = 1;
smp_mb();
if (vcpu->arch.ceded) {
- if (waitqueue_active(&vcpu->wq)) {
- wake_up_interruptible(&vcpu->wq);
+ if (swait_active(&vcpu->wq)) {
+ swake_up(&vcpu->wq);
vcpu->stat.halt_wakeup++;
}
}
@@ -1447,7 +1447,7 @@ static struct kvmppc_vcore *kvmppc_vcore_create(struct kvm *kvm, int core)
INIT_LIST_HEAD(&vcore->runnable_threads);
spin_lock_init(&vcore->lock);
spin_lock_init(&vcore->stoltb_lock);
- init_waitqueue_head(&vcore->wq);
+ init_swait_queue_head(&vcore->wq);
vcore->preempt_tb = TB_NIL;
vcore->lpcr = kvm->arch.lpcr;
vcore->first_vcpuid = core * threads_per_subcore;
@@ -2519,10 +2519,9 @@ static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
{
struct kvm_vcpu *vcpu;
int do_sleep = 1;
+ DECLARE_SWAITQUEUE(wait);
- DEFINE_WAIT(wait);
-
- prepare_to_wait(&vc->wq, &wait, TASK_INTERRUPTIBLE);
+ prepare_to_swait(&vc->wq, &wait, TASK_INTERRUPTIBLE);
/*
* Check one last time for pending exceptions and ceded state after
@@ -2536,7 +2535,7 @@ static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
}
if (!do_sleep) {
- finish_wait(&vc->wq, &wait);
+ finish_swait(&vc->wq, &wait);
return;
}
@@ -2544,7 +2543,7 @@ static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
trace_kvmppc_vcore_blocked(vc, 0);
spin_unlock(&vc->lock);
schedule();
- finish_wait(&vc->wq, &wait);
+ finish_swait(&vc->wq, &wait);
spin_lock(&vc->lock);
vc->vcore_state = VCORE_INACTIVE;
trace_kvmppc_vcore_blocked(vc, 1);
@@ -2600,7 +2599,7 @@ static int kvmppc_run_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
kvmppc_start_thread(vcpu, vc);
trace_kvm_guest_enter(vcpu);
} else if (vc->vcore_state == VCORE_SLEEPING) {
- wake_up(&vc->wq);
+ swake_up(&vc->wq);
}
}
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index efaac2c..c66831f 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -427,7 +427,7 @@ struct kvm_s390_irq_payload {
struct kvm_s390_local_interrupt {
spinlock_t lock;
struct kvm_s390_float_interrupt *float_int;
- wait_queue_head_t *wq;
+ struct swait_queue_head *wq;
atomic_t *cpuflags;
DECLARE_BITMAP(sigp_emerg_pending, KVM_MAX_VCPUS);
struct kvm_s390_irq_payload irq;
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 6a75352..cc862c4 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -868,13 +868,13 @@ no_timer:
void kvm_s390_vcpu_wakeup(struct kvm_vcpu *vcpu)
{
- if (waitqueue_active(&vcpu->wq)) {
+ if (swait_active(&vcpu->wq)) {
/*
* The vcpu gave up the cpu voluntarily, mark it as a good
* yield-candidate.
*/
vcpu->preempted = true;
- wake_up_interruptible(&vcpu->wq);
+ swake_up(&vcpu->wq);
vcpu->stat.halt_wakeup++;
}
}
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 4d30b86..34dc14f 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1195,7 +1195,7 @@ static void apic_update_lvtt(struct kvm_lapic *apic)
static void apic_timer_expired(struct kvm_lapic *apic)
{
struct kvm_vcpu *vcpu = apic->vcpu;
- wait_queue_head_t *q = &vcpu->wq;
+ struct swait_queue_head *q = &vcpu->wq;
struct kvm_timer *ktimer = &apic->lapic_timer;
if (atomic_read(&apic->lapic_timer.pending))
@@ -1204,8 +1204,8 @@ static void apic_timer_expired(struct kvm_lapic *apic)
atomic_inc(&apic->lapic_timer.pending);
kvm_set_pending_timer(vcpu);
- if (waitqueue_active(q))
- wake_up_interruptible(q);
+ if (swait_active(q))
+ swake_up(q);
if (apic_lvtt_tscdeadline(apic))
ktimer->expired_tscdeadline = ktimer->tscdeadline;
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index c923350..c690acc 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -25,6 +25,7 @@
#include <linux/irqflags.h>
#include <linux/context_tracking.h>
#include <linux/irqbypass.h>
+#include <linux/swait.h>
#include <asm/signal.h>
#include <linux/kvm.h>
@@ -243,7 +244,7 @@ struct kvm_vcpu {
int fpu_active;
int guest_fpu_loaded, guest_xcr0_loaded;
unsigned char fpu_counter;
- wait_queue_head_t wq;
+ struct swait_queue_head wq;
struct pid *pid;
int sigset_active;
sigset_t sigset;
@@ -794,7 +795,7 @@ static inline bool kvm_arch_has_assigned_device(struct kvm *kvm)
}
#endif
-static inline wait_queue_head_t *kvm_arch_vcpu_wq(struct kvm_vcpu *vcpu)
+static inline struct swait_queue_head *kvm_arch_vcpu_wq(struct kvm_vcpu *vcpu)
{
#ifdef __KVM_HAVE_ARCH_WQP
return vcpu->arch.wqp;
diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c
index 77d42be..cd8477c 100644
--- a/virt/kvm/async_pf.c
+++ b/virt/kvm/async_pf.c
@@ -98,8 +98,8 @@ static void async_pf_execute(struct work_struct *work)
* This memory barrier pairs with prepare_to_wait's set_current_state()
*/
smp_mb();
- if (waitqueue_active(&vcpu->wq))
- wake_up_interruptible(&vcpu->wq);
+ if (swait_active(&vcpu->wq))
+ swake_up(&vcpu->wq);
mmput(mm);
kvm_put_kvm(vcpu->kvm);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 484079e..43fad2e 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -226,8 +226,7 @@ int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
vcpu->kvm = kvm;
vcpu->vcpu_id = id;
vcpu->pid = NULL;
- vcpu->halt_poll_ns = 0;
- init_waitqueue_head(&vcpu->wq);
+ init_swait_queue_head(&vcpu->wq);
kvm_async_pf_vcpu_init(vcpu);
vcpu->pre_pcpu = -1;
@@ -1999,7 +1998,7 @@ static int kvm_vcpu_check_block(struct kvm_vcpu *vcpu)
void kvm_vcpu_block(struct kvm_vcpu *vcpu)
{
ktime_t start, cur;
- DEFINE_WAIT(wait);
+ DECLARE_SWAITQUEUE(wait);
bool waited = false;
u64 block_ns;
@@ -2024,7 +2023,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
kvm_arch_vcpu_blocking(vcpu);
for (;;) {
- prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
+ prepare_to_swait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
if (kvm_vcpu_check_block(vcpu) < 0)
break;
@@ -2033,7 +2032,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
schedule();
}
- finish_wait(&vcpu->wq, &wait);
+ finish_swait(&vcpu->wq, &wait);
cur = ktime_get();
kvm_arch_vcpu_unblocking(vcpu);
@@ -2065,11 +2064,11 @@ void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
{
int me;
int cpu = vcpu->cpu;
- wait_queue_head_t *wqp;
+ struct swait_queue_head *wqp;
wqp = kvm_arch_vcpu_wq(vcpu);
- if (waitqueue_active(wqp)) {
- wake_up_interruptible(wqp);
+ if (swait_active(wqp)) {
+ swake_up(wqp);
++vcpu->stat.halt_wakeup;
}
@@ -2170,7 +2169,7 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me)
continue;
if (vcpu == me)
continue;
- if (waitqueue_active(&vcpu->wq) && !kvm_arch_vcpu_runnable(vcpu))
+ if (swait_active(&vcpu->wq) && !kvm_arch_vcpu_runnable(vcpu))
continue;
if (!kvm_vcpu_eligible_for_directed_yield(vcpu))
continue;
--
2.5.0
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| From | Daniel Wagner <daniel.wagner@bmw-carit.de> |
|---|---|
| Date | 2016-01-29 15:10 +0100 |
| Subject | [PATCH tip v7 2/7] MIPS: Differentiate between 32 and 64 bit ELF header |
| Message-ID | <qWhUr-4fz-95@gated-at.bofh.it> |
| In reply to | #1321772 |
Depending on the configuration either the 32 or 64 bit version of
elf_check_arch() is defined. parse_crash_elf32_headers() does
some basic verification of the ELF header via elf_check_arch().
parse_crash_elf64_headers() does it via vmcore_elf64_check_arch()
which expands to the same elf_check_check().
In file included from include/linux/elf.h:4:0,
from fs/proc/vmcore.c:13:
fs/proc/vmcore.c: In function 'parse_crash_elf64_headers':
>> arch/mips/include/asm/elf.h:228:23: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
struct elfhdr *__h = (hdr); \
^
include/linux/crash_dump.h:41:37: note: in expansion of macro 'elf_check_arch'
#define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
^
fs/proc/vmcore.c:1015:4: note: in expansion of macro 'vmcore_elf64_check_arch'
!vmcore_elf64_check_arch(&ehdr) ||
^
Since the MIPS ELF header for 32 bit and 64 bit differ we need
to check accordingly.
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
---
arch/mips/include/asm/elf.h | 68 ++++++++++++++++++++++++---------------------
1 file changed, 37 insertions(+), 31 deletions(-)
diff --git a/arch/mips/include/asm/elf.h b/arch/mips/include/asm/elf.h
index b01a6ff..e311d60 100644
--- a/arch/mips/include/asm/elf.h
+++ b/arch/mips/include/asm/elf.h
@@ -205,27 +205,10 @@ struct mips_elf_abiflags_v0 {
#define MIPS_ABI_FP_64 6 /* -mips32r2 -mfp64 */
#define MIPS_ABI_FP_64A 7 /* -mips32r2 -mfp64 -mno-odd-spreg */
-#ifdef CONFIG_32BIT
-
-/*
- * In order to be sure that we don't attempt to execute an O32 binary which
- * requires 64 bit FP (FR=1) on a system which does not support it we refuse
- * to execute any binary which has bits specified by the following macro set
- * in its ELF header flags.
- */
-#ifdef CONFIG_MIPS_O32_FP64_SUPPORT
-# define __MIPS_O32_FP64_MUST_BE_ZERO 0
-#else
-# define __MIPS_O32_FP64_MUST_BE_ZERO EF_MIPS_FP64
-#endif
-
-/*
- * This is used to ensure we don't load something for the wrong architecture.
- */
-#define elf_check_arch(hdr) \
+#define elf_check_arch_32(hdr) \
({ \
int __res = 1; \
- struct elfhdr *__h = (hdr); \
+ Elf32_Ehdr *__h = (hdr); \
\
if (__h->e_machine != EM_MIPS) \
__res = 0; \
@@ -242,6 +225,40 @@ struct mips_elf_abiflags_v0 {
__res; \
})
+#define elf_check_arch_64(hdr) \
+({ \
+ int __res = 1; \
+ Elf64_Ehdr *__h = (hdr); \
+ \
+ if (__h->e_machine != EM_MIPS) \
+ __res = 0; \
+ if (__h->e_ident[EI_CLASS] != ELFCLASS64) \
+ __res = 0; \
+ \
+ __res; \
+})
+
+#define vmcore_elf64_check_arch(x) (elf_check_arch_64(x) || vmcore_elf_check_arch_cross(x))
+
+#ifdef CONFIG_32BIT
+
+/*
+ * In order to be sure that we don't attempt to execute an O32 binary which
+ * requires 64 bit FP (FR=1) on a system which does not support it we refuse
+ * to execute any binary which has bits specified by the following macro set
+ * in its ELF header flags.
+ */
+#ifdef CONFIG_MIPS_O32_FP64_SUPPORT
+# define __MIPS_O32_FP64_MUST_BE_ZERO 0
+#else
+# define __MIPS_O32_FP64_MUST_BE_ZERO EF_MIPS_FP64
+#endif
+
+/*
+ * This is used to ensure we don't load something for the wrong architecture.
+ */
+#define elf_check_arch(x) elf_check_arch_32(x)
+
/*
* These are used to set parameters in the core dumps.
*/
@@ -253,18 +270,7 @@ struct mips_elf_abiflags_v0 {
/*
* This is used to ensure we don't load something for the wrong architecture.
*/
-#define elf_check_arch(hdr) \
-({ \
- int __res = 1; \
- struct elfhdr *__h = (hdr); \
- \
- if (__h->e_machine != EM_MIPS) \
- __res = 0; \
- if (__h->e_ident[EI_CLASS] != ELFCLASS64) \
- __res = 0; \
- \
- __res; \
-})
+#define elf_check_arch(x) elf_check_arch_64(x)
/*
* These are used to set parameters in the core dumps.
--
2.5.0
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| From | Daniel Wagner <daniel.wagner@bmw-carit.de> |
|---|---|
| Date | 2016-01-29 15:10 +0100 |
| Subject | [PATCH tip v7 7/7] rcu: use simple wait queues where possible in rcutree |
| Message-ID | <qWhUr-4fz-99@gated-at.bofh.it> |
| In reply to | #1321772 |
From: Paul Gortmaker <paul.gortmaker@windriver.com>
As of commit dae6e64d2bcfd4b06304ab864c7e3a4f6b5fedf4 ("rcu: Introduce
proper blocking to no-CBs kthreads GP waits") the RCU subsystem started
making use of wait queues.
Here we convert all additions of RCU wait queues to use simple wait queues,
since they don't need the extra overhead of the full wait queue features.
Originally this was done for RT kernels[1], since we would get things like...
BUG: sleeping function called from invalid context at kernel/rtmutex.c:659
in_atomic(): 1, irqs_disabled(): 1, pid: 8, name: rcu_preempt
Pid: 8, comm: rcu_preempt Not tainted
Call Trace:
[<ffffffff8106c8d0>] __might_sleep+0xd0/0xf0
[<ffffffff817d77b4>] rt_spin_lock+0x24/0x50
[<ffffffff8106fcf6>] __wake_up+0x36/0x70
[<ffffffff810c4542>] rcu_gp_kthread+0x4d2/0x680
[<ffffffff8105f910>] ? __init_waitqueue_head+0x50/0x50
[<ffffffff810c4070>] ? rcu_gp_fqs+0x80/0x80
[<ffffffff8105eabb>] kthread+0xdb/0xe0
[<ffffffff8106b912>] ? finish_task_switch+0x52/0x100
[<ffffffff817e0754>] kernel_thread_helper+0x4/0x10
[<ffffffff8105e9e0>] ? __init_kthread_worker+0x60/0x60
[<ffffffff817e0750>] ? gs_change+0xb/0xb
...and hence simple wait queues were deployed on RT out of necessity
(as simple wait uses a raw lock), but mainline might as well take
advantage of the more streamline support as well.
[1] This is a carry forward of work from v3.10-rt; the original conversion
was by Thomas on an earlier -rt version, and Sebastian extended it to
additional post-3.10 added RCU waiters; here I've added a commit log and
unified the RCU changes into one, and uprev'd it to match mainline RCU.
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
---
kernel/rcu/tree.c | 22 +++++++++++-----------
kernel/rcu/tree.h | 13 +++++++------
kernel/rcu/tree_plugin.h | 26 +++++++++++++-------------
3 files changed, 31 insertions(+), 30 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index baf6d09..c3bfbaa 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1610,7 +1610,7 @@ static void rcu_gp_kthread_wake(struct rcu_state *rsp)
!READ_ONCE(rsp->gp_flags) ||
!rsp->gp_kthread)
return;
- wake_up(&rsp->gp_wq);
+ swake_up(&rsp->gp_wq);
}
/*
@@ -1990,7 +1990,7 @@ static void rcu_gp_cleanup(struct rcu_state *rsp)
int nocb = 0;
struct rcu_data *rdp;
struct rcu_node *rnp = rcu_get_root(rsp);
- wait_queue_head_t *sq;
+ struct swait_queue_head *sq;
WRITE_ONCE(rsp->gp_activity, jiffies);
raw_spin_lock_irq(&rnp->lock);
@@ -2078,7 +2078,7 @@ static int __noreturn rcu_gp_kthread(void *arg)
READ_ONCE(rsp->gpnum),
TPS("reqwait"));
rsp->gp_state = RCU_GP_WAIT_GPS;
- wait_event_interruptible(rsp->gp_wq,
+ swait_event_interruptible(rsp->gp_wq,
READ_ONCE(rsp->gp_flags) &
RCU_GP_FLAG_INIT);
rsp->gp_state = RCU_GP_DONE_GPS;
@@ -2108,7 +2108,7 @@ static int __noreturn rcu_gp_kthread(void *arg)
READ_ONCE(rsp->gpnum),
TPS("fqswait"));
rsp->gp_state = RCU_GP_WAIT_FQS;
- ret = wait_event_interruptible_timeout(rsp->gp_wq,
+ ret = swait_event_interruptible_timeout(rsp->gp_wq,
rcu_gp_fqs_check_wake(rsp, &gf), j);
rsp->gp_state = RCU_GP_DOING_FQS;
/* Locking provides needed memory barriers. */
@@ -2232,7 +2232,7 @@ static void rcu_report_qs_rsp(struct rcu_state *rsp, unsigned long flags)
WARN_ON_ONCE(!rcu_gp_in_progress(rsp));
WRITE_ONCE(rsp->gp_flags, READ_ONCE(rsp->gp_flags) | RCU_GP_FLAG_FQS);
raw_spin_unlock_irqrestore(&rcu_get_root(rsp)->lock, flags);
- rcu_gp_kthread_wake(rsp);
+ swake_up(&rsp->gp_wq); /* Memory barrier implied by swake_up() path. */
}
/*
@@ -2893,7 +2893,7 @@ static void force_quiescent_state(struct rcu_state *rsp)
}
WRITE_ONCE(rsp->gp_flags, READ_ONCE(rsp->gp_flags) | RCU_GP_FLAG_FQS);
raw_spin_unlock_irqrestore(&rnp_old->lock, flags);
- rcu_gp_kthread_wake(rsp);
+ swake_up(&rsp->gp_wq); /* Memory barrier implied by swake_up() path. */
}
/*
@@ -3526,7 +3526,7 @@ static void __rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp,
raw_spin_unlock_irqrestore(&rnp->lock, flags);
if (wake) {
smp_mb(); /* EGP done before wake_up(). */
- wake_up(&rsp->expedited_wq);
+ swake_up(&rsp->expedited_wq);
}
break;
}
@@ -3783,7 +3783,7 @@ static void synchronize_sched_expedited_wait(struct rcu_state *rsp)
jiffies_start = jiffies;
for (;;) {
- ret = wait_event_interruptible_timeout(
+ ret = swait_event_timeout(
rsp->expedited_wq,
sync_rcu_preempt_exp_done(rnp_root),
jiffies_stall);
@@ -3791,7 +3791,7 @@ static void synchronize_sched_expedited_wait(struct rcu_state *rsp)
return;
if (ret < 0) {
/* Hit a signal, disable CPU stall warnings. */
- wait_event(rsp->expedited_wq,
+ swait_event(rsp->expedited_wq,
sync_rcu_preempt_exp_done(rnp_root));
return;
}
@@ -4457,8 +4457,8 @@ static void __init rcu_init_one(struct rcu_state *rsp,
}
}
- init_waitqueue_head(&rsp->gp_wq);
- init_waitqueue_head(&rsp->expedited_wq);
+ init_swait_queue_head(&rsp->gp_wq);
+ init_swait_queue_head(&rsp->expedited_wq);
rnp = rsp->level[rcu_num_lvls - 1];
for_each_possible_cpu(i) {
while (i > rnp->grphi)
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index aa47e2c..8a69b6d 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -27,6 +27,7 @@
#include <linux/threads.h>
#include <linux/cpumask.h>
#include <linux/seqlock.h>
+#include <linux/swait.h>
#include <linux/stop_machine.h>
/*
@@ -241,7 +242,7 @@ struct rcu_node {
/* Refused to boost: not sure why, though. */
/* This can happen due to race conditions. */
#ifdef CONFIG_RCU_NOCB_CPU
- wait_queue_head_t nocb_gp_wq[2];
+ struct swait_queue_head nocb_gp_wq[2];
/* Place for rcu_nocb_kthread() to wait GP. */
#endif /* #ifdef CONFIG_RCU_NOCB_CPU */
int need_future_gp[2];
@@ -393,7 +394,7 @@ struct rcu_data {
atomic_long_t nocb_q_count_lazy; /* invocation (all stages). */
struct rcu_head *nocb_follower_head; /* CBs ready to invoke. */
struct rcu_head **nocb_follower_tail;
- wait_queue_head_t nocb_wq; /* For nocb kthreads to sleep on. */
+ struct swait_queue_head nocb_wq; /* For nocb kthreads to sleep on. */
struct task_struct *nocb_kthread;
int nocb_defer_wakeup; /* Defer wakeup of nocb_kthread. */
@@ -472,7 +473,7 @@ struct rcu_state {
unsigned long gpnum; /* Current gp number. */
unsigned long completed; /* # of last completed gp. */
struct task_struct *gp_kthread; /* Task for grace periods. */
- wait_queue_head_t gp_wq; /* Where GP task waits. */
+ struct swait_queue_head gp_wq; /* Where GP task waits. */
short gp_flags; /* Commands for GP task. */
short gp_state; /* GP kthread sleep state. */
@@ -504,7 +505,7 @@ struct rcu_state {
atomic_long_t expedited_workdone3; /* # done by others #3. */
atomic_long_t expedited_normal; /* # fallbacks to normal. */
atomic_t expedited_need_qs; /* # CPUs left to check in. */
- wait_queue_head_t expedited_wq; /* Wait for check-ins. */
+ struct swait_queue_head expedited_wq; /* Wait for check-ins. */
int ncpus_snap; /* # CPUs seen last time. */
unsigned long jiffies_force_qs; /* Time at which to invoke */
@@ -607,8 +608,8 @@ static void zero_cpu_stall_ticks(struct rcu_data *rdp);
static void increment_cpu_stall_ticks(void);
static bool rcu_nocb_cpu_needs_barrier(struct rcu_state *rsp, int cpu);
static void rcu_nocb_gp_set(struct rcu_node *rnp, int nrq);
-static wait_queue_head_t *rcu_nocb_gp_get(struct rcu_node *rnp);
-static void rcu_nocb_gp_cleanup(wait_queue_head_t *sq);
+static struct swait_queue_head *rcu_nocb_gp_get(struct rcu_node *rnp);
+static void rcu_nocb_gp_cleanup(struct swait_queue_head *sq);
static void rcu_init_one_nocb(struct rcu_node *rnp);
static bool __call_rcu_nocb(struct rcu_data *rdp, struct rcu_head *rhp,
bool lazy, unsigned long flags);
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 99b1ce6..3891984 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -1822,9 +1822,9 @@ early_param("rcu_nocb_poll", parse_rcu_nocb_poll);
* Wake up any no-CBs CPUs' kthreads that were waiting on the just-ended
* grace period.
*/
-static void rcu_nocb_gp_cleanup(wait_queue_head_t *sq)
+static void rcu_nocb_gp_cleanup(struct swait_queue_head *sq)
{
- wake_up_all(sq);
+ swake_up_all(sq);
}
/*
@@ -1840,15 +1840,15 @@ static void rcu_nocb_gp_set(struct rcu_node *rnp, int nrq)
rnp->need_future_gp[(rnp->completed + 1) & 0x1] += nrq;
}
-static wait_queue_head_t *rcu_nocb_gp_get(struct rcu_node *rnp)
+static struct swait_queue_head *rcu_nocb_gp_get(struct rcu_node *rnp)
{
return &rnp->nocb_gp_wq[rnp->completed & 0x1];
}
static void rcu_init_one_nocb(struct rcu_node *rnp)
{
- init_waitqueue_head(&rnp->nocb_gp_wq[0]);
- init_waitqueue_head(&rnp->nocb_gp_wq[1]);
+ init_swait_queue_head(&rnp->nocb_gp_wq[0]);
+ init_swait_queue_head(&rnp->nocb_gp_wq[1]);
}
#ifndef CONFIG_RCU_NOCB_CPU_ALL
@@ -1873,7 +1873,7 @@ static void wake_nocb_leader(struct rcu_data *rdp, bool force)
if (READ_ONCE(rdp_leader->nocb_leader_sleep) || force) {
/* Prior smp_mb__after_atomic() orders against prior enqueue. */
WRITE_ONCE(rdp_leader->nocb_leader_sleep, false);
- wake_up(&rdp_leader->nocb_wq);
+ swake_up(&rdp_leader->nocb_wq);
}
}
@@ -2086,7 +2086,7 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp)
*/
trace_rcu_future_gp(rnp, rdp, c, TPS("StartWait"));
for (;;) {
- wait_event_interruptible(
+ swait_event_interruptible(
rnp->nocb_gp_wq[c & 0x1],
(d = ULONG_CMP_GE(READ_ONCE(rnp->completed), c)));
if (likely(d))
@@ -2114,7 +2114,7 @@ wait_again:
/* Wait for callbacks to appear. */
if (!rcu_nocb_poll) {
trace_rcu_nocb_wake(my_rdp->rsp->name, my_rdp->cpu, "Sleep");
- wait_event_interruptible(my_rdp->nocb_wq,
+ swait_event_interruptible(my_rdp->nocb_wq,
!READ_ONCE(my_rdp->nocb_leader_sleep));
/* Memory barrier handled by smp_mb() calls below and repoll. */
} else if (firsttime) {
@@ -2189,7 +2189,7 @@ wait_again:
* List was empty, wake up the follower.
* Memory barriers supplied by atomic_long_add().
*/
- wake_up(&rdp->nocb_wq);
+ swake_up(&rdp->nocb_wq);
}
}
@@ -2210,7 +2210,7 @@ static void nocb_follower_wait(struct rcu_data *rdp)
if (!rcu_nocb_poll) {
trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu,
"FollowerSleep");
- wait_event_interruptible(rdp->nocb_wq,
+ swait_event_interruptible(rdp->nocb_wq,
READ_ONCE(rdp->nocb_follower_head));
} else if (firsttime) {
/* Don't drown trace log with "Poll"! */
@@ -2369,7 +2369,7 @@ void __init rcu_init_nohz(void)
static void __init rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp)
{
rdp->nocb_tail = &rdp->nocb_head;
- init_waitqueue_head(&rdp->nocb_wq);
+ init_swait_queue_head(&rdp->nocb_wq);
rdp->nocb_follower_tail = &rdp->nocb_follower_head;
}
@@ -2519,7 +2519,7 @@ static bool rcu_nocb_cpu_needs_barrier(struct rcu_state *rsp, int cpu)
return false;
}
-static void rcu_nocb_gp_cleanup(wait_queue_head_t *sq)
+static void rcu_nocb_gp_cleanup(struct swait_queue_head *sq)
{
}
@@ -2527,7 +2527,7 @@ static void rcu_nocb_gp_set(struct rcu_node *rnp, int nrq)
{
}
-static wait_queue_head_t *rcu_nocb_gp_get(struct rcu_node *rnp)
+static struct swait_queue_head *rcu_nocb_gp_get(struct rcu_node *rnp)
{
return NULL;
}
--
2.5.0
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