search for: config_ppc_pseries

...c/include/asm/spinlock.h > +++ b/arch/powerpc/include/asm/spinlock.h > @@ -52,6 +52,24 @@ > ?#define SYNC_IO > ?#endif > ? > +/* > + * This support kernel to check if one cpu is preempted or not. > + * Then we can fix some lock holder preemption issue. > + */ > +#ifdef CONFIG_PPC_PSERIES > +#define vcpu_is_preempted vcpu_is_preempted > +static inline bool vcpu_is_preempted(int cpu) > +{ > + /* > + ?* pSeries and powerNV can be built into same kernel image. In > + ?* principle we need return false directly if we are running as > + ?* powerNV. However the yield_c...

...c/include/asm/spinlock.h > +++ b/arch/powerpc/include/asm/spinlock.h > @@ -52,6 +52,24 @@ > ?#define SYNC_IO > ?#endif > ? > +/* > + * This support kernel to check if one cpu is preempted or not. > + * Then we can fix some lock holder preemption issue. > + */ > +#ifdef CONFIG_PPC_PSERIES > +#define vcpu_is_preempted vcpu_is_preempted > +static inline bool vcpu_is_preempted(int cpu) > +{ > + /* > + ?* pSeries and powerNV can be built into same kernel image. In > + ?* principle we need return false directly if we are running as > + ?* powerNV. However the yield_c...

....h index 523673d..3ac9fcb 100644 --- a/arch/powerpc/include/asm/spinlock.h +++ b/arch/powerpc/include/asm/spinlock.h @@ -52,6 +52,24 @@ #define SYNC_IO #endif +/* + * This support kernel to check if one cpu is preempted or not. + * Then we can fix some lock holder preemption issue. + */ +#ifdef CONFIG_PPC_PSERIES +#define vcpu_is_preempted vcpu_is_preempted +static inline bool vcpu_is_preempted(int cpu) +{ + /* + * pSeries and powerNV can be built into same kernel image. In + * principle we need return false directly if we are running as + * powerNV. However the yield_count is always zero on powerNV, So...

....h index 523673d..3ac9fcb 100644 --- a/arch/powerpc/include/asm/spinlock.h +++ b/arch/powerpc/include/asm/spinlock.h @@ -52,6 +52,24 @@ #define SYNC_IO #endif +/* + * This support kernel to check if one cpu is preempted or not. + * Then we can fix some lock holder preemption issue. + */ +#ifdef CONFIG_PPC_PSERIES +#define vcpu_is_preempted vcpu_is_preempted +static inline bool vcpu_is_preempted(int cpu) +{ + /* + * pSeries and powerNV can be built into same kernel image. In + * principle we need return false directly if we are running as + * powerNV. However the yield_count is always zero on powerNV, So...

...x/jump_label.h> #include <linux/irqflags.h> +#include <asm/paravirt.h> #ifdef CONFIG_PPC64 #include <asm/paca.h> -#include <asm/hvcall.h> #endif #include <asm/synch.h> #include <asm/ppc-opcode.h> @@ -35,18 +34,6 @@ #define LOCK_TOKEN 1 #endif -#ifdef CONFIG_PPC_PSERIES -DECLARE_STATIC_KEY_FALSE(shared_processor); - -#define vcpu_is_preempted vcpu_is_preempted -static inline bool vcpu_is_preempted(int cpu) -{ - if (!static_branch_unlikely(&shared_processor)) - return false; - return !!(be32_to_cpu(lppaca_of(cpu).yield_count) & 1); -} -#endif - static __a...

change fomr v1: a simplier definition of default vcpu_is_preempted skip mahcine type check on ppc, and add config. remove dedicated macro. add one patch to drop overload of rwsem_spin_on_owner and mutex_spin_on_owner. add more comments thanks boqun and Peter's suggestion. This patch set aims to fix lock holder preemption issues. test-case: perf record -a perf bench sched messaging -g

change fomr v1: a simplier definition of default vcpu_is_preempted skip mahcine type check on ppc, and add config. remove dedicated macro. add one patch to drop overload of rwsem_spin_on_owner and mutex_spin_on_owner. add more comments thanks boqun and Peter's suggestion. This patch set aims to fix lock holder preemption issues. test-case: perf record -a perf bench sched messaging -g

change from v2: no code change, fix typos, update some comments change from v1: a simplier definition of default vcpu_is_preempted skip mahcine type check on ppc, and add config. remove dedicated macro. add one patch to drop overload of rwsem_spin_on_owner and mutex_spin_on_owner. add more comments thanks boqun and Peter's suggestion. This patch set aims to fix lock holder preemption

change from v2: no code change, fix typos, update some comments change from v1: a simplier definition of default vcpu_is_preempted skip mahcine type check on ppc, and add config. remove dedicated macro. add one patch to drop overload of rwsem_spin_on_owner and mutex_spin_on_owner. add more comments thanks boqun and Peter's suggestion. This patch set aims to fix lock holder preemption

v2 is updated to account for feedback from Will, Peter, and Waiman (thank you), and trims off a couple of RFC and unrelated patches. Thanks, Nick Nicholas Piggin (6): powerpc/powernv: must include hvcall.h to get PAPR defines powerpc/pseries: move some PAPR paravirt functions to their own file powerpc: move spinlock implementation to simple_spinlock powerpc/64s: implement queued

change from v4: spilt x86 kvm vcpu preempted check into two patches. add documentation patch. add x86 vcpu preempted check patch under xen add s390 vcpu preempted check patch change from v3: add x86 vcpu preempted check patch change from v2: no code change, fix typos, update some comments change from v1: a simplier definition of default vcpu_is_preempted skip mahcine type check on ppc,

change from v4: spilt x86 kvm vcpu preempted check into two patches. add documentation patch. add x86 vcpu preempted check patch under xen add s390 vcpu preempted check patch change from v3: add x86 vcpu preempted check patch change from v2: no code change, fix typos, update some comments change from v1: a simplier definition of default vcpu_is_preempted skip mahcine type check on ppc,

Updated with everybody's feedback (thanks all), and more performance results. What I've found is I might have been measuring the worst load point for the paravirt case, and by looking at a range of loads it's clear that queued spinlocks are overall better even on PV, doubly so when you look at the generally much improved worst case latencies. I have defaulted it to N even though

change from v3: add x86 vcpu preempted check patch change from v2: no code change, fix typos, update some comments change from v1: a simplier definition of default vcpu_is_preempted skip mahcine type check on ppc, and add config. remove dedicated macro. add one patch to drop overload of rwsem_spin_on_owner and mutex_spin_on_owner. add more comments thanks boqun and Peter's suggestion.

change from v3: add x86 vcpu preempted check patch change from v2: no code change, fix typos, update some comments change from v1: a simplier definition of default vcpu_is_preempted skip mahcine type check on ppc, and add config. remove dedicated macro. add one patch to drop overload of rwsem_spin_on_owner and mutex_spin_on_owner. add more comments thanks boqun and Peter's suggestion.

change from v6: fix typos and remove uncessary comments. change from v5: spilt x86/kvm patch into guest/host part. introduce kvm_write_guest_offset_cached. fix some typos. rebase patch onto 4.9.2 change from v4: spilt x86 kvm vcpu preempted check into two patches. add documentation patch. add x86 vcpu preempted check patch under xen add s390 vcpu preempted check patch change from v3:

change from v6: fix typos and remove uncessary comments. change from v5: spilt x86/kvm patch into guest/host part. introduce kvm_write_guest_offset_cached. fix some typos. rebase patch onto 4.9.2 change from v4: spilt x86 kvm vcpu preempted check into two patches. add documentation patch. add x86 vcpu preempted check patch under xen add s390 vcpu preempted check patch change from v3:

change from v5: spilt x86/kvm patch into guest/host part. introduce kvm_write_guest_offset_cached. fix some typos. rebase patch onto 4.9.2 change from v4: spilt x86 kvm vcpu preempted check into two patches. add documentation patch. add x86 vcpu preempted check patch under xen add s390 vcpu preempted check patch change from v3: add x86 vcpu preempted check patch change from v2: no code

change from v5: spilt x86/kvm patch into guest/host part. introduce kvm_write_guest_offset_cached. fix some typos. rebase patch onto 4.9.2 change from v4: spilt x86 kvm vcpu preempted check into two patches. add documentation patch. add x86 vcpu preempted check patch under xen add s390 vcpu preempted check patch change from v3: add x86 vcpu preempted check patch change from v2: no code

This series adds an option to use queued spinlocks for powerpc, and makes it the default for the Book3S-64 subarch. This effort starts with the generic code so it's very simple but still very performant. There are optimisations that can be made to slowpaths, but I think it's better to attack those incrementally if/when we find things, and try to add the improvements to generic code as