kernel/linux.git/tools/perf/util/maps.h, branch v6.19.11

perf maps: Locking tidy up of nr_maps

2024-02-12T20:35:41+00:00

After this change maps__nr_maps is only used by tests, existing users are migrated to maps__empty. Compute maps__empty under the read lock. Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Cc: K Prateek Nayak Cc: James Clark Cc: Vincent Whitchurch Cc: Alexey Dobriyan Cc: Colin Ian King Cc: Changbin Du Cc: Masami Hiramatsu Cc: Song Liu Cc: Leo Yan Cc: Athira Rajeev Cc: Liam Howlett Cc: Artem Savkov Cc: bpf@vger.kernel.org Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240210031746.4057262-7-irogers@google.com

perf maps: Hide maps internals

2024-02-12T20:35:41+00:00

Move the struct into the C file. Add maps__equal to work around exposing the struct for reference count checking. Add accessors for the unwind_libunwind_ops. Move maps_list_node to its only use in symbol.c. Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Cc: K Prateek Nayak Cc: James Clark Cc: Vincent Whitchurch Cc: Alexey Dobriyan Cc: Colin Ian King Cc: Changbin Du Cc: Masami Hiramatsu Cc: Song Liu Cc: Leo Yan Cc: Athira Rajeev Cc: Liam Howlett Cc: Artem Savkov Cc: bpf@vger.kernel.org Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240210031746.4057262-6-irogers@google.com

perf maps: Switch from rbtree to lazily sorted array for addresses

2024-02-12T20:35:14+00:00

Maps is a collection of maps primarily sorted by the starting address of the map. Prior to this change the maps were held in an rbtree requiring 4 pointers per node. Prior to reference count checking, the rbnode was embedded in the map so 3 pointers per node were necessary. This change switches the rbtree to an array lazily sorted by address, much as the array sorting nodes by name. 1 pointer is needed per node, but to avoid excessive resizing the backing array may be twice the number of used elements. Meaning the memory overhead is roughly half that of the rbtree. For a perf record with "--no-bpf-event -g -a" of true, the memory overhead of perf inject is reduce fom 3.3MB to 3MB, so 10% or 300KB is saved. Map inserts always happen at the end of the array. The code tracks whether the insertion violates the sorting property. O(log n) rb-tree complexity is switched to O(1). Remove slides the array, so O(log n) rb-tree complexity is degraded to O(n). A find may need to sort the array using qsort which is O(n*log n), but in general the maps should be sorted and so average performance should be O(log n) as with the rbtree. An rbtree node consumes a cache line, but with the array 4 nodes fit on a cache line. Iteration is simplified to scanning an array rather than pointer chasing. Overall it is expected the performance after the change should be comparable to before, but with half of the memory consumed. To avoid a list and repeated logic around splitting maps, maps__merge_in is rewritten in terms of maps__fixup_overlap_and_insert. maps_merge_in splits the given mapping inserting remaining gaps. maps__fixup_overlap_and_insert splits the existing mappings, then adds the incoming mapping. By adding the new mapping first, then re-inserting the existing mappings the splitting behavior matches. Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Cc: K Prateek Nayak Cc: James Clark Cc: Vincent Whitchurch Cc: Alexey Dobriyan Cc: Colin Ian King Cc: Changbin Du Cc: Masami Hiramatsu Cc: Song Liu Cc: Leo Yan Cc: Athira Rajeev Cc: Liam Howlett Cc: Artem Savkov Cc: bpf@vger.kernel.org Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240210031746.4057262-2-irogers@google.com

perf maps: Reduce scope of map_rb_node and maps internals

2023-12-20T18:02:17+00:00

Avoid exposing the implementation of maps so that the internals can be refactored. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Athira Rajeev Cc: Changbin Du Cc: Colin Ian King Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: German Gomez Cc: Guilherme Amadio Cc: Huacai Chen Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: K Prateek Nayak Cc: Kajol Jain Cc: Kan Liang Cc: Leo Yan Cc: Li Dong Cc: Liam Howlett Cc: Mark Rutland Cc: Masami Hiramatsu Cc: Miguel Ojeda Cc: Ming Wang Cc: Namhyung Kim Cc: Nick Terrell Cc: Paolo Bonzini Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Sandipan Das Cc: Sean Christopherson Cc: Steinar H. Gunderson Cc: Vincent Whitchurch Cc: Wenyu Liu Cc: Yang Jihong Link: https://lore.kernel.org/r/20231207011722.1220634-22-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf maps: Add find next entry to give entry after the given map

2023-12-20T18:02:02+00:00

Use to remove map_rb_node use from machine.c. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Athira Rajeev Cc: Changbin Du Cc: Colin Ian King Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: German Gomez Cc: Guilherme Amadio Cc: Huacai Chen Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: K Prateek Nayak Cc: Kajol Jain Cc: Kan Liang Cc: Leo Yan Cc: Li Dong Cc: Liam Howlett Cc: Mark Rutland Cc: Masami Hiramatsu Cc: Miguel Ojeda Cc: Ming Wang Cc: Namhyung Kim Cc: Nick Terrell Cc: Paolo Bonzini Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Sandipan Das Cc: Sean Christopherson Cc: Steinar H. Gunderson Cc: Vincent Whitchurch Cc: Wenyu Liu Cc: Yang Jihong Link: https://lore.kernel.org/r/20231207011722.1220634-21-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf maps: Add maps__load_first()

2023-12-20T17:56:10+00:00

Avoid bpf_lock_contention_read touching the internal maps data structure by adding a helper function. As access is done directly on the map in maps, hold the read lock to stop it being removed. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Athira Rajeev Cc: Changbin Du Cc: Colin Ian King Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: German Gomez Cc: Guilherme Amadio Cc: Huacai Chen Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: K Prateek Nayak Cc: Kajol Jain Cc: Kan Liang Cc: Leo Yan Cc: Li Dong Cc: Liam Howlett Cc: Mark Rutland Cc: Masami Hiramatsu Cc: Miguel Ojeda Cc: Ming Wang Cc: Namhyung Kim Cc: Nick Terrell Cc: Paolo Bonzini Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Sandipan Das Cc: Sean Christopherson Cc: Steinar H. Gunderson Cc: Vincent Whitchurch Cc: Wenyu Liu Cc: Yang Jihong Link: https://lore.kernel.org/r/20231207011722.1220634-20-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf maps: Rename clone to copy from

2023-12-20T17:55:30+00:00

Rename maps__clone() to maps__copy_from() to be more intention revealing of its behavior. Pass the underlying maps rather than the thread. Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Athira Rajeev Cc: Changbin Du Cc: Colin Ian King Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: German Gomez Cc: Guilherme Amadio Cc: Huacai Chen Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: K Prateek Nayak Cc: Kajol Jain Cc: Kan Liang Cc: Leo Yan Cc: Li Dong Cc: Liam Howlett Cc: Mark Rutland Cc: Masami Hiramatsu Cc: Miguel Ojeda Cc: Ming Wang Cc: Nick Terrell Cc: Paolo Bonzini Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Sandipan Das Cc: Sean Christopherson Cc: Steinar H. Gunderson Cc: Vincent Whitchurch Cc: Wenyu Liu Cc: Yang Jihong Link: https://lore.kernel.org/r/20231207011722.1220634-19-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf maps: Refactor maps__fixup_overlappings()

2023-12-20T17:53:41+00:00

Rename to maps__fixup_overlap_and_insert() as the given mapping is always inserted. Factor out first_ending_after() as a utility function. Minor variable name changes. Switch to using debug_file() rather than passing a debug FILE*. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Athira Rajeev Cc: Changbin Du Cc: Colin Ian King Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: German Gomez Cc: Guilherme Amadio Cc: Huacai Chen Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: K Prateek Nayak Cc: Kajol Jain Cc: Kan Liang Cc: Leo Yan Cc: Li Dong Cc: Liam Howlett Cc: Mark Rutland Cc: Masami Hiramatsu Cc: Miguel Ojeda Cc: Ming Wang Cc: Namhyung Kim Cc: Nick Terrell Cc: Paolo Bonzini Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Sandipan Das Cc: Sean Christopherson Cc: Steinar H. Gunderson Cc: Vincent Whitchurch Cc: Wenyu Liu Cc: Yang Jihong Link: https://lore.kernel.org/r/20231207011722.1220634-17-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf maps: Add remove maps function to remove a map based on callback

2023-12-20T17:51:44+00:00

Removing maps wasn't being done under the write lock. Similar to maps__for_each_map(), iterate the entries but in this case remove the entry based on the result of the callback. If an entry was removed then maps_by_name() also needs updating, so add missed flush. In dso__load_kcore(), the test of map to save would always be false with REFCNT_CHECKING because of a missing RC_CHK_ACCESS/RC_CHK_EQUAL. Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Athira Rajeev Cc: Changbin Du Cc: Colin Ian King Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: German Gomez Cc: Guilherme Amadio Cc: Huacai Chen Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: K Prateek Nayak Cc: Kajol Jain Cc: Kan Liang Cc: Leo Yan Cc: Li Dong Cc: Liam Howlett Cc: Mark Rutland Cc: Masami Hiramatsu Cc: Miguel Ojeda Cc: Ming Wang Cc: Nick Terrell Cc: Paolo Bonzini Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Sandipan Das Cc: Sean Christopherson Cc: Steinar H. Gunderson Cc: Vincent Whitchurch Cc: Wenyu Liu Cc: Yang Jihong Link: https://lore.kernel.org/r/20231207011722.1220634-15-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf maps: Reduce scope of maps__for_each_entry()

2023-12-20T17:51:15+00:00

Reduce scope of maps__for_each_entry() as maps__for_each_map() is a safer alternative holding the maps lock during iteration. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Athira Rajeev Cc: Changbin Du Cc: Colin Ian King Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: German Gomez Cc: Guilherme Amadio Cc: Huacai Chen Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: K Prateek Nayak Cc: Kajol Jain Cc: Kan Liang Cc: Leo Yan Cc: Li Dong Cc: Liam Howlett Cc: Mark Rutland Cc: Masami Hiramatsu Cc: Miguel Ojeda Cc: Ming Wang Cc: Namhyung Kim Cc: Nick Terrell Cc: Paolo Bonzini Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Sandipan Das Cc: Sean Christopherson Cc: Steinar H. Gunderson Cc: Vincent Whitchurch Cc: Wenyu Liu Cc: Yang Jihong Link: https://lore.kernel.org/r/20231207011722.1220634-14-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo