c69bf11ad3
When we lookup an address and don't find a map we should filter that
sample if the user specified a list of --dso entries to filter on, fix
it.
Before:
$ perf script
sleep 274800 2843.556162: 1 cycles:u: ffffffffbb26bff4 [unknown] ([unknown])
sleep 274800 2843.556168: 1 cycles:u: ffffffffbb2b047d [unknown] ([unknown])
sleep 274800 2843.556171: 1 cycles:u: ffffffffbb2706b2 [unknown] ([unknown])
sleep 274800 2843.556174: 6 cycles:u: ffffffffbb2b0267 [unknown] ([unknown])
sleep 274800 2843.556176: 59 cycles:u: ffffffffbb2b03b1 [unknown] ([unknown])
sleep 274800 2843.556180: 691 cycles:u: ffffffffbb26bff4 [unknown] ([unknown])
sleep 274800 2843.556189: 9160 cycles:u: 7fa9550eeaa3 __GI___tunables_init+0xf3 (/usr/lib64/ld-2.32.so)
sleep 274800 2843.556312: 86937 cycles:u: 7fa9550e157b _dl_lookup_symbol_x+0x4b (/usr/lib64/ld-2.32.so)
$
So we have some samples we somehow didn't find in a map for, if we now
do:
$ perf report --stdio --dso /usr/lib64/ld-2.32.so
# dso: /usr/lib64/ld-2.32.so
#
# Total Lost Samples: 0
#
# Samples: 8 of event 'cycles:u'
# Event count (approx.): 96856
#
# Overhead Command Symbol
# ........ ....... ........................
#
89.76% sleep [.] _dl_lookup_symbol_x
9.46% sleep [.] __GI___tunables_init
0.71% sleep [k] 0xffffffffbb26bff4
0.06% sleep [k] 0xffffffffbb2b03b1
0.01% sleep [k] 0xffffffffbb2b0267
0.00% sleep [k] 0xffffffffbb2706b2
0.00% sleep [k] 0xffffffffbb2b047d
$
After this patch we get the right output with just entries for the DSOs
specified in --dso:
$ perf report --stdio --dso /usr/lib64/ld-2.32.so
# dso: /usr/lib64/ld-2.32.so
#
# Total Lost Samples: 0
#
# Samples: 8 of event 'cycles:u'
# Event count (approx.): 96856
#
# Overhead Command Symbol
# ........ ....... ........................
#
89.76% sleep [.] _dl_lookup_symbol_x
9.46% sleep [.] __GI___tunables_init
$
#
Fixes: 96415e4d3f5fdf9c ("perf symbols: Avoid unnecessary symbol loading when dso list is specified")
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210128131209.GD775562@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.