Babu Moger says:
====================
Enable queued rwlock and queued spinlock for SPARC
This series of patches enables queued rwlock and queued spinlock support
for SPARC. These features were introduced some time ago in upstream.
Here are some of the earlier discussions.
https://lwn.net/Articles/572765/
https://lwn.net/Articles/582200/
https://lwn.net/Articles/561775/
https://lwn.net/Articles/590243/
Tests: Ran AIM7 benchmark to verify the performance on various workloads.
https://github.com/davidlohr/areaim. Same benchmark was used when this
feature was introduced and enabled on x86. Here are the test results.
Kernel 4.11.0-rc6 4.11.0-rc6 + Change
baseline queued locks
(Avg No.of jobs) (Avg No.of jobs)
Workload
High systime 10-100 user 17290.48 17295.18 +0.02
High systime 200-1000 users 109814.95 110248.87 +0.39
High systime 1200-2000 users 107912.40 127923.16 +18.54
Disk IO 10-100 users 168910.16 158834.17 -5.96
Disk IO 200-1000 users 242781.74 281285.80 +15.85
Disk IO 1200-2000 users 228518.23 218421.23 -4.41
Disk IO 10-100 users 183933.77 207928.67 +13.04
Disk IO 200-1000 users 491981.56 500162.33 +1.66
Disk IO 1200-2000 users 463395.66 467312.70 +0.84
fserver 10-100 users 254177.53 270283.08 +6.33
fserver IO 200-1000 users 269017.35 324812.2 +20.74
fserver IO 1200-2000 users 229538.87 284713.77 +24.03
Disk I/O results are little bit in negative territory. But majority of the
performance changes are in positive and it is significant in some cases.
Changes:
v3 -> v4:
1. Took care of Geert Uytterhoeven's comment about patch #3(def_bool y)
2. Working on separate patch sets to define CPU_BIG_ENDIAN for all the
default big endian architectures based on feedback from Geert and Arnd.
v2 -> v3:
1. Rebased the patches on top of 4.12-rc2.
2. Re-ordered the patch #1 and patch #2. That is the same order I have seen
the issues. So, it should be addressed in the same order. Patch #1 removes
the check __LINUX_SPINLOCK_TYPES_H. Patch #2 addreses the compile error
with qrwlock.c. This addresses the comments from Dave Miller on v2.
v1 -> v2:
Addressed the comments from David Miller.
1. Added CPU_BIG_ENDIAN for all SPARC
2. Removed #ifndef __LINUX_SPINLOCK_TYPES_H guard from spinlock_types.h
3. Removed check for CONFIG_QUEUED_RWLOCKS in SPARC64 as it is the
default definition for SPARC64 now. Cleaned-up the previous arch_read_xxx
and arch_write_xxx definitions as it is defined now in qrwlock.h.
4. Removed check for CONFIG_QUEUED_SPINLOCKS in SPARC64 as it is the default
definition now for SPARC64 now. Cleaned-up the previous arch_spin_xxx
definitions as it is defined in qspinlock.h.
v1: Initial version
====================
Signed-off-by: David S. Miller <davem@davemloft.net>