kernel/linux.git/tools/perf/util/thread.h, branch v6.7.3

perf thread: Allow tools to register a thread->priv destructor

2023-07-20T14:22:46+00:00

So that when thread__delete() runs it can be called and free stuff tools stashed into thread->priv, like 'perf trace' does and will use this new facility to plug some leaks. Added an assert(thread__priv_destructor == NULL) as suggested in Ian's review. Acked-by: Ian Rogers Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lore.kernel.org/lkml/CAP-5=fV3Er=Ek8=iE=bSGbEBmM56_PJffMWot1g_5Bh8B5hO7A@mail.gmail.com Signed-off-by: Arnaldo Carvalho de Melo

perf thread: Add reference count checking

2023-06-12T18:57:53+00:00

Modify struct declaration and accessor functions for the reference count checkers additional layer of indirection. Make sure pid_cmp in builtin-sched.c uses the underlying/original struct in pointer arithmetic, and not the temporary get/put indirection. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ali Saidi Cc: Andi Kleen Cc: Athira Rajeev Cc: Brian Robbins Cc: Changbin Du Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: Fangrui Song Cc: German Gomez Cc: Ingo Molnar Cc: Ivan Babrou Cc: James Clark Cc: Jing Zhang Cc: Jiri Olsa Cc: John Garry Cc: K Prateek Nayak Cc: Kan Liang Cc: Leo Yan Cc: Liam Howlett Cc: Mark Rutland Cc: Miguel Ojeda Cc: Mike Leach Cc: Namhyung Kim Cc: Naveen N. Rao Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Sean Christopherson Cc: Steinar H. Gunderson Cc: Suzuki Poulouse Cc: Wenyu Liu Cc: Will Deacon Cc: Yang Jihong Cc: Ye Xingchen Cc: Yuan Can Cc: coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/r/20230608232823.4027869-8-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf thread: Add accessor functions for thread

2023-06-12T18:57:53+00:00

Using accessors will make it easier to add reference count checking in later patches. Committer notes: thread->nsinfo wasn't wrapped as it is used together with nsinfo__zput(), where does a trick to set the field with a refcount being dropped to NULL, and that doesn't work well with using thread__nsinfo(thread), that loses the &thread->nsinfo pointer. When refcount checking is added to 'struct thread', later in this series, nsinfo__zput(RC_CHK_ACCESS(thread)->nsinfo) will be used to check the thread pointer. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ali Saidi Cc: Andi Kleen Cc: Athira Rajeev Cc: Brian Robbins Cc: Changbin Du Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: Fangrui Song Cc: German Gomez Cc: Ingo Molnar Cc: Ivan Babrou Cc: James Clark Cc: Jing Zhang Cc: Jiri Olsa Cc: John Garry Cc: K Prateek Nayak Cc: Kan Liang Cc: Leo Yan Cc: Liam Howlett Cc: Mark Rutland Cc: Miguel Ojeda Cc: Mike Leach Cc: Namhyung Kim Cc: Naveen N. Rao Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Sean Christopherson Cc: Steinar H. Gunderson Cc: Suzuki Poulouse Cc: Wenyu Liu Cc: Will Deacon Cc: Yang Jihong Cc: Ye Xingchen Cc: Yuan Can Cc: coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/r/20230608232823.4027869-4-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf thread: Make threads rbtree non-invasive

2023-06-12T18:57:53+00:00

Separate the rbtree out of thread and into a new struct thread_rb_node. The refcnt is in thread and the rbtree is responsible for a single count. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ali Saidi Cc: Andi Kleen Cc: Athira Rajeev Cc: Brian Robbins Cc: Changbin Du Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: Fangrui Song Cc: German Gomez Cc: Ingo Molnar Cc: Ivan Babrou Cc: James Clark Cc: Jing Zhang Cc: Jiri Olsa Cc: John Garry Cc: K Prateek Nayak Cc: Kan Liang Cc: Leo Yan Cc: Liam Howlett Cc: Mark Rutland Cc: Miguel Ojeda Cc: Mike Leach Cc: Namhyung Kim Cc: Naveen N. Rao Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Sean Christopherson Cc: Steinar H. Gunderson Cc: Suzuki Poulouse Cc: Wenyu Liu Cc: Will Deacon Cc: Yang Jihong Cc: Ye Xingchen Cc: Yuan Can Cc: coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/r/20230608232823.4027869-3-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf thread: Remove notion of dead threads

2023-06-12T18:57:53+00:00

The dead thread list is best effort. Threads live on it until the reference count hits zero and they are removed. With correct reference counting this should never happen. It is, however, part of the 'perf sched' output that is now removed. If this is an issue we should implement tracking of dead threads in a robust not best-effort way. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ali Saidi Cc: Andi Kleen Cc: Athira Rajeev Cc: Brian Robbins Cc: Changbin Du Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: Fangrui Song Cc: German Gomez Cc: Ingo Molnar Cc: Ivan Babrou Cc: James Clark Cc: Jing Zhang Cc: Jiri Olsa Cc: John Garry Cc: K Prateek Nayak Cc: Kan Liang Cc: Leo Yan Cc: Liam Howlett Cc: Mark Rutland Cc: Miguel Ojeda Cc: Mike Leach Cc: Namhyung Kim Cc: Naveen N. Rao Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Sean Christopherson Cc: Steinar H. Gunderson Cc: Suzuki Poulouse Cc: Wenyu Liu Cc: Will Deacon Cc: Yang Jihong Cc: Ye Xingchen Cc: Yuan Can Cc: coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/r/20230608232823.4027869-2-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf thread: Move thread__resolve() from event.h

2022-10-31T14:07:03+00:00

Its a thread method, so move it to thread.h, this way some places that were using event.h just to get this prototype may stop doing so and speed up building and disentanble the header dependency graph. Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add guest_cpu to hypervisor threads

2022-07-20T14:08:04+00:00

It is possible to know which guest machine was running at a point in time based on the PID of the currently running host thread. That is, perf identifies guest machines by the PID of the hypervisor. To determine the guest CPU, put it on the hypervisor (QEMU) thread for that VCPU. This is done when processing the id_index which provides the necessary information. Signed-off-by: Adrian Hunter Cc: Andi Kleen Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Cc: kvm@vger.kernel.org Link: https://lore.kernel.org/r/20220711093218.10967-13-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf callchain: Stitch LBR call stack

2020-04-18T12:05:01+00:00

In LBR call stack mode, the depth of reconstructed LBR call stack limits to the number of LBR registers. For example, on skylake, the depth of reconstructed LBR call stack is always <= 32. # To display the perf.data header info, please use # --header/--header-only options. # # # Total Lost Samples: 0 # # Samples: 6K of event 'cycles' # Event count (approx.): 6487119731 # # Children Self Command Shared Object Symbol # ........ ........ ............... .................. # ................................ 99.97% 99.97% tchain_edit tchain_edit [.] f43 | --99.64%--f11 f12 f13 f14 f15 f16 f17 f18 f19 f20 f21 f22 f23 f24 f25 f26 f27 f28 f29 f30 f31 f32 f33 f34 f35 f36 f37 f38 f39 f40 f41 f42 f43 For a call stack which is deeper than LBR limit, HW will overwrite the LBR register with oldest branch. Only partial call stacks can be reconstructed. However, the overwritten LBRs may still be retrieved from previous sample. At that moment, HW hasn't overwritten the LBR registers yet. Perf tools can stitch those overwritten LBRs on current call stacks to get a more complete call stack. To determine if LBRs can be stitched, perf tools need to compare current sample with previous sample. - They should have identical LBR records (Same from, to and flags values, and the same physical index of LBR registers). - The searching starts from the base-of-stack of current sample. Once perf determines to stitch the previous LBRs, the corresponding LBR cursor nodes will be copied to 'lists'. The 'lists' is to track the LBR cursor nodes which are going to be stitched. When the stitching is over, the nodes will not be freed immediately. They will be moved to 'free_lists'. Next stitching may reuse the space. Both 'lists' and 'free_lists' will be freed when all samples are processed. Committer notes: Fix the intel-pt.c initialization of the union with 'struct branch_flags', that breaks the build with its unnamed union on older gcc versions. Uninline thread__free_stitch_list(), as it grew big and started dragging includes to thread.h, so move it to thread.c where what it needs in terms of headers are already there. This fixes the build in several systems such as debian:experimental when cross building to the MIPS32 architecture, i.e. in the other cases what was needed was being included by sheer luck. In file included from builtin-sched.c:11: util/thread.h: In function 'thread__free_stitch_list': util/thread.h:169:3: error: implicit declaration of function 'free' [-Werror=implicit-function-declaration] 169 | free(pos); | ^~~~ util/thread.h:169:3: error: incompatible implicit declaration of built-in function 'free' [-Werror] util/thread.h:19:1: note: include '' or provide a declaration of 'free' 18 | #include "callchain.h" +++ |+#include 19 | util/thread.h:174:3: error: incompatible implicit declaration of built-in function 'free' [-Werror] 174 | free(pos); | ^~~~ util/thread.h:174:3: note: include '' or provide a declaration of 'free' Signed-off-by: Kan Liang Reviewed-by: Andi Kleen Acked-by: Jiri Olsa Cc: Adrian Hunter Cc: Alexey Budankov Cc: Mathieu Poirier Cc: Michael Ellerman Cc: Namhyung Kim Cc: Pavel Gerasimov Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Stephane Eranian Cc: Vitaly Slobodskoy Link: http://lore.kernel.org/lkml/20200319202517.23423-13-kan.liang@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf callchain: Save previous cursor nodes for LBR stitching approach

2020-04-18T12:05:01+00:00

The cursor nodes which generates from sample are eventually added into callchain. To avoid generating cursor nodes from previous samples again, the previous cursor nodes are also saved for LBR stitching approach. Some option, e.g. hide-unresolved, may hide some LBRs. Add a variable 'valid' in struct callchain_cursor_node to indicate this case. The LBR stitching approach will only append the valid cursor nodes from previous samples later. Signed-off-by: Kan Liang Reviewed-by: Andi Kleen Acked-by: Jiri Olsa Cc: Adrian Hunter Cc: Alexey Budankov Cc: Mathieu Poirier Cc: Michael Ellerman Cc: Namhyung Kim Cc: Pavel Gerasimov Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Stephane Eranian Cc: Vitaly Slobodskoy Link: http://lore.kernel.org/lkml/20200319202517.23423-12-kan.liang@linux.intel.com [ Use zfree() instead of open coded equivalent, and use it when freeing members of structs ] Signed-off-by: Arnaldo Carvalho de Melo

perf thread: Save previous sample for LBR stitching approach

2020-04-18T12:05:01+00:00

To retrieve the overwritten LBRs from previous sample for LBR stitching approach, perf has to save the previous sample. Only allocate the struct lbr_stitch once, when LBR stitching approach is enabled and kernel supports hw_idx. Signed-off-by: Kan Liang Reviewed-by: Andi Kleen Acked-by: Jiri Olsa Cc: Adrian Hunter Cc: Alexey Budankov Cc: Mathieu Poirier Cc: Michael Ellerman Cc: Namhyung Kim Cc: Pavel Gerasimov Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Stephane Eranian Cc: Vitaly Slobodskoy Link: http://lore.kernel.org/lkml/20200319202517.23423-11-kan.liang@linux.intel.com [ Use zalloc()/zfree() for thread->lbr_stitch ] Signed-off-by: Arnaldo Carvalho de Melo