Commit Graph

42535 Commits

Author SHA1 Message Date
Peter Zijlstra
a866374aec [PATCH] mm: pagefault_{disable,enable}()
Introduce pagefault_{disable,enable}() and use these where previously we did
manual preempt increments/decrements to make the pagefault handler do the
atomic thing.

Currently they still rely on the increased preempt count, but do not rely on
the disabled preemption, this might go away in the future.

(NOTE: the extra barrier() in pagefault_disable might fix some holes on
       machines which have too many registers for their own good)

[heiko.carstens@de.ibm.com: s390 fix]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Nick Piggin <npiggin@suse.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:21 -08:00
Peter Zijlstra
6edaf68a87 [PATCH] mm: arch do_page_fault() vs in_atomic()
In light of the recent pagefault and filemap_copy_from_user work I've gone
through all the arch pagefault handlers to make sure the inc_preempt_count()
'feature' works as expected.

Several sections of code (including the new filemap_copy_from_user) rely on
the fact that faults do not take locks under increased preempt count.

arch/x86_64 - good
arch/powerpc - good
arch/cris - fixed
arch/i386 - good
arch/parisc - fixed
arch/sh - good
arch/sparc - good
arch/s390 - good
arch/m68k - fixed
arch/ppc - good
arch/alpha - fixed
arch/mips - good
arch/sparc64 - good
arch/ia64 - good
arch/arm - fixed
arch/um - good
arch/avr32 - good
arch/h8300 - NA
arch/m32r - good
arch/v850 - good
arch/frv - fixed
arch/m68knommu - NA
arch/arm26 - fixed
arch/sh64 - fixed
arch/xtensa - good

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:21 -08:00
Paul Menage
3395ee0588 [PATCH] mm: add noaliencache boot option to disable numa alien caches
When using numa=fake on non-NUMA hardware there is no benefit to having the
alien caches, and they consume much memory.

Add a kernel boot option to disable them.

Christoph sayeth "This is good to have even on large NUMA.  The problem is
that the alien caches grow by the square of the size of the system in terms of
nodes."

Cc: Christoph Lameter <clameter@engr.sgi.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:21 -08:00
Ravikiran G Thirumalai
8f5be20bf8 [PATCH] mm: slab: eliminate lock_cpu_hotplug from slab
Here's an attempt towards doing away with lock_cpu_hotplug in the slab
subsystem.  This approach also fixes a bug which shows up when cpus are
being offlined/onlined and slab caches are being tuned simultaneously.

http://marc.theaimsgroup.com/?l=linux-kernel&m=116098888100481&w=2

The patch has been stress tested overnight on a 2 socket 4 core AMD box with
repeated cpu online and offline, while dbench and kernbench process are
running, and slab caches being tuned at the same time.
There were no lockdep warnings either.  (This test on 2,6.18 as 2.6.19-rc
crashes at __drain_pages
http://marc.theaimsgroup.com/?l=linux-kernel&m=116172164217678&w=2 )

The approach here is to hold cache_chain_mutex from CPU_UP_PREPARE until
CPU_ONLINE (similar in approach as worqueue_mutex) .  Slab code sensitive
to cpu_online_map (kmem_cache_create, kmem_cache_destroy, slabinfo_write,
__cache_shrink) is already serialized with cache_chain_mutex.  (This patch
lengthens cache_chain_mutex hold time at kmem_cache_destroy to cover this).
 This patch also takes the cache_chain_sem at kmem_cache_shrink to protect
sanity of cpu_online_map at __cache_shrink, as viewed by slab.
(kmem_cache_shrink->__cache_shrink->drain_cpu_caches).  But, really,
kmem_cache_shrink is used at just one place in the acpi subsystem!  Do we
really need to keep kmem_cache_shrink at all?

Another note.  Looks like a cpu hotplug event can send  CPU_UP_CANCELED to
a registered subsystem even if the subsystem did not receive CPU_UP_PREPARE.
This could be due to a subsystem registered for notification earlier than
the current subsystem crapping out with NOTIFY_BAD. Badness can occur with
in the CPU_UP_CANCELED code path at slab if this happens (The same would
apply for workqueue.c as well).  To overcome this, we might have to use either
a) a per subsystem flag and avoid handling of CPU_UP_CANCELED, or
b) Use a special notifier events like LOCK_ACQUIRE/RELEASE as Gautham was
   using in his experiments, or
c) Do not send CPU_UP_CANCELED to a subsystem which did not receive
   CPU_UP_PREPARE.

I would prefer c).

Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Shai Fultheim <shai@scalex86.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:21 -08:00
Kevin Hilman
a44b56d354 [PATCH] slab debug and ARCH_SLAB_MINALIGN don't get along
When CONFIG_SLAB_DEBUG is used in combination with ARCH_SLAB_MINALIGN, some
debug flags should be disabled which depend on BYTES_PER_WORD alignment.

The disabling of these debug flags is not properly handled when
BYTES_PER_WORD < ARCH_SLAB_MEMALIGN < cache_line_size()

This patch fixes that and also adds an alignment check to
cache_alloc_debugcheck_after() when ARCH_SLAB_MINALIGN is used.

Signed-off-by: Kevin Hilman <khilman@mvista.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:21 -08:00
Chen, Kenneth W
cace673d37 [PATCH] htlb forget rss with pt sharing
Imprecise RSS accounting is an irritating ill effect with pt sharing.  After
consulted with several VM experts, I have tried various methods to solve that
problem: (1) iterate through all mm_structs that share the PT and increment
count; (2) keep RSS count in page table structure and then sum them up at
reporting time.  None of the above methods yield any satisfactory
implementation.

Since process RSS accounting is pure information only, I propose we don't
count them at all for hugetlb page.  rlimit has such field, though there is
absolutely no enforcement on limiting that resource.  One other method is to
account all RSS at hugetlb mmap time regardless they are faulted or not.  I
opt for the simplicity of no accounting at all.

Hugetlb page are special, they are reserved up front in global reservation
pool and is not reclaimable.  From physical memory resource point of view, it
is already consumed regardless whether there are users using them.

If the concern is that RSS can be used to control resource allocation, we
already can specify hugetlb fs size limit and sysadmin can enforce that at
mount time.  Combined with the two points mentioned above, I fail to see if
there is anything got affected because of this patch.

Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Acked-by: Hugh Dickins <hugh@veritas.com>
Cc: Dave McCracken <dmccr@us.ibm.com>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:21 -08:00
Chen, Kenneth W
39dde65c99 [PATCH] shared page table for hugetlb page
Following up with the work on shared page table done by Dave McCracken.  This
set of patch target shared page table for hugetlb memory only.

The shared page table is particular useful in the situation of large number of
independent processes sharing large shared memory segments.  In the normal
page case, the amount of memory saved from process' page table is quite
significant.  For hugetlb, the saving on page table memory is not the primary
objective (as hugetlb itself already cuts down page table overhead
significantly), instead, the purpose of using shared page table on hugetlb is
to allow faster TLB refill and smaller cache pollution upon TLB miss.

With PT sharing, pte entries are shared among hundreds of processes, the cache
consumption used by all the page table is smaller and in return, application
gets much higher cache hit ratio.  One other effect is that cache hit ratio
with hardware page walker hitting on pte in cache will be higher and this
helps to reduce tlb miss latency.  These two effects contribute to higher
application performance.

Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Acked-by: Hugh Dickins <hugh@veritas.com>
Cc: Dave McCracken <dmccr@us.ibm.com>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:21 -08:00
Andrew Morton
e1dbeda60a [PATCH] balance_pdgat() cleanup
Despaghettify balance_pdgat() a bit.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:21 -08:00
Nick Piggin
cc10250907 [PATCH] mm: add arch_alloc_page
Add an arch_alloc_page to match arch_free_page.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:21 -08:00
Ashwin Chaugule
7602bdf2fd [PATCH] new scheme to preempt swap token
The new swap token patches replace the current token traversal algo.  The old
algo had a crude timeout parameter that was used to handover the token from
one task to another.  This algo, transfers the token to the tasks that are in
need of the token.  The urgency for the token is based on the number of times
a task is required to swap-in pages.  Accordingly, the priority of a task is
incremented if it has been badly affected due to swap-outs.  To ensure that
the token doesnt bounce around rapidly, the token holders are given a priority
boost.  The priority of tasks is also decremented, if their rate of swap-in's
keeps reducing.  This way, the condition to check whether to pre-empt the swap
token, is a matter of comparing two task's priority fields.

[akpm@osdl.org: cleanups]
Signed-off-by: Ashwin Chaugule <ashwin.chaugule@celunite.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:21 -08:00
Ashwin Chaugule
098fe651f7 [PATCH] grab swap token reordered
Make sure the contention for the token happens _before_ any read-in and
kicks the swap-token algo only when the VM is under pressure.

Signed-off-by: Ashwin Chaugule <ashwin.chaugule@celunite.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:21 -08:00
Nick Piggin
cd54e7e543 [PATCH] mm: incorrect VM_FAULT_OOM returns from drivers
Some drivers are returning OOM when it is not in response to a memory
shortage.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Jaroslav Kysela <perex@suse.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:20 -08:00
Nick Piggin
f2a2a7108a [PATCH] oom: less memdie
Don't cause all threads in all other thread groups to gain TIF_MEMDIE
otherwise we'll get a thundering herd eating our memory reserve.  This may not
be the optimal scheme, but it fits our policy of allowing just one TIF_MEMDIE
in the system at once.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:20 -08:00
Nick Piggin
f3af38d30c [PATCH] oom: cleanup messages
Clean up the OOM killer messages to be more consistent.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:20 -08:00
Nick Piggin
c33e0fca35 [PATCH] oom: don't kill unkillable children or siblings
Abort the kill if any of our threads have OOM_DISABLE set.  Having this
test here also prevents any OOM_DISABLE child of the "selected" process
from being killed.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:20 -08:00
Paul Jackson
7253f4ef04 [PATCH] memory page_alloc zonelist caching reorder structure
Rearrange the struct members in the 'struct zonelist_cache' structure, so
as to put the readonly (once initialized) z_to_n[] array first, where it
will come right after the zones[] array in struct zonelist.

This pretty much eliminates the chance that the two frequently written
elements of 'struct zonelist_cache', the fullzones bitmap and last_full_zap
times, will end up on the same cache line as the performance sensitive,
frequently read, never (after init) written zones[] array.

Keeping frequently written data off frequently read cache lines is good for
performance.

Thanks to Rohit Seth for the suggestion.

Signed-off-by: Paul Jackson <pj@sgi.com>
Cc: Rohit Seth <rohitseth@google.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:20 -08:00
Paul Jackson
9276b1bc96 [PATCH] memory page_alloc zonelist caching speedup
Optimize the critical zonelist scanning for free pages in the kernel memory
allocator by caching the zones that were found to be full recently, and
skipping them.

Remembers the zones in a zonelist that were short of free memory in the
last second.  And it stashes a zone-to-node table in the zonelist struct,
to optimize that conversion (minimize its cache footprint.)

Recent changes:

    This differs in a significant way from a similar patch that I
    posted a week ago.  Now, instead of having a nodemask_t of
    recently full nodes, I have a bitmask of recently full zones.
    This solves a problem that last weeks patch had, which on
    systems with multiple zones per node (such as DMA zone) would
    take seeing any of these zones full as meaning that all zones
    on that node were full.

    Also I changed names - from "zonelist faster" to "zonelist cache",
    as that seemed to better convey what we're doing here - caching
    some of the key zonelist state (for faster access.)

    See below for some performance benchmark results.  After all that
    discussion with David on why I didn't need them, I went and got
    some ;).  I wanted to verify that I had not hurt the normal case
    of memory allocation noticeably.  At least for my one little
    microbenchmark, I found (1) the normal case wasn't affected, and
    (2) workloads that forced scanning across multiple nodes for
    memory improved up to 10% fewer System CPU cycles and lower
    elapsed clock time ('sys' and 'real').  Good.  See details, below.

    I didn't have the logic in get_page_from_freelist() for various
    full nodes and zone reclaim failures correct.  That should be
    fixed up now - notice the new goto labels zonelist_scan,
    this_zone_full, and try_next_zone, in get_page_from_freelist().

There are two reasons I persued this alternative, over some earlier
proposals that would have focused on optimizing the fake numa
emulation case by caching the last useful zone:

 1) Contrary to what I said before, we (SGI, on large ia64 sn2 systems)
    have seen real customer loads where the cost to scan the zonelist
    was a problem, due to many nodes being full of memory before
    we got to a node we could use.  Or at least, I think we have.
    This was related to me by another engineer, based on experiences
    from some time past.  So this is not guaranteed.  Most likely, though.

    The following approach should help such real numa systems just as
    much as it helps fake numa systems, or any combination thereof.

 2) The effort to distinguish fake from real numa, using node_distance,
    so that we could cache a fake numa node and optimize choosing
    it over equivalent distance fake nodes, while continuing to
    properly scan all real nodes in distance order, was going to
    require a nasty blob of zonelist and node distance munging.

    The following approach has no new dependency on node distances or
    zone sorting.

See comment in the patch below for a description of what it actually does.

Technical details of note (or controversy):

 - See the use of "zlc_active" and "did_zlc_setup" below, to delay
   adding any work for this new mechanism until we've looked at the
   first zone in zonelist.  I figured the odds of the first zone
   having the memory we needed were high enough that we should just
   look there, first, then get fancy only if we need to keep looking.

 - Some odd hackery was needed to add items to struct zonelist, while
   not tripping up the custom zonelists built by the mm/mempolicy.c
   code for MPOL_BIND.  My usual wordy comments below explain this.
   Search for "MPOL_BIND".

 - Some per-node data in the struct zonelist is now modified frequently,
   with no locking.  Multiple CPU cores on a node could hit and mangle
   this data.  The theory is that this is just performance hint data,
   and the memory allocator will work just fine despite any such mangling.
   The fields at risk are the struct 'zonelist_cache' fields 'fullzones'
   (a bitmask) and 'last_full_zap' (unsigned long jiffies).  It should
   all be self correcting after at most a one second delay.

 - This still does a linear scan of the same lengths as before.  All
   I've optimized is making the scan faster, not algorithmically
   shorter.  It is now able to scan a compact array of 'unsigned
   short' in the case of many full nodes, so one cache line should
   cover quite a few nodes, rather than each node hitting another
   one or two new and distinct cache lines.

 - If both Andi and Nick don't find this too complicated, I will be
   (pleasantly) flabbergasted.

 - I removed the comment claiming we only use one cachline's worth of
   zonelist.  We seem, at least in the fake numa case, to have put the
   lie to that claim.

 - I pay no attention to the various watermarks and such in this performance
   hint.  A node could be marked full for one watermark, and then skipped
   over when searching for a page using a different watermark.  I think
   that's actually quite ok, as it will tend to slightly increase the
   spreading of memory over other nodes, away from a memory stressed node.

===============

Performance - some benchmark results and analysis:

This benchmark runs a memory hog program that uses multiple
threads to touch alot of memory as quickly as it can.

Multiple runs were made, touching 12, 38, 64 or 90 GBytes out of
the total 96 GBytes on the system, and using 1, 19, 37, or 55
threads (on a 56 CPU system.)  System, user and real (elapsed)
timings were recorded for each run, shown in units of seconds,
in the table below.

Two kernels were tested - 2.6.18-mm3 and the same kernel with
this zonelist caching patch added.  The table also shows the
percentage improvement the zonelist caching sys time is over
(lower than) the stock *-mm kernel.

      number     2.6.18-mm3	   zonelist-cache    delta (< 0 good)	percent
 GBs    N  	------------	   --------------    ----------------	systime
 mem threads   sys user  real	  sys  user  real     sys  user  real	 better
  12	 1     153   24   177	  151	 24   176      -2     0    -1	   1%
  12	19	99   22     8	   99	 22	8	0     0     0	   0%
  12	37     111   25     6	  112	 25	6	1     0     0	  -0%
  12	55     115   25     5	  110	 23	5      -5    -2     0	   4%
  38	 1     502   74   576	  497	 73   570      -5    -1    -6	   0%
  38	19     426   78    48	  373	 76    39     -53    -2    -9	  12%
  38	37     544   83    36	  547	 82    36	3    -1     0	  -0%
  38	55     501   77    23	  511	 80    24      10     3     1	  -1%
  64	 1     917  125  1042	  890	124  1014     -27    -1   -28	   2%
  64	19    1118  138   119	  965	141   103    -153     3   -16	  13%
  64	37    1202  151    94	 1136	150    81     -66    -1   -13	   5%
  64	55    1118  141    61	 1072	140    58     -46    -1    -3	   4%
  90	 1    1342  177  1519	 1275	174  1450     -67    -3   -69	   4%
  90	19    2392  199   192	 2116	189   176    -276   -10   -16	  11%
  90	37    3313  238   175	 2972	225   145    -341   -13   -30	  10%
  90	55    1948  210   104	 1843	213   100    -105     3    -4	   5%

Notes:
 1) This test ran a memory hog program that started a specified number N of
    threads, and had each thread allocate and touch 1/N'th of
    the total memory to be used in the test run in a single loop,
    writing a constant word to memory, one store every 4096 bytes.
    Watching this test during some earlier trial runs, I would see
    each of these threads sit down on one CPU and stay there, for
    the remainder of the pass, a different CPU for each thread.

 2) The 'real' column is not comparable to the 'sys' or 'user' columns.
    The 'real' column is seconds wall clock time elapsed, from beginning
    to end of that test pass.  The 'sys' and 'user' columns are total
    CPU seconds spent on that test pass.  For a 19 thread test run,
    for example, the sum of 'sys' and 'user' could be up to 19 times the
    number of 'real' elapsed wall clock seconds.

 3) Tests were run on a fresh, single-user boot, to minimize the amount
    of memory already in use at the start of the test, and to minimize
    the amount of background activity that might interfere.

 4) Tests were done on a 56 CPU, 28 Node system with 96 GBytes of RAM.

 5) Notice that the 'real' time gets large for the single thread runs, even
    though the measured 'sys' and 'user' times are modest.  I'm not sure what
    that means - probably something to do with it being slow for one thread to
    be accessing memory along ways away.  Perhaps the fake numa system, running
    ostensibly the same workload, would not show this substantial degradation
    of 'real' time for one thread on many nodes -- lets hope not.

 6) The high thread count passes (one thread per CPU - on 55 of 56 CPUs)
    ran quite efficiently, as one might expect.  Each pair of threads needed
    to allocate and touch the memory on the node the two threads shared, a
    pleasantly parallizable workload.

 7) The intermediate thread count passes, when asking for alot of memory forcing
    them to go to a few neighboring nodes, improved the most with this zonelist
    caching patch.

Conclusions:
 * This zonelist cache patch probably makes little difference one way or the
   other for most workloads on real numa hardware, if those workloads avoid
   heavy off node allocations.
 * For memory intensive workloads requiring substantial off-node allocations
   on real numa hardware, this patch improves both kernel and elapsed timings
   up to ten per-cent.
 * For fake numa systems, I'm optimistic, but will have to leave that up to
   Rohit Seth to actually test (once I get him a 2.6.18 backport.)

Signed-off-by: Paul Jackson <pj@sgi.com>
Cc: Rohit Seth <rohitseth@google.com>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Cc: David Rientjes <rientjes@cs.washington.edu>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:20 -08:00
Christoph Lameter
89689ae7f9 [PATCH] Get rid of zone_table[]
The zone table is mostly not needed.  If we have a node in the page flags
then we can get to the zone via NODE_DATA() which is much more likely to be
already in the cpu cache.

In case of SMP and UP NODE_DATA() is a constant pointer which allows us to
access an exact replica of zonetable in the node_zones field.  In all of
the above cases there will be no need at all for the zone table.

The only remaining case is if in a NUMA system the node numbers do not fit
into the page flags.  In that case we make sparse generate a table that
maps sections to nodes and use that table to to figure out the node number.
 This table is sized to fit in a single cache line for the known 32 bit
NUMA platform which makes it very likely that the information can be
obtained without a cache miss.

For sparsemem the zone table seems to be have been fairly large based on
the maximum possible number of sections and the number of zones per node.
There is some memory saving by removing zone_table.  The main benefit is to
reduce the cache foootprint of the VM from the frequent lookups of zones.
Plus it simplifies the page allocator.

[akpm@osdl.org: build fix]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:20 -08:00
Chen, Kenneth W
c0a499c2c4 [PATCH] __unmap_hugepage_range(): add comment
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:20 -08:00
Paul Jackson
0798e5193c [PATCH] memory page alloc minor cleanups
- s/freeliest/freelist/ spelling fix

- Check for NULL *z zone seems useless - even if it could happen, so
  what?  Perhaps we should have a check later on if we are faced with an
  allocation request that is not allowed to fail - shouldn't that be a
  serious kernel error, passing an empty zonelist with a mandate to not
  fail?

- Initializing 'z' to zonelist->zones can wait until after the first
  get_page_from_freelist() fails; we only use 'z' in the wakeup_kswapd()
  loop, so let's initialize 'z' there, in a 'for' loop.  Seems clearer.

- Remove superfluous braces around a break

- Fix a couple errant spaces

- Adjust indentation on the cpuset_zone_allowed() check, to match the
  lines just before it -- seems easier to read in this case.

- Add another set of braces to the zone_watermark_ok logic

From: Paul Jackson <pj@sgi.com>

  Backout one item from a previous "memory page_alloc minor cleanups" patch.
   Until and unless we are certain that no one can ever pass an empty zonelist
  to __alloc_pages(), this check for an empty zonelist (or some BUG
  equivalent) is essential.  The code in get_page_from_freelist() blow ups if
  passed an empty zonelist.

Signed-off-by: Paul Jackson <pj@sgi.com>
Acked-by: Christoph Lameter <clameter@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:20 -08:00
Andrew Morton
a2ce774096 [PATCH] uml: workqueue build fix
arch/um/drivers/chan_kern.c:643: error: conflicting types for 'chan_interrupt'
  arch/um/include/chan_kern.h:31: error: previous declaration of 'chan_interrupt'

Cc: David Howells <dhowells@redhat.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:20 -08:00
Andrey Mirkin
822191a2fa [PATCH] skip data conversion in compat_sys_mount when data_page is NULL
OpenVZ Linux kernel team has found a problem with mounting in compat mode.

Simple command "mount -t smbfs ..." on Fedora Core 5 distro in 32-bit mode
leads to oops:

  Unable to handle kernel NULL pointer dereference at 0000000000000000 RIP: compat_sys_mount+0xd6/0x290
  Process mount (pid: 14656, veid=300, threadinfo ffff810034d30000, task ffff810034c86bc0)
  Call Trace: ia32_sysret+0x0/0xa

The problem is that data_page pointer can be NULL, so we should skip data
conversion in this case.

Signed-off-by: Andrey Mirkin <amirkin@openvz.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:20 -08:00
Andrew Morton
a1e85378ba [PATCH] drm-sis linkage fix
Fix http://bugzilla.kernel.org/show_bug.cgi?id=7606

WARNING: "drm_sman_set_manager" [drivers/char/drm/sis.ko] undefined!

Cc: <daniel-silveira@gee.inatel.br>
Cc: Dave Airlie <airlied@linux.ie>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:20 -08:00
Andrew Morton
676dcb8bc2 [PATCH] add bottom_half.h
With CONFIG_SMP=n:

  drivers/input/ff-memless.c:384: warning: implicit declaration of function 'local_bh_disable'
  drivers/input/ff-memless.c:393: warning: implicit declaration of function 'local_bh_enable'

Really linux/spinlock.h should include linux/interrupt.h.  But interrupt.h
includes sched.h which will need spinlock.h.

So the patch breaks the _bh declarations out into a separate header and
includes it in both interrupt.h and spinlock.h.

Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Cc: Andi Kleen <ak@suse.de>
Cc: <stable@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:20 -08:00
Jesper Juhl
620034c84d [PATCH] A few small additions and corrections to README
Here's a small patch which

 - adds a few archs to the current list of supported platforms.
 - adds a few missing slashes at the end of URLs.
 - adds a few references to additional documentation.
 - adds "make config" to the list of possible configuration targets.
 - makes a few other minor changes.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
[ Ben Nizette <ben.nizette@iinet.net.au> points out AVR32 arch too ]
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 16:41:21 -08:00
Jesper Juhl
6fc52f81a8 [PATCH] Clean up 'make help' output for documentation targets.
Here's a patch that cleans up the "make help" output a bit for the
documentation targets.

Currently the documentation targets are listed completely different than
all the other targets :

  Documentation targets:
    Linux kernel internal documentation in different formats:
    xmldocs (XML DocBook), psdocs (Postscript), pdfdocs (PDF)
    htmldocs (HTML), mandocs (man pages, use installmandocs to install)

with this patch they are more in line with the rest of the output :

  Documentation targets:
   Linux kernel internal documentation in different formats:
    htmldocs        - HTML
    installmandocs  - install man pages generated by mandocs
    mandocs         - man pages
    pdfdocs         - PDF
    psdocs          - Postscript
    xmldocs         - XML DocBook

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 16:38:58 -08:00
Linus Torvalds
3f5e573a08 Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus
* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
  [MIPS] Import updates from i386's i8259.c
  [MIPS] *-berr: Header inclusions for DEC bus error handlers
  [MIPS] Compile __do_IRQ() when really needed
  [MIPS] genirq: use name instead of typename
  [MIPS] Do not use handle_level_irq for ioasic_dma_irq_type.
  [MIPS] pte_offset(dir,addr): parenthesis fix
2006-12-06 16:17:37 -08:00
Linus Torvalds
9232d5876e Merge branch 'release' of master.kernel.org:/home/ftp/pub/scm/linux/kernel/git/aegl/linux-2.6
* 'release' of master.kernel.org:/home/ftp/pub/scm/linux/kernel/git/aegl/linux-2.6:
  [IA64] Fix pci.c kernel compilation breakage.
2006-12-06 16:16:35 -08:00
Al Viro
2fdb611d31 [PATCH] ... and then some more work_struct-induced breakage (ibmvscsi)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 14:51:14 -08:00
Al Viro
91c7c56855 [PATCH] ... and more work_struct-induced breakage (mips)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 14:51:14 -08:00
Al Viro
4927b3f74c [PATCH] More work_struct induced breakage (s390)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 14:51:14 -08:00
Linus Torvalds
f9e9dcb38f x86[-64]:Remove 'volatile' from atomic_t
Any code that relies on the volatile would be a bug waiting to happen
anyway.

Don't encourage people to think that putting 'volatile' on data
structures somehow fixes problems.  We should always use proper locking
(and other serialization) techniques.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 14:42:57 -08:00
Art Haas
16afea0255 [PATCH] Remove 'volatile' from spinlock_types
This is a resubmission of patches originally created by Ingo Molnar.
The link below is the initial (?) posting of the patch.

  http://marc.theaimsgroup.com/?l=linux-kernel&m=115217423929806&w=2

Remove 'volatile' from spinlock_types as it causes GCC to generate bad
code (see link) and locking should be used on kernel data.

Signed-off-by: Art Haas <ahaas@airmail.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 14:39:53 -08:00
Peter Chubb
c7f570a5ec [IA64] Fix pci.c kernel compilation breakage.
The recent change to convert the is_enabled flag in the PCI device to an
atomic count broke the IA64 compilation.

As pcibios_disable_device is only ever called if the reference count
is zero, convert the if to a BUG_ON.

Signed-off-by: Peter Chubb <peterc@gelato.unsw.edu.au>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2006-12-06 14:13:38 -08:00
Atsushi Nemoto
2cafe97846 [MIPS] Import updates from i386's i8259.c
Import many updates from i386's i8259.c, especially genirq transitions.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-12-06 20:16:09 +00:00
Maciej W. Rozycki
49afb1f67b [MIPS] *-berr: Header inclusions for DEC bus error handlers
A fixup to add missing header inclusions for bus error handlers for
DECstation system after the recent switch to get_irq_regs().

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-12-06 20:16:09 +00:00
Franck Bui-Huu
e77c232cfc [MIPS] Compile __do_IRQ() when really needed
__do_IRQ() is needed only by irq handlers that can't use
default handlers defined in kernel/irq/chip.c.

For others platforms there's no need to compile this function
since it won't be used. For those platforms this patch defines
GENERIC_HARDIRQS_NO__DO_IRQ symbol which is used exactly for
this purpose.

Futhermore for platforms which do not use __do_IRQ(), end()
method which is part of the 'irq_chip' structure is not used.
This patch simply removes this method in this case.

Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-12-06 20:16:08 +00:00
Atsushi Nemoto
1ccd1c1c35 [MIPS] genirq: use name instead of typename
The "typename" field was obsoleted by the "name" field.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-12-06 20:16:08 +00:00
Atsushi Nemoto
25ba2f506c [MIPS] Do not use handle_level_irq for ioasic_dma_irq_type.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-12-06 20:16:08 +00:00
Franck Bui-Huu
5b70a31708 [MIPS] pte_offset(dir,addr): parenthesis fix
This patch adds missing parenthesis around 'dir' argument in pte_offset()
macro definition.

It also removes an extra space in the definition of pte_offset_kernel()
macro.

Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-12-06 20:16:08 +00:00
Al Viro
3e577a80ea [PATCH] drivers/{char|isdn}: work_struct-induced breakage
part 1 of fsck-knows-how-many

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 11:09:08 -08:00
Al Viro
7a87b6c228 [PATCH] hamradio/dmascc: fix up work_struct-induced breakage
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 11:06:46 -08:00
Linus Torvalds
dd6a7c19e4 Merge master.kernel.org:/pub/scm/linux/kernel/git/lethal/sh-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/lethal/sh-2.6: (43 commits)
  sh: sh775x/titan fixes for irq header changes.
  sh: update r7780rp defconfig.
  sh: compile fixes for header cleanup.
  sh: Fixup pte_mkhuge() build failure.
  sh: set KBUILD_IMAGE to something sensible.
  sh: show held locks in stack trace with lockdep.
  sh: platform_pata support for R7780RP
  sh: stacktrace/lockdep/irqflags tracing support.
  sh: Fixup movli.l/movco.l atomic ops for gcc4.
  sh: dyntick infrastructure.
  sh: Clock framework tidying.
  sh: Turn off IRQs around get_timer_offset() calls.
  sh: Get the PGD right in oops case with 64-bit PTEs.
  sh: Fix store queue bitmap end.
  sh: More flexible + SH7780 earlyprintk SCIF support.
  sh: Fixup various PAGE_SIZE == 4096 assumptions.
  sh: Fixup 4K irq stacks.
  sh: dma-api channel capability extensions.
  sh: Drop name overload in dma-sh.
  sh: Make dma-isa depend on ISA_DMA_API.
  ...
2006-12-06 08:10:55 -08:00
Linus Torvalds
dd8856bda5 Merge git://git.infradead.org/users/dhowells/workq-2.6
* git://git.infradead.org/users/dhowells/workq-2.6:
  Actually update the fixed up compile failures.
  WorkQueue: Fix up arch-specific work items where possible
  WorkStruct: make allyesconfig
  WorkStruct: Pass the work_struct pointer instead of context data
  WorkStruct: Merge the pending bit into the wq_data pointer
  WorkStruct: Typedef the work function prototype
  WorkStruct: Separate delayable and non-delayable events.
2006-12-06 08:01:37 -08:00
Mike Frysinger
f81cff0d40 [PATCH] uclinux: fix mmap() of directory for nommu case
I was playing with blackfin when i hit a neat bug ... doing an open() on a
directory and then passing that fd to mmap() would cause the kernel to hang

after poking into the code a bit more, i found that
mm/nommu.c:validate_mmap_request() checks the length and if it is 0, just
returns the address ... this is in stark contrast to mmu's
mm/mmap.c:do_mmap_pgoff() where it returns -EINVAL for 0 length requests ...
i then noticed that some other parts of the logic is out of date between the
two funcs, so perhaps that's the easy fix ?

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 07:41:26 -08:00
Gavin Lambert
3363c9b0ed [PATCH] m68knommu: remove FP conditionals in ucontext struct
The first patch is to the 2.6 kernel include file (for m68knommu), to get
rid of the conditional definitions, otherwise the structures have different
sizes depending on whether there's an FPU or not.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 07:41:26 -08:00
Greg Ungerer
a8b8d57c25 [PATCH] m68knommu: ColdFire serial driver fixes
Some updates for the old ColdFire serial driver:

 . support 3 and 4 UARTs on some ColdFire parts that have them
 . enable multifunction pins to serial for 527x CPU's
 . support the 5272 UART's fractional baud rate divisor
 . switch driver name to "mcfserial"

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 07:41:26 -08:00
Greg Ungerer
dcb1477549 [PATCH] m68knommu: switch 68360 to using rtc_time
Adds support for RTCs (through genrtc) for M68KNOMMU.

Board-specific code will have to link the appropriate RTC driver to the
mach_hwclk callback, at minimum.

This patch switches the 68360 code over to using rtc_time.

Signed-off-by: Gavin Lambert <gavinl@compacsort.com>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 07:41:26 -08:00
Greg Ungerer
deb77c8501 [PATCH] m68knommu: fix timer register access on 523x ColdFire platforms
The 523x timer TRR register is a full 32bits, the older register (on
other ColdFire parts) was only 16 bits.  Use the right type of
__raw_read when accessing it.

Problem found by Yaroslav Vinogradov <yaroslav.vinogradov@freescale.com>

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 07:41:26 -08:00
Greg Ungerer
dd93e857fc [PATCH] m68knommu: implement irq_canonicalize()
Add a null definition for irq_canonicalize(). It is used in the gerneric
serial subsystem code, can't compile without it.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 07:41:26 -08:00