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  1. Jul 01, 2006
    • Christoph Lameter's avatar
      [PATCH] zoned vm counters: remove NR_FILE_MAPPED from scan control structure · bf02cf4b
      Christoph Lameter authored 
      

We can now access the number of pages in a mapped state in an inexpensive way
in shrink_active_list.  So drop the nr_mapped field from scan_control.

[akpm@osdl.org: bugfix]
Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      bf02cf4b
    • Christoph Lameter's avatar
      [PATCH] zoned vm counters: conversion of nr_pagecache to per zone counter · 347ce434
      Christoph Lameter authored 
      

Currently a single atomic variable is used to establish the size of the page
cache in the whole machine.  The zoned VM counters have the same method of
implementation as the nr_pagecache code but also allow the determination of
the pagecache size per zone.

Remove the special implementation for nr_pagecache and make it a zoned counter
named NR_FILE_PAGES.

Updates of the page cache counters are always performed with interrupts off.
We can therefore use the __ variant here.

Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      347ce434
    • Christoph Lameter's avatar
      [PATCH] zoned vm counters: convert nr_mapped to per zone counter · 65ba55f5
      Christoph Lameter authored 
      

nr_mapped is important because it allows a determination of how many pages of
a zone are not mapped, which would allow a more efficient means of determining
when we need to reclaim memory in a zone.

We take the nr_mapped field out of the page state structure and define a new
per zone counter named NR_FILE_MAPPED (the anonymous pages will be split off
from NR_MAPPED in the next patch).

We replace the use of nr_mapped in various kernel locations.  This avoids the
looping over all processors in try_to_free_pages(), writeback, reclaim (swap +
zone reclaim).

[akpm@osdl.org: bugfix]
Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      65ba55f5
    • Christoph Lameter's avatar
      [PATCH] zoned vm counters: basic ZVC (zoned vm counter) implementation · 2244b95a
      Christoph Lameter authored 
      

Per zone counter infrastructure

The counters that we currently have for the VM are split per processor.  The
processor however has not much to do with the zone these pages belong to.  We
cannot tell f.e.  how many ZONE_DMA pages are dirty.

So we are blind to potentially inbalances in the usage of memory in various
zones.  F.e.  in a NUMA system we cannot tell how many pages are dirty on a
particular node.  If we knew then we could put measures into the VM to balance
the use of memory between different zones and different nodes in a NUMA
system.  For example it would be possible to limit the dirty pages per node so
that fast local memory is kept available even if a process is dirtying huge
amounts of pages.

Another example is zone reclaim.  We do not know how many unmapped pages exist
per zone.  So we just have to try to reclaim.  If it is not working then we
pause and try again later.  It would be better if we knew when it makes sense
to reclaim unmapped pages from a zone.  This patchset allows the determination
of the number of unmapped pages per zone.  We can remove the zone reclaim
interval with the counters introduced here.

Futhermore the ability to have various usage statistics available will allow
the development of new NUMA balancing algorithms that may be able to improve
the decision making in the scheduler of when to move a process to another node
and hopefully will also enable automatic page migration through a user space
program that can analyse the memory load distribution and then rebalance
memory use in order to increase performance.

The counter framework here implements differential counters for each processor
in struct zone.  The differential counters are consolidated when a threshold
is exceeded (like done in the current implementation for nr_pageache), when
slab reaping occurs or when a consolidation function is called.

Consolidation uses atomic operations and accumulates counters per zone in the
zone structure and also globally in the vm_stat array.  VM functions can
access the counts by simply indexing a global or zone specific array.

The arrangement of counters in an array also simplifies processing when output
has to be generated for /proc/*.

Counters can be updated by calling inc/dec_zone_page_state or
_inc/dec_zone_page_state analogous to *_page_state.  The second group of
functions can be called if it is known that interrupts are disabled.

Special optimized increment and decrement functions are provided.  These can
avoid certain checks and use increment or decrement instructions that an
architecture may provide.

We also add a new CONFIG_DMA_IS_NORMAL that signifies that an architecture can
do DMA to all memory and therefore ZONE_NORMAL will not be populated.  This is
only currently set for IA64 SGI SN2 and currently only affects
node_page_state().  In the best case node_page_state can be reduced to
retrieving a single counter for the one zone on the node.

[akpm@osdl.org: cleanups]
[akpm@osdl.org: export vm_stat[] for filesystems]
Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      2244b95a
    • Christoph Lameter's avatar
      [PATCH] zoned vm counters: create vmstat.c/.h from page_alloc.c/.h · f6ac2354
      Christoph Lameter authored 
      NOTE: ZVC are *not* the lightweight event counters.  ZVCs are reliable whereas
event counters do not need to be.

Zone based VM statistics are necessary to be able to determine what the state
of memory in one zone is.  In a NUMA system this can be helpful for local
reclaim and other memory optimizations that may be able to shift VM load in
order to get more balanced memory use.

It is also useful to know how the computing load affects the memory
allocations on various zones.  This patchset allows the retrieval of that data
from userspace.

The patchset introduces a framework for counters that is a cross between the
existing page_stats --which are simply global counters split per cpu-- and the
approach of deferred incremental updates implemented for nr_pagecache.

Small per cpu 8 bit counters are added to struct zone.  If the counter exceeds
certain thresholds then the counters are accumulated in an array of
atomic_long in the zone and in a...
      f6ac2354
    • Adrian Bunk's avatar
      [PATCH] fix ISTALLION=y · 672b2714
      Adrian Bunk authored 
      

drivers/char/istallion.c: In function ‘stli_initbrds’:
drivers/char/istallion.c:4150: error: implicit declaration of function ‘stli_parsebrd’
drivers/char/istallion.c:4150: error: ‘stli_brdsp’ undeclared (first use in this function)
drivers/char/istallion.c:4150: error: (Each undeclared identifier is reported only once
drivers/char/istallion.c:4150: error: for each function it appears in.)
drivers/char/istallion.c:4164: error: implicit declaration of function ‘stli_argbrds’

While I was at it, I also removed the #ifdef MODULE around the initialation
code to allow it to perhaps work when built into the kernel and made a
needlessly global function static.

Signed-off-by: default avatarAdrian Bunk <bunk@stusta.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      672b2714
    • Andrew Morton's avatar
      [PATCH] msr.c: use register_hotcpu_notifier() · e09793bb
      Andrew Morton authored 
      

register_cpu_notifier() cannot do anything in a module, in a
!CONFIG_HOTPLUG_CPU kernel.

Cc: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      e09793bb
    • Ingo Molnar's avatar
      [PATCH] fix platform_device_put/del mishaps · 1017f6af
      Ingo Molnar authored 
      

This fixes drivers/char/pc8736x_gpio.c and drivers/char/scx200_gpio.c to
use the platform_device_del/put ops correctly.

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Cc: Jim Cromie <jim.cromie@gmail.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      1017f6af
    • Ingo Molnar's avatar
      [PATCH] fix drivers/video/imacfb.c compilation · 491d525f
      Ingo Molnar authored 
      

Fix build error on x86_64.  There's nothing even remotely close to
imacmp_seg in the kernel, so I removed the whole line.

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Cc: Edgar Hucek <hostmaster@ed-soft.at>
Cc: Antonino Daplas <adaplas@pol.net>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      491d525f
  3. Jun 30, 2006