linux-toradex.git/include/linux/vmstat.h, branch v2.6.20.21

[PATCH] fix vm_events_fold_cpu() build breakage

2006-12-22T16:55:48+00:00

fix vm_events_fold_cpu() build breakage

2.6.20-rc1 does not build properly if CONFIG_VM_EVENT_COUNTERS is set
and CONFIG_HOTPLUG is unset:

  CC      init/version.o
  LD      init/built-in.o
  LD      .tmp_vmlinux1
mm/built-in.o: In function `page_alloc_cpu_notify':
page_alloc.c:(.text+0x56eb): undefined reference to `vm_events_fold_cpu'
make: *** [.tmp_vmlinux1] Error 1

[akpm@osdl.org: cleanup]
Signed-off-by: Magnus Damm 
Cc: Christoph Lameter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] CONFIG_VM_EVENT_COUNTER comment decrustify

2006-12-22T16:55:46+00:00

The VM event counters, enabled by CONFIG_VM_EVENT_COUNTERS, which provides
VM event counters in /proc/vmstat, has become more essential to
non-EMBEDDED kernel configurations than they were in the past.  Comments in
the code and the Kconfig configuration explanation were stale, downplaying
their role excessively.

Refresh those comments to correctly reflect the current role of VM event
counters.

Signed-off-by: Paul Jackson 
Acked-by: Christoph Lameter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Remove another config.h

2006-09-29T16:18:13+00:00

After the asm/ uses of #include  this one is the next
biggest source of noise.

Signed-off-by: Dave Jones 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] reduce MAX_NR_ZONES: remove display of counters for unconfigured zones

2006-09-26T15:48:47+00:00

eventcounters: Do not display counters for zones that are not available on an
arch

Do not define or display counters for the DMA32 and the HIGHMEM zone if such
zones were not configured.

[akpm@osdl.org: s390 fix]
[heiko.carstens@de.ibm.com: s390 fix]
Signed-off-by: Christoph Lameter 
Cc: Martin Schwidefsky 
Signed-off-by: Heiko Carstens 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] reduce MAX_NR_ZONES: make ZONE_DMA32 optional

2006-09-26T15:48:46+00:00

Make ZONE_DMA32 optional

- Add #ifdefs around ZONE_DMA32 specific code and definitions.

- Add CONFIG_ZONE_DMA32 config option and use that for x86_64
  that alone needs this zone.

- Remove the use of CONFIG_DMA_IS_DMA32 and CONFIG_DMA_IS_NORMAL
  for ia64 and fix up the way per node ZVCs are calculated.

- Fall back to prior GFP_ZONEMASK of 0x03 if there is no
  DMA32 zone.

Signed-off-by: Christoph Lameter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] fix vmstat per cpu usage

2006-08-06T15:57:47+00:00

The per cpu variables are used incorrectly in vmstat.h.

Signed-off-by: Jan Blunck 
Cc: Christoph Lameter 
Acked-by: Steve Fox 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] ZVC: add __inc_zone_state for !SMP configuration

2006-07-10T20:24:18+00:00

It turns out that there is a way to build a kernel with NUMA and no SMP.
In that case we are missing one definition __inc_zone_state.

Provide that missing __inc_zone_state.

(akpm: NUMA && !SMP sounds odd, but I am told "But there is the concept of
cpuless nodes.  A NUMA system without SMP has a single processor but multiple
memory nodes.  This used to work before on IA64 (wasn't aware of it, never seen
anyone with this kind of thing).")

Acked-by: Tony Luck 
Signed-off-by: Christoph Lameter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] count_vm_events() fix

2006-07-10T20:24:13+00:00

Dopey bug.  Causes hopelessly-wrong numbers from vmstat(8) and several other
counters.

Cc: Christoph Lameter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Light weight event counters

2006-06-30T18:25:36+00:00

The remaining counters in page_state after the zoned VM counter patches
have been applied are all just for show in /proc/vmstat.  They have no
essential function for the VM.

We use a simple increment of per cpu variables.  In order to avoid the most
severe races we disable preempt.  Preempt does not prevent the race between
an increment and an interrupt handler incrementing the same statistics
counter.  However, that race is exceedingly rare, we may only loose one
increment or so and there is no requirement (at least not in kernel) that
the vm event counters have to be accurate.

In the non preempt case this results in a simple increment for each
counter.  For many architectures this will be reduced by the compiler to a
single instruction.  This single instruction is atomic for i386 and x86_64.
 And therefore even the rare race condition in an interrupt is avoided for
both architectures in most cases.

The patchset also adds an off switch for embedded systems that allows a
building of linux kernels without these counters.

The implementation of these counters is through inline code that hopefully
results in only a single instruction increment instruction being emitted
(i386, x86_64) or in the increment being hidden though instruction
concurrency (EPIC architectures such as ia64 can get that done).

Benefits:
- VM event counter operations usually reduce to a single inline instruction
  on i386 and x86_64.
- No interrupt disable, only preempt disable for the preempt case.
  Preempt disable can also be avoided by moving the counter into a spinlock.
- Handling is similar to zoned VM counters.
- Simple and easily extendable.
- Can be omitted to reduce memory use for embedded use.

References:

RFC http://marc.theaimsgroup.com/?l=linux-kernel&m=113512330605497&w=2
RFC http://marc.theaimsgroup.com/?l=linux-kernel&m=114988082814934&w=2
local_t http://marc.theaimsgroup.com/?l=linux-kernel&m=114991748606690&w=2
V2 http://marc.theaimsgroup.com/?t=115014808400007&r=1&w=2
V3 http://marc.theaimsgroup.com/?l=linux-kernel&m=115024767022346&w=2
V4 http://marc.theaimsgroup.com/?l=linux-kernel&m=115047968808926&w=2

Signed-off-by: Christoph Lameter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Use Zoned VM Counters for NUMA statistics

2006-06-30T18:25:36+00:00

The numa statistics are really event counters.  But they are per node and
so we have had special treatment for these counters through additional
fields on the pcp structure.  We can now use the per zone nature of the
zoned VM counters to realize these.

This will shrink the size of the pcp structure on NUMA systems.  We will
have some room to add additional per zone counters that will all still fit
in the same cacheline.

 Bits	Prior pcp size	  	Size after patch	We can add
 ------------------------------------------------------------------
 64	128 bytes (16 words)	80 bytes (10 words)	48
 32	 76 bytes (19 words)	56 bytes (14 words)	8 (64 byte cacheline)
							72 (128 byte)

Remove the special statistics for numa and replace them with zoned vm
counters.  This has the side effect that global sums of these events now
show up in /proc/vmstat.

Also take the opportunity to move the zone_statistics() function from
page_alloc.c into vmstat.c.

Discussions:
V2 http://marc.theaimsgroup.com/?t=115048227000002&r=1&w=2

Signed-off-by: Christoph Lameter 
Acked-by: Andi Kleen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds