Computing Performance 2022
What’s On the Horizon
Brendan Gregg
SYDNEY, AUSTRALIA
7–9 December, 2022
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Statement from the heart
I’d like to begin by acknowledging the Traditional Owners of this land and pay
my respects to Elders past and present.
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Disclaimers: About this talk
This is
a performance engineer and author's views about server performance
This isn't
necessarily about my employer, my employer’s views, or USENIX's views
an endorsement of any company/product or sponsored by anyone
professional market predictions (various companies sell such reports)
based on confidential materials
necessarily correct or fit for any purpose
My predictions may be wrong! They will be thought-provoking.
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Agenda
1. Processors
2. Memory
3. Disks
4. Networking
5. Kernels
6. Hypervisors
7. Observability
8. AI
Not covering: Languages/runtimes, databases, file systems, front-end, mobile, desktop.
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Take Aways
Awareness of current and future perf technologies
Design faster systems to meet SLOs and performance needs
Begin planning new technology support and maintenance
Slides: https://www.brendangregg.com/Slides/SREcon2022_ComputingPerformance
These contain extra footnotes as fine print!
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

1. Processors
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Clock rate
Early Intel Processors
Processor
Intel 8086
Intel 386 DX
Intel Pentium
Pentium Pro
Pentium III
Intel Xeon
GHz
Max GHz
Year
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Clock rate
Processor
Xeon X5550
Xeon E5-2665 0
Xeon E5-2680 v2
Platinum 8175M
Platinum 8259CL
Xeon ? (R7iz*)
Cores/T.
4/8
8/16
10/20
24/48
24/48
32/64
Max GHz
Threads
Max GHz
Hardware Threads
Year
Max GHz
Server Processor Examples (AWS EC2)
Increase has mostly leveled off due to power/efficiency
(Blue line.) Workstation processors are higher; E.g., 2020 Xeon W-1270P @5.1 GHz
Horizontal scaling instead
(Red line.) More CPU cores, hardware threads, and server instances.
* R7iz launched one week ago and is still preview only; core/thread count is inferred [Barr 22]
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Interconnects
Year
CPU Interconnect
2007 Intel FSB
2008 Intel QPI
2017 Intel UPI
Bandwidth
Gbytes/s
10 years:
4x core count
3.25x bus rate
Source: Systems Performance 2nd Edition
Figure 6.10 [Gregg 20]
Memory bus (covered later) also lagging
CPU utilization is wrong
Often mostly memory/interconnect stalls
90% CPU
...may mean:
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Lithography
Semiconductor Nanometer Process
32nm
TSMC expected volume production
of 3nm in 2022 [Quach 21a], now
expecting 2023 from Taiwan with a 4nm
Arizona fab in 2024 [Gooding 22]
3nm
2nm
Meanwhile Intel building USD$20B Ohio
"mega-fab" [Whalen 22]
IBM has already built one [Quach 21b]
Source: Semiconductor device fabrication [Wikipedia 21a]
BTW: Silicon atom diameter ~0.2 nm [Wikipedia 21b]
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)
Lithography limits expected to
be reached by 2029, switching
to stacked CPUs. [Moore 20]

Lithography
“Nanometer process”
since 2010 should be
considered a
marketing term
Semiconductor Nanometer Process
32nm
New terms proposed include [Moore 20]:
GMT (gate pitch, metal pitch, tiers)
LMC (logic, memory, interconnects)
TSMC expected volume production
of 3nm in 2022 [Quach 21a], now
expecting 2023 from Taiwan with a 4nm
Arizona fab in 2024 [Gooding 22]
3nm
2nm
Meanwhile Intel building USD$20B Ohio
"mega-fab" [Whalen 22]
Source: Semiconductor device fabrication [Wikipedia 21a]
BTW: Silicon atom diameter ~0.2 nm [Wikipedia 21b]
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)
IBM has already built one [Quach 21b]
(it has 12nm gate length)
Lithography limits expected to
be reached by 2029, switching
to stacked CPUs. [Moore 20]

Other processor scaling
Special instructions
E.g., AVX-512 Vector Neural Network Instructions (VNNI)
Connected chiplets
Using embedded multi-die interconnect bridge (EMIB) [Alcorn 17]. E.g., Intel Sapphire Rapids with 4 tiles
[Tyson 21]; AMD Milan-X with 9 chiplets [Bonshor 22].
3D stacking
E.g., Intel HBM, AMD Vcache [Cutress 21]
Hybrid core architecture
ARM big.LITTLE; Intel Alder Lake P-cores/E-cores [Alcorn 21]
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Recent server processor examples
Vendor Processor
Intel
AMD
ARMbased
Process
Xeon Platinum “10nm”
8380 (Ice Lake)
EPYC 9654P “7nm”
(Genoa)
Ampere Altra “7nm”
Max M128-30
Clock
Cores/T.
2.3 - 3.4
40/80
LLC
Date
Mbytes
Apr 2021
2.4 - 3.7
96/192
Nov 2022
128/128
Sep 2021
Intel Alder Lake for server (Sapphire Rapids) coming soon. In preview on the Intel Developer Cloud [Intel 22]
and AWS [Barr 22]. (Meanwhile: "Smuggler Hid Over 200 Alder Lake CPUs in Fake Silicone Belly" [Liu 22].)
Other server processors: IBM Z, RISC-V
Coming soon to a datacenter near you
Although there is a TSMC chip shortage that may last through to 2022/2023 [Quatch 21][Ridley 21]
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Cloud chip race
Amazon ARM/Graviton3
ARM Neoverse V1, 64 core, 2.6 GHz
Graviton3E: Customized for HPC
Generic processors
x86
AMD
ARM
AWS
Grav3
MSFT
Altra
Microsoft ARM/Ampere Altra
ARM-based something was rumored [Warren 20]
Ampere Altra-based types now launched in Azure [Nash 22]
Google SoC
GOOG
Cloud processors
Systems-on-Chip (SoC) coming soon [Vahdat 21]
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Accelerators
GPUs
Parallel workloads, thousands of GPU cores. Widespread adoption in machine learning.
FPGAs
Reprogrammable semiconductors
Great potential, but needs specialists to program
CPU
Good for algorithms: compression, cryptocurrency,
video encoding, genomics, search, etc.
Microsoft FPGA-based configurable cloud [Russinovich 17]
Also IPUs, DPUs, TPUs, etc.
Infrastructure processing units [Kummrow 21]
Tensor processing units (TPU) [Google 21]
AWS Trainium ML/AI accelerator Trn1n instances [Mann 22b]
Ease of use
The “other” CPUs you
may not be monitoring
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)
GPU
FPGA
Performance potential

Latest GPU examples
NVIDIA GeForce RTX 3090: 10,496 CUDA cores, 2020
[Burnes 20]
Cerebras Gen2 WSE: 850,000 AI-optimized cores, 2021
Use most of the silicon wafer for one chip.
2.6 trillion transistors, 23 kW. [Trader 21]
GPU
Previous version was already the “Largest chip ever built,”
and US$2M. [insideHPC 20]
Can now cluster them with Cerebras Wafer-Scale Cluster
for millions of cores [Cerebras 22]
SM: Streaming multiprocessor
SP: Streaming processor
Control
Control
Control
Control
Cores (SPs)
L2 Cache
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Latest FPGA examples
Xilinx Virtex UltraScale+ VU19P, 8,938,000 logic cells, 2019
Using 35B transistors. Also has 4.5 Tbit/s transceiver bandwidth (bidir), and 1.5 Tbit/sec DDR4 bandwidth
[Cutress 19]
Xilinx Virtex UltraScale+ VU9P, 2,586,000 logic cells, 2016
Deploy right now: AWS EC2 F1 instance type (up to 8 of these FPGAs per instance)
AMD acquired Xilinx in 2022
FPGA
BPF (covered later) already in FPGAs
E.g., 400 Gbit/s packet filter FFShark [Vega 20]
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Predictions
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: Multi-socket is doomed
Single socket is getting big enough (cores)
Already scaling horizontally (cloud)
And in datacenters, via “blades” or “microservers”
Why pay NUMA costs?
One gt;200
cores
Two 1-socket instances should out-perform one 2-socket instance
Multi-socket may hit some price/performance advantages given rack/chassis overheads and costs
2 hops
1 hop
Mem
CPU
CPU
Mem
Multi-socket future is mixed: one socket for cores, one GPU socket, one FPGA socket, etc. EMIB connected.
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: SMT future unclear
Simultaneous multithreading (SMT) == hardware threads
Performance variation
ARM cores competitive
Post meltdown/spectre
Some people turn them off
Possibilities:
SMT becomes “free”
Processor feature, not a cost basis
Turn “oh no! hardware threads” into
“great! bonus hardware threads!”
No more hardware threads
Future investment elsewhere
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: Core count limits
Imagine an 850,000-core server processor in today’s systems...
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: Core count limits
Worsening problems:
Memory-bound workloads
Kernel/app lock contention
False sharing
Power consumption
Core connectivity overheads
etc.
Source:
Figure 2.16
[Gregg 20]
General-purpose computing will hit a practical core limit
For a given memory subsystem & kernel, and running multiple applications
E.g., 1024 cores (except GPUs/ML/AI); Esperanto RISC-V is already reaching “kilocore” scale [Kostovic 21]
Apps themselves will hit an even smaller practical limit (some already have by design, e.g., Node.js and 2 CPUs)
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: P-cores & E-cores
Intel Alder Lake (desktop) has performance and efficiency cores
This will come to server
Efficiency core tasks:
Garbage collection
NUMA rebalancing
FS writeback compression & flushing
Backups
Security scanning
etc.
Server Processor
p-core
AVX-512
p-core
AVX-512
p-core
e-cores
AVX-512
p-core
AVX-512
Challenges include AVX-512
Currently p-cores only, therefore cores aren't symmetric [Cutress 21b]. OS binary/scheduling
challenges. Similar work: Linux 5.15 (2021) supports asymmetric scheduling for different ARM cores.
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: 3 Eras of processor scaling
Delivered processor characteristics:
Era 1: Clock frequency
Era 2: Core/thread count
Era 3: Cache size & policy
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: 3 Eras of processor scaling
Practical server limits:
Era 1: Clock frequency
→ already reached by ~2005 (3.5 GHz)
Era 2: Core/thread count
→ limited by mid 2030s (e.g., 1024)
Era 3: Cache size & policy → limited by end of 2030s
Mid-century will need an entirely new computer hardware architecture, kernel memory architecture, or logic gate
technology, to progress further.
E.g., use of graphine, carbon nanotubes [Hruska 12]
This is after moving more to stacked processors
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: More processor vendors
ARM licensed or RISC-V
Including Apple M1 for servers
Era of CPU choice
Cores
Beware: “optimizing for the benchmark”
Don’t believe microbenchmarks without doing
“active benchmarking”: Root-cause perf analysis
while the benchmark is still running.
Benchmark Optimizer Unit
(confidential)
Intel making changes to compete
LLC
Pat Gelsinger now CEO
MMU
DogeCPU “+AggressiveOpts” processor
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: Cloud CPU advantage
Large cloud vendors can analyze >gt;100,000 workloads directly
Via PMU PMCs and other processor features.
Vast real-world detail to aid processor design
More detail than traditional processor vendors have, and detail available immediately whenever they want.
Will processor vendors offer their own clouds?
Intel Developer Cloud launched Sep 2022 for early access to chips and software [Robinson 22]
Machine-learning aided processor design
Based on the vast detail. Please point it at real-world workloads and not microbenchmarks.
Vast detail example: processor trace showing timestamped instructions:
# perf script --insn-trace --xed
date 31979 [003] 653971.670163672: ... (/lib/x86_64-linux-gnu/ld-2.27.so) mov %rsp, %rdi
date 31979 [003] 653971.670163672: ... (/lib/x86_64-linux-gnu/ld-2.27.so) callq 0x7f3bfbf4dea0
date 31979 [003] 653971.670163672: ... (/lib/x86_64-linux-gnu/ld-2.27.so) pushq %rbp
[...]
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: FPGA turning point
Little adoption (outside crypto & HFT) until major app support
Solves the ease of use issue: Developers just configure the app (which may fetch and deploy an FMI)
BPF use cases are welcome, but still specialized/narrow
Needs runtime support, e.g., the JVM. Already work in this area (e.g., [TornadoVM 21]).
apt install openjdk-21
apt install openjdk-21-libfpga
JVM
JVM
FPGA
Accelerator
java -XX:+UseFPGA
(none of this is real, yet)
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

2. Memory
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Many workloads memory I/O bound
# ./pmcarch 1
K_CYCLES
K_INSTR
334937819 141680781
329721327 140928522
330388918 141393325
329889409 142876183
[...]
IPC
BR_RETIRED
BR_MISPRED
BMR%
LLCREF
LLCMISS
LLC%
# ./pmcarch 1
K_CYCLES
K_INSTR
[...]
IPC
BR_RETIRED
BR_MISPRED
BMR%
LLCREF
LLCMISS
LLC%
# ./pmcarch
K_CYCLES
K_INSTR
122697727 13892225
144881903 17918325
[...]
IPC
BR_RETIRED
BR_MISPRED
BMR%
LLCREF
LLCMISS
LLC%
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

DDR5 has better bandwidth
DDR5 has a faster bus
But not width
512GB DDR5 DIMMs
Already released by Samsung [Shilov 21]
Now arriving in clouds
Needs processor support
E.g., AWS Graviton2/3, Intel Sapphire Rapids
Year
Memory
DDR-333
DDR2-800
DDR3-1600
DDR4-3200
DDR5-6400
Peak Bandwidth
Gbytes/s
Desktop/Gamers have known for a while (Nov 2021):
Gbytes/s
2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

DDR latency
Year
Latency (ns)
Memory
DDR-333
Latency (ns)
DDR-333
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

DDR latency
Hasn’t changed in 20 years
This is single access latency
Same memory clock (200 MHz) [Greenberg 11]
Also see [Cutress 20][Goering 11]
Year
Low-latency DDR does exist
Reduced Latency DRAM (RLDRAM) by Infineon
and Micron: lower latency but lower density
Not seeing widespread server use (I’ve seen it
marketed towards HFT)
Latency (ns)
Memory
DDR-333
DDR2-800
DDR3-1600
DDR4-3200
DDR5-6400
Latency (ns)
DDR-333
DDR5-6400
:-(
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

HBM
High bandwidth memory, 3D stacking
Target uses cases include high performance computing, and virtual reality graphical processing [Macri 15]
GPUs already use it
Processors now including HBM on-package
Intel Sapphire Rapids (Xeon Max) has 64 Gbytes of HBM2e in 4 clusters, for >gt;1 Tbyte/s memory bandwidth
and >gt;1 Gbyte per core [Pirzada 22]
No DRAM systems now possible!
Intel's 3 modes:
HBM Only: No DRAM
HBM Flat: 2 memory regions, software to optimize placement
HBM Caching: HBM caches DDR
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)
Processor Package
cores
HBM
I/O

Server DRAM size
SuperMicro SuperServer B12SPE-CPU-25G
Single Socket (see earlier slides)
16 DIMM slots
4 TB DDR-4
Processor
socket
[SuperMicro 21]
Facebook Delta Lake (1S) OCP
6 DIMM slots
96 Gbytes DDR-4
DIMMs
Price/optimal for a typical WSS?
DIMMs
B12SPE-CPU-25G
[Haken 21]
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Additional memory tier not successful
Intel/Micron's 3D XPoint now cancelled [Mann 22]
- Could also operate in application direct mode and storage mode [Intel 21]
Main
memory
Persistent memory
Storage devices
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)
DRAM (

My Prediction: Extrapolation
Not a JEDEC announcement
Assumes miraculous
engineering work
For various challenges see [Peterson 20]
But will single-access latency
drop in DDR-6?
I’d guess not, DDR internals are already at
their cost-sweet-spot, leaving low-latency
for other memory technologies
Year
Memory
DDR-333
DDR2-800
DDR3-1600
DDR4-3200
DDR5-6400
DDR6-12800
DDR7-25600
DDR8-51200
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)
Peak Bandwidth
Gbytes/s
doubling

My Prediction: DDR5 “up to 2x” Wins
E.g., IPC 0.1 → ~0.2 for bandwidth-bound workloads
“good*”
>gt;2.0
Instruction bound
IPC
“bad”

My Prediction: HBM-only servers
Clouds offering “high bandwidth memory” HBM-only
instances
HBM on-processor
Finally helping memory catch up to core scaling
RLDRAM on-package as another option?
“Low latency memory” instance
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prior Prediction: Extra tier too late
Competition isn’t disks, it’s Tbytes of DRAM
SuperMicro’s single socket should hit 8 Tbytes DDR-5
AWS EC2 p4.24xl has 1.1 Tbytes of DRAM (deploy now!)
How often does your working set size (WSS) not fit?
Across several of these for redundancy?
Next tier needs to get much bigger than DRAM (10+x)
and much cheaper to find an extra-tier use case
(e.g., cost based).
Meanwhile, DRAM is still getting bigger and faster
I developed the first cache tier between main memory
and disks to see widespread use:
the ZFS L2ARC [Gregg 08]
Main
memory
Persistent memory
Storage devices
WSS
“cold”
data

3. Disks
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Recent timeline for rotational disks
2005: Perpendicular magnetic recording (PMR)
Writes vertically using a shaped magnetic field for higher density
2013: Shingled magnetic recording (SMR)
(next slide)
2019: Multi-actuator technology (MAT)
Two sets of heads and actuators; like 2-drive RAID 0 [Alcorn 17].
2020: Energy-assisted magnetic recording (EAMR)
Western Digital 18TB & 20TB [Salter 20]
2021: Heat-assisted magnetic recording (HAMR)
Seagate 20TB HAMR drives [Shilov 21b]
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Recent timeline for rotational disks
2005: Perpendicular magnetic recording (PMR)
Writes vertically using a shaped magnetic field for higher density
2013: Shingled magnetic recording (SMR)
(next slide)
2019: Multi-actuator technology (MAT)
Two sets of heads and actuators; like 2-drive RAID 0 [Alcorn 17].
2020: Energy-assisted magnetic recording (EAMR)
Western Digital 18TB & 20TB [Salter 20]
2021: Heat-assisted magnetic recording (HAMR)
Seagate 20TB HAMR drives [Shilov 21b]
I don’t know their perf characteristics yet
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

SMR
11-25% more storage, worse performance
Writes tracks in an overlapping way, like shingles on a roof. [Shimpi 13]
Overwritten data must be rewritten. Suited for archival (write once) workloads.
Read head
Written tracks
Look out for 18TB/20TB-with-SMR drive releases
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Flash memory-based disks
Single-Level Cell (SLC)
Multi-Level Cell (MLC)
Enterprise MLC (eMLC)
2009: Tri-Level Cell (TLC)
2009: Quad-Level Cell (QLC)
QLC is only rated for around 1,000 block-erase cycles [Liu 20].
2013: 3D NAND / Vertical NAND (V-NAND)
SK Hynix envisions 600-Layer 3D NAND [Shilov 21c]. Should be multi-Tbyte.
2017-2022: Intel Optane (3D XPoint persistent memory) disks, now cancelled; was used as an accelerator
SSD performance pathologies: latency from aging, wear-leveling, fragmentation, internal compression, etc.
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Storage Interconnects
SAS-4 cards in development
(Storage attached SCSI)
PCIe 5.0 coming soon
(Peripheral Component Interconnect Express)
Intel already demoed on Sapphire Rapids [Hruska 20]
NVMe 1.4 latest
(Non-Volatile Memory Express)
Storage over PCIe bus
Support zoned namespace SSDs (ZNS) [ZonedStorage 21]
Bandwidth bounded by PCIe bus
These have features other than speed
Reliability, power management, virtualization support, etc.
Year
Specified
202?
Interface
Year
Specified
Interface
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)
SAS-1
SAS-2
SAS-3
SAS-4
SAS-5
PCIe 1
PCIe 2
PCIe 3
PCIe 4
PCIe 5
Bandwidth
Gbit/s
Bandwidth 16
lane Gbyte/s

Latest storage device examples
2022 SSD: Samsung PM1743 [Smith 22]
Up to 15.36 Tbytes
PCIe Gen5
Sequential reads up to 13 Gbytes/sec
2022 HDD: Seagate Exos 2x18 [Seagate 22]
18 or 16 Tbytes
Helium sealed
Multi-actuator (2 x sets of heads) for "2x more performance"
Up to 554 Mbytes/sec: "SSD performance"
7200 RPM
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Linux Kyber I/O scheduler
Multi-queue, target read & write latency
Up to 300x lower 99th percentile latencies [Gregg 18]
Linux 4.12 [Corbet 17]
reads (sync)
writes (async)
Kyber (simplified)
dispatch
dispatch
queue size adjust
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)
completions

My Prediction: Slower rotational
Archive focus
There’s ever-increasing demand for storage (incl. social video today; social VR tomorrow?)
Needed for archives
More “weird” pathologies. SMR is just the start.
Even less tolerant to shouting
Bigger, slower, and weirder
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: More flash pathologies
Worse internal lifetime
More wear-leveling & logic
More latency outliers
Bigger, faster, and weirder
We need more observability of flash drive internals
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

4. Networking
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Latest Hardware
400 Gbit/s in use
E.g., 400 Gbit/s switches/routers by Cisco and Juniper, tranceivers by Arista and Intel
AWS EC2 P4 instance type (deploy now!)
On PCI, needs PCIe 5
800 Gbit/s next
[Charlene 20]
Terabit Ethernet (1 Tbit/s) not far away
More NIC features
E.g., inline kTLS (TLS offload to the NIC), e.g., Mellanox ConnectX-6-Dx [Gallatin 19]
FPGA, P4, and eBPF support.
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Protocols
QUIC / HTTP/3
TCP-like sessions over (fast) UDP.
0-RTT connection handshakes. For clients that have previously communicated.
MP-TCP
Multipath TCP. Use multiple paths in parallel to improve throughput and reliability. RFC-8684 [Ford 20]
Linux support starting in 5.6.
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Linux TCP Congestion Control Algorithms
DCTCP
Data Center TCP. Linux 3.18. [Borkmann 14]
TCP NV
New Vegas. Linux 4.8
TCP BBR
Bottleneck Bandwidth and RTT (BBR) improves performance on packet loss networks [Cardwell 16]
With 1% packet loss, Netflix sees 3x better throughput [Gregg 18]
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Linux Network Stack
Queues/
Tuning
Source: Systems Performance 2nd Edition, Figure 10.8 [Gregg 20]
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Linux TCP send path
Keeps adding performance features
Source: Systems Performance 2nd Edition, Figure 10.11 [Gregg 20]
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Software
eXpress Data Path (XDP) (uses eBPF)
Programmable fast lane for networking. In the Linux kernel.
A role previously served by DPDK and kernel bypass.
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: BPF in FPGAs/IPUs
Massive I/O tranceiver capabilities
Netronome already did BPF in hardware
Edge computing on the NICs
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: Cheap BPF routers
Linux + BPF + 400 GbE NIC
Cheap == commodity hardware
Use case from the beginning of eBPF (PLUMgrid)
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: More demand for network perf
Apps increasingly network
World of sensors
Remote work & video conferencing
Netflix 4K content
VR tourism & multiverse
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

5. Kernels
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Latest Kernels/OSes
May 2022: FreeBSD 13.1
Oct 2022: Linux 6.0 ("Hurr durr I'ma ninja sloth" [Torvalds 22])
Nov 2022: Windows 22H2 (10.0.22621.900)
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Recent Linux perf features
2022: IPv6 jumbograms, packets >gt;64 Kbytes (5.19)
2021: BPF kernel function calls, e.g., for TCP cong ctrl (5.13)
2020: Static calls to improve Spectre-fix (5.10)
2020: BPF on socket lookups (5.9)
2020: Thermal pressure (5.7)
2020: MultiPath TCP (5.6)
2019: MADV_COLD, MADV_PAGEOUT (5.4)
Plus lots more, including support for the
2019: io_uring (5.1)
latest x86/AMD/ARM/etc. instructions
(e.g., AMX in 5.16, LoongArch in 5.19)
2019: UDP GRO (5.0)
2019: Multi-queue I/O default (5.0)
For 2016-2018, see my summary: [Gregg 18].
Includes CPU schedulers (thermal, topology);
2018: TCP EDT (4.20)
Block I/O qdiscs; Kyber scheduler (earlier slide);
2018: PSI (4.20)
TCP congestion control algoritms (earlier slide); etc.
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Recent Linux perf features
2022: IPv6 jumbograms, packets >gt;64 Kbytes (5.19)
2021: BPF kernel function calls, e.g., for TCP cong ctrl (5.13)
2020: Static calls to improve Spectre-fix (5.10)
2020: BPF on socket lookups (5.9)
2020: Thermal pressure (5.7)
2020: MultiPath TCP (5.6)
2019: MADV_COLD, MADV_PAGEOUT (5.4)
Plus lots more, including support for the
2019: io_uring (5.1)
latest x86/AMD/ARM/etc. instructions
(e.g., AMX in 5.16, LoongArch in 5.19)
2019: UDP GRO (5.0)
2019: Multi-queue I/O default (5.0)
For 2016-2018, see my summary: [Gregg 18].
Includes CPU schedulers (thermal, topology);
2018: TCP EDT (4.20)
Block I/O qdiscs; Kyber scheduler (earlier slide);
2018: PSI (4.20)
TCP congestion control algoritms (earlier slide); etc.
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

io_uring
Faster syscalls using
shared ring buffers
Send and completion ring buffers
Allows I/O to be batched and async
Primary use cases network and disk I/O
Apps
syscalls
io_uring
Kernel
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

eBPF Everywhere
[Thaler 21]
Plus eBPF for BSD projects already started.
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

eBPF == BPF
2015:
BPF: Berkeley Packet Filter
eBPF: extended BPF
2022:
“Classic BPF”: Berkeley Packet Filter
BPF: A technology name (aka eBPF)
Kernel engineers like to use “BPF”; companies “eBPF”.
This is what happens when you don’t have marketing professionals help name your product.
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

BPF Future: Event-based Applications
User-mode
Applications
Kernel-mode
Applications (BPF)
U.E.
Scheduler
Kernel
Kernel
Events
Hardware Events (incl. clock)
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

https://twitter.com/srostedt/status/1177147373283418112
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Emerging BPF uses
Observability agents
Security intrusion detection, zero-day mitigation
TCP congestion control algorithms
Application accelerators
E.g., Orange bmc-cached accelerator for memcached [Ghigoff 21]
General kernel development
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: Future BPF Uses
File system buffering/readahead policies
CPU scheduler policies
Lightweight I/O-bound applications (e.g., proxies)
Or such apps can go to io_uring or FPGAs. “Three buses arrived at once.”
When I did engineering at University: “people ride buses and electrons ride busses.” Unfortunately that
usage has gone out of fashion, otherwise it would have been clear which bus I was referring to!
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: Easy/Auto PGO
PGO/AutoFDO shows ~10% wins, but hard to manage
Performance-guided optimization (PGO) / Auto feedback-directed optimization (AutoFDO)
Some companies already do kernel PGO (Google [Tolvanen 20], Microsoft [Bearman 20])
We can't leave 10% on the table forever, someone will do an easy-PGO product or it becomes a feature of AI
auto-tuners.
Partial JIT support?
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: Kernel emulation often slow
I can run gt; apps under gt;
by emulating gt; syscalls!
Cool project, but:
Missing latest kernel and perf features (E.g., Linux’s BPF, io_uring, WireGuard, etc. Plus certain syscall flags
return ENOTSUP. So it’s like a weird old fork of Linux.)
Some exceptions: E.g., another kernel may have better hardware support, which may benefit apps
more than the loss of kernel capabilities.
Debugging and security challenges. Better ROI with lightweight VMs.
In other words, WSL2 >gt;>gt; WSL1
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: OS performance
Linux: increasing complexity & worse perf defaults
Linux at FAANGs and other large companies is often very different to the Linux publicly available, as they have perf and
OS teams who can configure advanced technologies and tune and fix things (like enabling frame pointers). This means
most experts are not tuning the Linux you are using and various defaults get little attention and rot (e.g., high-speed
network engineers configure XDP and QUIC, and aren’t looking at defaults with TCP). A bit more room for a lightweight
kernel (e.g., BSD) with better perf defaults to compete. Similarities: Oracle DB vs MySQL; MULTICS vs UNIX.
BSD: high perf for narrow uses
Still serving some companies (including Netflix) very well thanks to tuned performance (see footnote on p124 of [Gregg
20]). Path to growth is better EC2/Azure performance support, but it may take years before a big customer (with a perf
team) migrates and gets everything fixed. There are over a dozen of perf engineers working on Linux on EC2; BSD needs
at least one full time senior EC2 (not metal) perf engineer.
Windows: community perf improvements
BPF tracing support allows outsiders to root cause kernel problems like never before (beyond ETW/Xperf). Will have a
wave of finding “low hanging fruit” to begin with, improving perf and reliability.
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: Unikernels
Finally gets one compelling published use case
“2x perf for X”
But few people run X
Needs to be really kernel heavy, and not many workloads are. And there’s already a lot of competition for
reducing kernel overhead (BPF, io_uring, FPGAs, DPDK, etc.)
Once one use case is found, it may form a valuable community around X and Unikernels. But it needs the
published use case to start, preferably from a FAANG.
Does need to be 2x or more, not 20%, to overcome the cost of retooling everything, redoing all observability
metrics, profilers, etc. It’s not impossible, but not easy [Gregg 16].
More OS-research-style wins found from hybrid- and micro-kernels.
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

6. Hypervisors
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Containers
Cgroup v2 rollout
Container scheduler adoption
Kubernetes, OpenStack, and more
Netflix develops its own called “Titus” [Joshi 18]
Price/performance gains: “Tetris packing” workloads without too much interference (clever scheduler)
Many perf tools still not “container aware”
Usage in a container not restricted to the container, or not permitted by default (needs CAP_PERFMON
CAP_SYS_PTRACE, CAP_SYS_ADMIN)
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Hardware Hypervisors
Source: Systems Performance 2nd Edition, Figure 11.17 [Gregg 20]
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

VM Improvements
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)
Source:
[Gregg 17]

Lightweight VMs
Examples:
Source: Systems Performance 2nd Edition, Figure 11.4 [Gregg 20]
AWS “Firecracker”
Intel/ARM/AMD/Microsoft/etc. "Cloud Hypervisor" [CloudHypervisor 22]
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: Containers
Perf tools take several years to be fully “container aware”
Includes non-root BPF work.
It’s a lot of work, and not enough engineers are working on it. We’ll use workarounds in the meantime (e.g.,
Kyle Anderson and Sargun Dhillon have made perf tools work in containers at Netflix).
Was the same with Solaris Zones (long slow process).
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: Landscape
Short term:
Containers everywhere
Long term:
More containers than VMs
More lightweight VM cores than container cores
Hottest workloads switch to dedicated kernels (no kernel resource sharing, no seccomp overhead,
no overlay overhead, full perf tool access, PGO kernels, etc.)
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: Evolution
1.FaaS
Light workload
2.Container
3.Lightweight VM
4.Metal
Heavy workload
Many apps aren’t heavy
Metal can also mean single container on metal
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: Cloud Computing
Microservice consolidation becomes a hot topic, to lower
communication costs
Container schedulers co-locating chatty services
With BPF-based accelerated networking between them (e.g., Cilium)
Cloud-wide runtime schedulers co-locating apps
Multiple apps under one JVM roof and process address space
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

7. Observability
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

USENIX 2010: Heat maps
2022: Latency heat maps everywhere
Computing Performance: On the Horizon (Brendan Gregg)
[Gregg 10]

USENIX 2013: Flame graphs
2022: Flame graphs everywhere
Computing Performance: On the Horizon (Brendan Gregg)
[Gregg 13]

USENIX 2016: BPF
2022: BPF heading everywhere
Computing Performance: On the Horizon (Brendan Gregg)
[Gregg 16b]

2022: Age of Seeing
Flame graphs everywhere
Latency heat maps
eBPF & bpftrace
PMCs in the cloud
More info: flame graphs [Gregg 13], heat maps [Gregg 10],
and eBPF [Gregg 16b]
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

BPF Perf Tools
(In red are the new open source
tools I developed for the
BPF book)
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Example BPF tool
# execsnoop.py -T
TIME(s) PCOMM
run
bash
svstat
perl
grep
sed
xargs
cut
echo
mkdir
[...]
run
bash
svstat
perl
[...]
PID
PPID
RET
ARGS
./run
/bin/bash
/command/svstat /service/httpd
/usr/bin/perl -e $l=gt;;$l=~/(\d+) sec/;p...
/bin/ps --ppid 1 -o pid,cmd,args
/bin/grep org.apache.catalina
/bin/sed s/^ *//;
/usr/bin/xargs
/usr/bin/cut -d -f 1
/bin/echo
/bin/mkdir -v -p /data/tomcat
./run
/bin/bash
/command/svstat /service/httpd
/usr/bin/perl -e $l=gt;;$l=~/(\d+) sec/;p...
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Example bpftrace one-liner
# bpftrace -e 't:block:block_rq_issue { @[args->gt;rwbs] = count(); }'
Attaching 1 probe...
@[R]: 1
@[RM]: 1
@[WFS]: 2
@[FF]: 3
@[WSM]: 9
@[RA]: 10
@[WM]: 12
@[WS]: 29
@[R]: 107
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

libbpf-tools
# ./opensnoop
PID
COMM
27974 opensnoop
redis-server
[…]
FD ERR PATH
0 /etc/localtime
0 /proc/1482/stat
# ldd opensnoop
linux-vdso.so.1 (0x00007ffddf3f1000)
libelf.so.1 =>gt; /usr/lib/x86_64-linux-gnu/libelf.so.1 (0x00007f9fb7836000)
libz.so.1 =>gt; /lib/x86_64-linux-gnu/libz.so.1 (0x00007f9fb7619000)
libc.so.6 =>gt; /lib/x86_64-linux-gnu/libc.so.6 (0x00007f9fb7228000)
/lib64/ld-linux-x86-64.so.2 (0x00007f9fb7c76000)
# ls -lh opensnoop opensnoop.stripped
-rwxr-xr-x 1 root root 645K Feb 28 23:18 opensnoop
-rwxr-xr-x 1 root root 151K Feb 28 23:33 opensnoop.stripped
151 Kbytes for a stand-alone BPF program!
(Note: A static bpftrace/BTF + scripts will also have a small average tool size)
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Modern Open Source Observability Stack
OpenTelemetry
Grafana
Standard for monitoring and tracing
Prometheus
Monitoring database
Grafana
UI with dashboards
Now supports flame graphs [GrafanaLabs 22]
Source: Figure 1.4 [Gregg 20]
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Zero-Instrumentation APM
(Application Performance Monitoring)
Installation instructions:
1) Install the agent
2) Done! (no code changes required)
Uses uprobes to instrument HTTP/SSL calls
Don't even need to restart anything. Great for apps where you can't change the code. But,
uprobes are slow and unstable: >gt;1.2us minimum, which is 15x higher than kprobes.
I would not recommend this approach until:
Someone does the Linux uprobe speedup work I discussed at LSFMMBPF22 in Palm Springs.
USDT is provided instead (which is based on uprobes) to fix stability.
Can also use eBPF for in-kernel aggregations and programs.
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: BPF tool front-ends
bpftrace
For one-liners and to hack up new tools
When you want to spend an afternoon developing some custom BPF tracing
libbpf-tools
For packaged BPF binary tools and BPF products
When you want to spend weeks developing BPF
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: Too many BPF tools
(I’m partly to blame)
2014: I have no tools for this problem
2024: I have too many tools for this problem
Tool creators: Focus on solving something no other tool can. Necessity is the mother of good BPF tools.
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: BPF perf tool future
GUIs, not CLI tools
Tool output, visualized
This GUI is in development by Susie Xia, Netflix
The end user may not even know it’s using BPF
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: Zero-instrumentation APM
Multiple startups will be selling this
Someone blogs: "OpenTelemetry more stable and faster"
This gives uprobes/eBPF a bad name, unfairly, as none of us in uprobe/eBPF land recommend this use case
until the speed/stability issues are fixed
Fast uprobes available in Linux in 2024?
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: Flame scope adoption
Analyze variance, perturbations:
Flame graph
Subsecond-offset heat map
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)
[Spier 20]

Recap so far
1. Processors
2. Memory
3. Disks
4. Networking
5. Kernels
6. Hypervisors
7. Observability
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Performance engineering is getting more complex
1. Processors: CPUs, GPUs, FPGAs, TPUs
2. Memory: DRAM, RLDRAM, HBM, 3D XPoint
3. Disks: PMR, SMR, MAT, EAMR, HAMR, SLC, MLC, ...
4. Networking: QUIC, MP-TCP, XDP, qdiscs, pacing, BQL, ...
5. Kernels: BPF, io_uring, PGO, Linux complexity
6. Hypervisors: VMs, Containers, LightweightVMs
7. Observability: BPF, PMCs, heat maps, flame graphs,
OpenTelemetry, Prometheus, Grafana
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Performance engineering is getting more fun!
1. Processors: CPUs, GPUs, FPGAs, TPUs
2. Memory: DRAM, RLDRAM, HBM, 3D XPoint
3. Disks: PMR, SMR, MAT, EAMR, HAMR, SLC, MLC, ...
4. Networking: QUIC, MP-TCP, XDP, qdiscs, pacing, BQL, ...
5. Kernels: BPF, io_uring, PGO, Linux complexity
6. Hypervisors: VMs, Containers, LightweightVMs
7. Observability: BPF, PMCs, heat maps, flame graphs,
OpenTelemetry, Prometheus, Grafana
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

8. AI
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

AI Auto-Tuning
One approach to deal with the complexity:
All The Things!
1. Processors: CPUs, GPUs, FPGAs, TPUs
2. Memory: DRAM, RLDRAM, HBM, 3D XPoint
3. Disks: PMR, SMR, MAT, EAMR, HAMR, SLC, MLC, ...
4. Networking: QUIC, MP-TCP, XDP, qdiscs, pacing, BQL, ...
5. Kernels: BPF, io_uring, PGO, Linux complexity
Server
tuning
6. Hypervisors: VMs, Containers, LightweightVMs
7. Observability: BPF, PMCs, heat maps, flame graphs,
OpenTelemetry, Prometheus, Grafana
E.g., Intel Granulate,
Akamas,
etc.
Implications for SRE? (E.g., change control)
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

My Prediction: AI useful but limited
Great at adapting the past, applying known tuning
Paint an astronaut in the style of Van Gogh
Apply system tuning in the style of Brendan Gregg (tunables I've shared in the past)
Should be a useful and more widely-adopted product, especially for small/medium sites that have little
time for tuning.
Turning point: "The Million Dollar Tunable"
Someone uses AI to find an overlooked tunable that they coud have enabled years ago.
The industry is getting more complex, and more chances things are overlooked. The time is right for
using AI to help.
Poor at solving "never seen before" mental-leap issues
I spend most of my time as a performance engineer solving these
Beyond past experience or extrapolation
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

References (1)
[Gregg 08] Brendan Gregg, “ZFS L2ARC,” http://www.brendangregg.com/blog/2008-07-22/zfs-l2arc.html, Jul 2008
[Gregg 10] Brendan Gregg, “Visualizations for Performance Analysis (and More),”
https://www.usenix.org/conference/lisa10/visualizations-performance-analysis-and-more, 2010
[Greenberg 11] Marc Greenberg, “DDR4: Double the speed, double the latency? Make sure your system can handle next-generation
DRAM,” https://www.chipestimate.com/DDR4-Double-the-speed-double-the-latencyMake-sure-your-system-can-handlenext-generation-DRAM/Cadence/Technical-Article/2011/11/22, Nov 2011
[Hruska 12] Joel Hruska, “The future of CPU scaling: Exploring options on the cutting edge,”
https://www.extremetech.com/computing/184946-14nm-7nm-5nm-how-low-can-cmos-go-it-depends-if-you-ask-theengineers-or-the-economists, Feb 2012
[Gregg 13] Brendan Gregg, “Blazing Performance with Flame Graphs,”
https://www.usenix.org/conference/lisa13/technical-sessions/plenary/gregg, 2013
[Shimpi 13] Anand Lal Shimpi, “Seagate to Ship 5TB HDD in 2014 using Shingled Magnetic Recording,”
https://www.anandtech.com/show/7290/seagate-to-ship-5tb-hdd-in-2014-using-shingled-magnetic-recording, Sep 2013
[Borkmann 14] Daniel Borkmann, “net: tcp: add DCTCP congestion control algorithm,”
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?
id=e3118e8359bb7c59555aca60c725106e6d78c5ce, 2014
[Macri 15] Joe Macri, “Introducing HBM,” https://www.amd.com/en/technologies/hbm, Jul 2015
[Cardwell 16] Neal Cardwell, et al., “BBR: Congestion-Based Congestion Control,” https://queue.acm.org/detail.cfm?id=3022184,
[Gregg 16] Brendan Gregg, “Unikernel Profiling: Flame Graphs from dom0,” http://www.brendangregg.com/blog/2016-01-27/unikernelprofiling-from-dom0.html, Jan 2016
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

References (2)
[Gregg 16b] Brendan Gregg, “Linux BPF Superpowers,” https://www.brendangregg.com/blog/2016-03-05/linux-bpf-superpowers.html,
[Alcorn 17] Paul Alcorn, “Seagate To Double HDD Speed With Multi-Actuator Technology,” https://www.tomshardware.com/news/hddmulti-actuator-heads-seagate,36132.html, 2017
[Alcorn 17b] Paul Alcorn, “Hot Chips 2017: Intel Deep Dives Into EMIB,” https://www.tomshardware.com/news/intel-emib-interconnectfpga-chiplet,35316.html#xenforo-comments-3112212, 2017
[Corbet 17] Jonathan Corbet, “Two new block I/O schedulers for 4.12,” https://lwn.net/Articles/720675, Apr 2017
[Gregg 17] Brendan Gregg, “AWS EC2 Virtualization 2017: Introducing Nitro,” http://www.brendangregg.com/blog/2017-11-29/awsec2-virtualization-2017.html, Nov 2017
[Russinovich 17] Mark Russinovich, “Inside the Microsoft FPGA-based configurable cloud,”
https://www.microsoft.com/en-us/research/video/inside-microsoft-fpga-based-configurable-cloud, 2017
[Gregg 18] Brendan Gregg, “Linux Performance 2018,” http://www.brendangregg.com/Slides/Percona2018_Linux_Performance.pdf,
[Hady 18] Frank Hady, “Achieve Consistent Low Latency for Your Storage-Intensive Workloads,”
https://www.intel.com/content/www/us/en/architecture-and-technology/optane-technology/low-latency-for-storageintensive-workloads-article-brief.html, 2018
[Joshi 18] Amit Joshi, et al., “Titus, the Netflix container management platform, is now open source,” https://netflixtechblog.com/titusthe-netflix-container-management-platform-is-now-open-source-f868c9fb5436, Apr 2018
[Cutress 19] Dr. Ian Cutress, “Xilinx Announces World Largest FPGA: Virtex Ultrascale+ VU19P with 9m Cells,”
https://www.anandtech.com/show/14798/xilinx-announces-world-largest-fpga-virtex-ultrascale-vu19p-with-9m-cells, Aug
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

References (3)
[Gallatin 19] Drew Gallatin, “Kernel TLS and hardware TLS offload in FreeBSD 13,”
https://people.freebsd.org/~gallatin/talks/euro2019-ktls.pdf, 2019
[Bearman 20] Ian Bearman, “Exploring Profile Guided Optimization of the Linux Kernel,”
https://linuxplumbersconf.org/event/7/contributions/771, 2020
[Burnes 20] Andrew Burnes, “GeForce RTX 30 Series Graphics Cards: The Ultimate Play,”
https://www.nvidia.com/en-us/geforce/news/introducing-rtx-30-series-graphics-cards, Sep 2020
[Charlene 20] Charlene, “800G Is Coming: Set Pace to More Higher Speed Applications,” https://community.fs.com/blog/800-gigabitethernet-and-optics.html, May 2020
[Cutress 20] Dr. Ian Cutress, “Insights into DDR5 Sub-timings and Latencies,” https://www.anandtech.com/show/16143/insights-intoddr5-subtimings-and-latencies, Oct 2020
[Ford 20] A. Ford, et al., “TCP Extensions for Multipath Operation with Multiple Addresses,”
https://datatracker.ietf.org/doc/html/rfc8684, Mar 2020
[Gregg 20] Brendan Gregg, “Systems Performance: Enterprise and the Cloud, Second Edition,” Addison-Wesley, 2020
[Hruska 20] Joel Hruska, “Intel Demos PCIe 5.0 on Upcoming Sapphire Rapids CPUs,”
https://www.extremetech.com/computing/316257-intel-demos-pcie-5-0-on-upcoming-sapphire-rapids-cpus,
Oct 2020
[Liu 20] Linda Liu, “Samsung QVO vs EVO vs PRO: What’s the Difference? [Clone Disk],”
https://www.partitionwizard.com/clone-disk/samsung-qvo-vs-evo.html, 2020
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

References (4)
[Moore 20] Samuel K. Moore, “A Better Way to Measure Progress in Semiconductors,”
https://spectrum.ieee.org/semiconductors/devices/a-better-way-to-measure-progress-in-semiconductors, Jul 2020
[Peterson 20] Zachariah Peterson, “DDR5 vs. DDR6: Here's What to Expect in RAM Modules,” https://resources.altium.com/p/ddr5-vsddr6-heres-what-expect-ram-modules, Nov 2020
[Salter 20] Jim Salter, “Western Digital releases new 18TB, 20TB EAMR drives,” https://arstechnica.com/gadgets/2020/07/westerndigital-releases-new-18tb-20tb-eamr-drives, Jul 2020
[Spier 20] Martin Spier, Brendan Gregg, et al., “FlameScope,” https://github.com/Netflix/flamescope, 2020
[Tolvanen 20] Sami Tolvanen, Bill Wendling, and Nick Desaulniers, “LTO, PGO, and AutoFDO in the Kernel,” Linux Plumber’s
Conference, https://linuxplumbersconf.org/event/7/contributions/798, 2020
[Vega 20] Juan Camilo Vega, Marco Antonio Merlini, Paul Chow, “FFShark: A 100G FPGA Implementation of BPF Filtering for
Wireshark,” IEEE 28th Annual International Symposium on Field-Programmable Custom Computing Machines (FCCM),
[Warren 20] Tom Warren, “Microsoft reportedly designing its own ARM-based chips for servers and Surface PCs,”
https://www.theverge.com/2020/12/18/22189450/microsoft-arm-processors-chips-servers-surface-report, Dec 2020
[Alcorn 21] Paul Alcorn, “Intel Shares Alder Lake Pricing, Specs and Gaming Performance: $589 for 16 Cores,”
https://www.tomshardware.com/features/intel-shares-alder-lake-pricing-specs-and-gaming-performance, Oct 2021
[Cutress 21] Ian Cutress, “AMD Demonstrates Stacked 3D V-Cache Technology: 192 MB at 2 TB/sec,”
https://www.anandtech.com/show/16725/amd-demonstrates-stacked-vcache-technology-2-tbsec-for-15-gaming, May 2021
[Google 21] Google, “Cloud TPU,” https://cloud.google.com/tpu, 2021
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

References (5)
[Haken 21] Michael Haken, et al., “Delta Lake 1S Server Design Specification 1v05, https://www.opencompute.org/documents/deltalake-1s-server-design-specification-1v05-pdf, 2021
[Intel 21] Intel corporation, “Intel® OptaneTM Technology,” https://www.intel.com/content/www/us/en/products/docs/storage/optanetechnology-brief.html, 2021
[Kostovic 21] Aleksandar Kostovic, “Esperanto Delivers Kilocore Processor in its Supercomputer-on-a-Chip Design,”
https://www.tomshardware.com/news/esperanto-kilocore-processor, Aug 2021
[Kummrow 21] Patricia Kummrow, “The IPU: A New, Strategic Resource for Cloud Service Providers,”
https://itpeernetwork.intel.com/ipu-cloud/#gs.g5pkub, Aug 2021
[Quach 21a] Katyanna Quach, “Global chip shortage probably won't let up until 2023, warns TSMC: CEO 'still expects capacity to
tighten more',” https://www.theregister.com/2021/04/16/tsmc_chip_forecast, Apr 2021
[Quach 21b] Katyanna Quach, “IBM says it's built the world's first 2nm semiconductor chips,”
https://www.theregister.com/2021/05/06/ibm_2nm_semiconductor_chips, May 2021
[Ridley 21] Jacob Ridley, “IBM agrees with Intel and TSMC: this chip shortage isn't going to end anytime soon,”
https://www.pcgamer.com/ibm-agrees-with-intel-and-tsmc-this-chip-shortage-isnt-going-to-end-anytime-soon, May 2021
[Shilov 21] Anton Shilov, “Samsung Develops 512GB DDR5 Module with HKMG DDR5 Chips,”
https://www.tomshardware.com/news/samsung-512gb-ddr5-memory-module, Mar 2021
[Shilov 21b] Anton Shilov, “Seagate Ships 20TB HAMR HDDs Commercially, Increases Shipments of Mach.2 Drives,”
https://www.tomshardware.com/news/seagate-ships-hamr-hdds-increases-dual-actuator-shipments, 2021
[Shilov 21c] Anton Shilov, “SK Hynix Envisions 600-Layer 3D NAND & EUV-Based DRAM,” https://www.tomshardware.com/news/skhynix-600-layer-3d-nand-euv-dram, Mar 2021
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

References (6)
[SuperMicro 21] SuperMicro, “B12SPE-CPU-25G (For SuperServer Only),”
https://www.supermicro.com/en/products/motherboard/B12SPE-CPU-25G, 2021
[Thaler 21] Dave Thaler, Poorna Gaddehosur, “Making eBPF work on Windows,”
https://cloudblogs.microsoft.com/opensource/2021/05/10/making-ebpf-work-on-windows, May 2021
[TornadoVM 21] TornadoVM, “TornadoVM Run your software faster and simpler!” https://www.tornadovm.org, 2021
[Trader 21] Tiffany Trader, “Cerebras Second-Gen 7nm Wafer Scale Engine Doubles AI Performance Over First-Gen Chip ,”
https://www.enterpriseai.news/2021/04/21/latest-cerebras-second-gen-7nm-wafer-scale-engine-doubles-ai-performanceover-first-gen-chip, Apr 2021
[Ghigoff 21] Yoann Ghigoff, et al., "BMC: Accelerating Memcached using Safe In-kernel Caching and Pre-stack Processing,"
Proceedings of the 18th USENIX Symposium on Networked Systems Design and Implementation,
https://www.usenix.org/system/files/nsdi21-ghigoff.pdf, Apr 2021
[Tyson 21] Mark Tyson, "Intel Sapphire Rapids utillises tiled, modular SoC architecture," https://hexus.net/tech/news/cpu/148266-intelsapphire-rapids-utillises-tiled-modular-soc-architecture/, Aug 2021
[Vahdat 21] Amin Vahdat, “The past, present and future of custom compute at Google,”
https://cloud.google.com/blog/topics/systems/the-past-present-and-future-of-custom-compute-at-google, Mar 2021
[Wikipedia 21] “Semiconductor device fabrication,” https://en.wikipedia.org/wiki/Semiconductor_device_fabrication, 2021
[Wikipedia 21b] “Silicon,” https://en.wikipedia.org/wiki/Silicon, 2021
[ZonedStorage 21] Zoned Storage, “Zoned Namespaces (ZNS) SSDs,” https://zonedstorage.io/introduction/zns, 2021
[Cutress 21b] Dr. Ian Cutress, Andrei Frumusanu, "The Intel 12th Gen Core i9-12900K Review: Hybrid Performance Brings Hybrid
Complexity," https://www.anandtech.com/show/17047/the-intel-12th-gen-core-i912900k-review-hybrid-performancebrings-hybrid-complexity, Nov 2021
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

References (7)
[Nash 22] Paul Nash, "Now in preview: Azure Virtual Machines with Ampere Altra Arm-based processors,"
https://azure.microsoft.com/en-us/blog/now-in-preview-azure-virtual-machines-with-ampere-altra-armbased-processors/,
Apr 2022
[Bonshor 22] Gavin Bonshor, "AMD Releases Milan-X CPUs With 3D V-Cache," https://www.anandtech.com/show/17323/amdreleases-milan-x-cpus-with-3d-vcache-epyc-7003, Mar 2022
[Mann 22] Tobias Mann, "Why Intel killed its Optane memory business,"
https://www.theregister.com/2022/07/29/intel_optane_memory_dead/, Jul 2022
[Torvalds 22] Linus Torvalds, “Linux 6.0-rc1,” https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?
id=568035b01cfb107af8d2e4bd2fb9aea22cf5b868, Aug 2022
[Whalen 22] Jeanne Whalen, "Biden’s visit shows high stakes of $20 billion Ohio chip factory," https://www.washingtonpost.com/uspolicy/2022/09/09/biden-intel-ohio-chip-factory/, Sep 2022
[Robinson 22] Dan Robinson, "Intel has a secret club in the cloud for devs to try out new chips – and you ain't in it,"
https://www.theregister.com/2022/09/28/intel_developer_cloud/, Sep 2022
[CloudHypervisor 22] Cloud Hypervisor Project (Linux Foundation), "Run Cloud Virtual Machines Securely and Efficiently,"
https://www.cloudhypervisor.org, accessed 2022
[Cerebras 22] Cerebras, "Cerebras Wafer-Scale Cluster," https://www.cerebras.net/product-cluster, accessed 2022
[GrafanaLabs 22] Grafana Labs, "https://grafana.com/docs/grafana/latest/panels-visualizations/visualizations/flame-graph/,"
https://grafana.com/docs/grafana/latest/panels-visualizations/visualizations/flame-graph/, accessed 2022
[Pirzada 22] Usman Pirzada, "Intel Announces The Worlds First x86 CPU With HBM Memory: Xeon Max ‘Sapphire Rapids’ Data
Center CPU," https://wccftech.com/intel-announces-the-worlds-first-x86-cpu-with-hbm-memory-xeon-max-sapphirerapids-data-center-cpu/, Nov 2022
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

References (8)
[Smith 22] Lyle Smith, "Samsung PM1743 PCIe Gen5 SSD First Take Review," https://www.storagereview.com/review/samsungpm1743-pcie-gen5-ssd-first-take-review, Jan 2022
[Barr 22] Jeff Barr, "New Amazon EC2 Instance Types In the Works – C7gn, R7iz, and Hpc7g,"
https://aws.amazon.com/blogs/aws/new-amazon-ec2-instance-types-in-the-works-c7gn-r7iz-and-hpc7g, Nov 2022
[Gooding 22] Matthew Gooding, "TSMC’s US fab will make 4nm chips for Apple, AMD and Nvidia,"
https://techmonitor.ai/technology/silicon/tsmcs-arizona-apple-amd-nvidia, Dec 2022
[Liu 22] Zhiye Liu, "Smuggler Hid Over 200 Alder Lake CPUs in Fake Silicone Belly," https://www.tomshardware.com/news/smugglerhid-over-200-alder-lake-cpus-in-fake-silicone-belly, Dec 2022
[Seagate 22] Seagato, "Exos X Series," https://www.seagate.com/au/en/products/enterprise-drives/exos-x/, accessed 2022
[Mann 22b] Tobais Mann, "Nvidia not cutting it? Google and Amazon’s latest AI chips have arrived,"
https://www.theregister.com/2022/10/11/google_amazon_ai_chips_nvidia/, Oct 2022
[Intel 22] Intel, "Intel® Developer Cloud," https://www.intel.com/content/www/us/en/developer/tools/devcloud/overview.html, accessed
Dec 2022
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Take Aways
Awareness of current and future perf technologies
Design faster systems to meet SLOs and performance needs
Begin planning new technology support and maintenance
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Old System
DRAM
Processor
Processor
DRAM
Bridge
NICs
HBAs
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)

Example Future System
Processor
chiplet chiplet
P-cores P-cores
chiplet chiplet
E-cores E-cores
HBM
IPU
NICs
eBPF
HBAs
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)
GPU
FPGA/
TPU/
DPU
No DRAM in this example!

Thanks
Thanks for attending Sydney's first USENIX event!
Slides: http://www.brendangregg.com
Thanks to colleagues Jason Koch, Sargun Dhillon, Drew Gallatin, and Guy Cirino for
their performance engineering expertise.
Thanks to USENIX organizers!
SYDNEY, AUSTRALIA
7–9 December, 2022
USENIX SREcon Computing Performance 2022: What’s On the Horizon (Brendan Gregg)