Messages in this thread | | | Date | Thu, 23 Oct 2014 17:51:27 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH 04/16] perf tools: Add a thread stack for synthesizing call chains |
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Em Thu, Oct 23, 2014 at 01:45:12PM +0300, Adrian Hunter escreveu: > Add a thread stack for synthesizing call chains from call > and return events. > > Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> > --- > tools/perf/Makefile.perf | 2 + > tools/perf/util/event.h | 26 +++++++ > tools/perf/util/thread-stack.c | 151 +++++++++++++++++++++++++++++++++++++++++ > tools/perf/util/thread-stack.h | 32 +++++++++ > tools/perf/util/thread.c | 3 + > tools/perf/util/thread.h | 3 + > 6 files changed, 217 insertions(+) > create mode 100644 tools/perf/util/thread-stack.c > create mode 100644 tools/perf/util/thread-stack.h > > diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf > index 262916f..5bbe1ff 100644 > --- a/tools/perf/Makefile.perf > +++ b/tools/perf/Makefile.perf > @@ -304,6 +304,7 @@ LIB_H += ui/util.h > LIB_H += ui/ui.h > LIB_H += util/data.h > LIB_H += util/kvm-stat.h > +LIB_H += util/thread-stack.h > > LIB_OBJS += $(OUTPUT)util/abspath.o > LIB_OBJS += $(OUTPUT)util/alias.o > @@ -380,6 +381,7 @@ LIB_OBJS += $(OUTPUT)util/srcline.o > LIB_OBJS += $(OUTPUT)util/data.o > LIB_OBJS += $(OUTPUT)util/tsc.o > LIB_OBJS += $(OUTPUT)util/cloexec.o > +LIB_OBJS += $(OUTPUT)util/thread-stack.o > > LIB_OBJS += $(OUTPUT)ui/setup.o > LIB_OBJS += $(OUTPUT)ui/helpline.o > diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h > index c89518e..e84f929 100644 > --- a/tools/perf/util/event.h > +++ b/tools/perf/util/event.h > @@ -143,6 +143,32 @@ struct branch_stack { > struct branch_entry entries[0]; > }; > > +enum { > + PERF_FLAG_BRANCH = 1ULL << 0, > + PERF_FLAG_CALL = 1ULL << 1, > + PERF_FLAG_RETURN = 1ULL << 2, > + PERF_FLAG_CONDITIONAL = 1ULL << 3, > + PERF_FLAG_SYSCALLRET = 1ULL << 4, > + PERF_FLAG_ASYNC = 1ULL << 5, > + PERF_FLAG_INTERRUPT = 1ULL << 6, > + PERF_FLAG_TX_ABORT = 1ULL << 7, > + PERF_FLAG_TRACE_BEGIN = 1ULL << 8, > + PERF_FLAG_TRACE_END = 1ULL << 9, > + PERF_FLAG_IN_TX = 1ULL << 10, > +}; > + > +#define PERF_BRANCH_MASK (\ > + PERF_FLAG_BRANCH |\ > + PERF_FLAG_CALL |\ > + PERF_FLAG_RETURN |\ > + PERF_FLAG_CONDITIONAL |\ > + PERF_FLAG_SYSCALLRET |\ > + PERF_FLAG_ASYNC |\ > + PERF_FLAG_INTERRUPT |\ > + PERF_FLAG_TX_ABORT |\ > + PERF_FLAG_TRACE_BEGIN |\ > + PERF_FLAG_TRACE_END) > + > struct perf_sample { > u64 ip; > u32 pid, tid; > diff --git a/tools/perf/util/thread-stack.c b/tools/perf/util/thread-stack.c > new file mode 100644 > index 0000000..c1ca2a9 > --- /dev/null > +++ b/tools/perf/util/thread-stack.c > @@ -0,0 +1,151 @@ > +/* > + * thread-stack.c: Synthesize a thread's stack using call / return events > + * Copyright (c) 2014, Intel Corporation. > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope it will be useful, but WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for > + * more details. > + * > + */ > + > +#include "thread.h" > +#include "event.h" > +#include "util.h" > +#include "thread-stack.h" > + > +#define STACK_GROWTH 4096 > + > +struct thread_stack_entry { > + u64 ret_addr; > +}; > + > +struct thread_stack { > + struct thread_stack_entry *stack; > + size_t cnt; > + size_t sz; > + u64 trace_nr; > +}; > + > +static void thread_stack__grow(struct thread_stack *ts) > +{ > + struct thread_stack_entry *new_stack; > + size_t sz, new_sz; > + > + new_sz = ts->sz + STACK_GROWTH; > + sz = new_sz * sizeof(struct thread_stack_entry); > + new_stack = realloc(ts->stack, sz); > + if (new_stack) { > + ts->stack = new_stack; > + ts->sz = new_sz; > + } > +} > + > +static struct thread_stack *thread_stack__new(void) > +{ > + struct thread_stack *ts; > + > + ts = zalloc(sizeof(struct thread_stack)); > + if (!ts) > + return NULL; > + > + thread_stack__grow(ts); > + if (!ts->stack) { > + free(ts); > + return NULL; > + } > + > + return ts; > +} > + > +static void thread_stack__push(struct thread_stack *ts, u64 ret_addr) > +{ > + if (ts->cnt == ts->sz) { > + thread_stack__grow(ts); > + if (ts->cnt == ts->sz) > + ts->cnt = 0; > + } > + > + ts->stack[ts->cnt++].ret_addr = ret_addr; > +}
So can you elaborate on the use case, i.e. this silently trows the existing stack contents away if it doesn't grow, looks strange :-\
Merits some explanation about why this is OK, to say the least.
> + > +static void thread_stack__pop(struct thread_stack *ts, u64 ret_addr) > +{ > + if (!ts->cnt) > + return; > + > + if (ts->stack[ts->cnt - 1].ret_addr == ret_addr) { > + ts->cnt -= 1; > + } else { > + size_t i = ts->cnt - 1; > + > + while (i--) { > + if (ts->stack[i].ret_addr == ret_addr) { > + ts->cnt = i; > + return; > + } > + } > + } > +} > + > +void thread_stack__event(struct thread *thread, u32 flags, u64 from_ip, > + u64 to_ip, u16 insn_len, u64 trace_nr) > +{ > + if (!thread) > + return; > + > + if (!thread->ts) { > + thread->ts = thread_stack__new(); > + if (!thread->ts) > + return; > + thread->ts->trace_nr = trace_nr; > + } > + > + if (trace_nr != thread->ts->trace_nr) { > + thread->ts->trace_nr = trace_nr; > + thread->ts->cnt = 0; > + } > + > + if (flags & PERF_FLAG_CALL) { > + u64 ret_addr; > + > + if (!to_ip) > + return; > + ret_addr = from_ip + insn_len; > + if (ret_addr == to_ip) > + return; /* Zero-length calls are excluded */ > + thread_stack__push(thread->ts, ret_addr); > + } else if (flags & PERF_FLAG_RETURN) { > + if (!from_ip) > + return; > + thread_stack__pop(thread->ts, to_ip); > + } > +} > + > +void thread_stack__free(struct thread *thread) > +{ > + if (thread->ts) { > + zfree(&thread->ts->stack); > + zfree(&thread->ts); > + } > +} > + > +void thread_stack__sample(struct thread *thread, struct ip_callchain *chain, > + size_t sz, u64 ip) > +{ > + size_t i; > + > + if (!thread || !thread->ts) > + chain->nr = 1; > + else > + chain->nr = min(sz, thread->ts->cnt + 1); > + > + chain->ips[0] = ip; > + > + for (i = 1; i < chain->nr; i++) > + chain->ips[i] = thread->ts->stack[thread->ts->cnt - i].ret_addr; > +} > diff --git a/tools/perf/util/thread-stack.h b/tools/perf/util/thread-stack.h > new file mode 100644 > index 0000000..c0ba4cf > --- /dev/null > +++ b/tools/perf/util/thread-stack.h > @@ -0,0 +1,32 @@ > +/* > + * thread-stack.h: Synthesize a thread's stack using call / return events > + * Copyright (c) 2014, Intel Corporation. > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope it will be useful, but WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for > + * more details. > + * > + */ > + > +#ifndef __PERF_THREAD_STACK_H > +#define __PERF_THREAD_STACK_H > + > +#include <sys/types.h> > + > +#include <linux/types.h> > + > +struct thread; > +struct ip_callchain; > + > +void thread_stack__event(struct thread *thread, u32 flags, u64 from_ip, > + u64 to_ip, u16 insn_len, u64 trace_nr); > +void thread_stack__sample(struct thread *thread, struct ip_callchain *chain, > + size_t sz, u64 ip); > +void thread_stack__free(struct thread *thread); > + > +#endif > diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c > index 2b7b2d9..4e3418d 100644 > --- a/tools/perf/util/thread.c > +++ b/tools/perf/util/thread.c > @@ -4,6 +4,7 @@ > #include <string.h> > #include "session.h" > #include "thread.h" > +#include "thread-stack.h" > #include "util.h" > #include "debug.h" > #include "comm.h" > @@ -66,6 +67,8 @@ void thread__delete(struct thread *thread) > { > struct comm *comm, *tmp; > > + thread_stack__free(thread); > + > if (thread->mg) { > map_groups__put(thread->mg); > thread->mg = NULL; > diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h > index 8c75fa7..a057820 100644 > --- a/tools/perf/util/thread.h > +++ b/tools/perf/util/thread.h > @@ -8,6 +8,8 @@ > #include "symbol.h" > #include <strlist.h> > > +struct thread_stack; > + > struct thread { > union { > struct rb_node rb_node; > @@ -25,6 +27,7 @@ struct thread { > int comm_len; > > void *priv; > + struct thread_stack *ts; > }; > > struct machine; > -- > 1.9.1
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