From f9188e023c248d73f5b4a589b480e065c1864068 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 18 Jun 2009 22:20:52 +0200 Subject: [PATCH] perf_counter: Make callchain samples extensible Before exposing upstream tools to a callchain-samples ABI, tidy it up to make it more extensible in the future: Use markers in the IP chain to denote context, use (u64)-1..-4095 range for these context markers because we use them for ERR_PTR(), so these addresses are unlikely to be mapped. Signed-off-by: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo LKML-Reference: Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_counter.c | 29 ++++++----------------------- include/linux/perf_counter.h | 28 +++++++++++++++++----------- 2 files changed, 23 insertions(+), 34 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c index ce1ae3f1f86c..76dfef23f789 100644 --- a/arch/x86/kernel/cpu/perf_counter.c +++ b/arch/x86/kernel/cpu/perf_counter.c @@ -1555,9 +1555,9 @@ const struct pmu *hw_perf_counter_init(struct perf_counter *counter) */ static inline -void callchain_store(struct perf_callchain_entry *entry, unsigned long ip) +void callchain_store(struct perf_callchain_entry *entry, u64 ip) { - if (entry->nr < MAX_STACK_DEPTH) + if (entry->nr < PERF_MAX_STACK_DEPTH) entry->ip[entry->nr++] = ip; } @@ -1602,22 +1602,10 @@ static const struct stacktrace_ops backtrace_ops = { static void perf_callchain_kernel(struct pt_regs *regs, struct perf_callchain_entry *entry) { - unsigned long bp; - char *stack; - int nr = entry->nr; - + callchain_store(entry, PERF_CONTEXT_KERNEL); callchain_store(entry, regs->ip); - stack = ((char *)regs + sizeof(struct pt_regs)); -#ifdef CONFIG_FRAME_POINTER - get_bp(bp); -#else - bp = 0; -#endif - - dump_trace(NULL, regs, (void *)&stack, bp, &backtrace_ops, entry); - - entry->kernel = entry->nr - nr; + dump_trace(NULL, regs, NULL, 0, &backtrace_ops, entry); } /* @@ -1669,16 +1657,16 @@ perf_callchain_user(struct pt_regs *regs, struct perf_callchain_entry *entry) { struct stack_frame frame; const void __user *fp; - int nr = entry->nr; if (!user_mode(regs)) regs = task_pt_regs(current); fp = (void __user *)regs->bp; + callchain_store(entry, PERF_CONTEXT_USER); callchain_store(entry, regs->ip); - while (entry->nr < MAX_STACK_DEPTH) { + while (entry->nr < PERF_MAX_STACK_DEPTH) { frame.next_frame = NULL; frame.return_address = 0; @@ -1691,8 +1679,6 @@ perf_callchain_user(struct pt_regs *regs, struct perf_callchain_entry *entry) callchain_store(entry, frame.return_address); fp = frame.next_frame; } - - entry->user = entry->nr - nr; } static void @@ -1728,9 +1714,6 @@ struct perf_callchain_entry *perf_callchain(struct pt_regs *regs) entry = &__get_cpu_var(irq_entry); entry->nr = 0; - entry->hv = 0; - entry->kernel = 0; - entry->user = 0; perf_do_callchain(regs, entry); diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index 0765e8e69843..e7e7e0242767 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -343,23 +343,22 @@ enum perf_event_type { * { u64 nr; * { u64 id, val; } cnt[nr]; } && PERF_SAMPLE_GROUP * - * { u16 nr, - * hv, - * kernel, - * user; + * { u64 nr, * u64 ips[nr]; } && PERF_SAMPLE_CALLCHAIN * }; */ }; -#define MAX_STACK_DEPTH 255 +enum perf_callchain_context { + PERF_CONTEXT_HV = (__u64)-32, + PERF_CONTEXT_KERNEL = (__u64)-128, + PERF_CONTEXT_USER = (__u64)-512, -struct perf_callchain_entry { - __u16 nr; - __u16 hv; - __u16 kernel; - __u16 user; - __u64 ip[MAX_STACK_DEPTH]; + PERF_CONTEXT_GUEST = (__u64)-2048, + PERF_CONTEXT_GUEST_KERNEL = (__u64)-2176, + PERF_CONTEXT_GUEST_USER = (__u64)-2560, + + PERF_CONTEXT_MAX = (__u64)-4095, }; #ifdef __KERNEL__ @@ -381,6 +380,13 @@ struct perf_callchain_entry { #include #include +#define PERF_MAX_STACK_DEPTH 255 + +struct perf_callchain_entry { + __u64 nr; + __u64 ip[PERF_MAX_STACK_DEPTH]; +}; + struct task_struct; /** -- 2.39.2