diff options
| author | Alexei Starovoitov <ast@fb.com> | 2016-02-17 19:58:57 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-02-20 00:21:44 -0500 |
| commit | 568b329a02f75ed3aaae5eb2cca384cb9e09cb29 (patch) | |
| tree | ae50fa4f98c1c7ad07ad834677be3304a282499e /include/linux/perf_event.h | |
| parent | 6b83d28a55a891a9d70fc61ccb1c138e47dcbe74 (diff) | |
| download | talos-obmc-linux-568b329a02f75ed3aaae5eb2cca384cb9e09cb29.tar.gz talos-obmc-linux-568b329a02f75ed3aaae5eb2cca384cb9e09cb29.zip | |
perf: generalize perf_callchain
. 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>
Diffstat (limited to 'include/linux/perf_event.h')
| -rw-r--r-- | include/linux/perf_event.h | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index b35a61a481fa..7da3c25999df 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -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; |
