Add --depth=1 to README

.gitignore

@@ -1,3 +1,111 @@
+#
+# NOTE! Don't add files that are generated in specific
+# subdirectories here. Add them in the ".gitignore" file
+# in that subdirectory instead.
+#
+# NOTE! Please use 'git ls-files -i --exclude-standard'
+# command after changing this file, to see if there are
+# any tracked files which get ignored after the change.
+#
+# Normal rules (sorted alphabetically)
+#
+.*
+*.a
+*.asn1.[ch]
+*.bin
+*.bz2
+*.c.[012]*.*
+*.dtb
+*.dtb.S
+*.dwo
+*.elf
+*.gcno
+*.gz
+*.i
+*.ko
+*.lex.c
+*.ll
+*.lst
+*.lz4
+*.lzma
+*.lzo
+*.mod.c
+*.o
+*.o.*
+*.order
+*.patch
+*.s
+*.so
+*.so.dbg
+*.su
+*.symtypes
+*.tab.[ch]
+*.tar
+*.xz
+Module.symvers
+modules.builtin
+
+#
+# RPM spec file (make rpm-pkg)
+#
+/*.spec
+
+#
+# git files that we don't want to ignore even if they are dot-files
+#
+!.gitignore
+!.mailmap
+!.cocciconfig
+!.clang-format
+
+#
+# Generated include files
+#
+include/config
+include/generated
+include/ksym
+arch/*/include/generated
+
+# stgit generated dirs
+patches-*
+
+# quilt's files
+patches
+series
+
+# cscope files
+cscope.*
+ncscope.*
+
+# gnu global files
+GPATH
+GRTAGS
+GSYMS
+GTAGS
+
+# id-utils files
+ID
+
+*.orig
+*~
+\#*#
+
+#
+# Leavings from module signing
+#
+extra_certificates
+signing_key.pem
+signing_key.priv
+signing_key.x509
+x509.genkey
+
+# Kconfig presets
+all.config
+
+# Kdevelop4
+*.kdev4
+
+# Perf specific
 PERF-CFLAGS
 PERF-GUI-VARS
 PERF-VERSION-FILE

README.md

@@ -0,0 +1,25 @@
+# Perf, `eh_elf` flavour
+
+This repository contains a fork of perf, the profiler from the Linux kernel
+repository, modified in a way to interface it with `eh_elfs` and (hopefully)
+speeding it up on complicated DWARF frames
+
+## Compiling
+
+Clone the [Linux kernel
+repository](https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git)
+or get a tarball of its source tree, then replace the `tools/perf` directory
+with a clone of this repo. If you wish to clone the Linux source tree, and if
+you're not going to work on it, you might consider passing `--depth=1` to `git
+clone`, in order not to download the history, to keep the download light.
+Then, `cd tools/perf` and `make`, without forgetting to give the compilation
+tools the right version of `libunwind`, eg. by setting `LD_RUN_PATH` and
+`LIBUNWIND_DIR`:
+
+```sh
+    export LD_RUN_PATH=$HOME/local/libunwind/lib
+    export LIBUNWIND_DIR=$HOME/local/libunwind
+    make
+```
+
+This works at least with the linux repository at v4.17-rc5

builtin-report.c

@@ -54,6 +54,8 @@
 #include <unistd.h>
 #include <linux/mman.h>
 
+#include <libunwind.h>
+
 struct report {
 	struct perf_tool	tool;
 	struct perf_session	*session;
@@ -1398,6 +1400,8 @@ repeat:
 	} else
 		ret = 0;
 
+    chrono_report_disp();
+
 error:
 	zfree(&report.ptime_range);
 

make-target

@@ -0,0 +1,43 @@
+#!/bin/bash
+
+case "$1" in
+    'eh_elf')
+        TARGET='eh_elf'
+        LIBUNWIND='eh_elf'
+        branch='eh_elf'
+        ;;
+    'vanilla')
+        TARGET='vanilla'
+        LIBUNWIND='vanilla'
+        branch='vanilla_timer'
+        ;;
+    'vanilla-nocache')
+        TARGET='vanilla-nocache'
+        LIBUNWIND='vanilla'
+        branch='vanilla_timer_nocache'
+        ;;
+    *)
+        >&2 echo "Usage: $0 [ eh_elf | vanilla | vanilla-nocache ]"
+        exit 1
+esac
+
+original_branch=$(git rev-parse --abbrev-ref HEAD)
+
+if ! git checkout "$branch" ; then
+    >&2 echo "Failed to checkout $branch - maybe your git isn't clean?"
+    exit 2
+fi
+
+LIBUNWIND_PREFIX="$HOME/local/libunwind-$LIBUNWIND-dbg"
+LIBUNWIND_LIB="$LIBUNWIND_PREFIX/lib"
+PREFIX="$HOME/local/perf-$TARGET"
+
+export CPATH=$LIBUNWIND_PREFIX/include
+export LD_LIBRARY_PATH=$LIBUNWIND_LIB
+export EXTRA_CFLAGS=-L$LIBUNWIND_LIB
+
+make -j
+mkdir -p $PREFIX/bin
+cp "perf" "$PREFIX/bin/"
+
+git checkout "$original_branch"

util/unwind-libunwind-local.c

@@ -473,10 +473,11 @@ get_proc_name(unw_addr_space_t __maybe_unused as,
 }
 
 static void
-get_mmap(unw_mmap_entry_t* entries, size_t* count, void* arg) {
+get_mmap(unw_mmap_entry_t** entries, size_t* count, void* arg) {
     struct unwind_info* unw_info = arg;
     struct map_groups* mgroups = unw_info->thread->mg;
     int id;
+    unw_mmap_entry_t* alloc_entries = NULL;
 
     // == Count entries ==
     *count = 0;
@@ -488,8 +489,9 @@ get_mmap(unw_mmap_entry_t* entries, size_t* count, void* arg) {
     }
 
     // == Allocate ==
-    entries = (unw_mmap_entry_t*)
-        malloc(sizeof(unw_mmap_entry_t) * (*count)); // Will be free'd
+    alloc_entries = (unw_mmap_entry_t*)
+        malloc(sizeof(unw_mmap_entry_t) * (*count)); // Will be free'd by user
+    *entries = alloc_entries;
 
     // == Fill entries ==
     id = 0;
@@ -497,11 +499,12 @@ get_mmap(unw_mmap_entry_t* entries, size_t* count, void* arg) {
             map;
             map = map_groups__next(map), ++id)
     {
-        entries[id].beg_ip = map->start;
-        entries[id].end_ip = map->end;
-        entries[id].offset = map->start - map->map_ip(map, map->start);
-        entries[id].object_name = malloc(strlen(map->dso->long_name) + 1);
-        strcpy(entries[id].object_name, map->dso->long_name);
+        alloc_entries[id].beg_ip = map->start;
+        alloc_entries[id].end_ip = map->end;
+        alloc_entries[id].offset = map->start - map->map_ip(map, map->start);
+        alloc_entries[id].object_name =
+            malloc(strlen(map->dso->long_name) + 1);
+        strcpy(alloc_entries[id].object_name, map->dso->long_name);
     }
 }