On Thu, Feb 14, 2019 at 11:54:47AM +0100, Geert Uytterhoeven wrote:
On Wed, Feb 13, 2019 at 11:01 PM Waiman Long <longman@xxxxxxxxxx> wrote:
Currently, we have two different implementation of rwsem:
1) CONFIG_RWSEM_GENERIC_SPINLOCK (rwsem-spinlock.c)
2) CONFIG_RWSEM_XCHGADD_ALGORITHM (rwsem-xadd.c)
As we are going to use a single generic implementation for rwsem-xadd.c
and no architecture-specific code will be needed, there is no point
in keeping two different implementations of rwsem. In most cases, the
performance of rwsem-spinlock.c will be worse. It also doesn't get all
the performance tuning and optimizations that had been implemented in
rwsem-xadd.c over the years.
For simplication, we are going to remove rwsem-spinlock.c and make all
architectures use a single implementation of rwsem - rwsem-xadd.c.
All references to RWSEM_GENERIC_SPINLOCK and RWSEM_XCHGADD_ALGORITHM
in the code are removed.
Suggested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
Note that this conflicts with "[PATCH 03/11] kernel/locks: consolidate
RWSEM_GENERIC_* options"
https://lore.kernel.org/lkml/20190213174005.28785-4-hch@xxxxxx/
*sigh*.. of that never was Cc'ed to locking people :/
