Messages in this thread | | | Date | Tue, 15 Dec 2020 10:58:49 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH 0/5] perf stat: Introduce --iiostat mode to provide I/O performance metrics |
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Em Mon, Dec 14, 2020 at 07:04:30PM -0800, Andi Kleen escreveu: > > My first thought was: Why not have a 'perf iiostat' subcommand?
> Same would apply to a lot of options in perf stat.
> I guess you could add some aliases to "perf" that give shortcuts > for common perf stat command lines.
Yeah, and we have a mechanism for that, that was exercised only in the 'perf archive' case:
~/libexec/perf-core/perf-archive
I tried this and it works:
[root@five ~]# ls -la ~/bin/perf lrwxrwxrwx. 1 root root 19 Feb 18 2020 /root/bin/perf -> /home/acme/bin/perf [root@five ~]# vim ~acme/libexec/perf-core/perf-cgtop [root@five ~]# chmod +x ~acme/libexec/perf-core/perf-cgtop [root@five ~]# cat ~acme/libexec/perf-core/perf-cgtop perf top --hierarchy --all-cgroups -s cgroup,dso,sym $* [root@five ~]# perf cgtop [root@five ~]#
use 'e' to expand collapse the current level (+ -> -), 'E'/'C' to expand/collapse all levels.
'perf help' doesn't show it, which is a shame, I'll add support for it to traverse ~/libexec/perf-core/perf-* and get the first non interpreter comment line as a description for the command, so to add a new one is just a matter of dropping a shell + man page, no need to change the perf binary.
To test that '$*' at the end:
[root@five ~]# perf cgtop -U
I.e.:
[acme@five perf]$ perf top -h -U
Usage: perf top [<options>]
-U, --hide_user_symbols hide user symbols
[acme@five perf]$
And it works, just kernel level samples grouped in an hierarchy, first cgroup, then dso, then the symbol.
Also, using this with the 'P' hotkey:
[root@five ~]# perf cgtop --percent-limit 1
Shows how it looks like:
[root@five ~]# cat perf.hist.0 - 86.77% /user.slice/user-1000.slice/session-2.scope - 36.18% [kernel] 2.24% [k] unmap_page_range 1.15% [k] clear_page_rep 1.10% [k] add_mm_counter_fast 1.03% [k] alloc_set_pte 1.03% [k] handle_mm_fault - 17.65% libc-2.32.so 2.04% [.] _int_malloc 1.82% [.] __memmove_avx_unaligned_erms 1.48% [.] __strlen_avx2 1.13% [.] _int_free 1.12% [.] malloc - 8.09% make 1.65% [.] jhash_string 1.05% [.] hash_find_slot - 6.90% ld-2.32.so 2.03% [.] do_lookup_x 1.49% [.] _dl_lookup_symbol_x - 4.78% cc1 - 4.60% libperl.so.5.32.0 - 2.86% bash - 1.98% libselinux.so.1 - 1.61% libpython2.7.so.1.0 - 1.06% libpcre2-8.so.0.10.0 - 9.17% /user.slice/user-1000.slice/session-4.scope - 4.66% perf - 2.40% libc-2.32.so - 1.82% [kernel] - 4.04% / - 4.02% [kernel] [root@five ~]#
So 'perf iiostat' would become:
[root@five ~]# cat ~acme/libexec/perf-core/perf-iiostat perf stat --iiostat $* [root@five ~]#
There are parameters to that '--iiostat' in the current patchset that may complicates this tho, with some changes I guess we get what we want.
- Arnaldo
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