|From:||Akihiro Nagai <email@example.com>|
|To:||Arnaldo Carvalho de Melo <firstname.lastname@example.org>, Ingo Molnar <email@example.com>, Peter Zijlstra <firstname.lastname@example.org>, Frederic Weisbecker <email@example.com>|
|Subject:||[PATCH -tip v4 0/7] perf: Introduce branch sub commands|
|Date:||Thu, 26 May 2011 14:02:46 +0900|
|Cc:||firstname.lastname@example.org, Masami Hiramatsu <email@example.com>, firstname.lastname@example.org|
Hi, This patch series provides the commands 'perf branch record' and 'perf branch trace' version 4. These commands record and analyze a BTS (Branch Trace Store) log. And, they provide the interface to use BTS log for application developers. BTS is a facility of Intel x86 processors, which records the address of 'branch to/from' on every branch/jump instruction and interrupt. This facility is very useful for developers to test their software, for example, coverage test, execution path analysis, dynamic step count ...etc. These test tools have a big advantage, which user doesn't have to modify target executable binaries, because the BTS is a hardware feauture. But, there are few applications using BTS. Reasons I guess are ... - Few people know what BTS is. - Few people know how to use BTS on Linux box. - It's hard to analyze the BTS log because it includes just a series of addresses. So, I want to provide a user-friendly interface to BTS for application developers. About new sub commands ======================== 'perf branch record' provides an easy way to record BTS log. Usage is 'perf branch record <command>'. This command is just an alias to 'perf record -e branches:u -c 1 -d <command>'. But, new one is more simple and more intuitive. 'perf branch trace' can parse and analyze recorded BTS log and print various information of execution path. This command can show address, pid, command name, function+offset, file path of elf. You can choose the printed information with option. Example: 'perf branch trace' function+offset _start+0x3 => _dl_start+0x0 _dl_start+0x71 => _dl_start+0x93 _dl_start+0x97 => _dl_start+0x78 _dl_start+0x97 => _dl_start+0x78 _dl_start+0xa3 => _dl_start+0x3c0 _dl_start+0x3c8 => _dl_start+0x3e8 ... This is the default behavior of 'perf branch trace'. It prints function+offset. Example2: 'perf branch -cas trace' command address function+offset ls 0x0000003e9b000b23 _start+0x3 => 0x0000003e9b004540 _dl_start+0x0 ls 0x0000003e9b0045b1 _dl_start+0x71 => 0x0000003e9b0045d3 _dl_start+0x93 ls 0x0000003e9b0045d7 _dl_start+0x97 => 0x0000003e9b0045b8 _dl_start+0x78 ls 0x0000003e9b0045d7 _dl_start+0x97 => 0x0000003e9b0045b8 _dl_start+0x78 ls 0x0000003e9b0045e3 _dl_start+0xa3 => 0x0000003e9b004900 _dl_start+0x3c0 ls 0x0000003e9b004908 _dl_start+0x3c8 => 0x0000003e9b004928 _dl_start+0x3e8 ... In the future, I'd like to make this more informative. For example - Show source file path - Show line number - Show inlined function name - Draw call graph - Browse source code and coloring - Make BTS record fast and more! Changes in V4: - Add kenel filter - Print PID and command only once in a line - Add output TSV mode Changes in V3: - Update to the latest -tip tree - Rename to 'perf branch' - Process only BTS records - Fix bug of getting elf_filepath - Fix return value of __cmd_trace Changes in V2: - Update to the latest -tip tree - Add bts explanation to the subcommand list - Remove the patch already merged (add OPT_CALLBACK_DEFAULT_NOOPT) - Add comments - Add new function to the todo list Thanks, --- Akihiro Nagai (7): perf branch trace: add kernel filter perf branch trace: add print all option perf branch trace: print function+offset perf branch trace: print file path of the executed elf perf branch trace: print pid and command perf branch: Introduce new sub command 'perf branch trace' perf: new subcommand perf branch record tools/perf/Documentation/perf-branch.txt | 62 +++++ tools/perf/Makefile | 1 tools/perf/builtin-branch.c | 361 ++++++++++++++++++++++++++++++ tools/perf/builtin.h | 1 tools/perf/command-list.txt | 1 tools/perf/perf.c | 1 6 files changed, 427 insertions(+), 0 deletions(-) create mode 100644 tools/perf/Documentation/perf-branch.txt create mode 100644 tools/perf/builtin-branch.c -- Akihiro Nagai (email@example.com) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to firstname.lastname@example.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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