Add dedicated README and borrow linux .gitignore

.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 +1,23 @@
+# 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.
+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