linux-toradex.git/include/linux/topology.h, branch v2.6.31.2

numa, cpumask: move numa_node_id default implementation to topology.h

2009-03-13T13:35:31+00:00

Impact: cleanup, potential bugfix

Not sure what changed to expose this, but clearly that numa_node_id()
doesn't belong in mmzone.h (the inline in gfp.h is probably overkill, too).

In file included from include/linux/topology.h:34,
                 from arch/x86/mm/numa.c:2:
/home/rusty/patches-cpumask/linux-2.6/arch/x86/include/asm/topology.h:64:1: warning: "numa_node_id" redefined
In file included from include/linux/topology.h:32,
                 from arch/x86/mm/numa.c:2:
include/linux/mmzone.h:770:1: warning: this is the location of the previous definition

Signed-off-by: Rusty Russell 
Cc: Mike Travis 
LKML-Reference: <200903132343.37661.rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar

cpumask: replace node_to_cpumask with cpumask_of_node.

2009-03-13T04:19:46+00:00

Impact: cleanup

node_to_cpumask (and the blecherous node_to_cpumask_ptr which
contained a declaration) are replaced now everyone implements
cpumask_of_node.

Signed-off-by: Rusty Russell

cpumask: Use topology_core_cpumask()/topology_thread_cpumask()

2009-01-11T18:12:49+00:00

Impact: reduce stack usage, use new cpumask API.

This actually uses topology_core_cpumask() and
topology_thread_cpumask(), removing the only users of
topology_core_siblings() and topology_thread_siblings()

Signed-off-by: Rusty Russell 
Signed-off-by: Mike Travis 
Cc: linux-net-drivers@solarflare.com

sched: add SD_BALANCE_NEWIDLE at MC and CPU level for sched_mc>0

2008-12-19T08:21:55+00:00

Impact: change task balancing to save power more agressively

Add SD_BALANCE_NEWIDLE flag at MC level and CPU level
if sched_mc is set.  This helps power savings and
will not affect performance when sched_mc=0

Ingo and Mike Galbraith have optimised the SD flags by
removing SD_BALANCE_NEWIDLE at MC and CPU level.  This
helps performance but hurts power savings since this
slows down task consolidation by reducing the number
of times load_balance is run.

    sched: fine-tune SD_MC_INIT
        commit 14800984706bf6936bbec5187f736e928be5c218
        Author: Mike Galbraith 
        Date:   Fri Nov 7 15:26:50 2008 +0100

    sched: re-tune balancing -- revert
        commit 9fcd18c9e63e325dbd2b4c726623f760788d5aa8
        Author: Ingo Molnar 
        Date:   Wed Nov 5 16:52:08 2008 +0100

This patch selectively enables SD_BALANCE_NEWIDLE flag
only when sched_mc is set to 1 or 2.  This helps power savings
by task consolidation and also does not hurt performance at
sched_mc=0 where all power saving optimisations are turned off.

Signed-off-by: Vaidyanathan Srinivasan 
Acked-by: Balbir Singh 
Acked-by: Peter Zijlstra 
Signed-off-by: Ingo Molnar

sched: convert BALANCE_FOR_xx_POWER to inline functions

2008-12-19T08:21:45+00:00

Impact: cleanup

BALANCE_FOR_MC_POWER and similar macros defined in sched.h are
not constants and have various condition checks and significant
amount of code that is not suitable to be contain in a macro.
Also there could be side effects on the expressions passed to
some of them like test_sd_parent().

This patch converts all complex macros related to power savings
balance to inline functions.

Signed-off-by: Vaidyanathan Srinivasan 
Acked-by: Balbir Singh 
Acked-by: Peter Zijlstra 
Signed-off-by: Ingo Molnar

sched: let arch_update_cpu_topology indicate if topology changed

2008-12-12T12:47:21+00:00

Change arch_update_cpu_topology so it returns 1 if the cpu topology changed
and 0 if it didn't change. This will be useful for the next patch which adds
a call to this function in partition_sched_domains.

Signed-off-by: Heiko Carstens 
Signed-off-by: Ingo Molnar

sched: fine-tune SD_SIBLING_INIT

2008-11-07T15:09:23+00:00

fine-tune the HT sched-domains parameters as well.

On a HT capable box, this increases lat_ctx performance from 23.87
usecs to 1.49 usecs:

 # before

 $ ./lat_ctx -s 0 2

   "size=0k ovr=1.89
    2 23.87

 # after

 $ ./lat_ctx -s 0 2

   "size=0k ovr=1.84
     2 1.49

Signed-off-by: Ingo Molnar

sched: fine-tune SD_MC_INIT

2008-11-07T14:35:11+00:00

Tune SD_MC_INIT the same way as SD_CPU_INIT:
unset SD_BALANCE_NEWIDLE, and set SD_WAKE_BALANCE.

This improves vmark by 5%:

vmark         132102 125968 125497 messages/sec    avg 127855.66    .984
vmark         139404 131719 131272 messages/sec    avg 134131.66   1.033

Signed-off-by: Mike Galbraith 
Acked-by: Peter Zijlstra 
Signed-off-by: Ingo Molnar 

 # *DOCUMENTATION*

sched: re-tune balancing

2008-11-05T17:04:38+00:00

Impact: improve wakeup affinity on NUMA systems, tweak SMP systems

Given the fixes+tweaks to the wakeup-buddy code, re-tweak the domain
balancing defaults on NUMA and SMP systems.

Turn on SD_WAKE_AFFINE which was off on x86 NUMA - there's no reason
why we would not want to have wakeup affinity across nodes as well.
(we already do this in the standard NUMA template.)

lat_ctx on a NUMA box is particularly happy about this change:

before:

 |   phoenix:~/l> ./lat_ctx -s 0 2
 |   "size=0k ovr=2.60
 |   2 5.70

after:

 |   phoenix:~/l> ./lat_ctx -s 0 2
 |   "size=0k ovr=2.65
 |   2 2.07

a 2.75x speedup.

pipe-test is similarly happy about it too:

 |  phoenix:~/sched-tests> ./pipe-test
 |   18.26 usecs/loop.
 |   14.70 usecs/loop.
 |   14.38 usecs/loop.
 |   10.55 usecs/loop.              # +WAKE_AFFINE on domain0+domain1
 |   8.63 usecs/loop.
 |   8.59 usecs/loop.
 |   9.03 usecs/loop.
 |   8.94 usecs/loop.
 |   8.96 usecs/loop.
 |   8.63 usecs/loop.

Also:

 - disable SD_BALANCE_NEWIDLE on NUMA and SMP domains (keep it for siblings)
 - enable SD_WAKE_BALANCE on SMP domains

Sysbench+postgresql improves all around the board, quite significantly:

           .28-rc3-11474e2c  .28-rc3-11474e2c-tune
-------------------------------------------------
    1:             571              688    +17.08%
    2:            1236             1206    -2.55%
    4:            2381             2642    +9.89%
    8:            4958             5164    +3.99%
   16:            9580             9574    -0.07%
   32:            7128             8118    +12.20%
   64:            7342             8266    +11.18%
  128:            7342             8064    +8.95%
  256:            7519             7884    +4.62%
  512:            7350             7731    +4.93%
-------------------------------------------------
  SUM:           55412            59341    +6.62%

So it's a win both for the runup portion, the peak area and the tail.

Signed-off-by: Ingo Molnar

cpu topology: always define CPU topology information

2008-06-13T08:09:46+00:00

This can result in an empty topology directory in sysfs, and requires
in-kernel users to protect all uses with #ifdef - see
.

The documentation of CPU topology specifies what the defaults should be if
only partial information is available from the hardware.  So we can
provide these defaults as a fallback.

This patch:

- Adds default definitions of the 4 topology macros to 
- Changes drivers/base/topology.c to use the topology macros unconditionally
  and to cope with definitions that aren't lvalues
- Updates documentation accordingly

[ From: Andrew Morton 
  - fold now-duplicated code
  - fix layout
]

Signed-off-by: Ben Hutchings 
Cc: Vegard Nossum 
Cc: Nick Piggin 
Cc: Chandra Seetharaman 
Cc: Suresh Siddha 
Cc: Mike Travis 
Cc: Christoph Lameter 
Cc: John Hawkes 
Cc: Zhang, Yanmin 
Signed-off-by: Andrew Morton 
Signed-off-by: Ingo Molnar