From 1b290d670ffa883b7e062177463a8efd00eaa2c1 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 23 Nov 2009 15:42:35 +0100 Subject: perf tools: Add support for breakpoint events in perf tools Add the breakpoint events support with this new sysnopsis: mem:addr[:access] Where addr is a raw addr value in the kernel and access can be either [r][w][x] Example to profile tasklist_lock: $ grep tasklist_lock /proc/kallsyms ffffffff8189c000 D tasklist_lock $ perf record -e mem:0xffffffff8189c000:rw -a -f -c 1 $ perf report # Samples: 62 # # Overhead Command Shared Object Symbol # ........ ............... ............. ...... # 29.03% swapper [kernel] [k] _raw_read_trylock 29.03% swapper [kernel] [k] _raw_read_unlock 19.35% init [kernel] [k] _raw_read_trylock 19.35% init [kernel] [k] _raw_read_unlock 1.61% events/0 [kernel] [k] _raw_read_trylock 1.61% events/0 [kernel] [k] _raw_read_unlock Coming soon: - Support for symbols in the event definition. - Default period to 1 for breakpoint events because these are not high frequency events. The same thing is needed for trace events. Signed-off-by: Frederic Weisbecker Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras Cc: Prasad LKML-Reference: <1258987355-8751-4-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras Cc: Prasad diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index 0ff23de..fc46c0b 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -26,11 +26,19 @@ OPTIONS -e:: --event=:: - Select the PMU event. Selection can be a symbolic event name - (use 'perf list' to list all events) or a raw PMU - event (eventsel+umask) in the form of rNNN where NNN is a - hexadecimal event descriptor. + Select the PMU event. Selection can be: + - a symbolic event name (use 'perf list' to list all events) + + - a raw PMU event (eventsel+umask) in the form of rNNN where NNN is a + hexadecimal event descriptor. + + - a hardware breakpoint event in the form of '\mem:addr[:access]' + where addr is the address in memory you want to break in. + Access is the memory access type (read, write, execute) it can + be passed as follows: '\mem:addr[:[r][w][x]]'. + If you want to profile read-write accesses in 0x1000, just set + 'mem:0x1000:rw'. -a:: System-wide collection. diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c index 0faf4f2..0700274 100644 --- a/tools/perf/util/parse-events.c +++ b/tools/perf/util/parse-events.c @@ -1,4 +1,4 @@ - +#include "../../../include/linux/hw_breakpoint.h" #include "util.h" #include "../perf.h" #include "parse-options.h" @@ -540,6 +540,81 @@ static enum event_result parse_tracepoint_event(const char **strp, attr, strp); } +static enum event_result +parse_breakpoint_type(const char *type, const char **strp, + struct perf_event_attr *attr) +{ + int i; + + for (i = 0; i < 3; i++) { + if (!type[i]) + break; + + switch (type[i]) { + case 'r': + attr->bp_type |= HW_BREAKPOINT_R; + break; + case 'w': + attr->bp_type |= HW_BREAKPOINT_W; + break; + case 'x': + attr->bp_type |= HW_BREAKPOINT_X; + break; + default: + return EVT_FAILED; + } + } + if (!attr->bp_type) /* Default */ + attr->bp_type = HW_BREAKPOINT_R | HW_BREAKPOINT_W; + + *strp = type + i; + + return EVT_HANDLED; +} + +static enum event_result +parse_breakpoint_event(const char **strp, struct perf_event_attr *attr) +{ + const char *target; + const char *type; + char *endaddr; + u64 addr; + enum event_result err; + + target = strchr(*strp, ':'); + if (!target) + return EVT_FAILED; + + if (strncmp(*strp, "mem", target - *strp) != 0) + return EVT_FAILED; + + target++; + + addr = strtoull(target, &endaddr, 0); + if (target == endaddr) + return EVT_FAILED; + + attr->bp_addr = addr; + *strp = endaddr; + + type = strchr(target, ':'); + + /* If no type is defined, just rw as default */ + if (!type) { + attr->bp_type = HW_BREAKPOINT_R | HW_BREAKPOINT_W; + } else { + err = parse_breakpoint_type(++type, strp, attr); + if (err == EVT_FAILED) + return EVT_FAILED; + } + + /* We should find a nice way to override the access type */ + attr->bp_len = HW_BREAKPOINT_LEN_4; + attr->type = PERF_TYPE_BREAKPOINT; + + return EVT_HANDLED; +} + static int check_events(const char *str, unsigned int i) { int n; @@ -673,6 +748,10 @@ parse_event_symbols(const char **str, struct perf_event_attr *attr) if (ret != EVT_FAILED) goto modifier; + ret = parse_breakpoint_event(str, attr); + if (ret != EVT_FAILED) + goto modifier; + fprintf(stderr, "invalid or unsupported event: '%s'\n", *str); fprintf(stderr, "Run 'perf list' for a list of valid events\n"); return EVT_FAILED; @@ -859,6 +938,9 @@ void print_events(void) "rNNN"); printf("\n"); + printf(" %-42s [hardware breakpoint]\n", "mem:[:access]"); + printf("\n"); + print_tracepoint_events(); exit(129); -- cgit v0.10.2