a7672d1df5
It was reported that --exclude-perf wasn't working, as tracepoints were
appearing in 'perf script' output as having the 'perf' COMM, that is
just the window in evlist__prepare_workload() after the fork() and
before the execvp() call for workloads specified in the command line.
Example:
# perf record -e kmem:kmalloc --filter 'bytes_alloc<650 && bytes_alloc>620' --exclude-perf -e kmem:kfree --exclude-perf -aR sleep 30
Then:
# perf script
perf 15905 [009] 1498.356094: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=(nil)
perf 15905 [009] 1498.356116: kmem:kfree: call_site=free_bprm+0x8f ptr=(nil)
perf 15905 [009] 1498.356116: kmem:kfree: call_site=do_execveat_common+0x19d ptr=0xffff9cf750421c00
perf 15905 [009] 1498.356138: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=(nil)
perf 15905 [009] 1498.356148: kmem:kfree: call_site=free_bprm+0x8f ptr=(nil)
perf 15905 [009] 1498.356148: kmem:kfree: call_site=do_execveat_common+0x19d ptr=0xffff9cf750421c00
perf 15905 [009] 1498.356168: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=(nil)
perf 15905 [009] 1498.356176: kmem:kfree: call_site=free_bprm+0x8f ptr=(nil)
<SNIP>
perf 15905 [009] 1498.356348: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=(nil)
perf 15905 [014] 1498.356386: kmem:kfree: call_site=security_compute_sid.part.0+0x3b2 ptr=(nil)
perf 15905 [014] 1498.356423: kmem:kfree: call_site=load_elf_binary+0x207 ptr=0xffff9cf5b2a34220
perf 15905 [014] 1498.356694: kmem:kfree: call_site=__free_slab+0xb5 ptr=0xffff9cf6d0b3b000
sleep 15905 [014] 1498.356739: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=(nil)
Use prctl() to show that that is just the preparation of the workload:
# perf script
perf-exec 19036 [009] 2199.357582: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=(nil)
perf-exec 19036 [009] 2199.357604: kmem:kfree: call_site=free_bprm+0x8f ptr=(nil)
perf-exec 19036 [009] 2199.357604: kmem:kfree: call_site=do_execveat_common+0x19d ptr=0xffff9cf786459800
perf-exec 19036 [009] 2199.357630: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=(nil)
<SNIP>
perf-exec 19036 [000] 2199.358277: kmem:kfree: call_site=__free_slab+0xb5 ptr=0xffff9cf786fb9c00
perf-exec 19036 [000] 2199.358278: kmem:kfree: call_site=__free_slab+0xb5 ptr=0xffff9cf786458200
perf-exec 19036 [000] 2199.358279: kmem:kfree: call_site=__free_slab+0xb5 ptr=0xffff9cf786458600
sleep 19036 [000] 2199.358316: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=(nil)
sleep 19036 [000] 2199.358323: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=(nil)
sleep 19036 [000] 2199.358330: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=0xffff9cf58be2d000
sleep 19036 [000] 2199.358337: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=0xffff9cf58be2d000
sleep 19036 [000] 2199.358339: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=0xffff9cf58be2d000
sleep 19036 [000] 2199.358341: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=0xffff9cf58be2d000
Reporter: zhanweiw <wingfancy@hotmail.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=212213
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.