[PATCH 0/5] cpusets: dynamical scheduler domain flags

From: Michael Wang
Date: Tue Jul 17 2012 - 05:03:57 EST

From: Michael Wang <wangyun@xxxxxxxxxxxxxxxxxx>

This patch set provide a way for user to dynamically configure the scheduler
domain flags, which usually to be static.

We can do the configuration through cpuset cgroup, new file will be found
under each hierarchy:

-- appear when CONFIG_SCHED_SMT enabled, stands for the domain flags
of cpuset on smt level

-- appear when CONFIG_SCHED_MC enabled, stands for the domain flags
of cpuset on mc level

-- appear when CONFIG_SCHED_BOOK enabled, stands for the domain flags
of cpuset on book level

-- stands for the domain flags of cpuset on cpu level

-- set to 1 if want to use the dynamical domain flags, domain will
be rebuild


Currently the domain flags bit are:
#define SD_LOAD_BALANCE 0x0001 /* Do load balancing on this domain. */
#define SD_BALANCE_NEWIDLE 0x0002 /* Balance when about to become idle */
#define SD_BALANCE_EXEC 0x0004 /* Balance on exec */
#define SD_BALANCE_FORK 0x0008 /* Balance on fork, clone */
#define SD_BALANCE_WAKE 0x0010 /* Balance on wakeup */
#define SD_WAKE_AFFINE 0x0020 /* Wake task to waking CPU */
#define SD_PREFER_LOCAL 0x0040 /* Prefer to keep tasks local to this domain */
#define SD_SHARE_CPUPOWER 0x0080 /* Domain members share cpu power */
#define SD_SHARE_PKG_RESOURCES 0x0200 /* Domain members share cpu pkg resources */
#define SD_SERIALIZE 0x0400 /* Only a single load balancing instance */
#define SD_ASYM_PACKING 0x0800 /* Place busy groups earlier in the domain */
#define SD_PREFER_SIBLING 0x1000 /* Prefer to place tasks in a sibling domain */
#define SD_OVERLAP 0x2000 /* sched_domains of this level overlap */
#define SD_NUMA 0x4000 /* cross-node balancing */

If we want to set SMT domain to be:
and other level domain only has SD_LOAD_BALANCE, then we can use:
echo 0x1011 > /sys/fs/cgroup/cpuset/cpuset.sched_smt_domain_flag
echo 0x1 > /sys/fs/cgroup/cpuset/cpuset.sched_mc_domain_flag
echo 0x1 > /sys/fs/cgroup/cpuset/cpuset.sched_book_domain_flag
echo 0x1 > /sys/fs/cgroup/cpuset/cpuset.sched_cpu_domain_flag
echo 1 > /sys/fs/cgroup/cpuset/cpuset.sched_enable_domain_flag

cpusets: add basic variables
cpusets: add functions and code for initialization
cpusets: enable the dynamical domain flags
cpusets: add fundamental functions for recording
cpusets: add the configuration facility

Signed-off-by: Michael Wang <wangyun@xxxxxxxxxxxxxxxxxx>
b/include/linux/sched.h | 22 ++++++++
b/kernel/cpuset.c | 7 ++
b/kernel/sched/core.c | 2
include/linux/sched.h | 10 ++-
kernel/cpuset.c | 131 +++++++++++++++++++++++++++++++++++++++++++++++-
kernel/sched/core.c | 10 +++
6 files changed, 176 insertions(+), 6 deletions(-)

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