unicorn/qemu/include
Emilio G. Cota 1677898a09
cputlb: read CPUTLBEntry.addr_write atomically
Updates can come from other threads, so readers that do not
take tlb_lock must use atomic_read to avoid undefined
behaviour (UB).

This completes the conversion to tlb_lock. This conversion results
on average in no performance loss, as the following experiments
(run on an Intel i7-6700K CPU @ 4.00GHz) show.

1. aarch64 bootup+shutdown test:

- Before:
Performance counter stats for 'taskset -c 0 ../img/aarch64/die.sh' (10 runs):

7487.087786 task-clock (msec) # 0.998 CPUs utilized ( +- 0.12% )
31,574,905,303 cycles # 4.217 GHz ( +- 0.12% )
57,097,908,812 instructions # 1.81 insns per cycle ( +- 0.08% )
10,255,415,367 branches # 1369.747 M/sec ( +- 0.08% )
173,278,962 branch-misses # 1.69% of all branches ( +- 0.18% )

7.504481349 seconds time elapsed ( +- 0.14% )

- After:
Performance counter stats for 'taskset -c 0 ../img/aarch64/die.sh' (10 runs):

7462.441328 task-clock (msec) # 0.998 CPUs utilized ( +- 0.07% )
31,478,476,520 cycles # 4.218 GHz ( +- 0.07% )
57,017,330,084 instructions # 1.81 insns per cycle ( +- 0.05% )
10,251,929,667 branches # 1373.804 M/sec ( +- 0.05% )
173,023,787 branch-misses # 1.69% of all branches ( +- 0.11% )

7.474970463 seconds time elapsed ( +- 0.07% )

2. SPEC06int:
SPEC06int (test set)
[Y axis: Speedup over master]
1.15 +-+----+------+------+------+------+------+-------+------+------+------+------+------+------+----+-+
| |
1.1 +-+.................................+++.............................+ tlb-lock-v2 (m+++x) +-+
| +++ | +++ tlb-lock-v3 (spinl|ck) |
| +++ | | +++ +++ | | |
1.05 +-+....+++...........####.........|####.+++.|......|.....###....+++...........+++....###.........+-+
| ### ++#| # |# |# ***### +++### +++#+# | +++ | #|# ### |
1 +-+++***+#++++####+++#++#++++++++++#++#+*+*++#++++#+#+****+#++++###++++###++++###++++#+#++++#+#+++-+
| *+* # #++# *** # #### *** # * *++# ****+# *| * # ****|# |# # #|# #+# # # |
0.95 +-+..*.*.#....#..#.*|*..#...#..#.*|*..#.*.*..#.*|.*.#.*++*.#.*++*+#.****.#....#+#....#.#..++#.#..+-+
| * * # # # *|* # # # *|* # * * # *++* # * * # * * # * |* # ++# # # # *** # |
| * * # ++# # *+* # # # *|* # * * # * * # * * # * * # *++* # **** # ++# # * * # |
0.9 +-+..*.*.#...|#..#.*.*..#.++#..#.*|*..#.*.*..#.*..*.#.*..*.#.*..*.#.*..*.#.*.|*.#...|#.#..*.*.#..+-+
| * * # *** # * * # |# # *+* # * * # * * # * * # * * # * * # *++* # |# # * * # |
0.85 +-+..*.*.#..*|*..#.*.*..#.***..#.*.*..#.*.*..#.*..*.#.*..*.#.*..*.#.*..*.#.*..*.#.****.#..*.*.#..+-+
| * * # *+* # * * # *|* # * * # * * # * * # * * # * * # * * # * * # * |* # * * # |
| * * # * * # * * # *+* # * * # * * # * * # * * # * * # * * # * * # * |* # * * # |
0.8 +-+..*.*.#..*.*..#.*.*..#.*.*..#.*.*..#.*.*..#.*..*.#.*..*.#.*..*.#.*..*.#.*..*.#.*++*.#..*.*.#..+-+
| * * # * * # * * # * * # * * # * * # * * # * * # * * # * * # * * # * * # * * # |
0.75 +-+--***##--***###-***###-***###-***###-***###-****##-****##-****##-****##-****##-****##--***##--+-+
400.perlben401.bzip2403.gcc429.m445.gob456.hmme45462.libqua464.h26471.omnet473483.xalancbmkgeomean

png: https://imgur.com/a/BHzpPTW

Notes:
- tlb-lock-v2 corresponds to an implementation with a mutex.
- tlb-lock-v3 corresponds to the current implementation, i.e.
a spinlock and a single lock acquisition in tlb_set_page_with_attrs.

Backports commit 403f290c0603f35f2d09c982bf5549b6d0803ec1 from qemu
2018-10-23 15:37:43 -04:00
..
crypto Drop unused crypto source files 2018-02-17 15:23:57 -05:00
exec cputlb: read CPUTLBEntry.addr_write atomically 2018-10-23 15:37:43 -04:00
fpu softfloat: remove float64_trunc_to_int 2018-10-08 14:15:11 -04:00
hw Use cpu_create(type) instead of cpu_init(cpu_model) 2018-03-20 14:20:30 -04:00
qapi qstring: Fix qstring_from_substr() not to provoke int overflow 2018-08-02 21:21:51 -04:00
qemu tcg: Split CONFIG_ATOMIC128 2018-10-23 15:17:39 -04:00
qom cpu: Assert asidx_from_attrs return value in range 2018-07-03 19:43:59 -04:00
sysemu tcg: add options for enabling MTTCG 2018-03-02 09:25:01 -05:00
config.h import 2015-08-21 15:04:50 +08:00
elf.h include/elf: Update elf.h to commit f71a8eaffba3271cf7cdad95572f6996f7523a5b 2018-03-11 15:34:35 -04:00
glib_compat.h Use cpu_create(type) instead of cpu_init(cpu_model) 2018-03-20 14:20:30 -04:00
qemu-common.h tcg: Add EXCP_ATOMIC 2018-02-27 11:57:58 -05:00