Re: [PATCHv4 00/25] perf: Add mmap2 build id support

Namhyung Kim
2020-11-27T04:41:42Z

Hi Jiri,

On Fri, Nov 27, 2020 at 2:00 AM Jiri Olsa <jolsa@kernel.org> wrote:
>
> hi,
> adding the support to have buildid stored in mmap2 event,
> so we can bypass the final perf record hunt on build ids.
>
> This patchset allows perf to record build ID in mmap2 event,
> and adds perf tooling to store/download binaries to .debug
> cache based on these build IDs.
>
> Note that the build id retrieval code is stolen from bpf
> code, where it's been used (together with file offsets)
> to replace IPs in user space stack traces. It's now added
> under lib directory.

For the series:

Acked-by: Namhyung Kim <namhyung@kernel.org>

Thanks,
Namhyung

>
> v4 changes:
> - fixed typo in changelog [Namhyung]
> - removed force_download bool from struct dso_store_data,
> because it's not used [Namhyung]
>
> v3 changes:
> - added acks
> - removed forgotten debug code [Arnaldo]
> - fixed readlink termination [Ian]
> - fixed doc for --debuginfod=URLs [Ian]
> - adopted kernel's memchr_inv function and used
> it in build_id__is_defined function [Arnaldo]
>
> On recording server:
>
> - on the recording server we can run record with --buildid-mmap
> option to store build ids in mmap2 events:
>
> # perf record --buildid-mmap
> ^C[ perf record: Woken up 2 times to write data ]
> [ perf record: Captured and wrote 0.836 MB perf.data ]
>
> - it stores nothing to ~/.debug cache:
>
> # find ~/.debug
> find: ‘/root/.debug’: No such file or directory
>
> - and still reports properly:
>
> # perf report --stdio
> ...
> 99.82% swapper [kernel.kallsyms] [k] native_safe_halt
> 0.03% swapper [kernel.kallsyms] [k] finish_task_switch
> 0.02% swapper [kernel.kallsyms] [k] __softirqentry_text_start
> 0.01% kcompactd0 [kernel.kallsyms] [k] _raw_spin_unlock_irqrestore
> 0.01% ksoftirqd/6 [kernel.kallsyms] [k] slab_free_freelist_hook
> 0.01% kworker/17:1H-x [kernel.kallsyms] [k] slab_free_freelist_hook
>
> - display used/hit build ids:
>
> # perf buildid-list | head -5
> 5dcec522abf136fcfd3128f47e131f2365834dd7 /proc/kcore
> 589e403a34f55486bcac848a45e00bcdeedd1ca8 /usr/lib64/libcrypto.so.1.1.1g
> 94569566d4eac7e9c87ba029d43d4e2158f9527e /usr/lib64/libpthread-2.30.so
> 559b9702bebe31c6d132c8dc5cc887673d65d5b5 /usr/lib64/libc-2.30.so
> 40da7abe89f631f60538a17686a7d65c6a02ed31 /usr/lib64/ld-2.30.so
>
> - store build id binaries into build id cache:
>
> # perf buildid-cache -a perf.data
> OK 5dcec522abf136fcfd3128f47e131f2365834dd7 /proc/kcore
> OK 589e403a34f55486bcac848a45e00bcdeedd1ca8 /usr/lib64/libcrypto.so.1.1.1g
> OK 94569566d4eac7e9c87ba029d43d4e2158f9527e /usr/lib64/libpthread-2.30.so
> OK 559b9702bebe31c6d132c8dc5cc887673d65d5b5 /usr/lib64/libc-2.30.so
> OK 40da7abe89f631f60538a17686a7d65c6a02ed31 /usr/lib64/ld-2.30.so
> OK a674f7a47c78e35a088104647b9640710277b489 /usr/sbin/sshd
> OK e5cb4ca25f46485bdbc691c3a92e7e111dac3ef2 /usr/bin/bash
> OK 9bc8589108223c944b452f0819298a0c3cba6215 /usr/bin/find
>
> # find ~/.debug | head -5
> /root/.debug
> /root/.debug/proc
> /root/.debug/proc/kcore
> /root/.debug/proc/kcore/5dcec522abf136fcfd3128f47e131f2365834dd7
> /root/.debug/proc/kcore/5dcec522abf136fcfd3128f47e131f2365834dd7/kallsyms
>
> - run debuginfod daemon to provide binaries to another server (below)
> (the initialization could take some time)
>
> # debuginfod -F /
>
>
> On another server:
>
> - copy perf.data from 'record' server and run:
>
> $ find ~/.debug/
> find: ‘/home/jolsa/.debug/’: No such file or directory
>
> $ perf buildid-list | head -5
> No kallsyms or vmlinux with build-id 5dcec522abf136fcfd3128f47e131f2365834dd7 was found
> 5dcec522abf136fcfd3128f47e131f2365834dd7 [kernel.kallsyms]
> 5784f813b727a50cfd3363234aef9fcbab685cc4 /lib/modules/5.10.0-rc2speed+/kernel/fs/xfs/xfs.ko
> 589e403a34f55486bcac848a45e00bcdeedd1ca8 /usr/lib64/libcrypto.so.1.1.1g
> 94569566d4eac7e9c87ba029d43d4e2158f9527e /usr/lib64/libpthread-2.30.so
> 559b9702bebe31c6d132c8dc5cc887673d65d5b5 /usr/lib64/libc-2.30.so
>
> - report does not show anything (kernel build id does not match):
>
> $ perf report --stdio
> ...
> 76.73% swapper [kernel.kallsyms] [k] 0xffffffff81aa8ebe
> 1.89% find [kernel.kallsyms] [k] 0xffffffff810f2167
> 0.93% sshd [kernel.kallsyms] [k] 0xffffffff8153380c
> 0.83% swapper [kernel.kallsyms] [k] 0xffffffff81104b0b
> 0.71% kworker/u40:2-e [kernel.kallsyms] [k] 0xffffffff810f3850
> 0.70% kworker/u40:0-e [kernel.kallsyms] [k] 0xffffffff810f3850
> 0.64% find [kernel.kallsyms] [k] 0xffffffff81a9ba0a
> 0.63% find [kernel.kallsyms] [k] 0xffffffff81aa93b0
>
> - add build ids does not work, because existing binaries (on another server)
> have different build ids:
>
> $ perf buildid-cache -a perf.data
> No kallsyms or vmlinux with build-id 5dcec522abf136fcfd3128f47e131f2365834dd7 was found
> FAIL 5dcec522abf136fcfd3128f47e131f2365834dd7 [kernel.kallsyms]
> FAIL 5784f813b727a50cfd3363234aef9fcbab685cc4 /lib/modules/5.10.0-rc2speed+/kernel/fs/xfs/xfs.ko
> FAIL 589e403a34f55486bcac848a45e00bcdeedd1ca8 /usr/lib64/libcrypto.so.1.1.1g
> FAIL 94569566d4eac7e9c87ba029d43d4e2158f9527e /usr/lib64/libpthread-2.30.so
> FAIL 559b9702bebe31c6d132c8dc5cc887673d65d5b5 /usr/lib64/libc-2.30.so
> FAIL 40da7abe89f631f60538a17686a7d65c6a02ed31 /usr/lib64/ld-2.30.so
> FAIL a674f7a47c78e35a088104647b9640710277b489 /usr/sbin/sshd
> FAIL e5cb4ca25f46485bdbc691c3a92e7e111dac3ef2 /usr/bin/bash
> FAIL 9bc8589108223c944b452f0819298a0c3cba6215 /usr/bin/find
>
> - add build ids with debuginfod setup pointing to record server:
>
> $ perf buildid-cache -a perf.data --debuginfod http://192.168.122.174:8002
> No kallsyms or vmlinux with build-id 5dcec522abf136fcfd3128f47e131f2365834dd7 was found
> OK 5dcec522abf136fcfd3128f47e131f2365834dd7 [kernel.kallsyms]
> OK 5784f813b727a50cfd3363234aef9fcbab685cc4 /lib/modules/5.10.0-rc2speed+/kernel/fs/xfs/xfs.ko
> OK 589e403a34f55486bcac848a45e00bcdeedd1ca8 /usr/lib64/libcrypto.so.1.1.1g
> OK 94569566d4eac7e9c87ba029d43d4e2158f9527e /usr/lib64/libpthread-2.30.so
> OK 559b9702bebe31c6d132c8dc5cc887673d65d5b5 /usr/lib64/libc-2.30.so
> OK 40da7abe89f631f60538a17686a7d65c6a02ed31 /usr/lib64/ld-2.30.so
> OK a674f7a47c78e35a088104647b9640710277b489 /usr/sbin/sshd
> OK e5cb4ca25f46485bdbc691c3a92e7e111dac3ef2 /usr/bin/bash
> OK 9bc8589108223c944b452f0819298a0c3cba6215 /usr/bin/find
>
> - and report works:
>
> $ perf report --stdio
> ...
> 76.73% swapper [kernel.kallsyms] [k] native_safe_halt
> 1.91% find [kernel.kallsyms] [k] queue_work_on
> 0.93% sshd [kernel.kallsyms] [k] iowrite16
> 0.83% swapper [kernel.kallsyms] [k] finish_task_switch
> 0.72% kworker/u40:2-e [kernel.kallsyms] [k] process_one_work
> 0.70% kworker/u40:0-e [kernel.kallsyms] [k] process_one_work
> 0.64% find [kernel.kallsyms] [k] syscall_enter_from_user_mode
> 0.63% find [kernel.kallsyms] [k] _raw_spin_unlock_irqrestore
>
> - because we have the data in build id cache:
>
> $ find ~/.debug | head -10
> .../.debug
> .../.debug/home
> .../.debug/home/jolsa
> .../.debug/home/jolsa/.cache
> .../.debug/home/jolsa/.cache/debuginfod_client
> .../.debug/home/jolsa/.cache/debuginfod_client/5dcec522abf136fcfd3128f47e131f2365834dd7
> .../.debug/home/jolsa/.cache/debuginfod_client/5dcec522abf136fcfd3128f47e131f2365834dd7/executable
> .../.debug/home/jolsa/.cache/debuginfod_client/5dcec522abf136fcfd3128f47e131f2365834dd7/executable/5dcec522abf136fcfd3128f47e131f2365834dd7
> .../.debug/home/jolsa/.cache/debuginfod_client/5dcec522abf136fcfd3128f47e131f2365834dd7/executable/5dcec522abf136fcfd3128f47e131f2365834dd7/elf
> .../.debug/home/jolsa/.cache/debuginfod_client/5dcec522abf136fcfd3128f47e131f2365834dd7/executable/5dcec522abf136fcfd3128f47e131f2365834dd7/debug
>
>
> Available also in:
> git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git
> perf/build_id
>
> thanks,
> jirka
>
>
> Cc: Frank Ch. Eigler <fche@redhat.com>
> Cc: Mark Wielaard <mjw@redhat.com>
> ---
> Jiri Olsa (25):
> bpf: Move stack_map_get_build_id into lib
> bpf: Add size arg to build_id_parse function
> perf: Add build id data in mmap2 event
> tools headers uapi: Sync tools/include/uapi/linux/perf_event.h
> tools lib: Adopt memchr_inv() from kernel
> perf tools: Do not swap mmap2 fields in case it contains build id
> perf tools: Add build_id__is_defined function
> perf tools: Add filename__decompress function
> perf tools: Add support to read build id from compressed elf
> perf tools: Add check for existing link in buildid dir
> perf tools: Use struct extra_kernel_map in machine__process_kernel_mmap_event
> perf tools: Try to load vmlinux from buildid database
> perf tools: Store build id from mmap2 events
> perf tools: Allow mmap2 event to synthesize kernel image
> perf tools: Allow mmap2 event to synthesize modules
> perf tools: Synthesize build id for kernel/modules/tasks
> perf tools: Add support to display build id for mmap2 events
> perf tools: Use machine__for_each_dso in perf_session__cache_build_ids
> perf tools: Add __perf_session__cache_build_ids function
> perf tools: Add is_perf_data function
> perf tools: Add build_id_cache__add function
> perf buildid-cache: Add support to add build ids from perf data
> perf buildid-cache: Add --debuginfod option
> perf buildid-list: Add support for mmap2's buildid events
> perf record: Add --buildid-mmap option to enable mmap's build id
>
> include/linux/buildid.h | 12 +++++
> include/uapi/linux/perf_event.h | 42 +++++++++++++++---
> kernel/bpf/stackmap.c | 143 ++----------------------------------------------------------
> kernel/events/core.c | 32 ++++++++++++--
> lib/Makefile | 3 +-
> lib/buildid.c | 149 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> tools/include/linux/string.h | 1 +
> tools/include/uapi/linux/perf_event.h | 42 +++++++++++++++---
> tools/lib/perf/include/perf/event.h | 18 ++++++--
> tools/lib/string.c | 58 +++++++++++++++++++++++++
> tools/perf/Documentation/perf-buildid-cache.txt | 18 +++++++-
> tools/perf/Documentation/perf-config.txt | 10 ++++-
> tools/perf/Documentation/perf-record.txt | 3 ++
> tools/perf/builtin-buildid-cache.c | 241 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---
> tools/perf/builtin-buildid-list.c | 3 ++
> tools/perf/builtin-record.c | 20 +++++++++
> tools/perf/tests/shell/trace+probe_vfs_getname.sh | 2 +-
> tools/perf/util/build-id.c | 127 ++++++++++++++++++++++++++++++++++-------------------
> tools/perf/util/build-id.h | 8 ++++
> tools/perf/util/data.c | 19 ++++++++
> tools/perf/util/data.h | 1 +
> tools/perf/util/dso.c | 31 ++++++++-----
> tools/perf/util/dso.h | 2 +
> tools/perf/util/event.c | 41 +++++++++++++-----
> tools/perf/util/evsel.c | 10 +++--
> tools/perf/util/machine.c | 80 +++++++++++++++++++++-------------
> tools/perf/util/map.c | 8 +++-
> tools/perf/util/map.h | 3 +-
> tools/perf/util/perf_api_probe.c | 10 +++++
> tools/perf/util/perf_api_probe.h | 1 +
> tools/perf/util/perf_event_attr_fprintf.c | 2 +
> tools/perf/util/probe-event.c | 6 +--
> tools/perf/util/record.h | 1 +
> tools/perf/util/session.c | 11 +++--
> tools/perf/util/symbol-elf.c | 37 +++++++++++++++-
> tools/perf/util/symbol.c | 16 +++++++
> tools/perf/util/symbol_conf.h | 3 +-
> tools/perf/util/synthetic-events.c | 121 ++++++++++++++++++++++++++++++++++++++-------------
> 38 files changed, 1024 insertions(+), 311 deletions(-)
> create mode 100644 include/linux/buildid.h
> create mode 100644 lib/buildid.c
>