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author | Paul Mundt <lethal@linux-sh.org> | 2009-11-05 16:20:09 +0900 |
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committer | Paul Mundt <lethal@linux-sh.org> | 2009-11-05 16:20:09 +0900 |
commit | 830fafecc211bef5bc6e253ab7e39c9e7560f758 (patch) | |
tree | 561181cfabc36698cc392b752b7bdc241ac8123b | |
parent | d1b261ef85bf63383b80b46b7cee525e0a63b3d3 (diff) | |
download | op-kernel-dev-830fafecc211bef5bc6e253ab7e39c9e7560f758.zip op-kernel-dev-830fafecc211bef5bc6e253ab7e39c9e7560f758.tar.gz |
sh: perf events: Preliminary callchain support.
This implements preliminary support for perf callchains (at the moment
only the kernel side is implemented). The actual implementation itself is
just a simple wrapper around the unwinder API, which allows for callchain
generation with or without the dwarf unwinder.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
-rw-r--r-- | arch/sh/kernel/Makefile | 2 | ||||
-rw-r--r-- | arch/sh/kernel/perf_callchain.c | 98 |
2 files changed, 99 insertions, 1 deletions
diff --git a/arch/sh/kernel/Makefile b/arch/sh/kernel/Makefile index 0a67baf..8edb927 100644 --- a/arch/sh/kernel/Makefile +++ b/arch/sh/kernel/Makefile @@ -39,7 +39,7 @@ obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o obj-$(CONFIG_DUMP_CODE) += disassemble.o obj-$(CONFIG_HIBERNATION) += swsusp.o obj-$(CONFIG_DWARF_UNWINDER) += dwarf.o -obj-$(CONFIG_PERF_EVENTS) += perf_event.o +obj-$(CONFIG_PERF_EVENTS) += perf_event.o perf_callchain.o obj-$(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) += localtimer.o diff --git a/arch/sh/kernel/perf_callchain.c b/arch/sh/kernel/perf_callchain.c new file mode 100644 index 0000000..24ea837 --- /dev/null +++ b/arch/sh/kernel/perf_callchain.c @@ -0,0 +1,98 @@ +/* + * Performance event callchain support - SuperH architecture code + * + * Copyright (C) 2009 Paul Mundt + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/perf_event.h> +#include <linux/percpu.h> +#include <asm/unwinder.h> +#include <asm/ptrace.h> + +static inline void callchain_store(struct perf_callchain_entry *entry, u64 ip) +{ + if (entry->nr < PERF_MAX_STACK_DEPTH) + entry->ip[entry->nr++] = ip; +} + +static void callchain_warning(void *data, char *msg) +{ +} + +static void +callchain_warning_symbol(void *data, char *msg, unsigned long symbol) +{ +} + +static int callchain_stack(void *data, char *name) +{ + return 0; +} + +static void callchain_address(void *data, unsigned long addr, int reliable) +{ + struct perf_callchain_entry *entry = data; + + if (reliable) + callchain_store(entry, addr); +} + +static const struct stacktrace_ops callchain_ops = { + .warning = callchain_warning, + .warning_symbol = callchain_warning_symbol, + .stack = callchain_stack, + .address = callchain_address, +}; + +static void +perf_callchain_kernel(struct pt_regs *regs, struct perf_callchain_entry *entry) +{ + callchain_store(entry, PERF_CONTEXT_KERNEL); + callchain_store(entry, regs->pc); + + unwind_stack(NULL, regs, NULL, &callchain_ops, entry); +} + +static void +perf_do_callchain(struct pt_regs *regs, struct perf_callchain_entry *entry) +{ + int is_user; + + if (!regs) + return; + + is_user = user_mode(regs); + + if (!current || current->pid == 0) + return; + + if (is_user && current->state != TASK_RUNNING) + return; + + /* + * Only the kernel side is implemented for now. + */ + if (!is_user) + perf_callchain_kernel(regs, entry); +} + +/* + * No need for separate IRQ and NMI entries. + */ +static DEFINE_PER_CPU(struct perf_callchain_entry, callchain); + +struct perf_callchain_entry *perf_callchain(struct pt_regs *regs) +{ + struct perf_callchain_entry *entry = &__get_cpu_var(callchain); + + entry->nr = 0; + + perf_do_callchain(regs, entry); + + return entry; +} |