kernel/linux.git/tools/perf/util/expr.h, branch linux-5.11.y

perf expr: Force encapsulation on expr_id_data

2020-11-16T17:09:18+00:00

This patch resolves some undefined behavior where variables in expr_id_data were accessed (for debugging) without being defined. To better enforce the tagged union behavior, the struct is moved into expr.c and accessors provided. Tag values (kinds) are explicitly identified. Signed-off-by: Ian Rogers Reviewed-By: Kajol Jain Acked-by: Jiri Olsa Link: https://lore.kernel.org/r/20200826153055.2067780-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf metric: Add recursion check when processing nested metrics

2020-07-30T10:01:49+00:00

Keeping the stack of nested metrics via 'struct expr_id' objects and checking if we are in recursion via already processed metric. The stack is implemented as static array within the struct egroup with 100 entries, which should be enough nesting depth for any metric we have or plan to have at the moment. Adding test that simulates the recursion and checks we can detect it. Committer notes: Bumped RECURSION_ID_MAX to 1000 as per Jiri's reply to Paul Clark on the patch series e-mail discussion. Fixed these: tests/parse-metric.c:308:7: error: missing field 'val' initializer [-Werror,-Wmissing-field-initializers] { 0 }, ^ util/metricgroup.c:924:28: error: missing field 'parent' initializer [-Werror,-Wmissing-field-initializers] struct expr_ids ids = { 0 }; ^ util/metricgroup.c:924:26: error: suggest braces around initialization of subobject [-Werror,-Wmissing-braces] struct expr_ids ids = { 0 }; ^ {} util/metricgroup.c:924:26: error: suggest braces around initialization of subobject [-Werror,-Wmissing-braces] struct expr_ids ids = { 0 }; ^ {} util/metricgroup.c:924:28: error: missing field 'cnt' initializer [-Werror,-Wmissing-field-initializers] struct expr_ids ids = { 0 }; ^ Signed-off-by: Jiri Olsa Reviewed-by: Kajol Jain Acked-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: John Garry Cc: Michael Petlan Cc: Namhyung Kim Cc: Paul Clarke Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20200719181320.785305-16-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf metric: Compute referenced metrics

2020-07-30T10:01:49+00:00

Adding computation (expr__parse call) of referenced metric at the point when it needs to be resolved during the parent metric computation. Once the inner metric is computed, the result is stored and used if there's another usage of that metric. Signed-off-by: Jiri Olsa Reviewed-by: Kajol Jain Acked-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: John Garry Cc: Michael Petlan Cc: Namhyung Kim Cc: Paul Clarke Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20200719181320.785305-12-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf metric: Add referenced metrics to hash data

2020-07-30T10:01:49+00:00

Adding referenced metrics to the parsing context so they can be resolved during the metric processing. Adding expr__add_ref function to store referenced metrics into parse context. Signed-off-by: Jiri Olsa Reviewed-by: Kajol Jain Acked-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: John Garry Cc: Michael Petlan Cc: Namhyung Kim Cc: Paul Clarke Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20200719181320.785305-11-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf metric: Add expr__del_id function

2020-07-30T10:01:49+00:00

Adding expr__del_id function to remove ID from hashmap. It will save us few lines in following changes. Signed-off-by: Jiri Olsa Reviewed-by: Kajol Jain Acked-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: John Garry Cc: Michael Petlan Cc: Namhyung Kim Cc: Paul Clarke Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20200719181320.785305-5-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf metric: Change expr__get_id to return struct expr_id_data

2020-07-30T10:01:49+00:00

Changing expr__get_id to use and return struct expr_id_data pointer as value for the ID. This way we can access data other than value for given ID in following changes. Signed-off-by: Jiri Olsa Reviewed-by: Kajol Jain Acked-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: John Garry Cc: Michael Petlan Cc: Namhyung Kim Cc: Paul Clarke Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20200719181320.785305-4-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf metric: Add expr__add_id function

2020-07-30T10:01:49+00:00

Add the expr__add_id() function to data for ID with zero value, which is used when scanning the expression for IDs. Signed-off-by: Jiri Olsa Reviewed-by: Kajol Jain Acked-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: John Garry Cc: Michael Petlan Cc: Namhyung Kim Cc: Paul Clarke Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20200719181320.785305-3-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf metric: Add 'struct expr_id_data' to keep expr value

2020-07-17T12:09:48+00:00

Add 'struct expr_id_data' to keep an expr value instead of just a simple double pointer, so we can store more data for ID in the following changes. Signed-off-by: Jiri Olsa Acked-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: John Garry Cc: Kajol Jain Cc: Michael Petlan Cc: Namhyung Kim Cc: Paul Clarke Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20200712132634.138901-3-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf metric: Rename expr__add_id() to expr__add_val()

2020-07-17T12:09:48+00:00

Rename expr__add_id() to expr__add_val() so we can use expr__add_id() to actually add just the id without any value in following changes. There's no functional change. Signed-off-by: Jiri Olsa Acked-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: John Garry Cc: Kajol Jain Cc: Michael Petlan Cc: Namhyung Kim Cc: Paul Clarke Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20200712132634.138901-2-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf expr: Migrate expr ids table to a hashmap

2020-05-28T13:03:26+00:00

Use a hashmap between a char* string and a double* value. While bpf's hashmap entries are size_t in size, we can't guarantee sizeof(size_t) >= sizeof(double). Avoid a memory allocation when gathering ids by making 0.0 a special value encoded as NULL. Original map suggestion by Andi Kleen: https://lore.kernel.org/lkml/20200224210308.GQ160988@tassilo.jf.intel.com/ and seconded by Jiri Olsa: https://lore.kernel.org/lkml/20200423112915.GH1136647@krava/ Committer notes: There are fixes that need to land upstream before we can use libbpf's headers, for now use our copy unconditionally, since the data structures at this point are exactly the same, no problem. When the fixes for libbpf's hashmap land upstream, we can fix this up. Testing it: Building with LIBBPF=1, i.e. the default: $ perf -vv | grep -i bpf bpf: [ on ] # HAVE_LIBBPF_SUPPORT $ nm ~/bin/perf | grep -i libbpf_ | wc -l 39 $ nm ~/bin/perf | grep -i hashmap_ | wc -l 17 $ Explicitely building without LIBBPF: $ perf -vv | grep -i bpf bpf: [ OFF ] # HAVE_LIBBPF_SUPPORT $ $ nm ~/bin/perf | grep -i libbpf_ | wc -l 0 $ nm ~/bin/perf | grep -i hashmap_ | wc -l 9 $ Signed-off-by: Ian Rogers Tested-by: Arnaldo Carvalho de Melo Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexei Starovoitov Cc: Andi Kleen Cc: Andrii Nakryiko Cc: Cong Wang Cc: Daniel Borkmann Cc: Jin Yao Cc: Jiri Olsa Cc: John Fastabend Cc: John Garry Cc: Kajol Jain Cc: Kan Liang Cc: Kim Phillips Cc: Leo Yan Cc: Mark Rutland Cc: Martin KaFai Lau Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Song Liu Cc: Stephane Eranian Cc: Yonghong Song Cc: bpf@vger.kernel.org Cc: kp singh Cc: netdev@vger.kernel.org Link: http://lore.kernel.org/lkml/20200515221732.44078-8-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo