Add support for core- and socket-scheduling in the Xen hypervisor.
Via boot parameter sched-gran=core (or sched-gran=socket)
it is possible to change the scheduling granularity from cpu (the
default) to either whole cores or even sockets.
All logical cpus (threads) of the core or socket are always scheduled
together. This means that on a core always vcpus of the same domain
will be active, and those vcpus will always be scheduled at the same
time.
This is achieved by switching the scheduler to no longer see vcpus as
the primary object to schedule, but "schedule items". Each schedule
item consists of as many vcpus as each core has threads on the current
system. The vcpu->item relation is fixed.
I have done some very basic performance testing: on a 4 cpu system
(2 cores with 2 threads each) I did a "make -j 4" for building the Xen
hypervisor. With This test has been run on dom0, once with no other
guest active and once with another guest with 4 vcpus running the same
test. The results are (always elapsed time, system time, user time):
sched-gran=cpu, no other guest: 116.10 177.65 207.84
sched-gran=core, no other guest: 114.04 175.47 207.45
sched-gran=cpu, other guest: 202.30 334.21 384.63
sched-gran=core, other guest: 207.24 293.04 371.37
All tests have been performed with credit2, the other schedulers are
untested up to now.
Cpupools are not yet working, as moving cpus between cpupools needs
more work (this is the reason for the series still being RFC). Same
applies to cpu add/remove.
Changes in RFC V2:
- ARM is building now
- HVM domains are working now
- idling will always be done with idle_vcpu active
- other small changes see individual patches
Juergen Gross (45):
xen/sched: add inline wrappers for calling per-scheduler functions
xen/sched: use new sched_item instead of vcpu in scheduler interfaces
xen/sched: alloc struct sched_item for each vcpu
xen/sched: move per-vcpu scheduler private data pointer to sched_item
xen/sched: build a linked list of struct sched_item
xen/sched: introduce struct sched_resource
xen/sched: let pick_cpu return a scheduler resource
xen/sched: switch schedule_data.curr to point at sched_item
xen/sched: move per cpu scheduler private data into struct
sched_resource
xen/sched: switch vcpu_schedule_lock to item_schedule_lock
xen/sched: move some per-vcpu items to struct sched_item
xen/sched: add scheduler helpers hiding vcpu
xen/sched: add domain pointer to struct sched_item
xen/sched: add id to struct sched_item
xen/sched: rename scheduler related perf counters
xen/sched: switch struct task_slice from vcpu to sched_item
xen/sched: add is_running indicator to struct sched_item
xen/sched: make null scheduler vcpu agnostic.
xen/sched: make rt scheduler vcpu agnostic.
xen/sched: make credit scheduler vcpu agnostic.
xen/sched: make credit2 scheduler vcpu agnostic.
xen/sched: make arinc653 scheduler vcpu agnostic.
xen: add sched_item_pause_nosync() and sched_item_unpause()
xen: let vcpu_create() select processor
xen/sched: use sched_resource cpu instead smp_processor_id in
schedulers
xen/sched: switch schedule() from vcpus to sched_items
xen/sched: switch sched_move_irqs() to take sched_item as parameter
xen: switch from for_each_vcpu() to for_each_sched_item()
xen/sched: add runstate counters to struct sched_item
xen/sched: rework and rename vcpu_force_reschedule()
xen/sched: Change vcpu_migrate_*() to operate on schedule item
xen/sched: move struct task_slice into struct sched_item
xen/sched: add code to sync scheduling of all vcpus of a sched item
xen/sched: introduce item_runnable_state()
xen/sched: add support for multiple vcpus per sched item where missing
x86: make loading of GDT at context switch more modular
x86: optimize loading of GDT at context switch
xen/sched: modify cpupool_domain_cpumask() to be an item mask
xen/sched: support allocating multiple vcpus into one sched item
xen/sched: add a scheduler_percpu_init() function
xen/sched: add a percpu resource index
xen/sched: add fall back to idle vcpu when scheduling item
xen/sched: make vcpu_wake() and vcpu_sleep() core scheduling aware
xen/sched: carve out freeing sched_item memory into dedicated function
xen/sched: add scheduling granularity enum
xen/arch/arm/domain.c | 2 +-
xen/arch/arm/domain_build.c | 13 +-
xen/arch/arm/smpboot.c | 2 +
xen/arch/x86/dom0_build.c | 10 +-
xen/arch/x86/domain.c | 95 ++-
xen/arch/x86/hvm/dom0_build.c | 9 +-
xen/arch/x86/pv/dom0_build.c | 10 +-
xen/arch/x86/pv/emul-priv-op.c | 1 +
xen/arch/x86/pv/shim.c | 4 +-
xen/arch/x86/pv/traps.c | 5 +-
xen/arch/x86/setup.c | 2 +
xen/arch/x86/smpboot.c | 2 +
xen/arch/x86/traps.c | 9 +-
xen/common/cpupool.c | 30 +-
xen/common/domain.c | 34 +-
xen/common/domctl.c | 23 +-
xen/common/keyhandler.c | 4 +-
xen/common/sched_arinc653.c | 258 ++++----
xen/common/sched_credit.c | 743 ++++++++++-----------
xen/common/sched_credit2.c | 1119 +++++++++++++++----------------
xen/common/sched_null.c | 424 ++++++------
xen/common/sched_rt.c | 544 +++++++--------
xen/common/schedule.c | 1348 +++++++++++++++++++++++++++++---------
xen/common/softirq.c | 6 +-
xen/common/wait.c | 4 +-
xen/include/asm-arm/current.h | 1 +
xen/include/asm-x86/cpuidle.h | 2 +-
xen/include/asm-x86/current.h | 7 +-
xen/include/asm-x86/dom0_build.h | 3 +-
xen/include/asm-x86/smp.h | 3 +
xen/include/xen/domain.h | 3 +-
xen/include/xen/perfc_defn.h | 32 +-
xen/include/xen/sched-if.h | 418 ++++++++++--
xen/include/xen/sched.h | 95 ++-
xen/include/xen/softirq.h | 1 +
35 files changed, 3198 insertions(+), 2068 deletions(-)
--
2.16.4
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