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author | johannst <johannes.stoelp@gmail.com> | 2020-03-14 14:10:41 +0100 |
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committer | johannst <johannes.stoelp@gmail.com> | 2020-03-14 14:10:41 +0100 |
commit | 3099cd5efceebcbbc5ab1202c2b183ccd4453a65 (patch) | |
tree | 966e24e1226e8e3b2f279cd651c13b6776537a9a /src | |
parent | c5dfa4b329e9db6c68a6f5da77b7150f674206ef (diff) | |
download | notes-3099cd5efceebcbbc5ab1202c2b183ccd4453a65.tar.gz notes-3099cd5efceebcbbc5ab1202c2b183ccd4453a65.zip |
split debug.txt into mdbook chapters
Diffstat (limited to 'src')
-rw-r--r-- | src/SUMMARY.md | 11 | ||||
-rw-r--r-- | src/debug_trace.md | 0 | ||||
-rw-r--r-- | src/lsof.md | 36 | ||||
-rw-r--r-- | src/oprofile.md | 15 | ||||
-rw-r--r-- | src/perf.md | 56 | ||||
-rw-r--r-- | src/pidstat.md | 13 | ||||
-rw-r--r-- | src/pmap.md | 7 | ||||
-rw-r--r-- | src/pstack.md | 6 | ||||
-rw-r--r-- | src/strace.md | 32 | ||||
-rw-r--r-- | src/time.md | 6 |
10 files changed, 182 insertions, 0 deletions
diff --git a/src/SUMMARY.md b/src/SUMMARY.md index f31e217..d0a4e62 100644 --- a/src/SUMMARY.md +++ b/src/SUMMARY.md @@ -1,3 +1,14 @@ # Summary - [gdb](./gdb.md) +- [debug & trace](./debug_trace.md) + - [strace](./strace.md) + - [lsof](./lsof.md) + - [pidstat](./pidstat.md) + - [time](./time.md) + - [pmap](./pmap.md) + - [pstack](./pstack.md) + - [perf](./perf.md) + - [OProfile](./oprofile.md) + + diff --git a/src/debug_trace.md b/src/debug_trace.md new file mode 100644 index 0000000..e69de29 --- /dev/null +++ b/src/debug_trace.md diff --git a/src/lsof.md b/src/lsof.md new file mode 100644 index 0000000..a7ed2d1 --- /dev/null +++ b/src/lsof.md @@ -0,0 +1,36 @@ +# lsof(8) + +```markdown +lsof + -a ......... AND slection filters instead ORing (OR: default) + -p <pid> ... list open file descriptors for process + +fg ........ show file flags for file descripros + -n ......... don't convert network addr to hostnames + -P ......... don't convert network port to know service names + -i <@h[:p]>. show connections to h (hostname|ip addr) with optional port p +``` + +```markdown +file flags: + R/W/RW ..... read/write/read-write + CR ......... create + AP ......... append + TR ......... truncate +``` + +# Examples + +Show open files with file flags: +```markdown +lsof +fg -p <pid> +``` + +Show open tcp connections from user: +```markdown +lsof -a -u $USER -i tcp +``` + +Show open connections to 'localhost' for user: +```markdown +lsof -a -u $USER -i @localhost +``` diff --git a/src/oprofile.md b/src/oprofile.md new file mode 100644 index 0000000..15e06f6 --- /dev/null +++ b/src/oprofile.md @@ -0,0 +1,15 @@ +# OProfile + +```markdown +operf -g -p <pid> + -g ...... caputre call-graph information + +opreport [opt] FILE + ...... show time spent per binary image + -l ...... show time spent per symbol + -c ...... show callgraph information (see below) + -a ...... add column with time spent accumulated over child nodes + +ophelp + ...... show supported hw/sw events +``` diff --git a/src/perf.md b/src/perf.md new file mode 100644 index 0000000..003e164 --- /dev/null +++ b/src/perf.md @@ -0,0 +1,56 @@ +# perf(1) + +```markdown +perf list + ......... show supported hw/sw events + +perf stat + -p <pid> .. show stats for running process + -I <ms> ... show stats periodically over interval <ms> + -e <ev> ... filter for events + +perf top + -p <pid> .. show stats for running process + -F <hz> ... sampling frequency + -K ........ hide kernel threads + +perf record + -p <pid> ............... record stats for running process + -F <hz> ................ sampling frequency + --call-graph <method> .. [fp, dwarf, lbr] method how to caputre backtrace + fp : use frame-pointer, need -fno-omit-frame-pointer + dwarf: use .cfi debug information + lbr : use hardware last branch record facility + -g ..................... short-hand for --call-graph fp + -e <ev> ................ filter for events + +perf report + -n .................... annotate symbols with nr of samples + --stdio ............... report to stdio, if not presen tui mode + -g graph,0.5,caller ... show caller based call chains with value >0.5 +``` + +## Useful `perf` events + +```markdown +useful <ev>: + page-faults + minor-faults + major-faults + cpu-cycles` + task-clock + ``` + +## [`Flamegraph`](https://github.com/brendangregg/FlameGraph) + +```markdown +# flamegraph for single event trace +perf record -g -p <pid> -e cpu-cycles +perf script | FlameGraph/stackcollapse-perf.pl | FlameGraph/flamegraph.pl > cycles-flamegraph.svg + +# flamegraphs for multiple events trace +perf record -g -p <pid> -e cpu-cycles,page-faults +perf script --per-event-dump +# fold & generate as above +``` + diff --git a/src/pidstat.md b/src/pidstat.md new file mode 100644 index 0000000..c17a2e6 --- /dev/null +++ b/src/pidstat.md @@ -0,0 +1,13 @@ +# pidstat(1) + +Trace minor/major page faults. +```markdown +pidstat -r -p <pid> [interval] + minor_pagefault: happens when the page needed is already in memory but not + allocated to the faulting process, in that case the kernel + only has to create a new page-table entry pointing to the + shared physical page + major_pagefault: happends when the page needed is NOT in memory, the kernel + has to create a new page-table entry and populate the + physical page +``` diff --git a/src/pmap.md b/src/pmap.md new file mode 100644 index 0000000..d2e0e79 --- /dev/null +++ b/src/pmap.md @@ -0,0 +1,7 @@ +# pmap(1) + +```markdown +pmap <pid> + ............. dump virtual memory map of process. + compared to /proc/<pid>/maps it shows the size of the mappings +``` diff --git a/src/pstack.md b/src/pstack.md new file mode 100644 index 0000000..06cbade --- /dev/null +++ b/src/pstack.md @@ -0,0 +1,6 @@ +# pstack(1) + +```markdown +pstack <pid> + ............. dump current stack of process + threads +``` diff --git a/src/strace.md b/src/strace.md new file mode 100644 index 0000000..ff0f9d3 --- /dev/null +++ b/src/strace.md @@ -0,0 +1,32 @@ +# strace(1) + +```markdown +strace [opts] [prg] + -f .......... follow child processes on fork(2) + -p <pid> .... attach to running process + -s <size> ... max string size (default: 32) + -e <expr> ... expression for trace filtering + -o <file> ... log output into <file> + -c .......... dump syscall statitics at the end +``` + +```markdown +<expr>: + trace=syscall[,syscall] .... trace only syscall listed + trace=file ................. trace all syscall that take a filename as arg + trace=process .............. trace process management related syscalls + trace=signal ............... trace signal related syscalls + signal ..................... trace signals delivered to the process +``` + +# Examples + +Trace `'open & socket` syscalls for a running process + childs. +```markdown +strace -f -p <pid> -e trace=open,socket +``` + +Trace signals delivered to a running process. +```markdown +strace -f -p <pid> -e signal +``` diff --git a/src/time.md b/src/time.md new file mode 100644 index 0000000..be404fb --- /dev/null +++ b/src/time.md @@ -0,0 +1,6 @@ +# /usr/bin/time(1) + +```markdown +# statistics of process run +/usr/bin/time -v <cmd> +``` |