BMC (BPF Memory Cache) is an in-kernel cache for memcached. It enables runtime, crash-safe extension of the Linux kernel to process specific memcached requests before the execution of the standard network stack. BMC does not require modification of neither the Linux kernel nor the memcached application. Running memcached with BMC improves throughput by up to 18x compared to the vanilla memcached application.

Linux kernel v5.3 or higher is required to run BMC.

Other software dependencies are required to build BMC and Memcached-SR (see Building BMC and Building Memcached-SR).

BMC must be compiled with libbpf and other header files obtained from kernel sources. The project does not include the kernel sources, but the kernel-src-download.sh and kernel-src-prepare.sh scripts automate the download of the kernel sources and prepare them for the compilation of BMC.

These scripts require the following software to be installed:

gpg curl tar xz make gcc flex bison libssl-dev libelf-dev

The project uses llvm and clang version 9 to build BMC, but more recent versions might work as well:

llvm-9 clang-9

Note that libelf-dev is also required to build libbpf and BMC.

With the previous software installed, BMC can be built with the following:

$ ./kernel-src-download.sh
$ ./kernel-src-prepare.sh
$ cd bmc && make

After BMC has been successfully built, kernel sources can be removed by running the kernel-src-remove.sh script from the project root.

Memcached-SR is based on memcached v1.5.19. Building it requires the following software:

clang-9 (or gcc-9) automake libevent-dev

Either clang-9 or gcc-9 is required in order to compile memcached without linking issues. Depending on your distribution, you might also need to use the -Wno-deprecated-declarations compilation flag.

Memcached-SR can be built with the following:

$ cd memcached-sr 
$ ./autogen.sh
$ CC=clang-9 CFLAGS='-DREUSEPORT_OPT=1 -Wno-deprecated-declarations' ./configure && make

The memcached binary will be located in the memcached-sr directory.

Files under the bmc directory are licensed under the GNU Lesser General Public License version 2.1 license.

Files under the memcached-sr directory are licensed under the BSD-3-Clause BSD license.