[PATCH] Add explanation of the profile feedback build to the README
From: Andi Kleen <ak@linux.intel.com>
Also explains that the are additional warnings.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
INSTALL | 13 +++++++++++++
1 files changed, 13 insertions(+), 0 deletions(-)
diff --git a/INSTALL b/INSTALL
index 16e45f1..bbb9d4d 100644
--- a/INSTALL
+++ b/INSTALL
@@ -25,6 +25,19 @@ set up install paths (via config.mak.autogen), so you can write instead
$ make all doc ;# as yourself
# make install install-doc install-html;# as root
+If you're willing to trade off (much) longer build time for a later
+faster git you can also do a profile feedback build with
+
+ $ make profile-all
+ # make prefix=... install
+
+This will run the complete test suite as training workload and then
+rebuild git with the generated profile feedback. This results in a git
+which is a few percent faster on CPU intensive workloads. This
+may be a good tradeoff for distribution packagers.
+
+Note that the profile feedback build stage currently generates
+a lot of additional compiler warnings.
Issues of note:
--
1.7.4.4