728db19886
Continuing from the previous cset comment, now that filter expression
works:
# perf trace -e msr:* --filter="msr!=FS_BASE && msr != IA32_TSC_DEADLINE && msr != 0x830 && msr != 0x83f && msr !=IA32_SPEC_CTRL" --filter-pids 3750
0.000 Timer/5033 msr:write_msr(msr: SYSCALL_MASK, val: 292608)
0.009 Timer/5033 msr:write_msr(msr: LSTAR, val: -1398800368)
0.010 Timer/5033 msr:write_msr(msr: TSC_AUX, val: 4)
0.050 :0/0 msr:read_msr(msr: IA32_TSC_ADJUST)
45.661 gnome-terminal/12595 msr:write_msr(msr: SYSCALL_MASK, val: 292608)
45.672 gnome-terminal/12595 msr:write_msr(msr: LSTAR, val: -1398800368)
45.675 gnome-terminal/12595 msr:write_msr(msr: TSC_AUX, val: 3)
54.852 :0/0 msr:read_msr(msr: IA32_TSC_ADJUST)
130.508 Timer/4050 msr:write_msr(msr: SYSCALL_MASK, val: 292608)
130.527 Timer/4050 msr:write_msr(msr: LSTAR, val: -1398800368)
130.531 Timer/4050 msr:write_msr(msr: TSC_AUX, val: 3)
140.924 :0/0 msr:read_msr(msr: IA32_TSC_ADJUST)
164.738 :0/0 msr:read_msr(msr: IA32_TSC_ADJUST)
603.578 :0/0 msr:read_msr(msr: IA32_TSC_ADJUST)
620.809 :0/0 msr:read_msr(msr: IA32_TSC_ADJUST)
690.115 JS Watchdog/4259 msr:write_msr(msr: SYSCALL_MASK, val: 292608)
690.136 JS Watchdog/4259 msr:write_msr(msr: LSTAR, val: -1398800368)
690.141 JS Watchdog/4259 msr:write_msr(msr: TSC_AUX, val: 3)
690.186 :0/0 msr:read_msr(msr: IA32_TSC_ADJUST)
759.016 :0/0 msr:read_msr(msr: IA32_TSC_ADJUST)
^C[root@quaco ~]#
Or look at the first 3 write_msr events for that IA32_TSC_DEADLINE to learn why
it happens so often:
# perf trace --max-events=3 --max-stack=8 -e msr:* --filter="msr==IA32_TSC_DEADLINE" --filter-pids 3750
0.000 :0/0 msr:write_msr(msr: IA32_TSC_DEADLINE, val: 19296732550862)
do_trace_write_msr ([kernel.kallsyms])
do_trace_write_msr ([kernel.kallsyms])
lapic_next_deadline ([kernel.kallsyms])
clockevents_program_event ([kernel.kallsyms])
hrtimer_interrupt ([kernel.kallsyms])
smp_apic_timer_interrupt ([kernel.kallsyms])
apic_timer_interrupt ([kernel.kallsyms])
cpuidle_enter_state ([kernel.kallsyms])
32.646 :0/0 msr:write_msr(msr: IA32_TSC_DEADLINE, val: 19296800134158)
do_trace_write_msr ([kernel.kallsyms])
do_trace_write_msr ([kernel.kallsyms])
lapic_next_deadline ([kernel.kallsyms])
clockevents_program_event ([kernel.kallsyms])
hrtimer_start_range_ns ([kernel.kallsyms])
tick_nohz_restart_sched_tick ([kernel.kallsyms])
tick_nohz_idle_exit ([kernel.kallsyms])
do_idle ([kernel.kallsyms])
32.802 :0/0 msr:write_msr(msr: IA32_TSC_DEADLINE, val: 19297507436922)
do_trace_write_msr ([kernel.kallsyms])
do_trace_write_msr ([kernel.kallsyms])
lapic_next_deadline ([kernel.kallsyms])
clockevents_program_event ([kernel.kallsyms])
hrtimer_try_to_cancel ([kernel.kallsyms])
hrtimer_cancel ([kernel.kallsyms])
tick_nohz_restart_sched_tick ([kernel.kallsyms])
tick_nohz_idle_exit ([kernel.kallsyms])
#
And if some of the strings can't be found:
# trace -e msr:* --filter="msr!=SPECULATIVE_EXECUTION_PROBLEMS_SOLUTION && msr != IA32_TSC_DEADLINE && msr != 0x830 && msr != 0x83f && msr !=IA32_SPEC_CTRL" --filter-pids 3750
"SPECULATIVE_EXECUTION_PROBLEMS_SOLUTION" not found for "msr" in "msr:read_msr", can't set filter "(msr!=SPECULATIVE_EXECUTION_PROBLEMS_SOLUTION && msr != IA32_TSC_DEADLINE && msr != 0x830 && msr != 0x83f && msr !=IA32_SPEC_CTRL) && (common_pid != 28131 && common_pid != 3750)"
#
Next step is to automatically wire up the pre-existing strarrays, which there
are quite a few.
The strtoul() methods will be further enhanced to allow for looking at other
arguments in a syscall/tracepoint, just like going from integer to string
(scnprintf methods), so that those "val" lines for the msr tracepoints can be
properly formatted or even resolved into some string.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-4qaai5iqjgefd11k4ddm7qg8@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.