Compiling Redis against libhugetlbfs to activate huge pages support

gistfile1.txt

Redis can be compiled against libhugetlbfs, so huge pages support can be activated with Linux >= 2.6.16.
It should cover Enterprise Linux distros such as SLES 10 or better, and RHEL/Centos/OEL 5 or better.

Be sure to read http://lwn.net/Articles/374424/ first.

Install libhugetlbfs source code in local directory $DIRHUGE
Source can be downloaded from http://libhugetlbfs.sourceforge.net/ 
Compile only the 64 bits version using make BUILDTYPE=NATIVEONLY
The library will be generated in $DIRHUGE/obj64 - add it in your LD_LIBRARY_PATH

Setup your huge page configuration (root access needed)
sudo sysctl -w vm.nr_hugepages=<N>
sudo mount -t hugetlbfs none /mnt/hugetlbfs

To compile Redis against libhugetlbfs, you need to build Redis against libc memory allocator.
Note that in 2.4 it is not anymore the default.

Alter the Redis makefile as follows:

27c27
<   CCLINK?= -lm -pthread -L $(DIRHUGE)/obj64 -l hugetlbfs
---
>   CCLINK?= -lm -pthread

Build Redis

To activate automatic usage of huge pages, the following variables should be declared
in Redis environment:

export LD_LIBRARY_PATH=$(DIRHUGE)/obj64:$LD_LIBRARY_PATH
export HUGETLB_MORECORE=yes

Then launch Redis as usual.