Hello, On 5/1/24 01:46, Ian Rogers wrote:
On Sat, Mar 23, 2024 at 12:07 PM Ian Rogers <irogers@xxxxxxxxxx> wrote:On Wed, Mar 13, 2024 at 11:30 PM Yang Jihong <yangjihong@xxxxxxxxxxxxx> wrote:Currently, when libtraceevent is not linked, perf does not support tracepoint: # ./perf record -e sched:sched_switch -a sleep 10 event syntax error: 'sched:sched_switch' \___ unsupported tracepoint libtraceevent is necessary for tracepoint support Run 'perf list' for a list of valid events Usage: perf record [<options>] [<command>] or: perf record [<options>] -- <command> [<options>] -e, --event <event> event selector. use 'perf list' to list available events For cross-compilation scenario, library may not be installed in the default system path. Based on the above requirements, add LIBTRACEEVENT_DIR build option to support specifying path of libtraceevent. Example: 1. Cross compile libtraceevent # cd /opt/libtraceevent # CROSS_COMPILE=aarch64-linux-gnu- make 2. Cross compile perf # cd tool/perf # make VF=1 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- NO_LIBELF=1 LDFLAGS=--static LIBTRACEEVENT_DIR=/opt/libtraceevent <SNIP> Auto-detecting system features: <SNIP> ... LIBTRACEEVENT_DIR: /opt/libtraceevent Signed-off-by: Yang Jihong <yangjihong@xxxxxxxxxxxxx>This all looks good to me, thanks! Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>--- tools/perf/Makefile.config | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config index 1fe8df97fe88..7783479de691 100644 --- a/tools/perf/Makefile.config +++ b/tools/perf/Makefile.config @@ -182,6 +182,16 @@ endif FEATURE_CHECK_CFLAGS-libzstd := $(LIBZSTD_CFLAGS) FEATURE_CHECK_LDFLAGS-libzstd := $(LIBZSTD_LDFLAGS) +# for linking with debug library, run like: +# make DEBUG=1 LIBTRACEEVENT_DIR=/opt/libtraceevent/ +TRACEEVENTLIBS := -ltraceevent +ifdef LIBTRACEEVENT_DIR + LIBTRACEEVENT_CFLAGS := -I$(LIBTRACEEVENT_DIR)/include + LIBTRACEEVENT_LDFLAGS := -L$(LIBTRACEEVENT_DIR)/lib +endifI'm finding to test a libtraceevent asan build on a system that has libtraceevent installed, I need to carry this change: ``` diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config index 7f1e016a9253..b356520d8291 100644 --- a/tools/perf/Makefile.config +++ b/tools/perf/Makefile.config @@ -187,7 +187,7 @@ FEATURE_CHECK_LDFLAGS-libzstd := $(LIBZSTD_LDFLAGS) TRACEEVENTLIBS := -ltraceevent ifdef LIBTRACEEVENT_DIR LIBTRACEEVENT_CFLAGS := -I$(LIBTRACEEVENT_DIR)/include - LIBTRACEEVENT_LDFLAGS := -L$(LIBTRACEEVENT_DIR)/lib + LIBTRACEEVENT_LDFLAGS := -Wl,-rpath,$(LIBTRACEEVENT_DIR)/lib64 endif FEATURE_CHECK_CFLAGS-libtraceevent := $(LIBTRACEEVENT_CFLAGS) FEATURE_CHECK_LDFLAGS-libtraceevent := $(LIBTRACEEVENT_LDFLAGS) $(TRACEEVENTLIBS) ``` I'm not sure how to make this something that'll work well with cross compilation, etc.
Because of the holiday, the reply is a bit late.It seems that perf built by asan/msan will not search for shared libraries in the -L directory. We generally use cross-compile perf to analyze performance problems. In most cases, it is static compilation (rpath does not work), and it will not enable sanitizers. so can we simply check if EXTRA_CFLAGS contains -fsanitize=address/memory, and add libtraceevent dir to rpath?
I submitted a patch, please see if the solution is feasible: https://lore.kernel.org/all/20240506081648.3890067-1-yangjihong@xxxxxxxxxxxxx/Or we can add libtraceevent's ld.so.conf to the environment. This requires manual configuration of the build environment, which is inconvenient.
# echo "/opt/libtraceevent/lib" > /etc/ld.so.conf.d/libtracevent.conf # ldconfig Thanks, Yang
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