Messages in this thread | | | Date | Mon, 23 Sep 2019 11:17:38 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH v2] perf record: fix priv level with branch sampling for paranoid=2 |
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Em Mon, Sep 23, 2019 at 11:03:45AM -0300, Arnaldo Carvalho de Melo escreveu: > Thanks, tested added Jiri's Acked-by, applied, added this note: > > Committer testing: > > After aplying the patch we get: > > [acme@quaco ~]$ perf record -b -e cycles date > WARNING: Kernel address maps (/proc/{kallsyms,modules}) are restricted, > check /proc/sys/kernel/kptr_restrict and /proc/sys/kernel/perf_event_paranoid. > > Samples in kernel functions may not be resolved if a suitable vmlinux > file is not found in the buildid cache or in the vmlinux path. > > Samples in kernel modules won't be resolved at all. > > If some relocation was applied (e.g. kexec) symbols may be misresolved > even with a suitable vmlinux or kallsyms file. > > Mon 23 Sep 2019 11:00:59 AM -03 > [ perf record: Woken up 1 times to write data ] > [ perf record: Captured and wrote 0.005 MB perf.data (14 samples) ] > [acme@quaco ~]$ perf evlist -v > cycles:u: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|PERIOD|BRANCH_STACK, read_format: ID, disabled: 1, inherit: 1, exclude_kernel: 1, exclude_hv: 1, mmap: 1, comm: 1, freq: 1, enable_on_exec: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1, branch_sample_type: ANY > [acme@quaco ~]$ > > That warning about restricted kernel maps will be suppressed in a follow > up patch, as perf_event_attr.exclude_kernel is set, i.e. no samples for > the kernel will be taken and thus no need for those maps
Its there:
https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/commit/?h=perf/core&id=c8b567c8a96a35acff746b1eef6f859e2a9fc195
- Arnaldo
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