mmalchuk · November 11, 2019 20:57 · Oct 16, 2019
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+https://getfedora.org/en/workstation/download/
+sudo systemct enable --now sshd
+# Need kernel to match kernel-devel
+sudo dnf update kernel
+# sudo reboot
+
+# https://elixir.bootlin.com/linux/latest/source
+# https://github.com/torvalds/linux/
+# https://blog.stgolabs.net/search/label/linux
+
+# BOOT UP
+# https://manybutfinite.com/post/cpu-rings-privilege-and-protection/
+# https://manybutfinite.com/post/kernel-boot-process/
+# https://manybutfinite.com/post/how-computers-boot-up/
+
+# Program memory
+# https://manybutfinite.com/post/system-calls/
+# https://manybutfinite.com/post/how-the-kernel-manages-your-memory/
+# https://manybutfinite.com/post/anatomy-of-a-program-in-memory/
+
+# Syscalls
+# https://alex.dzyoba.com/blog/os-interrupts/
+# https://manybutfinite.com/post/what-does-an-idle-cpu-do/
+# https://manybutfinite.com/post/when-does-your-os-run/
+
+# Stack
+# https://manybutfinite.com/post/journey-to-the-stack/
+# https://alex.dzyoba.com/blog/redzone/
+
+
+# All tools
+# syscall vs kernel function
+# http://brendangregg.com/Perf/linux_perf_tools_full.png
+# https://alex.dzyoba.com/blog/kernel-profiling/
+# https://alex.dzyoba.com/blog/systemtap/
+# https://medium.com/netflix-techblog/linux-performance-analysis-in-60-000-milliseconds-accc10403c55
+
+# Strace
+## How strace works
+sudo dnf install strace
+sudo strace  ping 8.8.8.8 -c 1
+
+# Trace-cmd
+## https://jvns.ca/blog/2017/03/19/getting-started-with-ftrace/
+## https://alex.dzyoba.com/blog/ftrace/
+## https://raw.githubusercontent.com/torvalds/linux/v4.4/Documentation/trace/ftrace.txt
+## https://raw.githubusercontent.com/torvalds/linux/v4.4/Documentation/trace/ftrace-design.txt
+## tell about ftrace
+## Flamescope? https://www.youtube.com/watch?v=03EC8uA30Pw
+### 5 key issues and how netflix cloud is architected to solve them
+#### 1. autoscaling (spinnaker)
+#### 2. bad push (rollback)
+#### 3. instance failure (hystrix timeouts)
+#### 4. region failure (zuul 2 reroute traffic)
+#### 5. overlooked issue (chaos engineering)
+## why do root scope analysis? 
+### high latency
+### growth
+### upgrades
+## methodologies http://www.brendangregg.com/methodology.html
+## red (RATE ERRORS DURATION) USE (utilization saturation errors)
+## Anti methods 
+### bad instance anti method(just delete)
+## checklist methodology
+## zipkin
+## http://brendangregg.com/linuxperf.html
+## @43:26 from perf to bpf
+## @45:48 ftrace/perf/ebpf
+## books http://www.brendangregg.com/books.html
+http://kernelshark.org/Documentation.html
+sudo dnf install trace-cmd kernelshark
+sudo trace-cmd record  -l "*ip_*" -l "*icmp*" -p function_graph ping 8.8.8.8 -c 1
+kernelshark
+
+
+# Bcc/ebpf
+## why not just pcap/tcpdump https://sdcast.ksdaemon.ru/2017/07/sdcast-58/ Павел Одинцов
+## xdp
+## https://www.youtube.com/watch?v=ZdVpKx6Wmc8 1 min
+## https://www.youtube.com/watch?v=GsMs3n8CB6g 15 min
+## https://www.youtube.com/watch?v=bj3qdEDbCD4 45 min Velocity 2017: Performance Analysis Superpowers with Linux eBPF @14:08 fast new way
+## https://www.youtube.com/watch?v=4SiWL5tULnQ More on ebpf 
+## https://en.wikipedia.org/wiki/IPv4
+sudo dnf install bcc
+sudo /usr/share/bcc/tools/trace -Ilinux/skbuff.h \
+    'ip_send_skb(struct net *netx, struct sk_buff *skb) "ip dst: %d %d %d %d", *(skb->data+16), *(skb->data+17), *(skb->data+18), *(skb->data+19)'
+# sudo /usr/share/bcc/tools/execsnoop
+# ls and echo difference - type hash which commands
+
+# Get pids
+## sudo /usr/share/bcc/tools/tcplife
+## curl localhost:8080
+
+# Part I
+https://www.youtube.com/watch?v=FJW8nGV4jxY
+# Part II
+https://www.youtube.com/watch?v=zrr2nUln9Kk
+# Slides
+https://www.slideshare.net/brendangregg/velocity-2015-linux-perf-tools
+# Perf labs
+https://github.com/brendangregg/perf-labs/tree/master/src
+
+# Perf
+## https://perf.wiki.kernel.org/index.php/Tutorial
+sudo dnf install git
+sudo dnf install perf
+sudo dnf install perl-open.noarch
+git clone https://github.com/brendangregg/FlameGraph  # or download it from github
+cd FlameGraph
+sudo perf record -F 9999 -a -g -- git clone https://github.com/brendangregg/FlameGraph
+sudo perf script | ./stackcollapse-perf.pl > out.perf-folded
+./flamegraph.pl out.perf-folded > perf-kernel.svg
+python3 -m http.server
+sudo rm -rf FlameGraph/ out.perf-folded perf-kernel.svg perf.data 
+
+# Рассказать о стеках
+sudo perf top
+
+#sudo perf record -g -a -e skb:kfree_skb
+# normal is consume_skb
+#sudo perf script
+
+# https://github.com/lukego/blog/issues/13
+# https://github.com/pavel-odintsov/drop_watch
+
+
+# ARP 
+sudo trace-cmd record  -l "*arp*" -l "icmp_rcv" -p function_graph python3 -m http.server
+sudo ip -s -s neigh flush all
+
+# Packet Fragmentation/Defragmentation
+sudo trace-cmd record   -l "ip_fragment*" -p function_graph python3 -m http.server
+ping 192.168.122.1 -s 2000 -c 5
+
+# Forwarding & Local Delivery
+
+
+# ICMP
+ICMP Header
+Применение ICMP
+Приём и передача ICMP сообщений
+
+# L4
+Available L4 Protocols
+L4 Protocol Registration
+L3 to L4 Delivery: ip_local_deliver_finish
+
+
+# Use kfree_skb to detect failures
+vm_ip=192.168.122.184
+curl $vm_ip
+sudo /usr/share/bcc/tools/trace -Ilinux/skbuff.h 'kfree_skb(struct sk_buff *skb) (*(skb->data+23)==80) "ip dst: %d %d %d %d %d", *(skb->data+16), *(skb->data+17), *(skb->data+18), *(skb->data+18), *(skb->data+23)'
+
+
+# https://sdcast.ksdaemon.ru/2019/01/sdcast-97/ Александр Тоболь
+
+
+# https://www.youtube.com/watch?v=L5msC6pswQs Debugging Linux Issues with eBPF
+
+sudo trace-cmd record  -l "*ip_fragment*" -p function_graph python3 -m http.server
+
+
+
+https://training.linuxfoundation.org/training/a-beginners-guide-to-linux-kernel-development-lfd103/
+
+https://lwn.net/Kernel/LDD3/
+
+https://github.com/lukego/blog/issues/13
+
+http://brendangregg.com/ebpf.html#bcc
+
+http://man7.org/linux/man-pages/man2/syscalls.2.html
+https://syscalls.kernelgrok.com/
+https://linux-kernel-labs.github.io/master/lectures/syscalls.html