• Siddha, Suresh B's avatar
    [PATCH] sched: new sched domain for representing multi-core · 1e9f28fa
    Siddha, Suresh B authored
    Add a new sched domain for representing multi-core with shared caches
    between cores.  Consider a dual package system, each package containing two
    cores and with last level cache shared between cores with in a package.  If
    there are two runnable processes, with this appended patch those two
    processes will be scheduled on different packages.
    
    On such systems, with this patch we have observed 8% perf improvement with
    specJBB(2 warehouse) benchmark and 35% improvement with CFP2000 rate(with 2
    users).
    
    This new domain will come into play only on multi-core systems with shared
    caches.  On other systems, this sched domain will be removed by domain
    degeneration code.  This new domain can be also used for implementing power
    savings policy (see OLS 2005 CMP kernel scheduler paper for more details..
    I will post another patch for power savings policy soon)
    
    Most of the arch/* file changes are for cpu_coregroup_map() implementation.
    Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
    Cc: Ingo Molnar <mingo@elte.hu>
    Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
    1e9f28fa
smpboot.c 31.6 KB