0cede15d6c
The patch changes the order in which L1 dcache and icache are looked up when a request comes in. Earlier, if a request came in for instruction fetch, the dcache was looked up before the icache, to correctly handle self-modifying code. But, in the common case, dcache is going to report a miss and the subsequent icache lookup is going to report a hit. Given the invariant - caches under the same controller keep track of disjoint sets of cache blocks, we can move the icache lookup before the dcache lookup. In case of a hit in the icache, using our invariant, we know that the dcache would have reported a miss. In case of a miss in the icache, we know that icache would have missed even if the dcache was looked up before looking up the icache. Effectively, we are doing the same thing as before, though in the common case, we expect reduction in the number of lookups. This was empirically confirmed for MOESI hammer. The ratio lookups to access requests is now about 1.1 to 1.
This is release 2.0_beta6 of the M5 simulator. For detailed information about building the simulator and getting started please refer to http://www.m5sim.org. Specific pages of interest are: http://www.m5sim.org/wiki/index.php/Compiling_M5 http://www.m5sim.org/wiki/index.php/Running_M5 Short version: 1. If you don't have SCons version 0.96.91 or newer, get it from http://wwww.scons.org. 2. If you don't have SWIG version 1.3.28 or newer, get it from http://wwww.swig.org. 3. In this directory, type 'scons build/ALPHA_SE/tests/debug/quick'. This will build the debug version of the m5 binary (m5.debug) for the Alpha syscall emulation target, and run the quick regression tests on it. If you have questions, please send mail to m5-users@m5sim.org WHAT'S INCLUDED (AND NOT) ------------------------- The basic source release includes these subdirectories: - m5: - src: source code of the m5 simulator - tests: regression tests - ext: less-common external packages needed to build m5 To run full-system simulations, you will need compiled console, PALcode, and kernel binaries and one or more disk images. These files are collected in a separate archive, m5_system.tar.bz2. This file can he downloaded separately. M5 supports Linux 2.4/2.6, FreeBSD, and the proprietary Compaq/HP Tru64 version of Unix. We are able to distribute Linux and FreeBSD bootdisks, but we are unable to distribute bootable disk images of Tru64 Unix. If you have a Tru64 license and are interested in obtaining disk images, contact us at m5-users@m5sim.org