Re: [PATCH v3 0/5] Switch arm64 over to qrwlock

[Adam Wallis]

On 10/12/2017 8:20 AM, Will Deacon wrote:
> Hello,
> 
> This is version three of the patches previously posted here:
> 
> v1: http://lists.infradead.org/pipermail/linux-arm-kernel/2017-October/534666.html
> v2: http://lists.infradead.org/pipermail/linux-arm-kernel/2017-October/534981.html
> 
> Changes since v2 include:
> 
>   * Drop unused cnt argument
>   * Fix typo in UNLOCK Kconfig inlining options
>   * Added Tested-by tags
> 
> Thanks to all of those who provided review and testing feedback!
> 
> Will
> 
> --->8
> 
> Will Deacon (5):
>   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
> 
>  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           |  37 ++-----
>  include/asm-generic/qrwlock_types.h     |  15 ++-
>  include/linux/atomic.h                  |   4 +
>  kernel/locking/qrwlock.c                |  86 +++--------------
>  9 files changed, 61 insertions(+), 272 deletions(-)
> 

Will, I see the same performance improvements that I was getting in v2 of the
patch. I will continue to run these patches on multiple systems over the next
few weeks, months for stability/functionality testing as well.

Tested-by: Adam Wallis <awallis@xxxxxxxxxxxxxx>

-- 
Adam Wallis
Qualcomm Datacenter Technologies as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project.