search for: arch_spinlock

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

...orporation of various review comments. The latter part of the series converts from pv spinlocks to pv ticket locks (ie, using the ticket lock fastpath as-is, but adding pv ops for the ticketlock slowpaths). The significant difference here is that rather than adding a new ticket_t-sized element to arch_spinlock_t - effectively doubling the size - I steal the LSB of the tickets themselves to store a bit. This allows the structure to remain the same size, but at the cost of halving the max number of CPUs (127 for a 8-bit ticket, and a hard max of 32767 overall). The extra bit (well, two, but one is unused...

...orporation of various review comments. The latter part of the series converts from pv spinlocks to pv ticket locks (ie, using the ticket lock fastpath as-is, but adding pv ops for the ticketlock slowpaths). The significant difference here is that rather than adding a new ticket_t-sized element to arch_spinlock_t - effectively doubling the size - I steal the LSB of the tickets themselves to store a bit. This allows the structure to remain the same size, but at the cost of halving the max number of CPUs (127 for a 8-bit ticket, and a hard max of 32767 overall). The extra bit (well, two, but one is unused...

...orporation of various review comments. The latter part of the series converts from pv spinlocks to pv ticket locks (ie, using the ticket lock fastpath as-is, but adding pv ops for the ticketlock slowpaths). The significant difference here is that rather than adding a new ticket_t-sized element to arch_spinlock_t - effectively doubling the size - I steal the LSB of the tickets themselves to store a bit. This allows the structure to remain the same size, but at the cost of halving the max number of CPUs (127 for a 8-bit ticket, and a hard max of 32767 overall). The extra bit (well, two, but one is unused...

Signed-off-by: Chen Baozi <baozich@gmail.com> --- extras/mini-os/include/spinlock.h | 2 +- extras/mini-os/include/x86/arch_spinlock.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/extras/mini-os/include/spinlock.h b/extras/mini-os/include/spinlock.h index 70cf20f..6604e3c 100644 --- a/extras/mini-os/include/spinlock.h +++ b/extras/mini-os/include/spinlock.h @@ -30,7 +30,7 @@ typedef struct { #define...

...k). This is is all unnecessary complication if you're not using PV ticket locks, it also uses the jump-label machinery to use the standard "add"-based unlock in the non-PV case. if (TICKET_SLOWPATH_FLAG && unlikely(static_branch(&paravirt_ticketlocks_enabled))) { arch_spinlock_t prev; prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); } else __add(&lock->tickets.head, TICKET_LOCK_INC, UNLOCK_LOCK_PREFI...

...k). This is is all unnecessary complication if you're not using PV ticket locks, it also uses the jump-label machinery to use the standard "add"-based unlock in the non-PV case. if (TICKET_SLOWPATH_FLAG && unlikely(static_branch(&paravirt_ticketlocks_enabled))) { arch_spinlock_t prev; prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); } else __add(&lock->tickets.head, TICKET_LOCK_INC, UNLOCK_LOCK_PREFI...

...adlock). This is is all unnecessary complication if you're not using PV ticket locks, it also uses the jump-label machinery to use the standard "add"-based unlock in the non-PV case. if (TICKET_SLOWPATH_FLAG && static_key_false(&paravirt_ticketlocks_enabled))) { arch_spinlock_t prev; prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); } else __add(&lock->tickets.head, TICKET_LOCK_INC, UNLOCK_LOCK_PREFI...

...adlock). This is is all unnecessary complication if you're not using PV ticket locks, it also uses the jump-label machinery to use the standard "add"-based unlock in the non-PV case. if (TICKET_SLOWPATH_FLAG && static_key_false(&paravirt_ticketlocks_enabled))) { arch_spinlock_t prev; prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); } else __add(&lock->tickets.head, TICKET_LOCK_INC, UNLOCK_LOCK_PREFI...

...adlock). This is is all unnecessary complication if you're not using PV ticket locks, it also uses the jump-label machinery to use the standard "add"-based unlock in the non-PV case. if (TICKET_SLOWPATH_FLAG && static_key_false(&paravirt_ticketlocks_enabled))) { arch_spinlock_t prev; prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); } else __add(&lock->tickets.head, TICKET_LOCK_INC, UNLOCK_LOCK_PREFI...

...adlock). This is is all unnecessary complication if you're not using PV ticket locks, it also uses the jump-label machinery to use the standard "add"-based unlock in the non-PV case. if (TICKET_SLOWPATH_FLAG && static_key_false(&paravirt_ticketlocks_enabled))) { arch_spinlock_t prev; prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); } else __add(&lock->tickets.head, TICKET_LOCK_INC, UNLOCK_LOCK_PREFI...

...adlock). This is is all unnecessary complication if you're not using PV ticket locks, it also uses the jump-label machinery to use the standard "add"-based unlock in the non-PV case. if (TICKET_SLOWPATH_FLAG && static_key_false(&paravirt_ticketlocks_enabled))) { arch_spinlock_t prev; prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); } else __add(&lock->tickets.head, TICKET_LOCK_INC, UNLOCK_LOCK_PREFI...

...adlock). This is is all unnecessary complication if you're not using PV ticket locks, it also uses the jump-label machinery to use the standard "add"-based unlock in the non-PV case. if (TICKET_SLOWPATH_FLAG && static_key_false(&paravirt_ticketlocks_enabled))) { arch_spinlock_t prev; prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); } else __add(&lock->tickets.head, TICKET_LOCK_INC, UNLOCK_LOCK_PREFI...

...adlock). This is is all unnecessary complication if you're not using PV ticket locks, it also uses the jump-label machinery to use the standard "add"-based unlock in the non-PV case. if (TICKET_SLOWPATH_FLAG && static_key_false(&paravirt_ticketlocks_enabled))) { arch_spinlock_t prev; prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); } else __add(&lock->tickets.head, TICKET_LOCK_INC, UNLOCK_LOCK_PREFI...

...adlock). This is is all unnecessary complication if you're not using PV ticket locks, it also uses the jump-label machinery to use the standard "add"-based unlock in the non-PV case. if (TICKET_SLOWPATH_FLAG && static_key_false(&paravirt_ticketlocks_enabled))) { arch_spinlock_t prev; prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); } else __add(&lock->tickets.head, TICKET_LOCK_INC, UNLOCK_LOCK_PREFI...

...adlock). This is is all unnecessary complication if you're not using PV ticket locks, it also uses the jump-label machinery to use the standard "add"-based unlock in the non-PV case. if (TICKET_SLOWPATH_FLAG && static_key_false(&paravirt_ticketlocks_enabled))) { arch_spinlock_t prev; prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); } else __add(&lock->tickets.head, TICKET_LOCK_INC, UNLOCK_LOCK_PREFI...

...adlock). This is is all unnecessary complication if you're not using PV ticket locks, it also uses the jump-label machinery to use the standard "add"-based unlock in the non-PV case. if (TICKET_SLOWPATH_FLAG && static_key_false(&paravirt_ticketlocks_enabled))) { arch_spinlock_t prev; prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); } else __add(&lock->tickets.head, TICKET_LOCK_INC, UNLOCK_LOCK_PREFI...

...adlock). This is is all unnecessary complication if you're not using PV ticket locks, it also uses the jump-label machinery to use the standard "add"-based unlock in the non-PV case. if (TICKET_SLOWPATH_FLAG && static_key_false(&paravirt_ticketlocks_enabled))) { arch_spinlock_t prev; prev = *lock; add_smp(&lock->tickets.head, TICKET_LOCK_INC); /* add_smp() is a full mb() */ if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG)) __ticket_unlock_slowpath(lock, prev); } else __add(&lock->tickets.head, TICKET_LOCK_INC, UNLOCK_LOCK_PREFI...