1fcc57b7e5
A group mixed with hybrid event and global event is allowed. For
example, group leader is 'intel_pt//' and the group member is
'cpu_atom/cycles/'.
e.g.:
# perf record --aux-sample -e '{intel_pt//,cpu_atom/cycles/}:u'
The challenge is that their available cpus are not fully matched. For
example, 'intel_pt//' is available on CPU0-CPU23, but 'cpu_atom/cycles/'
is available on CPU16-CPU23.
When getting the group id for group member, we must be very careful.
Because the cpu for 'intel_pt//' is not equal to the cpu for
'cpu_atom/cycles/'. Actually the cpu here is the index of evsel->core.cpus,
not the real CPU ID.
e.g. cpu0 for 'intel_pt//' is CPU0, but cpu0 for 'cpu_atom/cycles/' is CPU16.
Before:
# perf record --aux-sample -e '{intel_pt//,cpu_atom/cycles/}:u' -vv uname
...
------------------------------------------------------------
perf_event_attr:
type 10
size 128
config 0xe601
{ sample_period, sample_freq } 1
sample_type IP|TID|TIME|CPU|IDENTIFIER
read_format ID
disabled 1
inherit 1
exclude_kernel 1
exclude_hv 1
enable_on_exec 1
sample_id_all 1
exclude_guest 1
------------------------------------------------------------
sys_perf_event_open: pid 4084 cpu 0 group_fd -1 flags 0x8 = 5
sys_perf_event_open: pid 4084 cpu 1 group_fd -1 flags 0x8 = 6
sys_perf_event_open: pid 4084 cpu 2 group_fd -1 flags 0x8 = 7
sys_perf_event_open: pid 4084 cpu 3 group_fd -1 flags 0x8 = 9
sys_perf_event_open: pid 4084 cpu 4 group_fd -1 flags 0x8 = 10
sys_perf_event_open: pid 4084 cpu 5 group_fd -1 flags 0x8 = 11
sys_perf_event_open: pid 4084 cpu 6 group_fd -1 flags 0x8 = 12
sys_perf_event_open: pid 4084 cpu 7 group_fd -1 flags 0x8 = 13
sys_perf_event_open: pid 4084 cpu 8 group_fd -1 flags 0x8 = 14
sys_perf_event_open: pid 4084 cpu 9 group_fd -1 flags 0x8 = 15
sys_perf_event_open: pid 4084 cpu 10 group_fd -1 flags 0x8 = 16
sys_perf_event_open: pid 4084 cpu 11 group_fd -1 flags 0x8 = 17
sys_perf_event_open: pid 4084 cpu 12 group_fd -1 flags 0x8 = 18
sys_perf_event_open: pid 4084 cpu 13 group_fd -1 flags 0x8 = 19
sys_perf_event_open: pid 4084 cpu 14 group_fd -1 flags 0x8 = 20
sys_perf_event_open: pid 4084 cpu 15 group_fd -1 flags 0x8 = 21
sys_perf_event_open: pid 4084 cpu 16 group_fd -1 flags 0x8 = 22
sys_perf_event_open: pid 4084 cpu 17 group_fd -1 flags 0x8 = 23
sys_perf_event_open: pid 4084 cpu 18 group_fd -1 flags 0x8 = 24
sys_perf_event_open: pid 4084 cpu 19 group_fd -1 flags 0x8 = 25
sys_perf_event_open: pid 4084 cpu 20 group_fd -1 flags 0x8 = 26
sys_perf_event_open: pid 4084 cpu 21 group_fd -1 flags 0x8 = 27
sys_perf_event_open: pid 4084 cpu 22 group_fd -1 flags 0x8 = 28
sys_perf_event_open: pid 4084 cpu 23 group_fd -1 flags 0x8 = 29
------------------------------------------------------------
perf_event_attr:
size 128
config 0x800000000
{ sample_period, sample_freq } 4000
sample_type IP|TID|TIME|PERIOD|IDENTIFIER|AUX
read_format ID
inherit 1
exclude_kernel 1
exclude_hv 1
freq 1
sample_id_all 1
exclude_guest 1
aux_sample_size 4096
------------------------------------------------------------
sys_perf_event_open: pid 4084 cpu 16 group_fd 5 flags 0x8
sys_perf_event_open failed, error -22
The group_fd 5 is not correct. It should be 22 (the fd of
'intel_pt' on CPU16).
After:
# perf record --aux-sample -e '{intel_pt//,cpu_atom/cycles/}:u' -vv uname
...
------------------------------------------------------------
perf_event_attr:
type 10
size 128
config 0xe601
{ sample_period, sample_freq } 1
sample_type IP|TID|TIME|CPU|IDENTIFIER
read_format ID
disabled 1
inherit 1
exclude_kernel 1
exclude_hv 1
enable_on_exec 1
sample_id_all 1
exclude_guest 1
------------------------------------------------------------
sys_perf_event_open: pid 5162 cpu 0 group_fd -1 flags 0x8 = 5
sys_perf_event_open: pid 5162 cpu 1 group_fd -1 flags 0x8 = 6
sys_perf_event_open: pid 5162 cpu 2 group_fd -1 flags 0x8 = 7
sys_perf_event_open: pid 5162 cpu 3 group_fd -1 flags 0x8 = 9
sys_perf_event_open: pid 5162 cpu 4 group_fd -1 flags 0x8 = 10
sys_perf_event_open: pid 5162 cpu 5 group_fd -1 flags 0x8 = 11
sys_perf_event_open: pid 5162 cpu 6 group_fd -1 flags 0x8 = 12
sys_perf_event_open: pid 5162 cpu 7 group_fd -1 flags 0x8 = 13
sys_perf_event_open: pid 5162 cpu 8 group_fd -1 flags 0x8 = 14
sys_perf_event_open: pid 5162 cpu 9 group_fd -1 flags 0x8 = 15
sys_perf_event_open: pid 5162 cpu 10 group_fd -1 flags 0x8 = 16
sys_perf_event_open: pid 5162 cpu 11 group_fd -1 flags 0x8 = 17
sys_perf_event_open: pid 5162 cpu 12 group_fd -1 flags 0x8 = 18
sys_perf_event_open: pid 5162 cpu 13 group_fd -1 flags 0x8 = 19
sys_perf_event_open: pid 5162 cpu 14 group_fd -1 flags 0x8 = 20
sys_perf_event_open: pid 5162 cpu 15 group_fd -1 flags 0x8 = 21
sys_perf_event_open: pid 5162 cpu 16 group_fd -1 flags 0x8 = 22
sys_perf_event_open: pid 5162 cpu 17 group_fd -1 flags 0x8 = 23
sys_perf_event_open: pid 5162 cpu 18 group_fd -1 flags 0x8 = 24
sys_perf_event_open: pid 5162 cpu 19 group_fd -1 flags 0x8 = 25
sys_perf_event_open: pid 5162 cpu 20 group_fd -1 flags 0x8 = 26
sys_perf_event_open: pid 5162 cpu 21 group_fd -1 flags 0x8 = 27
sys_perf_event_open: pid 5162 cpu 22 group_fd -1 flags 0x8 = 28
sys_perf_event_open: pid 5162 cpu 23 group_fd -1 flags 0x8 = 29
------------------------------------------------------------
perf_event_attr:
size 128
config 0x800000000
{ sample_period, sample_freq } 4000
sample_type IP|TID|TIME|PERIOD|IDENTIFIER|AUX
read_format ID
inherit 1
exclude_kernel 1
exclude_hv 1
freq 1
sample_id_all 1
exclude_guest 1
aux_sample_size 4096
------------------------------------------------------------
sys_perf_event_open: pid 5162 cpu 16 group_fd 22 flags 0x8 = 30
sys_perf_event_open: pid 5162 cpu 17 group_fd 23 flags 0x8 = 31
sys_perf_event_open: pid 5162 cpu 18 group_fd 24 flags 0x8 = 32
sys_perf_event_open: pid 5162 cpu 19 group_fd 25 flags 0x8 = 33
sys_perf_event_open: pid 5162 cpu 20 group_fd 26 flags 0x8 = 34
sys_perf_event_open: pid 5162 cpu 21 group_fd 27 flags 0x8 = 35
sys_perf_event_open: pid 5162 cpu 22 group_fd 28 flags 0x8 = 36
sys_perf_event_open: pid 5162 cpu 23 group_fd 29 flags 0x8 = 37
------------------------------------------------------------
...
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210609044555.27180-1-yao.jin@linux.intel.com
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.