linux-toradex.git/mm/page_alloc.c, branch v2.6.16-rc4

[PATCH] Handle holes in node mask in node fallback list setup

2006-02-17T21:27:06+00:00

Change the find_next_best_node algorithm to correctly skip
over holes in the node online mask. Previously it would not handle
missing nodes correctly and cause crashes at boot.

[Written by Linus, tested by AK]

Signed-off-by: Andi Kleen 
Signed-off-by: Linus Torvalds

[PATCH] compound page: default destructor

2006-02-15T00:09:33+00:00

Somehow I imagined that calling a NULL destructor would free a compound page
rather than oopsing.  No, we must supply a default destructor, __free_pages_ok
using the order noted by prep_compound_page.  hugetlb can still replace this
as before with its own free_huge_page pointer.

The case that needs this is not common: rarely does put_compound_page's
put_page_testzero bring the count down to 0.  But if get_user_pages is applied
to some part of a compound page, without immediate release (e.g.  AIO or
Infiniband), then it's possible for its put_page to come after the containing
vma has been unmapped and the driver done its free_pages.

That's just the kind of case compound pages are supposed to be guarding
against (but Nick points out, nor did PageReserved handle this right).

Signed-off-by: Hugh Dickins 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] compound page: use page[1].lru

2006-02-15T00:09:33+00:00

If a compound page has its own put_page_testzero destructor (the only current
example is free_huge_page), that is noted in page[1].mapping of the compound
page.  But that's rather a poor place to keep it: functions which call
set_page_dirty_lock after get_user_pages (e.g.  Infiniband's
__ib_umem_release) ought to be checking first, otherwise set_page_dirty is
liable to crash on what's not the address of a struct address_space.

And now I'm about to make that worse: it turns out that every compound page
needs a destructor, so we can no longer rely on hugetlb pages going their own
special way, to avoid further problems of page->mapping reuse.  For example,
not many people know that: on 50% of i386 -Os builds, the first tail page of a
compound page purports to be PageAnon (when its destructor has an odd
address), which surprises page_add_file_rmap.

Keep the compound page destructor in page[1].lru.next instead.  And to free up
the common pairing of mapping and index, also move compound page order from
index to lru.prev.  Slab reuses page->lru too: but if we ever need slab to use
compound pages, it can easily stack its use above this.

(akpm: decoded version of the above: the tail pages of a compound page now
have ->mapping==NULL, so there's no need for the set_page_dirty[_lock]()
caller to check that they're not compund pages before doing the dirty).

Signed-off-by: Hugh Dickins 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] percpu data: only iterate over possible CPUs

2006-02-05T19:06:51+00:00

percpu_data blindly allocates bootmem memory to store NR_CPUS instances of
cpudata, instead of allocating memory only for possible cpus.

As a preparation for changing that, we need to convert various 0 -> NR_CPUS
loops to use for_each_cpu().

(The above only applies to users of asm-generic/percpu.h.  powerpc has gone it
alone and is presently only allocating memory for present CPUs, so it's
currently corrupting memory).

Signed-off-by: Eric Dumazet 
Cc: "David S. Miller" 
Cc: James Bottomley 
Acked-by: Ingo Molnar 
Cc: Jens Axboe 
Cc: Anton Blanchard 
Acked-by: William Irwin 
Cc: Andi Kleen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] cpuinit functions wrongly marked meminit

2006-02-01T16:53:09+00:00

__meminit has overzelously been modified and crept its way into marking
cpuup callbacks as __meminit.

Signed-off-by: Ashok Raj 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Zone reclaim: Reclaim logic

2006-01-19T03:20:17+00:00

Some bits for zone reclaim exists in 2.6.15 but they are not usable.  This
patch fixes them up, removes unused code and makes zone reclaim usable.

Zone reclaim allows the reclaiming of pages from a zone if the number of
free pages falls below the watermarks even if other zones still have enough
pages available.  Zone reclaim is of particular importance for NUMA
machines.  It can be more beneficial to reclaim a page than taking the
performance penalties that come with allocating a page on a remote zone.

Zone reclaim is enabled if the maximum distance to another node is higher
than RECLAIM_DISTANCE, which may be defined by an arch.  By default
RECLAIM_DISTANCE is 20.  20 is the distance to another node in the same
component (enclosure or motherboard) on IA64.  The meaning of the NUMA
distance information seems to vary by arch.

If zone reclaim is not successful then no further reclaim attempts will
occur for a certain time period (ZONE_RECLAIM_INTERVAL).

This patch was discussed before. See

http://marc.theaimsgroup.com/?l=linux-kernel&m=113519961504207&w=2
http://marc.theaimsgroup.com/?l=linux-kernel&m=113408418232531&w=2
http://marc.theaimsgroup.com/?l=linux-kernel&m=113389027420032&w=2
http://marc.theaimsgroup.com/?l=linux-kernel&m=113380938612205&w=2

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

[PATCH] x86_64: add __meminit for memory hotplug

2006-01-17T07:18:35+00:00

Add __meminit to the __init lineup to ensure functions default
to __init when memory hotplug is not enabled.  Replace __devinit
with __meminit on functions that were changed when the memory
hotplug code was introduced.

Signed-off-by: Matt Tolentino 
Signed-off-by: Andi Kleen 
Signed-off-by: Linus Torvalds

[PATCH] memmap_init_zone(): remove uneccesary page++

2006-01-12T17:08:49+00:00

Remove unecessary page++ from memmap_init_zone loop.

Signed-off-by: Greg Ungerer 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] mm: gfp_atomic comments

2006-01-12T02:42:09+00:00

Clarify in comments that GFP_ATOMIC means both "don't sleep" and "use
emergency pools", hence both ALLOC_HARDER and ALLOC_HIGH.

Signed-off-by: Paul Jackson 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Restore KERN_EMERG to each line printed by bad_page

2006-01-12T02:42:08+00:00

Signed-off-by: Hugh Dickins 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds