search for: xen_clear_irq_pending

...I wrote, except I think you broke it. > +static void xen_qlock_wait(u8 *byte, u8 val) > +{ > + int irq = __this_cpu_read(lock_kicker_irq); > + > + /* If kicker interrupts not initialized yet, just spin */ > + if (irq == -1) > + return; > + > + /* clear pending */ > + xen_clear_irq_pending(irq); > + > + /* > + * We check the byte value after clearing pending IRQ to make sure > + * that we won't miss a wakeup event because of the clearing. My version had a barrier() here to ensure this. The documentation of READ_ONCE() suggests that it is not sufficient to meet thi...

...I wrote, except I think you broke it. > +static void xen_qlock_wait(u8 *byte, u8 val) > +{ > + int irq = __this_cpu_read(lock_kicker_irq); > + > + /* If kicker interrupts not initialized yet, just spin */ > + if (irq == -1) > + return; > + > + /* clear pending */ > + xen_clear_irq_pending(irq); > + > + /* > + * We check the byte value after clearing pending IRQ to make sure > + * that we won't miss a wakeup event because of the clearing. My version had a barrier() here to ensure this. The documentation of READ_ONCE() suggests that it is not sufficient to meet thi...

...UNLOCK_VECTOR); +} + +/* + * Halt the current CPU & release it back to the host + */ +static void xen_qlock_wait(u8 *byte, u8 val) +{ + int irq = __this_cpu_read(lock_kicker_irq); + + /* If kicker interrupts not initialized yet, just spin */ + if (irq == -1) + return; + + /* clear pending */ + xen_clear_irq_pending(irq); + + /* + * We check the byte value after clearing pending IRQ to make sure + * that we won't miss a wakeup event because of the clearing. + * + * The sync_clear_bit() call in xen_clear_irq_pending() is atomic. + * So it is effectively a memory barrier for x86. + */ + if (READ_ONCE(*...

...-1; +static DEFINE_PER_CPU(char *, irq_name); +static bool xen_pvspin = true; + +#ifdef CONFIG_QUEUE_SPINLOCK + +#include <asm/qspinlock.h> + +PV_CALLEE_SAVE_REGS_THUNK(__pv_queue_spin_unlock); + +static void xen_qlock_wait(u8 *ptr, u8 val) +{ + int irq = __this_cpu_read(lock_kicker_irq); + + xen_clear_irq_pending(irq); + + barrier(); + + if (READ_ONCE(*ptr) == val) + xen_poll_irq(irq); +} + +static void xen_qlock_kick(int cpu) +{ + xen_send_IPI_one(cpu, XEN_SPIN_UNLOCK_VECTOR); +} + +#else + struct xen_lock_waiting { struct arch_spinlock *lock; __ticket_t want; }; -static DEFINE_PER_CPU(int, lock_k...

...-1; +static DEFINE_PER_CPU(char *, irq_name); +static bool xen_pvspin = true; + +#ifdef CONFIG_QUEUE_SPINLOCK + +#include <asm/qspinlock.h> + +PV_CALLEE_SAVE_REGS_THUNK(__pv_queue_spin_unlock); + +static void xen_qlock_wait(u8 *ptr, u8 val) +{ + int irq = __this_cpu_read(lock_kicker_irq); + + xen_clear_irq_pending(irq); + + barrier(); + + if (READ_ONCE(*ptr) == val) + xen_poll_irq(irq); +} + +static void xen_qlock_kick(int cpu) +{ + xen_send_IPI_one(cpu, XEN_SPIN_UNLOCK_VECTOR); +} + +#else + struct xen_lock_waiting { struct arch_spinlock *lock; __ticket_t want; }; -static DEFINE_PER_CPU(int, lock_k...

..._irq); + unsigned long flags; + + /* If kicker interrupts not initialized yet, just spin */ + if (irq == -1) + return; + + /* + * Make sure an interrupt handler can't upset things in a + * partially setup state. + */ + local_irq_save(flags); + + xen_halt_stats(type); + /* clear pending */ + xen_clear_irq_pending(irq); + + /* Allow interrupts while blocked */ + local_irq_restore(flags); + + /* + * If an interrupt happens here, it will leave the wakeup irq + * pending, which will cause xen_poll_irq() to return + * immediately. + */ + + /* Block until irq becomes pending (or perhaps a spurious wakeup) */...

...g flags; + u64 start; + + /* If kicker interrupts not initialized yet, just spin */ + if (irq == -1) + return -1; + + /* + * Make sure an interrupt handler can't upset things in a + * partially setup state. + */ + local_irq_save(flags); + start = spin_time_start(); + + /* clear pending */ + xen_clear_irq_pending(irq); + + /* Allow interrupts while blocked */ + local_irq_restore(flags); + /* + * Don't halt if the content of the given byte address differs from + * the expected value. A read memory barrier is added to make sure that + * the latest value of the byte address is fetched. + */ + smp_rmb()...

...g flags; + u64 start; + + /* If kicker interrupts not initialized yet, just spin */ + if (irq == -1) + return -1; + + /* + * Make sure an interrupt handler can't upset things in a + * partially setup state. + */ + local_irq_save(flags); + start = spin_time_start(); + + /* clear pending */ + xen_clear_irq_pending(irq); + + /* Allow interrupts while blocked */ + local_irq_restore(flags); + /* + * Don't halt if the content of the given byte address differs from + * the expected value. A read memory barrier is added to make sure that + * the latest value of the byte address is fetched. + */ + smp_rmb()...

v13->v14: - Patches 1 & 2: Add queue_spin_unlock_wait() to accommodate commit 78bff1c86 from Oleg Nesterov. - Fix the system hang problem when using PV qspinlock in an over-committed guest due to a racing condition in the pv_set_head_in_tail() function. - Increase the MAYHALT_THRESHOLD from 10 to 1024. - Change kick_cpu into a regular function pointer instead of a

v13->v14: - Patches 1 & 2: Add queue_spin_unlock_wait() to accommodate commit 78bff1c86 from Oleg Nesterov. - Fix the system hang problem when using PV qspinlock in an over-committed guest due to a racing condition in the pv_set_head_in_tail() function. - Increase the MAYHALT_THRESHOLD from 10 to 1024. - Change kick_cpu into a regular function pointer instead of a

v14->v15: - Incorporate PeterZ's v15 qspinlock patch and improve upon the PV qspinlock code by dynamically allocating the hash table as well as some other performance optimization. - Simplified the Xen PV qspinlock code as suggested by David Vrabel <david.vrabel at citrix.com>. - Add benchmarking data for 3.19 kernel to compare the performance of a spinlock heavy test

v14->v15: - Incorporate PeterZ's v15 qspinlock patch and improve upon the PV qspinlock code by dynamically allocating the hash table as well as some other performance optimization. - Simplified the Xen PV qspinlock code as suggested by David Vrabel <david.vrabel at citrix.com>. - Add benchmarking data for 3.19 kernel to compare the performance of a spinlock heavy test

From: Jeremy Fitzhardinge <jeremy.fitzhardinge at citrix.com> Hi all, This is a revised version of the pvticket lock series. The early part of the series is mostly unchanged: it converts the bulk of the ticket lock code into C and makes the "small" and "large" ticket code common. The only changes are the incorporation of various review comments. The latter part of

From: Jeremy Fitzhardinge <jeremy.fitzhardinge at citrix.com> Hi all, This is a revised version of the pvticket lock series. The early part of the series is mostly unchanged: it converts the bulk of the ticket lock code into C and makes the "small" and "large" ticket code common. The only changes are the incorporation of various review comments. The latter part of

From: Jeremy Fitzhardinge <jeremy.fitzhardinge at citrix.com> Hi all, This is a revised version of the pvticket lock series. The early part of the series is mostly unchanged: it converts the bulk of the ticket lock code into C and makes the "small" and "large" ticket code common. The only changes are the incorporation of various review comments. The latter part of

From: Jeremy Fitzhardinge <jeremy.fitzhardinge at citrix.com> Hi all, This series does two major things: 1. It converts the bulk of the implementation to C, and makes the "small ticket" and "large ticket" code common. Only the actual size-dependent asm instructions are specific to the ticket size. The resulting generated asm is very similar to the current

From: Jeremy Fitzhardinge <jeremy.fitzhardinge at citrix.com> Hi all, This series does two major things: 1. It converts the bulk of the implementation to C, and makes the "small ticket" and "large ticket" code common. Only the actual size-dependent asm instructions are specific to the ticket size. The resulting generated asm is very similar to the current

From: Jeremy Fitzhardinge <jeremy.fitzhardinge at citrix.com> Hi all, This series does two major things: 1. It converts the bulk of the implementation to C, and makes the "small ticket" and "large ticket" code common. Only the actual size-dependent asm instructions are specific to the ticket size. The resulting generated asm is very similar to the current

From: Jeremy Fitzhardinge <jeremy.fitzhardinge at citrix.com> Changes since last posting: (Raghavendra K T) [ - Rebased to linux-3.3-rc6. - used function+enum in place of macro (better type checking) - use cmpxchg while resetting zero status for possible race [suggested by Dave Hansen for KVM patches ] ] This series replaces the existing paravirtualized spinlock mechanism with a

From: Jeremy Fitzhardinge <jeremy.fitzhardinge at citrix.com> Changes since last posting: (Raghavendra K T) [ - Rebased to linux-3.3-rc6. - used function+enum in place of macro (better type checking) - use cmpxchg while resetting zero status for possible race [suggested by Dave Hansen for KVM patches ] ] This series replaces the existing paravirtualized spinlock mechanism with a