kernel/linux.git/tools/perf/util/thread.h, branch linux-6.9.y

perf machine: Move machine's threads into its own abstraction

2024-03-04T06:51:44+00:00

Move thread_rb_node into the machine.c file. This hides the implementation of threads from the rest of the code allowing for it to be refactored. Locking discipline is tightened up in this change. As the lock is now encapsulated in threads, the findnew function requires holding it (as it already did in machine). Rather than do conditionals with locks based on whether the thread should be created (which could potentially be error prone with a read lock match with a write unlock), have a separate threads__find that won't create the thread and only holds the read lock. This effectively duplicates the findnew logic, with the existing findnew logic only operating under a write lock assuming creation is necessary as a previous find failed. The creation may still fail with the write lock due to another thread. The duplication is removed in a later next patch that delegates the implementation to hashtable. Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Cc: Yang Jihong Cc: Oliver Upton Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240301053646.1449657-5-irogers@google.com

perf: util: use capstone disasm engine to show assembly instructions

2024-02-21T02:06:48+00:00

Currently, the instructions of samples are shown as raw hex strings which are hard to read. x86 has a special option '--xed' to disassemble the hex string via intel XED tool. Here we use capstone as our disassembler engine to give more friendly instructions. We select libcapstone because capstone can provide more insn details. Perf will fallback to raw instructions if libcapstone is not available. The advantages compared to XED tool: * Support arm, arm64, x86-32, x86_64 (more could be supported), xed only for x86_64. * Immediate address operands are shown as symbol+offs. Signed-off-by: Changbin Du Reviewed-by: Adrian Hunter Cc: changbin.du@gmail.com Cc: Thomas Richter Cc: Andi Kleen Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240217074046.4100789-3-changbin.du@huawei.com

perf machine thread: Remove exited threads by default

2023-11-09T16:49:32+00:00

'struct thread' values hold onto references to mmaps, DSOs, etc. When a thread exits it is necessary to clean all of this memory up by removing the thread from the machine's threads. Some tools require this doesn't happen, such as auxtrace events, 'perf report' if offcpu events exist or if a task list is being generated, so add a 'struct symbol_conf' member to make the behavior optional. When an exited thread is left in the machine's threads, mark it as exited. This change relates to commit 40826c45eb0b8856 ("perf thread: Remove notion of dead threads") . Dead threads were removed as they had a reference count of 0 and were difficult to reason about with the reference count checker. Here a thread is removed from threads when it exits, unless via symbol_conf the exited thread isn't remove and is marked as exited. Reference counting behaves as it normally does. Reviewed-by: Adrian Hunter Signed-off-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: Athira Jajeev Cc: Changbin Du Cc: Colin Ian King Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: German Gomez 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/20231102175735.2272696-6-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

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