linux-toradex.git/arch/x86/include/asm/pgtable.h, branch v3.2

thp: don't allow transparent hugepage support without PSE

2011-01-14T01:32:45+00:00

Archs implementing Transparent Hugepage Support must implement a function
called has_transparent_hugepage to be sure the virtual or physical CPU
supports Transparent Hugepages.

Signed-off-by: Andrea Arcangeli 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

thp: add pmd_modify

2011-01-14T01:32:44+00:00

Add pmd_modify() for use with mprotect() on huge pmds.

Signed-off-by: Johannes Weiner 
Signed-off-by: Andrea Arcangeli 
Reviewed-by: Rik van Riel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

thp: add x86 32bit support

2011-01-14T01:32:44+00:00

Add support for transparent hugepages to x86 32bit.

Share the same VM_ bitflag for VM_MAPPED_COPY.  mm/nommu.c will never
support transparent hugepages.

Signed-off-by: Johannes Weiner 
Signed-off-by: Andrea Arcangeli 
Reviewed-by: Rik van Riel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

thp: add pmd mangling functions to x86

2011-01-14T01:32:40+00:00

Add needed pmd mangling functions with symmetry with their pte
counterparts.  pmdp_splitting_flush() is the only new addition on the pmd_
methods and it's needed to serialize the VM against split_huge_page.  It
simply atomically sets the splitting bit in a similar way
pmdp_clear_flush_young atomically clears the accessed bit.
pmdp_splitting_flush() also has to flush the tlb to make it effective
against gup_fast, but it wouldn't really require to flush the tlb too.
Just the tlb flush is the simplest operation we can invoke to serialize
pmdp_splitting_flush() against gup_fast.

Signed-off-by: Andrea Arcangeli 
Acked-by: Rik van Riel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

thp: no paravirt version of pmd ops

2011-01-14T01:32:39+00:00

No paravirt version of set_pmd_at/pmd_update/pmd_update_defer.

Signed-off-by: Andrea Arcangeli 
Acked-by: Rik van Riel 
Acked-by: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

thp: add native_set_pmd_at

2011-01-14T01:32:39+00:00

Used by paravirt and not paravirt set_pmd_at.

Signed-off-by: Andrea Arcangeli 
Acked-by: Rik van Riel 
Acked-by: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

x86, mm: Hold mm->page_table_lock while doing vmalloc_sync

2010-10-19T20:57:08+00:00

Take mm->page_table_lock while syncing the vmalloc region.  This prevents
a race with the Xen pagetable pin/unpin code, which expects that the
page_table_lock is already held.  If this race occurs, then Xen can see
an inconsistent page type (a page can either be read/write or a pagetable
page, and pin/unpin converts it between them), which will cause either
the pin or the set_p[gm]d to fail; either will crash the kernel.

vmalloc_sync_all() should be called rarely, so this extra use of
page_table_lock should not interfere with its normal users.

The mm pointer is stashed in the pgd page's index field, as that won't
be otherwise used for pgds.

Reported-by: Ian Campbell 
Originally-by: Jan Beulich 
LKML-Reference: <4CB88A4C.1080305@goop.org>
Signed-off-by: Jeremy Fitzhardinge 
Signed-off-by: H. Peter Anvin

x86, mm: Avoid unnecessary TLB flush

2010-08-23T17:04:57+00:00

In x86, access and dirty bits are set automatically by CPU when CPU accesses
memory. When we go into the code path of below flush_tlb_fix_spurious_fault(),
we already set dirty bit for pte and don't need flush tlb. This might mean
tlb entry in some CPUs hasn't dirty bit set, but this doesn't matter. When
the CPUs do page write, they will automatically check the bit and no software
involved.

On the other hand, flush tlb in below position is harmful. Test creates CPU
number of threads, each thread writes to a same but random address in same vma
range and we measure the total time. Under a 4 socket system, original time is
1.96s, while with the patch, the time is 0.8s. Under a 2 socket system, there is
20% time cut too. perf shows a lot of time are taking to send ipi/handle ipi for
tlb flush.

Signed-off-by: Shaohua Li 
LKML-Reference: <20100816011655.GA362@sli10-desk.sh.intel.com>
Acked-by: Suresh Siddha 
Cc: Andrea Archangeli 
Signed-off-by: H. Peter Anvin

x86, mm: is_untracked_pat_range() takes a normal semiclosed range

2009-11-24T01:09:59+00:00

is_untracked_pat_range() -- like its components, is_ISA_range() and
is_GRU_range(), takes a normal semiclosed interval (>=, <) whereas the
PAT code called it as if it took a closed range (>=, <=).  Fix.

Although this is a bug, I believe it is non-manifest, simply because
none of the callers will call this with non-page-aligned addresses.

Signed-off-by: H. Peter Anvin 
Acked-by: Thomas Gleixner 
Acked-by: Suresh Siddha 
LKML-Reference: <20091119202341.GA4420@sgi.com>

x86, mm: Call is_untracked_pat_range() rather than is_ISA_range()

2009-11-24T01:09:59+00:00

Checkin fd12a0d69aee6d90fa9b9890db24368a897f8423 made the PAT
untracked range a platform configurable, but missed on occurrence of
is_ISA_range() which still refers to PAT-untracked memory, and
therefore should be using the configurable.

Signed-off-by: H. Peter Anvin 
Cc: Jack Steiner 
Cc: Suresh Siddha 
LKML-Reference: <20091119202341.GA4420@sgi.com>