kernel/tools/perf/util/sort.c, branch linux-4.1.y

perf diff: Support for different binaries

2015-02-27T13:08:38Z

Currently, the perf diff only works with same binaries. That's because it compares the symbol start address. It doesn't work if the perf.data comes from different binaries. This patch matches the symbol names. Actually, perf diff once intended to compare the symbol names. The commit as below can look for a pair by name. 604c5c92972d (perf diff: Change the default sort order to "dso,symbol") However, at that time, perf diff used a global list of dsos. That means the binaries which has same name can only be loaded once. That's a problem for comparing different binaries. For example, we have an old binary and an updated binary. They very likely have same name and most of the functions, so only dsos from old binary will be loaded. When processing the data from updated binary, perf still use the symbol information from old binary. That's wrong. Then the commit as below used IP to replace symbol name. 9c443dfdd31e ("perf diff: Fix support for all --sort combinations") >From that time, perf diff starts to compare the symbol address. The global dsos is discarded from a patch in 2010. a1645ce12adb ("perf: 'perf kvm' tool for monitoring guest performance from host") However, at that time, perf diff already compared by address. So perf diff cannot work for different binaries as well. This patch actually rolls back the perf diff to original design. The document is also changed, so everybody knows the original design is to compare the symbol names. Here are some examples: The only difference between example_v1.c and example_v2.c is the location of f2 and f3. There is no change in behavior, but the previous perf diff display the wrong differential profile. example_v1.c noinline void f3(void) { volatile int i; for (i = 0; i < 10000;) { if(i%2) i++; else i++; } } noinline void f2(void) { volatile int a = 100, b, c; for (b = 0; b < 10000; b++) c = a * b; } noinline void f1(void) { f2(); f3(); } int main() { int i; for (i = 0; i < 100000; i++) f1(); } example_v2.c noinline void f2(void) { volatile int a = 100, b, c; for (b = 0; b < 10000; b++) c = a * b; } noinline void f3(void) { volatile int i; for (i = 0; i < 10000;) { if(i%2) i++; else i++; } } noinline void f1(void) { f2(); f3(); } int main() { int i; for (i = 0; i < 100000; i++) f1(); } [lk@localhost perf_diff]$ gcc example_v1.c -o example [lk@localhost perf_diff]$ perf record -o example_v1.data ./example [ perf record: Woken up 4 times to write data ] [ perf record: Captured and wrote 0.813 MB example_v1.data (~35522 samples) ] [lk@localhost perf_diff]$ gcc example_v2.c -o example [lk@localhost perf_diff]$ perf record -o example_v2.data ./example [ perf record: Woken up 4 times to write data ] [ perf record: Captured and wrote 0.824 MB example_v2.data (~36015 samples) ] Old perf diff result: [lk@localhost perf_diff]$ perf diff example_v1.data example_v2.data Event 'cycles' Baseline Delta Shared Object Symbol ........ ....... ................ ............................... [kernel.vmlinux] [k] __perf_event_task_sched_out 0.00% [kernel.vmlinux] [k] apic_timer_interrupt [kernel.vmlinux] [k] idle_cpu [kernel.vmlinux] [k] intel_pstate_timer_func [kernel.vmlinux] [k] native_read_msr_safe 0.00% [kernel.vmlinux] [k] native_read_tsc 0.00% [kernel.vmlinux] [k] native_write_msr_safe [kernel.vmlinux] [k] ntp_tick_length 0.00% [kernel.vmlinux] [k] rb_erase 0.00% [kernel.vmlinux] [k] tick_sched_timer 0.00% [kernel.vmlinux] [k] unmap_single_vma 0.00% [kernel.vmlinux] [k] update_wall_time 0.00% example [.] f1 46.24% example [.] f2 53.71% -7.55% example [.] f3 +53.81% example [.] f3 0.02% example [.] main New perf diff result: [lk@localhost perf_diff]$ perf diff example_v1.data example_v2.data [kernel.vmlinux] [k] __perf_event_task_sched_out 0.00% [kernel.vmlinux] [k] apic_timer_interrupt [kernel.vmlinux] [k] idle_cpu [kernel.vmlinux] [k] intel_pstate_timer_func [kernel.vmlinux] [k] native_read_msr_safe 0.00% [kernel.vmlinux] [k] native_read_tsc 0.00% [kernel.vmlinux] [k] native_write_msr_safe [kernel.vmlinux] [k] ntp_tick_length 0.00% [kernel.vmlinux] [k] rb_erase 0.00% [kernel.vmlinux] [k] tick_sched_timer 0.00% [kernel.vmlinux] [k] unmap_single_vma 0.00% [kernel.vmlinux] [k] update_wall_time 0.00% example [.] f1 46.24% -0.08% example [.] f2 53.71% +0.11% example [.] f3 0.02% example [.] main Signed-off-by: Kan Liang Acked-by: Jiri Olsa Acked-by: Namhyung Kim Cc: Andi Kleen Link: http://lkml.kernel.org/r/1423460384-11645-1-git-send-email-kan.liang@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Pass struct perf_hpp_fmt to its callbacks

2015-01-21T16:24:34Z

Currently ->cmp, ->collapse and ->sort callbacks doesn't pass corresponding fmt. But it'll be needed by upcoming changes in perf diff command. Suggested-by: Jiri Olsa Signed-off-by: Namhyung Kim Acked-by: Jiri Olsa Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kan Liang Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1420677949-6719-6-git-send-email-namhyung@kernel.org [ fix build by passing perf_hpp_fmt pointer to hist_entry__cmp_ methods ] Signed-off-by: Arnaldo Carvalho de Melo

perf callchain: Make get_srcline fall back to sym+offset

2014-11-24T21:03:47Z

When the source line is not found fall back to sym + offset. This is generally much more useful than a raw address. For this we need to pass in the symbol from the caller. For some callers it's awkward to compute, so we stay at the old behaviour. Signed-off-by: Andi Kleen Cc: Jiri Olsa Cc: Namhyung Kim Link: http://lkml.kernel.org/r/1415844328-4884-10-git-send-email-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo

perf hists: Fix up srcline histogram key formatting

2014-11-19T15:33:48Z

Problem introduced in: commit 5b5916696051 "perf report: Honor column width setting" Where the left justification signal was after the width, which ended up, when the width was, say, 11, always printing: %11.11-s Instead of src:line left justified and limited to 11 chars. Resulting in a like: 70.93% %11.11-s [.] f2 tcall When it should instead be: 70.93% tcall.c:5 [.] f2 tcall Cc: Adrian Hunter Cc: Andi Kleen Cc: Borislav Petkov Cc: David Ahern Cc: Don Zickus Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Mike Galbraith Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-2xnt0vqkoox52etq2qhyetr0@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix report -F dso_from for data without branch info

2014-10-29T12:29:05Z

The branch field sorting code assumes hist_entry::branch_info is allocated, which is wrong and following perf session ends up with report segfault. $ perf record ls $ perf report -F dso_from perf: Segmentation fault Checking that hist_entry::branch_info is valid and display "N/A" string in snprint callback if it's not. Signed-off-by: Jiri Olsa Cc: Andi Kleen Cc: Corey Ashford Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1413468427-31049-8-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix report -F dso_to for data without branch info

2014-10-29T12:28:48Z

The branch field sorting code assumes hist_entry::branch_info is allocated, which is wrong and following perf session ends up with report segfault. $ perf record ls $ perf report -F dso_to perf: Segmentation fault Checking that hist_entry::branch_info is valid and display "N/A" string in snprint callback if it's not. Signed-off-by: Jiri Olsa Acked-by: Namhyung Kim Cc: Andi Kleen Cc: Corey Ashford Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1413468427-31049-7-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix report -F symbol_from for data without branch info

2014-10-29T12:28:39Z

The branch field sorting code assumes hist_entry::branch_info is allocated, which is wrong and following perf session ends up with report segfault. $ perf record ls $ perf report -F symbol_from perf: Segmentation fault Checking that hist_entry::branch_info is valid and display "N/A" string in snprint callback if it's not. Signed-off-by: Jiri Olsa Acked-by: Namhyung Kim Cc: Andi Kleen Cc: Corey Ashford Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1413468427-31049-6-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix report -F symbol_to for data without branch info

2014-10-29T12:28:30Z

The branch field sorting code assumes hist_entry::branch_info is allocated, which is wrong and following perf session ends up with report segfault. $ perf record ls $ perf report -F symbol_to perf: Segmentation fault Checking that hist_entry::branch_info is valid and display "N/A" string in snprint callback if it's not. Signed-off-by: Jiri Olsa Acked-by: Namhyung Kim Cc: Andi Kleen Cc: Corey Ashford Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1413468427-31049-5-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix report -F mispredict for data without branch info

2014-10-29T12:28:20Z

The branch field sorting code assumes hist_entry::branch_info is allocated, which is wrong and following perf session ends up with report segfault. $ perf record ls $ perf report -F mispredict perf: Segmentation fault Checking that hist_entry::branch_info is valid and display "N/A" string in snprint callback if it's not. Signed-off-by: Jiri Olsa Acked-by: Namhyung Kim Cc: Andi Kleen Cc: Corey Ashford Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1413468427-31049-4-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix report -F in_tx for data without branch info

2014-10-29T12:28:10Z

The branch field sorting code assumes hist_entry::branch_info is allocated, which is wrong and following perf session ends up with report segfault. $ perf record ls $ perf report -F in_tx perf: Segmentation fault Checking that hist_entry::branch_info is valid and display "N/A" string in snprint callback if it's not. Signed-off-by: Jiri Olsa Acked-by: Namhyung Kim Cc: Andi Kleen Cc: Corey Ashford Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1413468427-31049-3-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo