Re: [PATCH 00/17] sched: EEVDF using latency-nice
From: Shrikanth Hegde
Date: Mon Apr 03 2023 - 03:43:57 EST
On 3/28/23 2:56 PM, Peter Zijlstra wrote:
> Hi!
>
> Latest version of the EEVDF [1] patches.
>
> Many changes since last time; most notably it now fully replaces CFS and uses
> lag based placement for migrations. Smaller changes include:
>
> - uses scale_load_down() for avg_vruntime; I measured the max delta to be ~44
> bits on a system/cgroup based kernel build.
> - fixed a bunch of reweight / cgroup placement issues
> - adaptive placement strategy for smaller slices
> - rename se->lag to se->vlag
>
> There's a bunch of RFC patches at the end and one DEBUG patch. Of those, the
> PLACE_BONUS patch is a mixed bag of pain. A number of benchmarks regress
> because EEVDF is actually fair and gives a 100% parent vs a 50% child a 67%/33%
> split (stress-futex, stress-nanosleep, starve, etc..) instead of a 50%/50%
> split that sleeper bonus achieves. Mostly I think these benchmarks are somewhat
> artificial/daft but who knows.
>
> The PLACE_BONUS thing horribly messes up things like hackbench and latency-nice
> because it places things too far to the left in the tree. Basically it messes
> with the whole 'when', by placing a task back in history you're putting a
> burden on the now to accomodate catching up. More tinkering required.
>
> But over-all the thing seems to be fairly usable and could do with more
> extensive testing.
>
> [1] https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=805acf7726282721504c8f00575d91ebfd750564
>
> Results:
>
> hackbech -g $nr_cpu + cyclictest --policy other results:
>
> EEVDF CFS
>
> # Min Latencies: 00054
> LNICE(19) # Avg Latencies: 00660
> # Max Latencies: 23103
>
> # Min Latencies: 00052 00053
> LNICE(0) # Avg Latencies: 00318 00687
> # Max Latencies: 08593 13913
>
> # Min Latencies: 00054
> LNICE(-19) # Avg Latencies: 00055
> # Max Latencies: 00061
>
>
> Some preliminary results from Chen Yu on a slightly older version:
>
> schbench (95% tail latency, lower is better)
> =================================================================================
> case nr_instance baseline (std%) compare% ( std%)
> normal 25% 1.00 (2.49%) -81.2% (4.27%)
> normal 50% 1.00 (2.47%) -84.5% (0.47%)
> normal 75% 1.00 (2.5%) -81.3% (1.27%)
> normal 100% 1.00 (3.14%) -79.2% (0.72%)
> normal 125% 1.00 (3.07%) -77.5% (0.85%)
> normal 150% 1.00 (3.35%) -76.4% (0.10%)
> normal 175% 1.00 (3.06%) -76.2% (0.56%)
> normal 200% 1.00 (3.11%) -76.3% (0.39%)
> ==================================================================================
>
> hackbench (throughput, higher is better)
> ==============================================================================
> case nr_instance baseline(std%) compare%( std%)
> threads-pipe 25% 1.00 (<2%) -17.5 (<2%)
> threads-socket 25% 1.00 (<2%) -1.9 (<2%)
> threads-pipe 50% 1.00 (<2%) +6.7 (<2%)
> threads-socket 50% 1.00 (<2%) -6.3 (<2%)
> threads-pipe 100% 1.00 (3%) +110.1 (3%)
> threads-socket 100% 1.00 (<2%) -40.2 (<2%)
> threads-pipe 150% 1.00 (<2%) +125.4 (<2%)
> threads-socket 150% 1.00 (<2%) -24.7 (<2%)
> threads-pipe 200% 1.00 (<2%) -89.5 (<2%)
> threads-socket 200% 1.00 (<2%) -27.4 (<2%)
> process-pipe 25% 1.00 (<2%) -15.0 (<2%)
> process-socket 25% 1.00 (<2%) -3.9 (<2%)
> process-pipe 50% 1.00 (<2%) -0.4 (<2%)
> process-socket 50% 1.00 (<2%) -5.3 (<2%)
> process-pipe 100% 1.00 (<2%) +62.0 (<2%)
> process-socket 100% 1.00 (<2%) -39.5 (<2%)
> process-pipe 150% 1.00 (<2%) +70.0 (<2%)
> process-socket 150% 1.00 (<2%) -20.3 (<2%)
> process-pipe 200% 1.00 (<2%) +79.2 (<2%)
> process-socket 200% 1.00 (<2%) -22.4 (<2%)
> ==============================================================================
>
> stress-ng (throughput, higher is better)
> ==============================================================================
> case nr_instance baseline(std%) compare%( std%)
> switch 25% 1.00 (<2%) -6.5 (<2%)
> switch 50% 1.00 (<2%) -9.2 (<2%)
> switch 75% 1.00 (<2%) -1.2 (<2%)
> switch 100% 1.00 (<2%) +11.1 (<2%)
> switch 125% 1.00 (<2%) -16.7% (9%)
> switch 150% 1.00 (<2%) -13.6 (<2%)
> switch 175% 1.00 (<2%) -16.2 (<2%)
> switch 200% 1.00 (<2%) -19.4% (<2%)
> fork 50% 1.00 (<2%) -0.1 (<2%)
> fork 75% 1.00 (<2%) -0.3 (<2%)
> fork 100% 1.00 (<2%) -0.1 (<2%)
> fork 125% 1.00 (<2%) -6.9 (<2%)
> fork 150% 1.00 (<2%) -8.8 (<2%)
> fork 200% 1.00 (<2%) -3.3 (<2%)
> futex 25% 1.00 (<2%) -3.2 (<2%)
> futex 50% 1.00 (3%) -19.9 (5%)
> futex 75% 1.00 (6%) -19.1 (2%)
> futex 100% 1.00 (16%) -30.5 (10%)
> futex 125% 1.00 (25%) -39.3 (11%)
> futex 150% 1.00 (20%) -27.2% (17%)
> futex 175% 1.00 (<2%) -18.6 (<2%)
> futex 200% 1.00 (<2%) -47.5 (<2%)
> nanosleep 25% 1.00 (<2%) -0.1 (<2%)
> nanosleep 50% 1.00 (<2%) -0.0% (<2%)
> nanosleep 75% 1.00 (<2%) +15.2% (<2%)
> nanosleep 100% 1.00 (<2%) -26.4 (<2%)
> nanosleep 125% 1.00 (<2%) -1.3 (<2%)
> nanosleep 150% 1.00 (<2%) +2.1 (<2%)
> nanosleep 175% 1.00 (<2%) +8.3 (<2%)
> nanosleep 200% 1.00 (<2%) +2.0% (<2%)
> ===============================================================================
>
> unixbench (throughput, higher is better)
> ==============================================================================
> case nr_instance baseline(std%) compare%( std%)
> spawn 125% 1.00 (<2%) +8.1 (<2%)
> context1 100% 1.00 (6%) +17.4 (6%)
> context1 75% 1.00 (13%) +18.8 (8%)
> =================================================================================
>
> netperf (throughput, higher is better)
> ===========================================================================
> case nr_instance baseline(std%) compare%( std%)
> UDP_RR 25% 1.00 (<2%) -1.5% (<2%)
> UDP_RR 50% 1.00 (<2%) -0.3% (<2%)
> UDP_RR 75% 1.00 (<2%) +12.5% (<2%)
> UDP_RR 100% 1.00 (<2%) -4.3% (<2%)
> UDP_RR 125% 1.00 (<2%) -4.9% (<2%)
> UDP_RR 150% 1.00 (<2%) -4.7% (<2%)
> UDP_RR 175% 1.00 (<2%) -6.1% (<2%)
> UDP_RR 200% 1.00 (<2%) -6.6% (<2%)
> TCP_RR 25% 1.00 (<2%) -1.4% (<2%)
> TCP_RR 50% 1.00 (<2%) -0.2% (<2%)
> TCP_RR 75% 1.00 (<2%) -3.9% (<2%)
> TCP_RR 100% 1.00 (2%) +3.6% (5%)
> TCP_RR 125% 1.00 (<2%) -4.2% (<2%)
> TCP_RR 150% 1.00 (<2%) -6.0% (<2%)
> TCP_RR 175% 1.00 (<2%) -7.4% (<2%)
> TCP_RR 200% 1.00 (<2%) -8.4% (<2%)
> ==========================================================================
>
>
> ---
> Also available at:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/eevdf
>
> ---
> Parth Shah (1):
> sched: Introduce latency-nice as a per-task attribute
>
> Peter Zijlstra (14):
> sched/fair: Add avg_vruntime
> sched/fair: Remove START_DEBIT
> sched/fair: Add lag based placement
> rbtree: Add rb_add_augmented_cached() helper
> sched/fair: Implement an EEVDF like policy
> sched: Commit to lag based placement
> sched/smp: Use lag to simplify cross-runqueue placement
> sched: Commit to EEVDF
> sched/debug: Rename min_granularity to base_slice
> sched: Merge latency_offset into slice
> sched/eevdf: Better handle mixed slice length
> sched/eevdf: Sleeper bonus
> sched/eevdf: Minimal vavg option
> sched/eevdf: Debug / validation crud
>
> Vincent Guittot (2):
> sched/fair: Add latency_offset
> sched/fair: Add sched group latency support
>
> Documentation/admin-guide/cgroup-v2.rst | 10 +
> include/linux/rbtree_augmented.h | 26 +
> include/linux/sched.h | 6 +
> include/uapi/linux/sched.h | 4 +-
> include/uapi/linux/sched/types.h | 19 +
> init/init_task.c | 3 +-
> kernel/sched/core.c | 65 +-
> kernel/sched/debug.c | 49 +-
> kernel/sched/fair.c | 1199 ++++++++++++++++---------------
> kernel/sched/features.h | 29 +-
> kernel/sched/sched.h | 23 +-
> tools/include/uapi/linux/sched.h | 4 +-
> 12 files changed, 794 insertions(+), 643 deletions(-)
>
Tested the patch on power system with 60 cores with SMT=8. Total of 480 CPU's.
System has four NUMA nodes.
TL;DR
Real life workload like daytrader shows improvement in different cases, while
microbenchmarks shows gains and regress as well.
Tested with microbenchmarks (hackbench, schbench, unixbench, STREAM and lmbench)
and DB workload called day trader. daytrader simulates the real life trading
activities which gives total transaction/s. It uses around 70% CPU.
Comparison is between tip/master vs +this_patch. tip/master was at 4b7aa0abddff
small nit: Applies cleanly to tip/master. patch fails to apply cleanly for
sched/core. sched/core is at 05bfb338fa8d
===============================================================================
Summary of methods and observations.
===============================================================================
Method 1: Ran microbenchmarks on an idle system without any cgroups.
Observation: hackbench, unixbench shows gain. schbench shows regression.
Stream and lmbench values are same.
Method 2: Ran microbenchmarks on an idle system. Created a cgroup and ran
benchmarks in that cgroup. Latency values are assigned to the cgroup.
This is almost same as Method 1.
Observation: hackbench pipe shows improvement. schbench shows regression. lmbench and stream
are same more or less.
Method 3: Ran microbenchmarks in a cgroup and in another terminal running stress-ng
at 50% utilization. here, also tried different latency nice values
for cgroup.
Observation: Hackbench shows gain in latency values. Schbench shows good gain in
latency values except, 1 thread case. lmbench and stream regress
slightly. unixbench is mixed.
One concerning throughput is 4 X Shell Scripts (8 concurrent) which
shows 50% regression. This is verified with additional run. The
same holds true for 25% utilization as well.
Method 4: Ran daytrader with no cgroups on idle system.
Observation: we see around 7% gain in throughput.
Method 5: Ran daytrader in a cgroup and running stress-ng at 50% utilization.
Observation: we see around 9% gain in throughput.
===============================================================================
Note:
positive values show improvement and negative values shows regression.
hackbench has 50 iterations.
schbench has 10 iterations
unixbench has 10 iterations.
lmbench has 50 iterations.
# lscpu
Architecture: ppc64le
Byte Order: Little Endian
CPU(s): 480
On-line CPU(s) list: 0-479
Thread(s) per core: 8
Core(s) per socket: 15
Socket(s): 4
Physical sockets: 4
Physical chips: 1
Physical cores/chip: 15
NUMA:
NUMA node(s): 4
NUMA node0 CPU(s): 0-119
NUMA node1 CPU(s): 120-239
NUMA node2 CPU(s): 240-359
NUMA node3 CPU(s): 360-479
===============================================================================
Detailed logs from each method.
================
Method 1:
================
This is to compare the out of box performance of the two. no load on the system
benchmarks are run without any cgroup.
Hackbench shows improvement. schbench results are mixed. But schebench has run
to variance. stream and lmbench are same.
-------------------------------------------------------------------------------
lmbench tip/master eevdf
-------------------------------------------------------------------------------
latency process fork : 120.56, 120.32(+0.20)
latency process Exec : 176.70, 177.22(-0.30)
latency process Exec : 5.59, 5.89(-5.47)
latency syscall fstat : 0.26, 0.26( 0.00)
latency syscall open : 2.27, 2.29(-0.88)
AF_UNIX sock stream latency: 9.13, 9.34(-2.30)
Select on 200 fd's : 2.16, 2.15(-0.46)
semaphore latency : 0.85, 0.85(+0.00)
-------------------------------------------------------------------------------
Stream tip/master eevdf
-------------------------------------------------------------------------------
copy latency : 0.58, 0.59(-1.72)
copy bandwidth : 27357.05, 27009.15(-1.27)
scale latency : 0.61, 0.61(0.00)
scale bandwidth : 26268.65, 26057.07(-0.81)
add latency : 1.25, 1.25(0.00)
add bandwidth : 19176.21, 19177.24(0.01)
triad latency : 0.74, 0.74(0.00)
triad bandwidth : 32591.51, 32506.32(-0.26)
-------------------------------------------------------------------------------
Unixbench tip/master eevdf
-------------------------------------------------------------------------------
1 X Execl Throughput : 5158.07, 5228.97(1.37)
4 X Execl Throughput : 12745.19, 12927.75(1.43)
1 X Pipe-based Context Switching : 178280.42, 170140.15(-4.57)
4 X Pipe-based Context Switching : 594414.36, 560509.01(-5.70)
1 X Process Creation : 8657.10, 8659.28(0.03)
4 X Process Creation : 16476.56, 17007.43(3.22)
1 X Shell Scripts (1 concurrent) : 10179.24, 10307.21(1.26)
4 X Shell Scripts (1 concurrent) : 32990.17, 33251.73(0.79)
1 X Shell Scripts (8 concurrent) : 4878.56, 4940.22(1.26)
4 X Shell Scripts (8 concurrent) : 14001.89, 13568.88(-3.09)
-------------------------------------------------------------------------------
Schbench tip/master eevdf
-------------------------------------------------------------------------------
1 Threads
50.0th: 7.20, 7.00(2.78)
75.0th: 8.20, 7.90(3.66)
90.0th: 10.10, 8.30(17.82)
95.0th: 11.40, 9.30(18.42)
99.0th: 13.30, 11.00(17.29)
99.5th: 13.60, 11.70(13.97)
99.9th: 15.40, 13.40(12.99)
2 Threads
50.0th: 8.60, 8.00(6.98)
75.0th: 9.80, 8.80(10.20)
90.0th: 11.50, 9.90(13.91)
95.0th: 12.40, 10.70(13.71)
99.0th: 13.50, 13.70(-1.48)
99.5th: 14.90, 15.00(-0.67)
99.9th: 27.60, 23.60(14.49)
4 Threads
50.0th: 10.00, 9.90(1.00)
75.0th: 11.70, 12.00(-2.56)
90.0th: 13.60, 14.30(-5.15)
95.0th: 14.90, 15.40(-3.36)
99.0th: 17.80, 18.50(-3.93)
99.5th: 19.00, 19.30(-1.58)
99.9th: 27.60, 32.10(-16.30)
8 Threads
50.0th: 12.20, 13.30(-9.02)
75.0th: 15.20, 17.50(-15.13)
90.0th: 18.40, 21.60(-17.39)
95.0th: 20.70, 24.10(-16.43)
99.0th: 26.30, 30.20(-14.83)
99.5th: 30.50, 37.90(-24.26)
99.9th: 53.10, 92.10(-73.45)
16 Threads
50.0th: 20.70, 19.70(4.83)
75.0th: 28.20, 27.20(3.55)
90.0th: 36.20, 33.80(6.63)
95.0th: 40.70, 37.50(7.86)
99.0th: 51.50, 45.30(12.04)
99.5th: 62.70, 49.40(21.21)
99.9th: 120.70, 88.40(26.76)
32 Threads
50.0th: 39.50, 38.60(2.28)
75.0th: 58.30, 56.10(3.77)
90.0th: 76.40, 72.60(4.97)
95.0th: 86.30, 82.20(4.75)
99.0th: 102.20, 98.90(3.23)
99.5th: 108.00, 105.30(2.50)
99.9th: 179.30, 188.80(-5.30)
-------------------------------------------------------------------------------
Hackbench tip/master eevdf
-------------------------------------------------------------------------------
Process 10 groups : 0.19, 0.19(0.00)
Process 20 groups : 0.24, 0.26(-8.33)
Process 30 groups : 0.30, 0.31(-3.33)
Process 40 groups : 0.35, 0.37(-5.71)
Process 50 groups : 0.41, 0.44(-7.32)
Process 60 groups : 0.47, 0.50(-6.38)
thread 10 groups : 0.22, 0.23(-4.55)
thread 20 groups : 0.28, 0.27(3.57)
Process(Pipe) 10 groups : 0.16, 0.16(0.00)
Process(Pipe) 20 groups : 0.26, 0.24(7.69)
Process(Pipe) 30 groups : 0.36, 0.30(16.67)
Process(Pipe) 40 groups : 0.40, 0.35(12.50)
Process(Pipe) 50 groups : 0.48, 0.40(16.67)
Process(Pipe) 60 groups : 0.55, 0.44(20.00)
thread (Pipe) 10 groups : 0.16, 0.14(12.50)
thread (Pipe) 20 groups : 0.24, 0.22(8.33)
================
Method 2:
================
This was to compare baseline performance with the eevdf by assigning different
latency nice values. In order to do that, created a cgroup and assigned latency
nice values to cgroup. microbenchmarks are run from that cgroup.
hackbench pipe shows improvement. schbench shows regression. lmbench and stream
are same more or less.
-------------------------------------------------------------------------------
lmbench tip/master eevdf(LN=0) eevdf(LN=-20) eevdf(LN=19)
-------------------------------------------------------------------------------
latency process fork : 121.20, 121.35(-0.12), 121.75(-0.45), 120.61(0.49)
latency process Exec : 177.60, 180.84(-1.82), 177.93(-0.18), 177.44(0.09)
latency process Exec : 5.80, 6.16(-6.27), 6.14(-5.89), 6.14(-5.91)
latency syscall fstat : 0.26, 0.26(0.00) , 0.26(0.00) , 0.26(0.00)
latency syscall open : 2.27, 2.29(-0.88), 2.29(-0.88), 2.29(-0.88)
AF_UNIX sock_stream latency: 9.31, 9.61(-3.22), 9.61(-3.22), 9.53(-2.36)
Select on 200 fd'si : 2.17, 2.15(0.92) , 2.15(0.92) , 2.15(0.92)
semaphore latency : 0.88, 0.89(-1.14), 0.88(0.00) , 0.88(0.00)
-------------------------------------------------------------------------------
Stream tip/master eevdf(LN=0) eevdf(LN=-20) eevdf(LN=19)
-------------------------------------------------------------------------------
copy latency : 0.56, 0.58(-3.57), 0.58(-3.57), 0.58(-3.57)
copy bandwidth : 28767.80, 27520.04(-4.34), 27506.95(-4.38), 27381.61(-4.82)
scale latency : 0.60, 0.61(-1.67), 0.61(-1.67), 0.61(-1.67)
scale bandwidth: 26875.58, 26385.22(-1.82), 26339.94(-1.99), 26302.86(-2.13)
add latency : 1.25, 1.25(0.00) , 1.25(0.00) , 1.25(0.00)
add bandwidth : 19175.76, 19177.48(0.01) , 19177.60(0.01) , 19176.32(0.00)
triad latency : 0.74, 0.73(1.35) , 0.74(0.00) , 0.74(0.00)
triad bandwidth: 32545.70, 32658.95(0.35) , 32581.78(0.11) , 32561.74(0.05)
--------------------------------------------------------------------------------------------------
Unixbench tip/master eevdf(LN=0) eevdf(LN=-20) eevdf(LN=19)
--------------------------------------------------------------------------------------------------
1 X Execl Throughput : 5147.23, 5184.87(0.73), 5217.16(1.36), 5218.21(1.38)
4 X Execl Throughput : 13225.55, 13638.36(3.12), 13643.07(3.16), 13636.50(3.11)
1 X Pipe-based Context Switching:171413.56, 162720.69(-5.07), 163420.54(-4.66), 163446.67(-4.65)
4 X Pipe-based Context Switching:564887.90, 554545.01(-1.83), 555561.24(-1.65), 547421.20(-3.09)
1 X Process Creation : 8555.73, 8503.18(-0.61), 8556.39(0.01), 8621.36(0.77)
4 X Process Creation : 17007.47, 16372.44(-3.73), 17002.88(-0.03), 16611.47(-2.33)
1 X Shell Scripts (1 concurrent): 10104.23, 10235.09(1.30), 10171.44(0.67), 10275.76(1.70)
4 X Shell Scripts (1 concurrent): 33752.14, 32278.50(-4.37), 32885.92(-2.57), 32256.58(-4.43)
1 X Shell Scripts (8 concurrent): 4864.71, 4909.30(0.92), 4914.62(1.03), 4896.45(0.65)
4 X Shell Scripts (8 concurrent): 14237.17, 13395.20(-5.91), 13599.52(-4.48), 12923.93(-9.22)
-------------------------------------------------------------------------------
schbench tip/master eevdf(LN=0) eevdf(LN=-20) eevdf(LN=19)
-------------------------------------------------------------------------------
1 Threads
50.0th: 6.90, 7.30(-5.80), 7.30(-5.80), 7.10(-2.90)
75.0th: 7.90, 8.40(-6.33), 8.60(-8.86), 8.00(-1.27)
90.0th: 10.10, 9.60(4.95), 10.50(-3.96), 8.90(11.88)
95.0th: 11.20, 10.60(5.36), 11.10(0.89), 9.40(16.07)
99.0th: 13.30, 12.70(4.51), 12.80(3.76), 11.80(11.28)
99.5th: 13.90, 13.50(2.88), 13.60(2.16), 12.40(10.79)
99.9th: 15.00, 15.40(-2.67), 15.20(-1.33), 13.70(8.67)
2 Threads
50.0th: 7.20, 8.10(-12.50), 8.00(-11.11), 8.40(-16.67)
75.0th: 8.30, 9.20(-10.84), 9.00(-8.43), 9.70(-16.87)
90.0th: 10.10, 11.00(-8.91), 10.00(0.99), 11.00(-8.91)
95.0th: 11.30, 12.60(-11.50), 10.60(6.19), 11.60(-2.65)
99.0th: 14.40, 15.40(-6.94), 11.90(17.36), 13.70(4.86)
99.5th: 15.20, 16.10(-5.92), 13.20(13.16), 14.60(3.95)
99.9th: 16.40, 17.30(-5.49), 14.70(10.37), 16.20(1.22)
4 Threads
50.0th: 8.90, 10.30(-15.73), 10.00(-12.36), 10.10(-13.48)
75.0th: 10.80, 12.10(-12.04), 11.80(-9.26), 12.00(-11.11)
90.0th: 13.00, 14.00(-7.69), 13.70(-5.38), 14.30(-10.00)
95.0th: 14.40, 15.20(-5.56), 14.90(-3.47), 15.80(-9.72)
99.0th: 16.90, 17.50(-3.55), 18.70(-10.65), 19.80(-17.16)
99.5th: 17.40, 18.50(-6.32), 19.80(-13.79), 22.10(-27.01)
99.9th: 18.70, 22.30(-19.25), 22.70(-21.39), 37.50(-100.53)
8 Threads
50.0th: 11.50, 12.80(-11.30), 13.30(-15.65), 12.80(-11.30)
75.0th: 15.00, 16.30(-8.67), 16.90(-12.67), 16.20(-8.00)
90.0th: 18.80, 19.50(-3.72), 20.30(-7.98), 19.90(-5.85)
95.0th: 21.40, 21.80(-1.87), 22.30(-4.21), 22.10(-3.27)
99.0th: 27.60, 26.30(4.71) , 27.60(0.00), 27.30(1.09)
99.5th: 30.40, 32.40(-6.58), 36.40(-19.74), 30.00(1.32)
99.9th: 56.90, 59.10(-3.87), 66.70(-17.22), 60.90(-7.03)
16 Threads
50.0th: 19.20, 20.90(-8.85), 20.60(-7.29), 21.00(-9.38)
75.0th: 25.30, 27.50(-8.70), 27.80(-9.88), 28.30(-11.86)
90.0th: 31.20, 34.60(-10.90), 35.10(-12.50), 35.20(-12.82)
95.0th: 35.40, 38.90(-9.89), 39.50(-11.58), 39.20(-10.73)
99.0th: 44.90, 47.60(-6.01), 47.50(-5.79), 47.60(-6.01)
99.5th: 48.50, 50.50(-4.12), 50.20(-3.51), 55.60(-14.64)
99.9th: 70.80, 84.70(-19.63), 81.40(-14.97), 103.50(-46.19)
32 Threads
50.0th: 39.10, 38.60(1.28), 36.10(7.67), 39.50(-1.02)
75.0th: 57.20, 56.10(1.92), 52.00(9.09), 57.70(-0.87)
90.0th: 74.00, 73.70(0.41), 65.70(11.22), 74.40(-0.54)
95.0th: 82.30, 83.50(-1.46), 74.20(9.84), 84.50(-2.67)
99.0th: 95.80, 98.60(-2.92), 92.10(3.86), 100.50(-4.91)
99.5th: 101.50, 104.10(-2.56), 98.90(2.56), 108.20(-6.60)
99.9th: 185.70, 179.90(3.12), 163.50(11.95), 193.00(-3.93)
-------------------------------------------------------------------------------
Hackbench tip/master eevdf(LN=0) eevdf(LN=-20) eevdf(LN=19)
-------------------------------------------------------------------------------
Process 10 groups : 0.19, 0.19(0.00), 0.19(0.00), 0.19(0.00)
Process 20 groups : 0.24, 0.25(-4.17), 0.26(-8.33), 0.25(-4.17)
Process 30 groups : 0.30, 0.31(-3.33), 0.31(-3.33), 0.30(0.00)
Process 40 groups : 0.35, 0.37(-5.71), 0.38(-8.57), 0.38(-8.57)
Process 50 groups : 0.43, 0.44(-2.33), 0.44(-2.33), 0.44(-2.33)
Process 60 groups : 0.49, 0.52(-6.12), 0.51(-4.08), 0.51(-4.08)
thread 10 groups : 0.23, 0.22(4.35), 0.23(0.00), 0.23(0.00)
thread 20 groups : 0.28, 0.28(0.00), 0.27(3.57), 0.28(0.00)
Process(Pipe) 10 groups : 0.17, 0.16(5.88), 0.16(5.88), 0.16(5.88)
Process(Pipe) 20 groups : 0.25, 0.24(4.00), 0.24(4.00), 0.24(4.00)
Process(Pipe) 30 groups : 0.32, 0.29(9.38), 0.29(9.38), 0.29(9.38)
Process(Pipe) 40 groups : 0.39, 0.34(12.82), 0.34(12.82), 0.34(12.82)
Process(Pipe) 50 groups : 0.45, 0.39(13.33), 0.39(13.33), 0.38(15.56)
Process(Pipe) 60 groups : 0.51, 0.43(15.69), 0.43(15.69), 0.43(15.69)
thread(Pipe) 10 groups : 0.16, 0.15(6.25), 0.15(6.25), 0.15(6.25)
thread(Pipe) 20 groups : 0.24, 0.22(8.33), 0.22(8.33), 0.22(8.33)
================
Method 3:
================
Comparing baseline vs eevdf when the system utilization is 50%. A cpu cgroup is
created and different latency nice values are assigned to it. on another bash
terminal stress-ng is running at 50% utilization(stress-ng --cpu=480 -l 50).
Hackbench shows gain in latency values. Schbench shows good gain in latency values
except, 1 thread case. lmbench and stream regress slightly. unixbench is mixed.
One concerning throughput is 4 X Shell Scripts (8 concurrent) which shows 50%
regression. This is verified with additional run. The same holds true for 25%
utilization as well.
-------------------------------------------------------------------------------
lmbench tip/master eevdf(LN=0) eevdf(LN=-20) eevdf(LN=19)
-------------------------------------------------------------------------------
latency process fork :152.98, 158.34(-3.50), 155.07(-1.36), 157.57(-3.00)
latency process Exec :214.30, 214.08(0.10), 214.41(-0.05), 215.16(-0.40)
latency process Exec : 12.44, 11.86(4.66), 10.60(14.79), 10.58(14.94)
latency syscall fstat : 0.44, 0.45(-2.27), 0.43(2.27), 0.45(-2.27)
latency syscall open : 3.71, 3.68(0.81), 3.70(0.27), 3.74(-0.81)
AF_UNIX sock stream latency: 14.07, 13.44(4.48), 14.69(-4.41), 13.65(2.99)
Select on 200 fd'si : 3.97, 4.16(-4.79), 4.02(-1.26), 4.21(-6.05)
semaphore latency : 1.83, 1.82(0.55), 1.77(3.28), 1.75(4.37)
-------------------------------------------------------------------------------
Stream tip/master eevdf(LN=0) eevdf(LN=-20) eevdf(LN=19)
-------------------------------------------------------------------------------
copy latency : 0.69, 0.69(0.00), 0.76(-10.14), 0.72(-4.35)
copy bandwidth : 23947.02, 24275.24(1.37), 22032.30(-8.00), 23487.29(-1.92)
scale latency : 0.71, 0.74(-4.23), 0.75(-5.63), 0.77(-8.45)
scale bandwidth: 23490.27, 22713.99(-3.30), 22168.98(-5.62), 21782.47(-7.27)
add latency : 1.34, 1.36(-1.49), 1.39(-3.73), 1.42(-5.97)
add bandwidth : 17986.34, 17771.92(-1.19), 17461.59(-2.92), 17276.34(-3.95)
triad latency : 0.91, 0.93(-2.20), 0.91(0.00), 0.94(-3.30)
triad bandwidth: 27948.13, 27652.98(-1.06), 28134.58(0.67), 27269.73(-2.43)
-------------------------------------------------------------------------------------------------
Unixbench tip/master eevdf(LN=0) eevdf(LN=-20) eevdf(LN=19)
-------------------------------------------------------------------------------------------------
1 X Execl Throughput : 4940.56, 4944.30(0.08), 4991.69(1.03), 4982.80(0.85)
4 X Execl Throughput : 10737.13, 10885.69(1.38), 10615.75(-1.13), 10803.82(0.62)
1 X Pipe-based Context Switching: 91313.57, 103426.11(13.26), 102985.91(12.78), 104614.22(14.57)
4 X Pipe-based Context Switching: 370430.07, 408075.33(10.16), 409273.07(10.49), 431360.88(16.45)
1 X Process Creation : 6844.45, 6854.06(0.14), 6887.63(0.63), 6894.30(0.73)
4 X Process Creation : 18690.31, 19307.50(3.30), 19425.39(3.93), 19128.43(2.34)
1 X Shell Scripts (1 concurrent): 8184.52, 8135.30(-0.60), 8185.53(0.01), 8163.10(-0.26)
4 X Shell Scripts (1 concurrent): 25737.71, 22583.29(-12.26), 22470.35(-12.69), 22615.13(-12.13)
1 X Shell Scripts (8 concurrent): 3653.71, 3115.03(-14.74), 3156.26(-13.61), 3106.63(-14.97) <<<<< This may be of concern.
4 X Shell Scripts (8 concurrent): 9625.38, 4505.63(-53.19), 4484.03(-53.41), 4468.70(-53.57) <<<<< This is a concerning one.
-------------------------------------------------------------------------------
schbench tip/master eevdf(LN=0) eevdf(LN=-20) eevdf(LN=19)
-------------------------------------------------------------------------------
1 Threads
50.0th: 15.10, 15.20(-0.66), 15.10(0.00), 15.10(0.00)
75.0th: 17.20, 17.70(-2.91), 17.20(0.00), 17.40(-1.16)
90.0th: 20.10, 20.70(-2.99), 20.40(-1.49), 20.70(-2.99)
95.0th: 22.20, 22.80(-2.70), 22.60(-1.80), 23.10(-4.05)
99.0th: 45.10, 51.50(-14.19), 37.20(17.52), 44.50(1.33)
99.5th: 79.80, 106.20(-33.08), 103.10(-29.20), 101.00(-26.57)
99.9th: 206.60, 771.40(-273.38), 1003.50(-385.72), 905.50(-338.29)
2 Threads
50.0th: 16.50, 17.00(-3.03), 16.70(-1.21), 16.20(1.82)
75.0th: 19.20, 19.90(-3.65), 19.40(-1.04), 18.90(1.56)
90.0th: 22.20, 23.10(-4.05), 22.80(-2.70), 22.00(0.90)
95.0th: 24.30, 25.40(-4.53), 25.20(-3.70), 24.50(-0.82)
99.0th: 97.00, 41.70(57.01), 43.00(55.67), 45.10(53.51)
99.5th: 367.10, 96.70(73.66), 98.80(73.09), 104.60(71.51)
99.9th: 3770.80, 811.40(78.48), 1414.70(62.48), 886.90(76.48)
4 Threads
50.0th: 20.00, 20.10(-0.50), 19.70(1.50), 19.50(2.50)
75.0th: 23.50, 23.40(0.43), 22.80(2.98), 23.00(2.13)
90.0th: 28.00, 27.00(3.57), 26.50(5.36), 26.60(5.00)
95.0th: 37.20, 29.50(20.70), 28.90(22.31), 28.80(22.58)
99.0th: 2792.50, 42.80(98.47), 38.30(98.63), 37.00(98.68)
99.5th: 4964.00, 101.50(97.96), 85.00(98.29), 70.20(98.59)
99.9th: 7864.80, 1722.20(78.10), 755.40(90.40), 817.10(89.61)
8 Threads
50.0th: 25.30, 24.50(3.16), 24.30(3.95), 23.60(6.72)
75.0th: 31.80, 30.00(5.66), 29.90(5.97), 29.30(7.86)
90.0th: 39.30, 35.00(10.94), 35.00(10.94), 34.20(12.98)
95.0th: 198.00, 38.20(80.71), 38.20(80.71), 37.40(81.11)
99.0th: 4601.20, 56.30(98.78), 85.90(98.13), 65.30(98.58)
99.5th: 6422.40, 162.70(97.47), 195.30(96.96), 153.40(97.61)
99.9th: 9684.00, 3237.60(66.57), 3726.40(61.52), 3965.60(59.05)
16 Threads
50.0th: 37.00, 35.20(4.86), 33.90(8.38), 34.00(8.11)
75.0th: 49.20, 46.00(6.50), 44.20(10.16), 44.40(9.76)
90.0th: 64.20, 54.80(14.64), 52.80(17.76), 53.20(17.13)
95.0th: 890.20, 59.70(93.29), 58.20(93.46), 58.60(93.42)
99.0th: 5369.60, 85.30(98.41), 124.90(97.67), 116.90(97.82)
99.5th: 6952.00, 228.00(96.72), 680.20(90.22), 339.40(95.12)
99.9th: 9222.40, 4896.80(46.90), 4648.40(49.60), 4365.20(52.67)
32 Threads
50.0th: 59.60, 56.80(4.70), 55.30(7.21), 56.00(6.04)
75.0th: 83.70, 78.70(5.97), 75.90(9.32), 77.50(7.41)
90.0th: 122.70, 95.50(22.17), 92.40(24.69), 93.80(23.55)
95.0th: 1680.40, 105.00(93.75), 102.20(93.92), 103.70(93.83)
99.0th: 6540.80, 382.10(94.16), 321.10(95.09), 489.30(92.52)
99.5th: 8094.40, 2144.20(73.51), 2172.70(73.16), 1990.70(75.41)
99.9th: 11417.60, 6672.80(41.56), 6903.20(39.54), 6268.80(45.10)
-------------------------------------------------------------------------------
Hackbench tip/master eevdf(LN=0) eevdf(LN=-20) eevdf(LN=19)
-------------------------------------------------------------------------------
Process 10 groups : 0.18, 0.18(0.00), 0.18(0.00), 0.18(0.00)
Process 20 groups : 0.32, 0.33(-3.13), 0.33(-3.13), 0.33(-3.13)
Process 30 groups : 0.42, 0.43(-2.38), 0.43(-2.38), 0.43(-2.38)
Process 40 groups : 0.51, 0.53(-3.92), 0.53(-3.92), 0.53(-3.92)
Process 50 groups : 0.62, 0.64(-3.23), 0.65(-4.84), 0.64(-3.23)
Process 60 groups : 0.72, 0.73(-1.39), 0.74(-2.78), 0.74(-2.78)
thread 10 groups : 0.19, 0.19(0.00), 0.19(0.00), 0.19(0.00)
thread 20 groups : 0.33, 0.34(-3.03), 0.34(-3.03), 0.34(-3.03)
Process(Pipe) 10 groups: 0.17, 0.16(5.88), 0.16(5.88), 0.16(5.88)
Process(Pipe) 20 groups: 0.25, 0.23(8.00), 0.23(8.00), 0.23(8.00)
Process(Pipe) 30 groups: 0.36, 0.31(13.89), 0.31(13.89), 0.31(13.89)
Process(Pipe) 40 groups: 0.42, 0.36(14.29), 0.36(14.29), 0.36(14.29)
Process(Pipe) 50 groups: 0.49, 0.42(14.29), 0.41(16.33), 0.42(14.29)
Process(Pipe) 60 groups: 0.53, 0.44(16.98), 0.44(16.98), 0.44(16.98)
thread(Pipe) 10 groups: 0.14, 0.14(0.00), 0.14(0.00), 0.14(0.00)
thread(Pipe) 20 groups: 0.24, 0.24(0.00), 0.22(8.33), 0.23(4.17)
================
Method 4:
================
Running daytrader on an idle system without any cgroup. daytrader is a trading
simulator application which does buy/sell and intraday trading etc. It is a
throughput oriented workload running with Jmeter.
reference: https://www.ibm.com/docs/en/linux-on-systems?topic=bad-daytrader
We see around 7% improvement in throughput with eevdf.
--------------------------------------------------------------------------
daytrader tip/master eevdf
--------------------------------------------------------------------------
Total throughputs 1x 1.0717x(7.17)
================
Method 5:
================
Running daytrader on a system where utilization is 50%. created a cgroup and ran
microbenchmark in it and assigned different latency values to it. On another
bash terminal stress-ng is running at 50% utilization.
At LN=0, we see a 9% improvement with eevdf compared to baseline.
-------------------------------------------------------------------------
daytrader tip/master eevdf eevdf eevdf
(LN=0) (LN=-20) (LN=19)
-------------------------------------------------------------------------
Total throughputs 1x 1.0923x(9.2%) 1.0759x(7.6) 1.111x(11.1)
Tested-by: Shrikanth Hegde <sshegde@xxxxxxxxxxxxxxxxxx>