tools/perf/python/sampling.py | 49 +++++++++ tools/perf/util/python.c | 186 +++++++++++++++++++++++++++++++++- 2 files changed, 232 insertions(+), 3 deletions(-) create mode 100755 tools/perf/python/sampling.py
Add an example for sampling events with python. Patch 1 adds support for record_opts struct and patch 2 adds an example for sampling. The example also demonstrates usage of the record_opts struct to customize the evsel initialization from python. Gautam Menghani (2): perf python: Add support for record_opts struct perf python: Add sampling.py as example for sampling tools/perf/python/sampling.py | 49 +++++++++ tools/perf/util/python.c | 186 +++++++++++++++++++++++++++++++++- 2 files changed, 232 insertions(+), 3 deletions(-) create mode 100755 tools/perf/python/sampling.py -- 2.49.0
Hi Ian/Arnaldo, Can you please review this series and let me know if any changes are needed? Thanks, Gautam
On Tue, Sep 16, 2025 at 07:00:48PM +0530, Gautam Menghani wrote: > Hi Ian/Arnaldo, > > Can you please review this series and let me know if any changes are > needed? Looking at it now, sry for the delay, - Arnaldo
On Tue, Sep 16, 2025 at 12:25 PM Arnaldo Carvalho de Melo
<acme@kernel.org> wrote:
>
> On Tue, Sep 16, 2025 at 07:00:48PM +0530, Gautam Menghani wrote:
> > Hi Ian/Arnaldo,
> >
> > Can you please review this series and let me know if any changes are
> > needed?
>
> Looking at it now, sry for the delay,
I think the patches look good. I'm a little concerned that the python
APIs are a chance to do something better than the C APIs that have
evolved. For example, we removed UID out of target recently [1] as the
BPF alternative was better. Had this patch come earlier then it seems
likely we'd have had target with UIDs. I wonder rather than having a
kwlist of:
+ static char *kwlist[] = { "target", "inherit_stat", "no_buffering",
"no_inherit",
+ "no_inherit_set", "no_samples", "raw_samples",
+ "sample_address", "sample_phys_addr", "sample_data_page_size",
+ "sample_code_page_size", "sample_weight", "sample_time",
+ "sample_time_set", "sample_cpu", "sample_identifier",
+ "sample_data_src", "period", "period_set", "running_time",
+ "full_auxtrace", "auxtrace_snapshot_mode",
+ "auxtrace_snapshot_on_exit", "auxtrace_sample_mode",
+ "record_namespaces", "record_cgroup", "record_switch_events",
+ "record_switch_events_set", "all_kernel", "all_user",
+ "kernel_callchains", "user_callchains", "tail_synthesize",
+ "overwrite", "ignore_missing_thread", "strict_freq", "sample_id",
+ "no_bpf_event", "kcore", "text_poke", "build_id", "freq",
+ "mmap_pages", "auxtrace_mmap_pages", "user_freq", "branch_stack",
+ "sample_intr_regs", "sample_user_regs", "default_interval",
+ "user_interval", "auxtrace_snapshot_size", "auxtrace_snapshot_opts",
+ "auxtrace_sample_opts", "sample_transaction", "use_clockid",
+ "clockid", "clockid_res_ns", "nr_cblocks", "affinity", "mmap_flush",
+ "comp_level", "nr_threads_synthesize", "ctl_fd", "ctl_fd_ack",
+ "ctl_fd_close", "synth", "threads_spec", "threads_user_spec",
+ "off_cpu_thresh_ns", NULL };
but then just using this subset:
+ opts = perf.record_opts(freq=1000, target=tgt, sample_time=True,
+ sample_cpu=True, no_buffering=True,
no_inherit=True)
The kwlist should be kept to just those necessary values for the
example to work? I kind of see this as Arnaldo's baby, so he may just
want everything, so this needn't be a blocker.
Bigger picture I wonder about migrating the `perf script` code to just
being regular python programs like the example here. I sent out
deprecating the libperl code to this ends (looking for reviews):
https://lore.kernel.org/linux-perf-users/20250908181918.3533480-1-irogers@google.com/
The issue is that `perf script` being the main thread inhibits things
like textual running until trace_end. This means we can't do things
like incremental loading support. We may want to make the perf events
support something like an asyncio interface for that.
Refactoring that support will likely raise backward compatibility
concerns. It'd be a really nice thing to do as the API has some fairly
major overheads like turning everything in a sample into a Dict
whether needed or not:
https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/perf/util/scripting-engines/trace-event-python.c#n838
I mention this just to say why I'd like to minimize the API when possible.
Thanks,
Ian
[1] https://lore.kernel.org/r/20250604174545.2853620-10-irogers@google.com
On Tue, Sep 16, 2025 at 01:07:43PM -0700, Ian Rogers wrote:
> On Tue, Sep 16, 2025 at 12:25 PM Arnaldo Carvalho de Melo
> <acme@kernel.org> wrote:
> >
> > On Tue, Sep 16, 2025 at 07:00:48PM +0530, Gautam Menghani wrote:
> > > Hi Ian/Arnaldo,
> > >
> > > Can you please review this series and let me know if any changes are
> > > needed?
> >
> > Looking at it now, sry for the delay,
>
> I think the patches look good. I'm a little concerned that the python
> APIs are a chance to do something better than the C APIs that have
> evolved. For example, we removed UID out of target recently [1] as the
> BPF alternative was better. Had this patch come earlier then it seems
> likely we'd have had target with UIDs. I wonder rather than having a
> kwlist of:
>
> + static char *kwlist[] = { "target", "inherit_stat", "no_buffering",
> "no_inherit",
> + "no_inherit_set", "no_samples", "raw_samples",
> + "sample_address", "sample_phys_addr", "sample_data_page_size",
> + "sample_code_page_size", "sample_weight", "sample_time",
> + "sample_time_set", "sample_cpu", "sample_identifier",
> + "sample_data_src", "period", "period_set", "running_time",
> + "full_auxtrace", "auxtrace_snapshot_mode",
> + "auxtrace_snapshot_on_exit", "auxtrace_sample_mode",
> + "record_namespaces", "record_cgroup", "record_switch_events",
> + "record_switch_events_set", "all_kernel", "all_user",
> + "kernel_callchains", "user_callchains", "tail_synthesize",
> + "overwrite", "ignore_missing_thread", "strict_freq", "sample_id",
> + "no_bpf_event", "kcore", "text_poke", "build_id", "freq",
> + "mmap_pages", "auxtrace_mmap_pages", "user_freq", "branch_stack",
> + "sample_intr_regs", "sample_user_regs", "default_interval",
> + "user_interval", "auxtrace_snapshot_size", "auxtrace_snapshot_opts",
> + "auxtrace_sample_opts", "sample_transaction", "use_clockid",
> + "clockid", "clockid_res_ns", "nr_cblocks", "affinity", "mmap_flush",
> + "comp_level", "nr_threads_synthesize", "ctl_fd", "ctl_fd_ack",
> + "ctl_fd_close", "synth", "threads_spec", "threads_user_spec",
> + "off_cpu_thresh_ns", NULL };
>
> but then just using this subset:
>
> + opts = perf.record_opts(freq=1000, target=tgt, sample_time=True,
> + sample_cpu=True, no_buffering=True,
> no_inherit=True)
>
> The kwlist should be kept to just those necessary values for the
> example to work? I kind of see this as Arnaldo's baby, so he may just
> want everything, so this needn't be a blocker.
>
> Bigger picture I wonder about migrating the `perf script` code to just
> being regular python programs like the example here.
You mean:
acme@number:~/git/perf-tools-next$ ls -la tools/perf/scripts/python/
total 452
drwxr-xr-x. 1 acme acme 902 Aug 20 14:18 .
drwxr-xr-x. 1 acme acme 30 Sep 17 09:27 ..
-rwxr-xr-x. 1 acme acme 11865 Aug 20 14:06 arm-cs-trace-disasm.py
drwxr-xr-x. 1 acme acme 1640 Aug 20 14:18 bin
-rw-r--r--. 1 acme acme 2461 Apr 16 10:06 check-perf-trace.py
-rw-r--r--. 1 acme acme 7923 Apr 16 10:06 compaction-times.py
-rw-r--r--. 1 acme acme 7497 Apr 16 10:06 event_analyzing_sample.py
-rwxr-xr-x. 1 acme acme 157369 Aug 20 14:18 exported-sql-viewer.py
-rw-r--r--. 1 acme acme 39845 Apr 16 10:06 export-to-postgresql.py
-rw-r--r--. 1 acme acme 24671 Apr 16 10:06 export-to-sqlite.py
-rw-r--r--. 1 acme acme 2173 Apr 16 10:06 failed-syscalls-by-pid.py
-rwxr-xr-x. 1 acme acme 10377 Aug 20 14:18 flamegraph.py
-rw-r--r--. 1 acme acme 1717 Apr 16 10:06 futex-contention.py
-rw-r--r--. 1 acme acme 13302 Apr 16 10:06 gecko.py
-rw-r--r--. 1 acme acme 14636 Apr 16 10:06 intel-pt-events.py
-rw-r--r--. 1 acme acme 3395 Apr 16 10:06 libxed.py
-rw-r--r--. 1 acme acme 4230 Aug 20 14:13 mem-phys-addr.py
-rw-r--r--. 1 acme acme 15420 Aug 20 14:05 netdev-times.py
-rwxr-xr-x. 1 acme acme 1833 Apr 16 10:06 net_dropmonitor.py
-rwxr-xr-x. 1 acme acme 30683 Aug 20 14:05 parallel-perf.py
drwxr-xr-x. 1 acme acme 34 Sep 17 09:27 Perf-Trace-Util
-rw-r--r--. 1 acme acme 4509 Apr 16 10:06 powerpc-hcalls.py
-rw-r--r--. 1 acme acme 12095 Apr 16 10:06 sched-migration.py
-rw-r--r--. 1 acme acme 2183 Apr 16 10:06 sctop.py
-rwxr-xr-x. 1 acme acme 4408 Apr 16 10:06 stackcollapse.py
-rw-r--r--. 1 acme acme 2444 Apr 16 10:06 stat-cpi.py
-rw-r--r--. 1 acme acme 2055 Apr 16 10:06 syscall-counts-by-pid.py
-rw-r--r--. 1 acme acme 1673 Apr 16 10:06 syscall-counts.py
-rwxr-xr-x. 1 acme acme 34014 Apr 16 10:06 task-analyzer.py
acme@number:~/git/perf-tools-next$
And then make:
acme@number:~/git/perf-tools-next$ perf script -l
List of available trace scripts:
compaction-times [-h] [-u] [-p|-pv] [-t | [-m] [-fs] [-ms]] [pid|pid-range|comm-regex] display time taken by mm compaction
event_analyzing_sample analyze all perf samples
export-to-postgresql [database name] [columns] [calls] export perf data to a postgresql database
export-to-sqlite [database name] [columns] [calls] export perf data to a sqlite3 database
failed-syscalls-by-pid [comm] system-wide failed syscalls, by pid
flamegraph create flame graphs
futex-contention futext contention measurement
gecko create firefox gecko profile json format from perf.data
intel-pt-events print Intel PT Events including Power Events and PTWRITE
mem-phys-addr resolve physical address samples
net_dropmonitor display a table of dropped frames
netdev-times [tx] [rx] [dev=] [debug] display a process of packet and processing time
powerpc-hcalls
sched-migration sched migration overview
sctop [comm] [interval] syscall top
stackcollapse produce callgraphs in short form for scripting use
syscall-counts-by-pid [comm] system-wide syscall counts, by pid
syscall-counts [comm] system-wide syscall counts
task-analyzer analyze timings of tasks
failed-syscalls [comm] system-wide failed syscalls
rw-by-file <comm> r/w activity for a program, by file
rw-by-pid system-wide r/w activity
rwtop [interval] system-wide r/w top
wakeup-latency system-wide min/max/avg wakeup latency
acme@number:~/git/perf-tools-next$
And make:
perf script rwtop
Just call 'python PATH_TO_PYTHON_SCRIPTS/rwtop.py' transparently?
That looks interesting indeed, that way we would stop linking with
libpython, etc.
I wonder if there are out of tree scripts using the current tools/perf/util/scripting-engines/trace-event-python.c
mechanism...
But even that can fallback to a python based mechanism, right?
Import the script, if it has a given structure, use the new way, if not,
call a glue that reads the events and feed to the old style code.
Seems doable and would save code on the main perf binary and headaches
with the libpython and libperl build processes.
- Arnaldo
> I sent out
> deprecating the libperl code to this ends (looking for reviews):
> https://lore.kernel.org/linux-perf-users/20250908181918.3533480-1-irogers@google.com/
> The issue is that `perf script` being the main thread inhibits things
> like textual running until trace_end. This means we can't do things
> like incremental loading support. We may want to make the perf events
> support something like an asyncio interface for that.
>
> Refactoring that support will likely raise backward compatibility
> concerns. It'd be a really nice thing to do as the API has some fairly
> major overheads like turning everything in a sample into a Dict
> whether needed or not:
> https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/perf/util/scripting-engines/trace-event-python.c#n838
> I mention this just to say why I'd like to minimize the API when possible.
>
> Thanks,
> Ian
>
> [1] https://lore.kernel.org/r/20250604174545.2853620-10-irogers@google.com
On Wed, Sep 17, 2025 at 5:37 AM Arnaldo Carvalho de Melo
<acme@kernel.org> wrote:
>
> On Tue, Sep 16, 2025 at 01:07:43PM -0700, Ian Rogers wrote:
> > On Tue, Sep 16, 2025 at 12:25 PM Arnaldo Carvalho de Melo
> > <acme@kernel.org> wrote:
> > >
> > > On Tue, Sep 16, 2025 at 07:00:48PM +0530, Gautam Menghani wrote:
> > > > Hi Ian/Arnaldo,
> > > >
> > > > Can you please review this series and let me know if any changes are
> > > > needed?
> > >
> > > Looking at it now, sry for the delay,
> >
> > I think the patches look good. I'm a little concerned that the python
> > APIs are a chance to do something better than the C APIs that have
> > evolved. For example, we removed UID out of target recently [1] as the
> > BPF alternative was better. Had this patch come earlier then it seems
> > likely we'd have had target with UIDs. I wonder rather than having a
> > kwlist of:
> >
> > + static char *kwlist[] = { "target", "inherit_stat", "no_buffering",
> > "no_inherit",
> > + "no_inherit_set", "no_samples", "raw_samples",
> > + "sample_address", "sample_phys_addr", "sample_data_page_size",
> > + "sample_code_page_size", "sample_weight", "sample_time",
> > + "sample_time_set", "sample_cpu", "sample_identifier",
> > + "sample_data_src", "period", "period_set", "running_time",
> > + "full_auxtrace", "auxtrace_snapshot_mode",
> > + "auxtrace_snapshot_on_exit", "auxtrace_sample_mode",
> > + "record_namespaces", "record_cgroup", "record_switch_events",
> > + "record_switch_events_set", "all_kernel", "all_user",
> > + "kernel_callchains", "user_callchains", "tail_synthesize",
> > + "overwrite", "ignore_missing_thread", "strict_freq", "sample_id",
> > + "no_bpf_event", "kcore", "text_poke", "build_id", "freq",
> > + "mmap_pages", "auxtrace_mmap_pages", "user_freq", "branch_stack",
> > + "sample_intr_regs", "sample_user_regs", "default_interval",
> > + "user_interval", "auxtrace_snapshot_size", "auxtrace_snapshot_opts",
> > + "auxtrace_sample_opts", "sample_transaction", "use_clockid",
> > + "clockid", "clockid_res_ns", "nr_cblocks", "affinity", "mmap_flush",
> > + "comp_level", "nr_threads_synthesize", "ctl_fd", "ctl_fd_ack",
> > + "ctl_fd_close", "synth", "threads_spec", "threads_user_spec",
> > + "off_cpu_thresh_ns", NULL };
> >
> > but then just using this subset:
> >
> > + opts = perf.record_opts(freq=1000, target=tgt, sample_time=True,
> > + sample_cpu=True, no_buffering=True,
> > no_inherit=True)
> >
> > The kwlist should be kept to just those necessary values for the
> > example to work? I kind of see this as Arnaldo's baby, so he may just
> > want everything, so this needn't be a blocker.
> >
> > Bigger picture I wonder about migrating the `perf script` code to just
> > being regular python programs like the example here.
>
> You mean:
>
> acme@number:~/git/perf-tools-next$ ls -la tools/perf/scripts/python/
> total 452
> drwxr-xr-x. 1 acme acme 902 Aug 20 14:18 .
> drwxr-xr-x. 1 acme acme 30 Sep 17 09:27 ..
> -rwxr-xr-x. 1 acme acme 11865 Aug 20 14:06 arm-cs-trace-disasm.py
> drwxr-xr-x. 1 acme acme 1640 Aug 20 14:18 bin
> -rw-r--r--. 1 acme acme 2461 Apr 16 10:06 check-perf-trace.py
> -rw-r--r--. 1 acme acme 7923 Apr 16 10:06 compaction-times.py
> -rw-r--r--. 1 acme acme 7497 Apr 16 10:06 event_analyzing_sample.py
> -rwxr-xr-x. 1 acme acme 157369 Aug 20 14:18 exported-sql-viewer.py
> -rw-r--r--. 1 acme acme 39845 Apr 16 10:06 export-to-postgresql.py
> -rw-r--r--. 1 acme acme 24671 Apr 16 10:06 export-to-sqlite.py
> -rw-r--r--. 1 acme acme 2173 Apr 16 10:06 failed-syscalls-by-pid.py
> -rwxr-xr-x. 1 acme acme 10377 Aug 20 14:18 flamegraph.py
> -rw-r--r--. 1 acme acme 1717 Apr 16 10:06 futex-contention.py
> -rw-r--r--. 1 acme acme 13302 Apr 16 10:06 gecko.py
> -rw-r--r--. 1 acme acme 14636 Apr 16 10:06 intel-pt-events.py
> -rw-r--r--. 1 acme acme 3395 Apr 16 10:06 libxed.py
> -rw-r--r--. 1 acme acme 4230 Aug 20 14:13 mem-phys-addr.py
> -rw-r--r--. 1 acme acme 15420 Aug 20 14:05 netdev-times.py
> -rwxr-xr-x. 1 acme acme 1833 Apr 16 10:06 net_dropmonitor.py
> -rwxr-xr-x. 1 acme acme 30683 Aug 20 14:05 parallel-perf.py
> drwxr-xr-x. 1 acme acme 34 Sep 17 09:27 Perf-Trace-Util
> -rw-r--r--. 1 acme acme 4509 Apr 16 10:06 powerpc-hcalls.py
> -rw-r--r--. 1 acme acme 12095 Apr 16 10:06 sched-migration.py
> -rw-r--r--. 1 acme acme 2183 Apr 16 10:06 sctop.py
> -rwxr-xr-x. 1 acme acme 4408 Apr 16 10:06 stackcollapse.py
> -rw-r--r--. 1 acme acme 2444 Apr 16 10:06 stat-cpi.py
> -rw-r--r--. 1 acme acme 2055 Apr 16 10:06 syscall-counts-by-pid.py
> -rw-r--r--. 1 acme acme 1673 Apr 16 10:06 syscall-counts.py
> -rwxr-xr-x. 1 acme acme 34014 Apr 16 10:06 task-analyzer.py
> acme@number:~/git/perf-tools-next$
>
> And then make:
>
> acme@number:~/git/perf-tools-next$ perf script -l
> List of available trace scripts:
> compaction-times [-h] [-u] [-p|-pv] [-t | [-m] [-fs] [-ms]] [pid|pid-range|comm-regex] display time taken by mm compaction
> event_analyzing_sample analyze all perf samples
> export-to-postgresql [database name] [columns] [calls] export perf data to a postgresql database
> export-to-sqlite [database name] [columns] [calls] export perf data to a sqlite3 database
> failed-syscalls-by-pid [comm] system-wide failed syscalls, by pid
> flamegraph create flame graphs
> futex-contention futext contention measurement
> gecko create firefox gecko profile json format from perf.data
> intel-pt-events print Intel PT Events including Power Events and PTWRITE
> mem-phys-addr resolve physical address samples
> net_dropmonitor display a table of dropped frames
> netdev-times [tx] [rx] [dev=] [debug] display a process of packet and processing time
> powerpc-hcalls
> sched-migration sched migration overview
> sctop [comm] [interval] syscall top
> stackcollapse produce callgraphs in short form for scripting use
> syscall-counts-by-pid [comm] system-wide syscall counts, by pid
> syscall-counts [comm] system-wide syscall counts
> task-analyzer analyze timings of tasks
> failed-syscalls [comm] system-wide failed syscalls
> rw-by-file <comm> r/w activity for a program, by file
> rw-by-pid system-wide r/w activity
> rwtop [interval] system-wide r/w top
> wakeup-latency system-wide min/max/avg wakeup latency
> acme@number:~/git/perf-tools-next$
>
> And make:
>
> perf script rwtop
>
> Just call 'python PATH_TO_PYTHON_SCRIPTS/rwtop.py' transparently?
Yeah, that's it. The perf script libpython stuff is just providing
trace_begin, process_event and trace_end. Using the sampling
mechanism, as shown in Gautum's patches, it is pretty easy to migrate
them to being stand alone bits of python.
> That looks interesting indeed, that way we would stop linking with
> libpython, etc.
>
> I wonder if there are out of tree scripts using the current tools/perf/util/scripting-engines/trace-event-python.c
> mechanism...
>
> But even that can fallback to a python based mechanism, right?
I think so. Like I said about the use of a Dict for process_event, we
may want to streamline things so there is a tension with what the API
should be and compatibility. We can always have 2 APIs and try to
deprecate one of them.
> Import the script, if it has a given structure, use the new way, if not,
> call a glue that reads the events and feed to the old style code.
>
> Seems doable and would save code on the main perf binary and headaches
> with the libpython and libperl build processes.
So I see this for libpython, and I think it'd be pretty cool if we
could have things work like this for say "perf script ilist" and
Alice's textual flamegraph work. I worry what the work for libperl
would be like and whether it is worth it (hence sending the patch to
at least start to make it opt-in rather than opt-out).
Do you need my tags for these changes or wdyt about making the
kwlist/API surface smaller?
Thanks!
Ian
> - Arnaldo
>
> > I sent out
> > deprecating the libperl code to this ends (looking for reviews):
> > https://lore.kernel.org/linux-perf-users/20250908181918.3533480-1-irogers@google.com/
> > The issue is that `perf script` being the main thread inhibits things
> > like textual running until trace_end. This means we can't do things
> > like incremental loading support. We may want to make the perf events
> > support something like an asyncio interface for that.
> >
> > Refactoring that support will likely raise backward compatibility
> > concerns. It'd be a really nice thing to do as the API has some fairly
> > major overheads like turning everything in a sample into a Dict
> > whether needed or not:
> > https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/perf/util/scripting-engines/trace-event-python.c#n838
> > I mention this just to say why I'd like to minimize the API when possible.
> >
> > Thanks,
> > Ian
> >
> > [1] https://lore.kernel.org/r/20250604174545.2853620-10-irogers@google.com
On Wed, Sep 17, 2025 at 08:29:24AM -0700, Ian Rogers wrote: > On Wed, Sep 17, 2025 at 5:37 AM Arnaldo Carvalho de Melo <acme@kernel.org> wrote: > > And make: > > perf script rwtop > > Just call 'python PATH_TO_PYTHON_SCRIPTS/rwtop.py' transparently? > Yeah, that's it. The perf script libpython stuff is just providing > trace_begin, process_event and trace_end. Using the sampling > mechanism, as shown in Gautum's patches, it is pretty easy to migrate > them to being stand alone bits of python. > > That looks interesting indeed, that way we would stop linking with > > libpython, etc. > > I wonder if there are out of tree scripts using the current tools/perf/util/scripting-engines/trace-event-python.c > > mechanism... > > But even that can fallback to a python based mechanism, right? > I think so. Like I said about the use of a Dict for process_event, we > may want to streamline things so there is a tension with what the API > should be and compatibility. We can always have 2 APIs and try to > deprecate one of them. > > Import the script, if it has a given structure, use the new way, if not, > > call a glue that reads the events and feed to the old style code. > > Seems doable and would save code on the main perf binary and headaches > > with the libpython and libperl build processes. > So I see this for libpython, and I think it'd be pretty cool if we > could have things work like this for say "perf script ilist" and I think we could even try to, not having a builtin-ilist.c convert 'perf ilist' to 'perf script ilist' automagically. > Alice's textual flamegraph work. I worry what the work for libperl > would be like and whether it is worth it (hence sending the patch to > at least start to make it opt-in rather than opt-out). Maybe we should be a tad more cautious and start with emitting a warning that "libperl is deprecated (holler if you disagree if you use it!)" and then make it opt-in, and then remove it. > Do you need my tags for these changes or wdyt about making the > kwlist/API surface smaller? Lemme look at the original post... - Arnaldo
On Wed, Sep 17, 2025 at 9:41 AM Arnaldo Carvalho de Melo <acme@kernel.org> wrote: > > On Wed, Sep 17, 2025 at 08:29:24AM -0700, Ian Rogers wrote: > > On Wed, Sep 17, 2025 at 5:37 AM Arnaldo Carvalho de Melo <acme@kernel.org> wrote: > > > And make: > > > > perf script rwtop > > > > Just call 'python PATH_TO_PYTHON_SCRIPTS/rwtop.py' transparently? > > > Yeah, that's it. The perf script libpython stuff is just providing > > trace_begin, process_event and trace_end. Using the sampling > > mechanism, as shown in Gautum's patches, it is pretty easy to migrate > > them to being stand alone bits of python. > > > > That looks interesting indeed, that way we would stop linking with > > > libpython, etc. > > > > I wonder if there are out of tree scripts using the current tools/perf/util/scripting-engines/trace-event-python.c > > > mechanism... > > > > But even that can fallback to a python based mechanism, right? > > > I think so. Like I said about the use of a Dict for process_event, we > > may want to streamline things so there is a tension with what the API > > should be and compatibility. We can always have 2 APIs and try to > > deprecate one of them. > > > > Import the script, if it has a given structure, use the new way, if not, > > > call a glue that reads the events and feed to the old style code. > > > > Seems doable and would save code on the main perf binary and headaches > > > with the libpython and libperl build processes. > > > So I see this for libpython, and I think it'd be pretty cool if we > > could have things work like this for say "perf script ilist" and > > I think we could even try to, not having a builtin-ilist.c convert > 'perf ilist' to 'perf script ilist' automagically. > > > Alice's textual flamegraph work. I worry what the work for libperl > > would be like and whether it is worth it (hence sending the patch to > > at least start to make it opt-in rather than opt-out). > > Maybe we should be a tad more cautious and start with emitting a warning > that "libperl is deprecated (holler if you disagree if you use it!)" and > then make it opt-in, and then remove it. Not sure I follow, let's move the conversation to that patch. > > Do you need my tags for these changes or wdyt about making the > > kwlist/API surface smaller? > > Lemme look at the original post... Thanks, Ian > - Arnaldo
Hi, Gentle ping. Please review this series and let me know if any changes are needed. Thanks, Gautam
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