| Age | Commit message (Collapse) | Author | Files | Lines | |
|---|---|---|---|---|---|
| 2015-01-14 | locking/mcs: Better differentiate between MCS variants | Davidlohr Bueso | 1 | -2/+10 | |
| We have two flavors of the MCS spinlock: standard and cancelable (OSQ). While each one is independent of the other, we currently mix and match them. This patch: - Moves the OSQ code out of mcs_spinlock.h (which only deals with the traditional version) into include/linux/osq_lock.h. No unnecessary code is added to the more global header file, anything locks that make use of OSQ must include it anyway. - Renames mcs_spinlock.c to osq_lock.c. This file only contains osq code. - Introduces a CONFIG_LOCK_SPIN_ON_OWNER in order to only build osq_lock if there is support for it. Signed-off-by: Davidlohr Bueso <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: "Paul E. McKenney" <[email protected]> Cc: Jason Low <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mikulas Patocka <[email protected]> Cc: Waiman Long <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> | |||||
| 2014-07-16 | locking/spinlocks/mcs: Introduce and use init macro and function for osq locks | Jason Low | 1 | -0/+8 | |
| Currently, we initialize the osq lock by directly setting the lock's values. It would be preferable if we use an init macro to do the initialization like we do with other locks. This patch introduces and uses a macro and function for initializing the osq lock. Signed-off-by: Jason Low <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Cc: Scott Norton <[email protected]> Cc: "Paul E. McKenney" <[email protected]> Cc: Dave Chinner <[email protected]> Cc: Waiman Long <[email protected]> Cc: Davidlohr Bueso <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Andrew Morton <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Tim Chen <[email protected]> Cc: Konrad Rzeszutek Wilk <[email protected]> Cc: Aswin Chandramouleeswaran <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Chris Mason <[email protected]> Cc: Josef Bacik <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> | |||||
| 2014-07-16 | locking/spinlocks/mcs: Convert osq lock to atomic_t to reduce overhead | Jason Low | 1 | -0/+19 | |
| The cancellable MCS spinlock is currently used to queue threads that are doing optimistic spinning. It uses per-cpu nodes, where a thread obtaining the lock would access and queue the local node corresponding to the CPU that it's running on. Currently, the cancellable MCS lock is implemented by using pointers to these nodes. In this patch, instead of operating on pointers to the per-cpu nodes, we store the CPU numbers in which the per-cpu nodes correspond to in atomic_t. A similar concept is used with the qspinlock. By operating on the CPU # of the nodes using atomic_t instead of pointers to those nodes, this can reduce the overhead of the cancellable MCS spinlock by 32 bits (on 64 bit systems). Signed-off-by: Jason Low <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Cc: Scott Norton <[email protected]> Cc: "Paul E. McKenney" <[email protected]> Cc: Dave Chinner <[email protected]> Cc: Waiman Long <[email protected]> Cc: Davidlohr Bueso <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Andrew Morton <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Tim Chen <[email protected]> Cc: Konrad Rzeszutek Wilk <[email protected]> Cc: Aswin Chandramouleeswaran <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Chris Mason <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Josef Bacik <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> | |||||