2b337e33b4
This patch saves almost 20 GB (!!) of disk space in Urchin's build
directory, as well as a lot of memory during the link phase of the
build (which can be noticable on low-memory machines which leads to
slow swapping).
Because of C++'s extremely lengthy mangled names, and extremely numerous
functions, the debugging information generated for Seastar code is absurdly
large, and added to every single executable we generate. This is most
noticable in tests - we currently have over 30 tests (with hopefully much
more to come), each compiled into a separate excutable with its own copy of
all this debug information. Many of these executables are half a gigabyte,
each!
So this patch creates all test executables - whether debug or release mode -
stripped. When a user encounters a failing test he wants debug information
for (for gdb or the sanitizer), he can trivially relink it unstripped,
with a command like:
ninja build/release/tests/urchin/sstable_test_g
note the added "_g". This links the already existing object files (which
still have their debug information, which takes just a fraction of a second.
On my machine, this patch reduces the Urchin built tests from about
27 GB to 8.1 GB. The build/release/tests directory drops from 10 GB to
just 0.6 GB! The build/debug/tests directory is still huge (7.5 GB),
although still smaller than what it was (17 GB). This remaining hugeness
is not because of the debug information, but because of the undefined-
behavior sanitizer (-fsanitize=undefined), which unfortunately adds a
huge data segment to each executable and I still don't know how to improve
on that. Nevertheless, it's still a significant reduction in space and will
be even more important as we write more tests.
Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
#Urchin
##Building Urchin
In addition to required packages by Seastar, the following packages are required by Urchin.
Submodules
Urchin uses submodules, so make sure you pull the submodules first by doing:
git submodule init
git submodule update
Building urchin on Fedora
Installing required packages:
sudo yum install yaml-cpp-devel lz4-devel zlib-devel snappy-devel jsoncpp-devel
Building urchin on Ubuntu 14.04
Installing required packages:
sudo apt-get install libyaml-cpp-dev liblz4-dev zlib1g-dev libsnappy-dev libjsoncpp-dev