search for: pv_locks

...d and that in turn does the smp_prepare_cpus which now changes the pv_lock_ops again, *but not* run any patching again. So the _raw_spin_*lock calls still use the ticket calls. start_kernel setup_arch -> xen_hvm_smp_init (set smp_ops) ... check_bugs -> alternative_instructions (patches pv_locks sites) ... rest_init (triggers kernel_init as a thread) kernel_init ... smp_prepare_cpus (calls xen_init_spinlocks through smp_ops hook) To make things even more fun, there is the possibility that some spinlock functions are forced to be inlined and others are not (CONFIG_INLIN...

Hi Steve, On 2019/12/17 22:21, Steven Price wrote: > On Tue, Dec 17, 2019 at 01:55:45PM +0000, yezengruan at huawei.com wrote: >> From: Zengruan Ye <yezengruan at huawei.com> >> >> Introduce a paravirtualization interface for KVM/arm64 to obtain the vcpu >> is currently running or not. >> >> A hypercall interface is provided for the guest to

As we need let pv-qspinlock-kernel run on all environment which might have no powervm, we should runtime choose which qspinlock version to use. The default pv-qspinlock use native version. pv_lock initialization should be done in bootstage with irq disabled. And if possible, restore pv_lock_ops callbacks to pv version. Signed-off-by: Pan Xinhui <xinhui.pan at linux.vnet.ibm.com> ---

From: Zengruan Ye <yezengruan at huawei.com> This patch set aims to support the vcpu_is_preempted() functionality under KVM/arm64, which allowing the guest to obtain the vcpu is currently running or not. 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

From: Zengruan Ye <yezengruan at huawei.com> This patch set aims to support the vcpu_is_preempted() functionality under KVM/arm64, which allowing the guest to obtain the vcpu is currently running or not. 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

change fome v1: separate into 6 pathes from one patch some minor code changes. benchmark test results are below. run 3 tests on pseries IBM,8408-E8E with 32cpus, 64GB memory perf bench futex hash perf bench futex lock-pi perf record -advRT || perf bench sched messaging -g 1000 || perf report summary: _____test________________spinlcok______________pv-qspinlcok_____ |futex hash | 556370 ops |

change fome v1: separate into 6 pathes from one patch some minor code changes. benchmark test results are below. run 3 tests on pseries IBM,8408-E8E with 32cpus, 64GB memory perf bench futex hash perf bench futex lock-pi perf record -advRT || perf bench sched messaging -g 1000 || perf report summary: _____test________________spinlcok______________pv-qspinlcok_____ |futex hash | 556370 ops |

change from v2: __spin_yeild_cpu() will yield slices to lpar if target cpu is running. remove unnecessary rmb() in __spin_yield/wake_cpu. __pv_wait() will check the *ptr == val. some commit message change change fome v1: separate into 6 pathes from one patch some minor code changes. I do several tests on pseries IBM,8408-E8E with 32cpus, 64GB memory. benchmark test results are below. 2

change from v2: __spin_yeild_cpu() will yield slices to lpar if target cpu is running. remove unnecessary rmb() in __spin_yield/wake_cpu. __pv_wait() will check the *ptr == val. some commit message change change fome v1: separate into 6 pathes from one patch some minor code changes. I do several tests on pseries IBM,8408-E8E with 32cpus, 64GB memory. benchmark test results are below. 2

change from v4: BUG FIX. thanks boqun reporting this issue. struct __qspinlock has different layout in bigendian mahcine. native_queued_spin_unlock() may write value to a wrong address. now fix it. sorry for not even doing a test on bigendian machine before!!! change from v3: a big change in [PATCH v4 4/6] pv-qspinlock: powerpc support pv-qspinlock no other patch changed. and the patch

change from v4: BUG FIX. thanks boqun reporting this issue. struct __qspinlock has different layout in bigendian mahcine. native_queued_spin_unlock() may write value to a wrong address. now fix it. sorry for not even doing a test on bigendian machine before!!! change from v3: a big change in [PATCH v4 4/6] pv-qspinlock: powerpc support pv-qspinlock no other patch changed. and the patch

From: root <root at ltcalpine2-lp13.aus.stglabs.ibm.com> change from v4: BUG FIX. thanks boqun reporting this issue. struct __qspinlock has different layout in bigendian mahcine. native_queued_spin_unlock() may write value to a wrong address. now fix it. change from v3: a big change in [PATCH v4 4/6] pv-qspinlock: powerpc support pv-qspinlock no other patch changed. and the patch

From: root <root at ltcalpine2-lp13.aus.stglabs.ibm.com> change from v4: BUG FIX. thanks boqun reporting this issue. struct __qspinlock has different layout in bigendian mahcine. native_queued_spin_unlock() may write value to a wrong address. now fix it. change from v3: a big change in [PATCH v4 4/6] pv-qspinlock: powerpc support pv-qspinlock no other patch changed. and the patch

Hi All, this is the fairlock patchset. You can apply them and build successfully. patches are based on linux-next qspinlock can avoid waiter starved issue. It has about the same speed in single-thread and it can be much faster in high contention situations especially when the spinlock is embedded within the data structure to be protected. v8 -> v9: mv qspinlocm config entry to

Hi All, this is the fairlock patchset. You can apply them and build successfully. patches are based on linux-next qspinlock can avoid waiter starved issue. It has about the same speed in single-thread and it can be much faster in high contention situations especially when the spinlock is embedded within the data structure to be protected. v8 -> v9: mv qspinlocm config entry to

This patch set aims to support the vcpu_is_preempted() functionality under KVM/arm64, which allowing the guest to obtain the VCPU is currently running or not. 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. We have observed some

Hi All, this is the fairlock patchset. You can apply them and build successfully. patches are based on linux-next qspinlock can avoid waiter starved issue. It has about the same speed in single-thread and it can be much faster in high contention situations especially when the spinlock is embedded within the data structure to be protected. v7 -> v8: add one patch to drop a function call

Hi All, this is the fairlock patchset. You can apply them and build successfully. patches are based on linux-next qspinlock can avoid waiter starved issue. It has about the same speed in single-thread and it can be much faster in high contention situations especially when the spinlock is embedded within the data structure to be protected. v7 -> v8: add one patch to drop a function call