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authorLinus Torvalds <torvalds@linux-foundation.org>2012-05-24 22:39:34 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-24 22:39:34 +0400
commit654443e20dfc0617231f28a07c96a979ee1a0239 (patch)
treea0dc3f093eb13892539082e663607c34b4fc2d07 /tools/perf/util/probe-event.h
parent2c01e7bc46f10e9190818437e564f7e0db875ae9 (diff)
parent9cba26e66d09bf394ae5a739627a1dc8b7cae6f4 (diff)
downloadlinux-654443e20dfc0617231f28a07c96a979ee1a0239.tar.xz
Merge branch 'perf-uprobes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull user-space probe instrumentation from Ingo Molnar: "The uprobes code originates from SystemTap and has been used for years in Fedora and RHEL kernels. This version is much rewritten, reviews from PeterZ, Oleg and myself shaped the end result. This tree includes uprobes support in 'perf probe' - but SystemTap (and other tools) can take advantage of user probe points as well. Sample usage of uprobes via perf, for example to profile malloc() calls without modifying user-space binaries. First boot a new kernel with CONFIG_UPROBE_EVENT=y enabled. If you don't know which function you want to probe you can pick one from 'perf top' or can get a list all functions that can be probed within libc (binaries can be specified as well): $ perf probe -F -x /lib/libc.so.6 To probe libc's malloc(): $ perf probe -x /lib64/libc.so.6 malloc Added new event: probe_libc:malloc (on 0x7eac0) You can now use it in all perf tools, such as: perf record -e probe_libc:malloc -aR sleep 1 Make use of it to create a call graph (as the flat profile is going to look very boring): $ perf record -e probe_libc:malloc -gR make [ perf record: Woken up 173 times to write data ] [ perf record: Captured and wrote 44.190 MB perf.data (~1930712 $ perf report | less 32.03% git libc-2.15.so [.] malloc | --- malloc 29.49% cc1 libc-2.15.so [.] malloc | --- malloc | |--0.95%-- 0x208eb1000000000 | |--0.63%-- htab_traverse_noresize 11.04% as libc-2.15.so [.] malloc | --- malloc | 7.15% ld libc-2.15.so [.] malloc | --- malloc | 5.07% sh libc-2.15.so [.] malloc | --- malloc | 4.99% python-config libc-2.15.so [.] malloc | --- malloc | 4.54% make libc-2.15.so [.] malloc | --- malloc | |--7.34%-- glob | | | |--93.18%-- 0x41588f | | | --6.82%-- glob | 0x41588f ... Or: $ perf report -g flat | less # Overhead Command Shared Object Symbol # ........ ............. ............. .......... # 32.03% git libc-2.15.so [.] malloc 27.19% malloc 29.49% cc1 libc-2.15.so [.] malloc 24.77% malloc 11.04% as libc-2.15.so [.] malloc 11.02% malloc 7.15% ld libc-2.15.so [.] malloc 6.57% malloc ... The core uprobes design is fairly straightforward: uprobes probe points register themselves at (inode:offset) addresses of libraries/binaries, after which all existing (or new) vmas that map that address will have a software breakpoint injected at that address. vmas are COW-ed to preserve original content. The probe points are kept in an rbtree. If user-space executes the probed inode:offset instruction address then an event is generated which can be recovered from the regular perf event channels and mmap-ed ring-buffer. Multiple probes at the same address are supported, they create a dynamic callback list of event consumers. The basic model is further complicated by the XOL speedup: the original instruction that is probed is copied (in an architecture specific fashion) and executed out of line when the probe triggers. The XOL area is a single vma per process, with a fixed number of entries (which limits probe execution parallelism). The API: uprobes are installed/removed via /sys/kernel/debug/tracing/uprobe_events, the API is integrated to align with the kprobes interface as much as possible, but is separate to it. Injecting a probe point is privileged operation, which can be relaxed by setting perf_paranoid to -1. You can use multiple probes as well and mix them with kprobes and regular PMU events or tracepoints, when instrumenting a task." Fix up trivial conflicts in mm/memory.c due to previous cleanup of unmap_single_vma(). * 'perf-uprobes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits) perf probe: Detect probe target when m/x options are absent perf probe: Provide perf interface for uprobes tracing: Fix kconfig warning due to a typo tracing: Provide trace events interface for uprobes tracing: Extract out common code for kprobes/uprobes trace events tracing: Modify is_delete, is_return from int to bool uprobes/core: Decrement uprobe count before the pages are unmapped uprobes/core: Make background page replacement logic account for rss_stat counters uprobes/core: Optimize probe hits with the help of a counter uprobes/core: Allocate XOL slots for uprobes use uprobes/core: Handle breakpoint and singlestep exceptions uprobes/core: Rename bkpt to swbp uprobes/core: Make order of function parameters consistent across functions uprobes/core: Make macro names consistent uprobes: Update copyright notices uprobes/core: Move insn to arch specific structure uprobes/core: Remove uprobe_opcode_sz uprobes/core: Make instruction tables volatile uprobes: Move to kernel/events/ uprobes/core: Clean up, refactor and improve the code ...
Diffstat (limited to 'tools/perf/util/probe-event.h')
-rw-r--r--tools/perf/util/probe-event.h12
1 files changed, 7 insertions, 5 deletions
diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h
index a7dee835f49c..f9f3de8b4220 100644
--- a/tools/perf/util/probe-event.h
+++ b/tools/perf/util/probe-event.h
@@ -7,7 +7,7 @@
extern bool probe_event_dry_run;
-/* kprobe-tracer tracing point */
+/* kprobe-tracer and uprobe-tracer tracing point */
struct probe_trace_point {
char *symbol; /* Base symbol */
char *module; /* Module name */
@@ -21,7 +21,7 @@ struct probe_trace_arg_ref {
long offset; /* Offset value */
};
-/* kprobe-tracer tracing argument */
+/* kprobe-tracer and uprobe-tracer tracing argument */
struct probe_trace_arg {
char *name; /* Argument name */
char *value; /* Base value */
@@ -29,12 +29,13 @@ struct probe_trace_arg {
struct probe_trace_arg_ref *ref; /* Referencing offset */
};
-/* kprobe-tracer tracing event (point + arg) */
+/* kprobe-tracer and uprobe-tracer tracing event (point + arg) */
struct probe_trace_event {
char *event; /* Event name */
char *group; /* Group name */
struct probe_trace_point point; /* Trace point */
int nargs; /* Number of args */
+ bool uprobes; /* uprobes only */
struct probe_trace_arg *args; /* Arguments */
};
@@ -70,6 +71,7 @@ struct perf_probe_event {
char *group; /* Group name */
struct perf_probe_point point; /* Probe point */
int nargs; /* Number of arguments */
+ bool uprobes;
struct perf_probe_arg *args; /* Arguments */
};
@@ -129,8 +131,8 @@ extern int show_line_range(struct line_range *lr, const char *module);
extern int show_available_vars(struct perf_probe_event *pevs, int npevs,
int max_probe_points, const char *module,
struct strfilter *filter, bool externs);
-extern int show_available_funcs(const char *module, struct strfilter *filter);
-
+extern int show_available_funcs(const char *module, struct strfilter *filter,
+ bool user);
/* Maximum index number of event-name postfix */
#define MAX_EVENT_INDEX 1024