[PATCH] README: Add build speed up tip in BUILD section.

[Davidlohr Bueso <dave.bueso@gmail.com>]

Hi,

IMHO the README file could benefit from GNU make's -j[N] option in BUILD section, as a general tip for users.

Not entirely sure who deals with this file, so sending to Linus.

Thanks.

Signed-off-by: Davidlohr Bueso <dave@gnu.org>
---
 README |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/README b/README
index 737838f..fda7d52 100644
--- a/README
+++ b/README
@@ -154,6 +154,11 @@ BUILD directory for the kernel:
    Please note: If the 'O=output/dir' option is used then it must be
    used for all invocations of make.
 
+   Depending on the system and configuration, building the kernel can
+   take some time. To speed things up you can use GNU make's -j[N] option
+   to specify the number of jobs to run simultaneously. The N value should
+   be twice the amount of the machine's CPUs.  
+
 CONFIGURING the kernel:
 
    Do not skip this step even if you are only upgrading one minor
-- 
1.7.0.4