Messages in this thread | | | From | Will Deacon <> | Subject | [PATCH 0/6] Switch arm64 over to qrwlock | Date | Thu, 5 Oct 2017 13:54:51 +0100 |
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Hi all,
This patch series reworks bits of the qrwlock code that it can be used to replace the asm rwlocks currently implemented for arm64. The structure of the series is:
Patches 1-3 : Work WFE into qrwlock using atomic_cond_read_acquire so we can avoid busy-waiting.
Patch 4 : Enable qrwlocks for arm64
Patch 5-6 : Ensure writer slowpath fairness. This has a potential performance impact on the writer unlock path, so I've kept them at the end.
The patches apply on top of my other locking cleanups:
http://lkml.kernel.org/r/1507055129-12300-1-git-send-email-will.deacon@arm.com
although the conflict with mainline is trivial to resolve without those. The full stack is also pushed here:
git://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git qrwlock
All comments (particularly related to testing and performance) welcome!
Cheers,
Will
--->8
Will Deacon (6): kernel/locking: Use struct qrwlock instead of struct __qrwlock locking/atomic: Add atomic_cond_read_acquire kernel/locking: Use atomic_cond_read_acquire when spinning in qrwlock arm64: locking: Move rwlock implementation over to qrwlocks kernel/locking: Prevent slowpath writers getting held up by fastpath kernel/locking: Remove unused union members from struct qrwlock
arch/arm64/Kconfig | 17 ++++ arch/arm64/include/asm/Kbuild | 1 + arch/arm64/include/asm/spinlock.h | 164 +------------------------------- arch/arm64/include/asm/spinlock_types.h | 6 +- include/asm-generic/atomic-long.h | 3 + include/asm-generic/qrwlock.h | 14 +-- include/asm-generic/qrwlock_types.h | 2 +- include/linux/atomic.h | 4 + kernel/locking/qrwlock.c | 83 +++------------- 9 files changed, 43 insertions(+), 251 deletions(-)
-- 2.1.4
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