Emilio G. Cota 3dc16ebca3 target-i386: remove helper_lock() ... It's been superseded by the atomic helpers. The use of the atomic helpers provides a significant performance and scalability improvement. Below is the result of running the atomic_add-test microbenchmark with: $ x86_64-linux-user/qemu-x86_64 tests/atomic_add-bench -o 5000000 -r $r -n $n , where $n is the number of threads and $r is the allowed range for the additions. The scenarios measured are: - atomic: implements x86' ADDL with the atomic_add helper (i.e. this patchset) - cmpxchg: implement x86' ADDL with a TCG loop using the cmpxchg helper - master: before this patchset Results sorted in ascending range, i.e. descending degree of contention. Y axis is Throughput in Mops/s. Tests are run on an AMD machine with 64 Opteron 6376 cores. atomic_add-bench: 5000000 ops/thread, [0,1] range 25 ++---------+----------+---------+----------+----------+----------+---++ + atomic +-E--+ + + + + + | |cmpxchg +-H--+ | 20 +Emaster +-N--+ ++ || | |++ | || | 15 +++ ++ |N| | |+| | 10 ++| ++ |+|+ | | | -+E+------ +++ ---+E+------+E+------+E+-----+E+------+E| |+E+E+- +++ +E+------+E+-- | 5 ++|+ ++ |+N+H+--- +++ | ++++N+--+H++----+++ + +++ --++H+------+H+------+H++----+H+---+--- | 0 ++---------+-----H----+---H-----+----------+----------+----------+---H+ 0 10 20 30 40 50 60 Number of threads atomic_add-bench: 5000000 ops/thread, [0,2] range 25 ++---------+----------+---------+----------+----------+----------+---++ ++atomic +-E--+ + + + + + | |cmpxchg +-H--+ | 20 ++master +-N--+ ++ |E| | |++ | ||E | 15 ++| ++ |N|| | |+|| ---+E+------+E+-----+E+------+E| 10 ++| | ---+E+------+E+-----+E+--- +++ +++ ||H+E+--+E+-- | |+++++ | | || | 5 ++|+H+-- +++ ++ |+N+ - ---+H+------+H+------ | + +N+--+H++----+H+---+--+H+----++H+--- + + +H+---+--+H| 0 ++---------+----------+---------+----------+----------+----------+---++ 0 10 20 30 40 50 60 Number of threads atomic_add-bench: 5000000 ops/thread, [0,8] range 40 ++---------+----------+---------+----------+----------+----------+---++ ++atomic +-E--+ + + + + + | 35 +cmpxchg +-H--+ ++ | master +-N--+ ---+E+------+E+------+E+-----+E+------+E| 30 ++| ---+E+-- +++ ++ | | -+E+--- | 25 ++E ---- +++ ++ |+++++ -+E+ | 20 +E+ E-- +++ ++ |H|+++ | |+| +H+------- | 15 ++H+ ---+++ +H+------ ++ |N++H+-- +++--- +H+------++| 10 ++ +++ - +++ ---+H+ +++ +H+ | | +H+-----+H+------+H+-- | 5 ++| +++ ++ ++N+N+--+N++ + + + + + | 0 ++---------+----------+---------+----------+----------+----------+---++ 0 10 20 30 40 50 60 Number of threads atomic_add-bench: 5000000 ops/thread, [0,128] range 160 ++---------+---------+----------+---------+----------+----------+---++ + atomic +-E--+ + + + + + | 140 +cmpxchg +-H--+ +++ +++ ++ | master +-N--+ E--------E------+E+------++| 120 ++ --| | +++ E+ | -- +++ +++ ++| 100 ++ - ++ | +++- +++ ++| 80 ++ -+E+ -+H+------+H+------H--------++ | ---- ---- +++ H| | ---+E+-----+E+- ---+H+ ++| 60 ++ +E+--- +++ ---+H+--- ++ | --+++ ---+H+-- | 40 ++ +E+-+H+--- ++ | +H+ | 20 +EE+ ++ +N+ + + + + + + | 0 ++N-N---N--+---------+----------+---------+----------+----------+---++ 0 10 20 30 40 50 60 Number of threads atomic_add-bench: 5000000 ops/thread, [0,1024] range 350 ++---------+---------+----------+---------+----------+----------+---++ + atomic +-E--+ + + + + + | 300 +cmpxchg +-H--+ +++ | master +-N--+ +++ || | +++ | ----E| 250 ++ | ----E---- ++ | ----E--- | ---+H| 200 ++ -+E+--- +++ ---+H+--- ++ | ---- -+H+-- | | +E+ +++ ---- +++ | 150 ++ ---+++ ---+H+- ++ | --- -+H+-- | 100 ++ ---+E+ ---- +++ ++ | +++ ---+E+-----+H+- | | -+E+------+H+-- | 50 ++ +E+ ++ +EE+ + + + + + + | 0 ++N-N---N--+---------+----------+---------+----------+----------+---++ 0 10 20 30 40 50 60 Number of threads hi-res: http://imgur.com/a/fMRmq For master I stopped measuring master after 8 threads, because there is little point in measuring the well-known performance collapse of a contended lock. Backports commit 37b995f6e7a1cb6fa378c5cd4217b9dd9e1fc98b from qemu		2018-02-27 23:43:22 -05:00
..
arch_memory_mapping.c
bpt_helper.c	cpu-exec: Rename cpu_resume_from_signal() to cpu_loop_exit_noexc()	2018-02-24 17:25:28 -05:00
cc_helper.c
cc_helper_template.h
cpu-qom.h	target-i386: List CPU models using subclass list	2018-02-26 08:17:04 -05:00
cpu.c	target-i386: Don't use cpu->migratable when filtering features	2018-02-26 09:51:14 -05:00
cpu.h	target-i386: Move xsave component mask to features array	2018-02-26 04:45:35 -05:00
excp_helper.c	cpu: move exec-all.h inclusion out of cpu.h	2018-02-24 02:39:08 -05:00
fpu_helper.c	target-i386: Use struct X86XSaveArea in fpu_helper.c	2018-02-26 03:38:53 -05:00
helper.c	cpus: pass CPUState to run_on_cpu helpers	2018-02-26 04:54:55 -05:00
helper.h	target-i386: remove helper_lock()	2018-02-27 23:43:22 -05:00
int_helper.c	cpu: move exec-all.h inclusion out of cpu.h	2018-02-24 02:39:08 -05:00
Makefile.objs
mem_helper.c	target-i386: remove helper_lock()	2018-02-27 23:43:22 -05:00
misc_helper.c	cpu: move exec-all.h inclusion out of cpu.h	2018-02-24 02:39:08 -05:00
mpx_helper.c	cpu: move exec-all.h inclusion out of cpu.h	2018-02-24 02:39:08 -05:00
ops_sse.h
ops_sse_header.h
seg_helper.c	target-i386: Fixed syscall posssible segfault	2018-02-26 02:36:09 -05:00
shift_helper_template.h
smm_helper.c	target-i386: Include log.h in smm_helper	2018-02-24 03:06:07 -05:00
svm.h	Clean up ill-advised or unusual header guards	2018-02-25 04:22:46 -05:00
svm_helper.c	cpu: move exec-all.h inclusion out of cpu.h	2018-02-24 02:39:08 -05:00
TODO
topology.h	pc: Add x86_topo_ids_from_apicid()	2018-02-25 20:31:36 -05:00
translate.c	target-i386: remove helper_lock()	2018-02-27 23:43:22 -05:00
unicorn.c
unicorn.h