Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-12-28 05:41:55 +00:00
Code Issues Packages Projects Releases Wiki Activity

perf: generalize perf_callchain

Browse Source 
. avoid walking the stack when there is no room left in the buffer
. generalize get_perf_callchain() to be called from bpf helper

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alexei Starovoitov 2016-02-17 19:58:57 -08:00 committed by David S. Miller
parent 6b83d28a55
commit 568b329a02
8 changed files with 51 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/x86/include/asm/stacktrace.h
View File

@ -37,7 +37,7 @@ print_context_stack_bp(struct thread_info *tinfo,
/* Generic stack tracer with callbacks */
struct stacktrace_ops {
void (*address)(void *data, unsigned long address, int reliable);
int (*address)(void *data, unsigned long address, int reliable);
/* On negative return stop dumping */
int (*stack)(void *data, char *name);
walk_stack_t walk_stack;

4
arch/x86/kernel/cpu/perf_event.c
View File

@ -2180,11 +2180,11 @@ static int backtrace_stack(void *data, char *name)
return 0;
}
static void backtrace_address(void *data, unsigned long addr, int reliable)
static int backtrace_address(void *data, unsigned long addr, int reliable)
{
struct perf_callchain_entry *entry = data;
perf_callchain_store(entry, addr);
return perf_callchain_store(entry, addr);
}
static const struct stacktrace_ops backtrace_ops = {

6
arch/x86/kernel/dumpstack.c
View File

@ -135,7 +135,8 @@ print_context_stack_bp(struct thread_info *tinfo,
if (!__kernel_text_address(addr))
break;
ops->address(data, addr, 1);
if (ops->address(data, addr, 1))
break;
frame = frame->next_frame;
ret_addr = &frame->return_address;
print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
@ -154,10 +155,11 @@ static int print_trace_stack(void *data, char *name)
/*
* Print one address/symbol entries per line.
*/
static void print_trace_address(void *data, unsigned long addr, int reliable)
static int print_trace_address(void *data, unsigned long addr, int reliable)
{
touch_nmi_watchdog();
printk_stack_address(addr, reliable, data);
return 0;
}
static const struct stacktrace_ops print_trace_ops = {

18
arch/x86/kernel/stacktrace.c
View File

@ -14,30 +14,34 @@ static int save_stack_stack(void *data, char *name)
return 0;
}
static void
static int
__save_stack_address(void *data, unsigned long addr, bool reliable, bool nosched)
{
struct stack_trace *trace = data;
#ifdef CONFIG_FRAME_POINTER
if (!reliable)
return;
return 0;
#endif
if (nosched && in_sched_functions(addr))
return;
return 0;
if (trace->skip > 0) {
trace->skip--;
return;
return 0;
}
if (trace->nr_entries < trace->max_entries)
if (trace->nr_entries < trace->max_entries) {
trace->entries[trace->nr_entries++] = addr;
return 0;
} else {
return -1; /* no more room, stop walking the stack */
}
}
static void save_stack_address(void *data, unsigned long addr, int reliable)
static int save_stack_address(void *data, unsigned long addr, int reliable)
{
return __save_stack_address(data, addr, reliable, false);
}
static void
static int
save_stack_address_nosched(void *data, unsigned long addr, int reliable)
{
return __save_stack_address(data, addr, reliable, true);

3
arch/x86/oprofile/backtrace.c
View File

@ -23,12 +23,13 @@ static int backtrace_stack(void *data, char *name)
return 0;
}
static void backtrace_address(void *data, unsigned long addr, int reliable)
static int backtrace_address(void *data, unsigned long addr, int reliable)
{
unsigned int *depth = data;
if ((*depth)--)
oprofile_add_trace(addr);
return 0;
}
static struct stacktrace_ops backtrace_ops = {

13
include/linux/perf_event.h
View File

@ -964,11 +964,20 @@ DECLARE_PER_CPU(struct perf_callchain_entry, perf_callchain_entry);
extern void perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs);
extern void perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs);
extern struct perf_callchain_entry *
get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user,
bool crosstask, bool add_mark);
extern int get_callchain_buffers(void);
extern void put_callchain_buffers(void);
static inline void perf_callchain_store(struct perf_callchain_entry *entry, u64 ip)
static inline int perf_callchain_store(struct perf_callchain_entry *entry, u64 ip)
{
if (entry->nr < PERF_MAX_STACK_DEPTH)
if (entry->nr < PERF_MAX_STACK_DEPTH) {
entry->ip[entry->nr++] = ip;
return 0;
} else {
return -1; /* no more room, stop walking the stack */
}
}
extern int sysctl_perf_event_paranoid;

32
kernel/events/callchain.c
View File

@ -159,15 +159,24 @@ put_callchain_entry(int rctx)
struct perf_callchain_entry *
perf_callchain(struct perf_event *event, struct pt_regs *regs)
{
int rctx;
struct perf_callchain_entry *entry;
int kernel = !event->attr.exclude_callchain_kernel;
int user = !event->attr.exclude_callchain_user;
bool kernel = !event->attr.exclude_callchain_kernel;
bool user = !event->attr.exclude_callchain_user;
/* Disallow cross-task user callchains. */
bool crosstask = event->ctx->task && event->ctx->task != current;
if (!kernel && !user)
return NULL;
return get_perf_callchain(regs, 0, kernel, user, crosstask, true);
}
struct perf_callchain_entry *
get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user,
bool crosstask, bool add_mark)
{
struct perf_callchain_entry *entry;
int rctx;
entry = get_callchain_entry(&rctx);
if (rctx == -1)
return NULL;
@ -175,10 +184,11 @@ perf_callchain(struct perf_event *event, struct pt_regs *regs)
if (!entry)
goto exit_put;
entry->nr = 0;
entry->nr = init_nr;
if (kernel && !user_mode(regs)) {
perf_callchain_store(entry, PERF_CONTEXT_KERNEL);
if (add_mark)
perf_callchain_store(entry, PERF_CONTEXT_KERNEL);
perf_callchain_kernel(entry, regs);
}
@ -191,13 +201,11 @@ perf_callchain(struct perf_event *event, struct pt_regs *regs)
}
if (regs) {
/*
* Disallow cross-task user callchains.
*/
if (event->ctx->task && event->ctx->task != current)
if (crosstask)
goto exit_put;
perf_callchain_store(entry, PERF_CONTEXT_USER);
if (add_mark)
perf_callchain_store(entry, PERF_CONTEXT_USER);
perf_callchain_user(entry, regs);
}
}

2
kernel/events/internal.h
View File

@ -182,8 +182,6 @@ DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
/* Callchain handling */
extern struct perf_callchain_entry *
perf_callchain(struct perf_event *event, struct pt_regs *regs);
extern int get_callchain_buffers(void);
extern void put_callchain_buffers(void);
static inline int get_recursion_context(int *recursion)
{