03 Apr, 2009
1 commit
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Fix a number of issues with the per-MM VMA patch:
(1) Make mmap_pages_allocated an atomic_long_t, just in case this is used on
a NOMMU system with more than 2G pages. Makes no difference on a 32-bit
system.(2) Report vma->vm_pgoff * PAGE_SIZE as a 64-bit value, not a 32-bit value,
lest it overflow.(3) Move the allocation of the vm_area_struct slab back for fork.c.
(4) Use KMEM_CACHE() for both vm_area_struct and vm_region slabs.
(5) Use BUG_ON() rather than if () BUG().
(6) Make the default validate_nommu_regions() a static inline rather than a
#define.(7) Make free_page_series()'s objection to pages with a refcount != 1 more
informative.(8) Adjust the __put_nommu_region() banner comment to indicate that the
semaphore must be held for writing.(9) Limit the number of warnings about munmaps of non-mmapped regions.
Reported-by: Andrew Morton
Signed-off-by: David Howells
Cc: Greg Ungerer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Apr, 2009
2 commits
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Change the page_mkwrite prototype to take a struct vm_fault, and return
VM_FAULT_xxx flags. There should be no functional change.This makes it possible to return much more detailed error information to
the VM (and also can provide more information eg. virtual_address to the
driver, which might be important in some special cases).This is required for a subsequent fix. And will also make it easier to
merge page_mkwrite() with fault() in future.Signed-off-by: Nick Piggin
Cc: Chris Mason
Cc: Trond Myklebust
Cc: Miklos Szeredi
Cc: Steven Whitehouse
Cc: Mark Fasheh
Cc: Joel Becker
Cc: Artem Bityutskiy
Cc: Felix Blyakher
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add a helper function account_page_dirtied(). Use that from two
callsites. reiser4 adds a function which adds a third callsite.Signed-off-by: Edward Shishkin
Cc: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
14 Mar, 2009
1 commit
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Impact: cleanup
Add a new vm flag VM_PFN_AT_MMAP to identify a PFNMAP that is
fully mapped with remap_pfn_range. Patch removes the overloading
of VM_INSERTPAGE from the earlier patch.Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Suresh Siddha
Acked-by: Nick Piggin
LKML-Reference:
Signed-off-by: Ingo Molnar
13 Mar, 2009
1 commit
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Impact: fix false positive PAT warnings - also fix VirtalBox hang
Use of vma->vm_pgoff to identify the pfnmaps that are fully
mapped at mmap time is broken. vm_pgoff is set by generic mmap
code even for cases where drivers are setting up the mappings
at the fault time.The problem was originally reported here:
http://marc.info/?l=linux-kernel&m=123383810628583&w=2
Change is_linear_pfn_mapping logic to overload VM_INSERTPAGE
flag along with VM_PFNMAP to mean full PFNMAP setup at mmap
time.Problem also tracked at:
http://bugzilla.kernel.org/show_bug.cgi?id=12800
Reported-by: Thomas Hellstrom
Tested-by: Frans Pop
Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Suresh Siddha @intel.com>
Cc: Nick Piggin
Cc: "ebiederm@xmission.com"
Cc: # only for 2.6.29.1, not .28
LKML-Reference:
Signed-off-by: Ingo Molnar
19 Feb, 2009
2 commits
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What's happening is that the assertion in mm/page_alloc.c:move_freepages()
is triggering:BUG_ON(page_zone(start_page) != page_zone(end_page));
Once I knew this is what was happening, I added some annotations:
if (unlikely(page_zone(start_page) != page_zone(end_page))) {
printk(KERN_ERR "move_freepages: Bogus zones: "
"start_page[%p] end_page[%p] zone[%p]\n",
start_page, end_page, zone);
printk(KERN_ERR "move_freepages: "
"start_zone[%p] end_zone[%p]\n",
page_zone(start_page), page_zone(end_page));
printk(KERN_ERR "move_freepages: "
"start_pfn[0x%lx] end_pfn[0x%lx]\n",
page_to_pfn(start_page), page_to_pfn(end_page));
printk(KERN_ERR "move_freepages: "
"start_nid[%d] end_nid[%d]\n",
page_to_nid(start_page), page_to_nid(end_page));
...And here's what I got:
move_freepages: Bogus zones: start_page[2207d0000] end_page[2207dffc0] zone[fffff8103effcb00]
move_freepages: start_zone[fffff8103effcb00] end_zone[fffff8003fffeb00]
move_freepages: start_pfn[0x81f600] end_pfn[0x81f7ff]
move_freepages: start_nid[1] end_nid[0]My memory layout on this box is:
[ 0.000000] Zone PFN ranges:
[ 0.000000] Normal 0x00000000 -> 0x0081ff5d
[ 0.000000] Movable zone start PFN for each node
[ 0.000000] early_node_map[8] active PFN ranges
[ 0.000000] 0: 0x00000000 -> 0x00020000
[ 0.000000] 1: 0x00800000 -> 0x0081f7ff
[ 0.000000] 1: 0x0081f800 -> 0x0081fe50
[ 0.000000] 1: 0x0081fed1 -> 0x0081fed8
[ 0.000000] 1: 0x0081feda -> 0x0081fedb
[ 0.000000] 1: 0x0081fedd -> 0x0081fee5
[ 0.000000] 1: 0x0081fee7 -> 0x0081ff51
[ 0.000000] 1: 0x0081ff59 -> 0x0081ff5dSo it's a block move in that 0x81f600-->0x81f7ff region which triggers
the problem.This patch:
Declaration of early_pfn_to_nid() is scattered over per-arch include
files, and it seems it's complicated to know when the declaration is used.
I think it makes fix-for-memmap-init not easy.This patch moves all declaration to include/linux/mm.h
After this,
if !CONFIG_NODES_POPULATES_NODE_MAP && !CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
-> Use static definition in include/linux/mm.h
else if !CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
-> Use generic definition in mm/page_alloc.c
else
-> per-arch back end function will be called.Signed-off-by: KAMEZAWA Hiroyuki
Tested-by: KOSAKI Motohiro
Reported-by: David Miller
Cc: Mel Gorman
Cc: Heiko Carstens
Cc: [2.6.25.x, 2.6.26.x, 2.6.27.x, 2.6.28.x]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
YAMAMOTO-san noticed that task_dirty_inc doesn't seem to be called properly for
cases where set_page_dirty is not used to dirty a page (eg. mark_buffer_dirty).Additionally, there is some inconsistency about when task_dirty_inc is
called. It is used for dirty balancing, however it even gets called for
__set_page_dirty_no_writeback.So rather than increment it in a set_page_dirty wrapper, move it down to
exactly where the dirty page accounting stats are incremented.Cc: YAMAMOTO Takashi
Signed-off-by: Nick Piggin
Acked-by: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
18 Feb, 2009
1 commit
-
…git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, vm86: fix preemption bug
x86, olpc: fix model detection without OFW
x86, hpet: fix for LS21 + HPET = boot hang
x86: CPA avoid repeated lazy mmu flush
x86: warn if arch_flush_lazy_mmu_cpu is called in preemptible context
x86/paravirt: make arch_flush_lazy_mmu/cpu disable preemption
x86, pat: fix warn_on_once() while mapping 0-1MB range with /dev/mem
x86/cpa: make sure cpa is safe to call in lazy mmu mode
x86, ptrace, mm: fix double-free on race
11 Feb, 2009
2 commits
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Ptrace_detach() races with __ptrace_unlink() if the traced task is
reaped while detaching. This might cause a double-free of the BTS
buffer.Change the ptrace_detach() path to only do the memory accounting in
ptrace_bts_detach() and leave the buffer free to ptrace_bts_untrace()
which will be called from __ptrace_unlink().The fix follows a proposal from Oleg Nesterov.
Reported-by: Oleg Nesterov
Signed-off-by: Markus Metzger
Signed-off-by: Ingo Molnar -
When overcommit is disabled, the core VM accounts for pages used by anonymous
shared, private mappings and special mappings. It keeps track of VMAs that
should be accounted for with VM_ACCOUNT and VMAs that never had a reserve
with VM_NORESERVE.Overcommit for hugetlbfs is much riskier than overcommit for base pages
due to contiguity requirements. It avoids overcommiting on both shared and
private mappings using reservation counters that are checked and updated
during mmap(). This ensures (within limits) that hugepages exist in the
future when faults occurs or it is too easy to applications to be SIGKILLed.As hugetlbfs makes its own reservations of a different unit to the base page
size, VM_ACCOUNT should never be set. Even if the units were correct, we would
double account for the usage in the core VM and hugetlbfs. VM_NORESERVE may
be set because an application can request no reserves be made for hugetlbfs
at the risk of getting killed later.With commit fc8744adc870a8d4366908221508bb113d8b72ee, VM_NORESERVE and
VM_ACCOUNT are getting unconditionally set for hugetlbfs-backed mappings. This
breaks the accounting for both the core VM and hugetlbfs, can trigger an
OOM storm when hugepage pools are too small lockups and corrupted counters
otherwise are used. This patch brings hugetlbfs more in line with how the
core VM treats VM_NORESERVE but prevents VM_ACCOUNT being set.Signed-off-by: Mel Gorman
Signed-off-by: Linus Torvalds
14 Jan, 2009
1 commit
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This assertion is incorrect for lockless pagecache. By definition if we
have an unpinned page that we are trying to take a speculative reference
to, it may become the tail of a compound page at any time (if it is
freed, then reallocated as a compound page).It was still a valid assertion for the vmscan.c LRU isolation case, but
it doesn't seem incredibly helpful... if somebody wants it, they can
put it back directly where it applies in the vmscan code.Signed-off-by: Nick Piggin
Signed-off-by: Linus Torvalds
08 Jan, 2009
1 commit
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Make VMAs per mm_struct as for MMU-mode linux. This solves two problems:
(1) In SYSV SHM where nattch for a segment does not reflect the number of
shmat's (and forks) done.(2) In mmap() where the VMA's vm_mm is set to point to the parent mm by an
exec'ing process when VM_EXECUTABLE is specified, regardless of the fact
that a VMA might be shared and already have its vm_mm assigned to another
process or a dead process.A new struct (vm_region) is introduced to track a mapped region and to remember
the circumstances under which it may be shared and the vm_list_struct structure
is discarded as it's no longer required.This patch makes the following additional changes:
(1) Regions are now allocated with alloc_pages() rather than kmalloc() and
with no recourse to __GFP_COMP, so the pages are not composite. Instead,
each page has a reference on it held by the region. Anything else that is
interested in such a page will have to get a reference on it to retain it.
When the pages are released due to unmapping, each page is passed to
put_page() and will be freed when the page usage count reaches zero.(2) Excess pages are trimmed after an allocation as the allocation must be
made as a power-of-2 quantity of pages.(3) VMAs are added to the parent MM's R/B tree and mmap lists. As an MM may
end up with overlapping VMAs within the tree, the VMA struct address is
appended to the sort key.(4) Non-anonymous VMAs are now added to the backing inode's prio list.
(5) Holes may be punched in anonymous VMAs with munmap(), releasing parts of
the backing region. The VMA and region structs will be split if
necessary.(6) sys_shmdt() only releases one attachment to a SYSV IPC shared memory
segment instead of all the attachments at that addresss. Multiple
shmat()'s return the same address under NOMMU-mode instead of different
virtual addresses as under MMU-mode.(7) Core dumping for ELF-FDPIC requires fewer exceptions for NOMMU-mode.
(8) /proc/maps is now the global list of mapped regions, and may list bits
that aren't actually mapped anywhere.(9) /proc/meminfo gains a line (tagged "MmapCopy") that indicates the amount
of RAM currently allocated by mmap to hold mappable regions that can't be
mapped directly. These are copies of the backing device or file if not
anonymous.These changes make NOMMU mode more similar to MMU mode. The downside is that
NOMMU mode requires some extra memory to track things over NOMMU without this
patch (VMAs are no longer shared, and there are now region structs).Signed-off-by: David Howells
Tested-by: Mike Frysinger
Acked-by: Paul Mundt
07 Jan, 2009
1 commit
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Rather than have the pagefault handler kill a process directly if it gets
a VM_FAULT_OOM, have it call into the OOM killer.With increasingly sophisticated oom behaviour (cpusets, memory cgroups,
oom killing throttling, oom priority adjustment or selective disabling,
panic on oom, etc), it's silly to unconditionally kill the faulting
process at page fault time. Create a hook for pagefault oom path to call
into instead.Only converted x86 and uml so far.
[akpm@linux-foundation.org: make __out_of_memory() static]
[akpm@linux-foundation.org: fix comment]
Signed-off-by: Nick Piggin
Cc: Jeff Dike
Acked-by: Ingo Molnar
Cc: Thomas Gleixner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Dec, 2008
1 commit
-
…el/git/tip/linux-2.6-tip
* 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (241 commits)
sched, trace: update trace_sched_wakeup()
tracing/ftrace: don't trace on early stage of a secondary cpu boot, v3
Revert "x86: disable X86_PTRACE_BTS"
ring-buffer: prevent false positive warning
ring-buffer: fix dangling commit race
ftrace: enable format arguments checking
x86, bts: memory accounting
x86, bts: add fork and exit handling
ftrace: introduce tracing_reset_online_cpus() helper
tracing: fix warnings in kernel/trace/trace_sched_switch.c
tracing: fix warning in kernel/trace/trace.c
tracing/ring-buffer: remove unused ring_buffer size
trace: fix task state printout
ftrace: add not to regex on filtering functions
trace: better use of stack_trace_enabled for boot up code
trace: add a way to enable or disable the stack tracer
x86: entry_64 - introduce FTRACE_ frame macro v2
tracing/ftrace: add the printk-msg-only option
tracing/ftrace: use preempt_enable_no_resched_notrace in ring_buffer_time_stamp()
x86, bts: correctly report invalid bts records
...Fixed up trivial conflict in scripts/recordmcount.pl due to SH bits
being already partly merged by the SH merge.
20 Dec, 2008
5 commits
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Impact: move the BTS buffer accounting to the mlock bucket
Add alloc_locked_buffer() and free_locked_buffer() functions to mm/mlock.c
to kalloc a buffer and account the locked memory to current.Account the memory for the BTS buffer to the tracer.
Signed-off-by: Markus Metzger
Signed-off-by: Ingo Molnar -
Impact: Cleanup and branch hints only.
Move the track and untrack pfn stub routines from memory.c to asm-generic.
Also add unlikely to pfnmap related calls in fork and exit path.Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Suresh Siddha
Signed-off-by: H. Peter Anvin -
Impact: Cleanup - removes a new function in favor of a recently modified older one.
Replace follow_pfnmap_pte in pat code with follow_phys. follow_phys lso
returns protection eliminating the need of pte_pgprot call. Using follow_phys
also eliminates the need for pte_pa.Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Suresh Siddha
Signed-off-by: H. Peter Anvin -
Impact: Changes and globalizes an existing static interface.
Follow_phys does similar things as follow_pfnmap_pte. Make a minor change
to follow_phys so that it can be used in place of follow_pfnmap_pte.
Physical address return value with 0 as error return does not work in
follow_phys as the actual physical address 0 mapping may exist in pte.Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Suresh Siddha
Signed-off-by: H. Peter Anvin -
Impact: Documentation only
Incremental patches to address the review comments from Nick Piggin
for v3 version of x86 PAT pfnmap changes patchset herehttp://lkml.indiana.edu/hypermail/linux/kernel/0812.2/01330.html
This patch:
Clarify is_linear_pfn_mapping() and its usage.
It is used by x86 PAT code for performance reasons. Identifying pfnmap
as linear over entire vma helps speedup reserve and free of memtype
for the region.Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Suresh Siddha
Signed-off-by: H. Peter Anvin
19 Dec, 2008
3 commits
-
Impact: Introduces new hooks, which are currently null.
Introduce generic hooks in remap_pfn_range and vm_insert_pfn and
corresponding copy and free routines with reserve and free tracking.Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Suresh Siddha
Signed-off-by: H. Peter Anvin -
Impact: New currently unused interface.
Add a generic interface to follow pfn in a pfnmap vma range. This is used by
one of the subsequent x86 PAT related patch to keep track of memory types
for vma regions across vma copy and free.Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Suresh Siddha
Signed-off-by: H. Peter Anvin -
Impact: Code transformation, new functions added should have no effect.
Drivers use mmap followed by pgprot_* and remap_pfn_range or vm_insert_pfn,
in order to export reserved memory to userspace. Currently, such mappings are
not tracked and hence not kept consistent with other mappings (/dev/mem,
pci resource, ioremap) for the sme memory, that may exist in the system.The following patchset adds x86 PAT attribute tracking and untracking for
pfnmap related APIs.First three patches in the patchset are changing the generic mm code to fit
in this tracking. Last four patches are x86 specific to make things work
with x86 PAT code. The patchset aso introduces pgprot_writecombine interface,
which gives writecombine mapping when enabled, falling back to
pgprot_noncached otherwise.This patch:
While working on x86 PAT, we faced some hurdles with trackking
remap_pfn_range() regions, as we do not have any information to say
whether that PFNMAP mapping is linear for the entire vma range or
it is smaller granularity regions within the vma.A simple solution to this is to use vm_pgoff as an indicator for
linear mapping over the vma region. Currently, remap_pfn_range
only sets vm_pgoff for COW mappings. Below patch changes the
logic and sets the vm_pgoff irrespective of COW. This will still not
be enough for the case where pfn is zero (vma region mapped to
physical address zero). But, for all the other cases, we can look at
pfnmap VMAs and say whether the mappng is for the entire vma region
or not.Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Suresh Siddha
Signed-off-by: H. Peter Anvin
20 Oct, 2008
2 commits
-
Make sure that mlocked pages also live on the unevictable LRU, so kswapd
will not scan them over and over again.This is achieved through various strategies:
1) add yet another page flag--PG_mlocked--to indicate that
the page is locked for efficient testing in vmscan and,
optionally, fault path. This allows early culling of
unevictable pages, preventing them from getting to
page_referenced()/try_to_unmap(). Also allows separate
accounting of mlock'd pages, as Nick's original patch
did.Note: Nick's original mlock patch used a PG_mlocked
flag. I had removed this in favor of the PG_unevictable
flag + an mlock_count [new page struct member]. I
restored the PG_mlocked flag to eliminate the new
count field.2) add the mlock/unevictable infrastructure to mm/mlock.c,
with internal APIs in mm/internal.h. This is a rework
of Nick's original patch to these files, taking into
account that mlocked pages are now kept on unevictable
LRU list.3) update vmscan.c:page_evictable() to check PageMlocked()
and, if vma passed in, the vm_flags. Note that the vma
will only be passed in for new pages in the fault path;
and then only if the "cull unevictable pages in fault
path" patch is included.4) add try_to_unlock() to rmap.c to walk a page's rmap and
ClearPageMlocked() if no other vmas have it mlocked.
Reuses as much of try_to_unmap() as possible. This
effectively replaces the use of one of the lru list links
as an mlock count. If this mechanism let's pages in mlocked
vmas leak through w/o PG_mlocked set [I don't know that it
does], we should catch them later in try_to_unmap(). One
hopes this will be rare, as it will be relatively expensive.Original mm/internal.h, mm/rmap.c and mm/mlock.c changes:
Signed-off-by: Nick Pigginsplitlru: introduce __get_user_pages():
New munlock processing need to GUP_FLAGS_IGNORE_VMA_PERMISSIONS.
because current get_user_pages() can't grab PROT_NONE pages theresore it
cause PROT_NONE pages can't munlock.[akpm@linux-foundation.org: fix this for pagemap-pass-mm-into-pagewalkers.patch]
[akpm@linux-foundation.org: untangle patch interdependencies]
[akpm@linux-foundation.org: fix things after out-of-order merging]
[hugh@veritas.com: fix page-flags mess]
[lee.schermerhorn@hp.com: fix munlock page table walk - now requires 'mm']
[kosaki.motohiro@jp.fujitsu.com: build fix]
[kosaki.motohiro@jp.fujitsu.com: fix truncate race and sevaral comments]
[kosaki.motohiro@jp.fujitsu.com: splitlru: introduce __get_user_pages()]
Signed-off-by: KOSAKI Motohiro
Signed-off-by: Rik van Riel
Signed-off-by: Lee Schermerhorn
Cc: Nick Piggin
Cc: Dave Hansen
Cc: Matt Mackall
Signed-off-by: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Shmem segments locked into memory via shmctl(SHM_LOCKED) should not be
kept on the normal LRU, since scanning them is a waste of time and might
throw off kswapd's balancing algorithms. Place them on the unevictable
LRU list instead.Use the AS_UNEVICTABLE flag to mark address_space of SHM_LOCKed shared
memory regions as unevictable. Then these pages will be culled off the
normal LRU lists during vmscan.Add new wrapper function to clear the mapping's unevictable state when/if
shared memory segment is munlocked.Add 'scan_mapping_unevictable_page()' to mm/vmscan.c to scan all pages in
the shmem segment's mapping [struct address_space] for evictability now
that they're no longer locked. If so, move them to the appropriate zone
lru list.Changes depend on [CONFIG_]UNEVICTABLE_LRU.
[kosaki.motohiro@jp.fujitsu.com: revert shm change]
Signed-off-by: Lee Schermerhorn
Signed-off-by: Rik van Riel
Signed-off-by: Kosaki Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
12 Oct, 2008
1 commit
-
…memory-corruption-check', 'x86/early-printk', 'x86/xsave', 'x86/ptrace-v2', 'x86/quirks', 'x86/setup', 'x86/spinlocks' and 'x86/signal' into x86/core-v2
10 Sep, 2008
1 commit
-
Define USE_SPLIT_PTLOCKS as a constant expression rather than repeating
"NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS" all over the place.Signed-off-by: Jeremy Fitzhardinge
Acked-by: Hugh Dickins
Signed-off-by: Ingo Molnar
17 Aug, 2008
1 commit
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Try to comment away a little of the confusion between mm's vm_area_struct
vm_flags and vmalloc's vm_struct flags: based on an idea by Ulrich Drepper.Signed-off-by: Hugh Dickins
Signed-off-by: Linus Torvalds
12 Aug, 2008
1 commit
-
Out of line get_user_pages_fast fallback implementation, make it a weak
symbol, get rid of CONFIG_HAVE_GET_USER_PAGES_FAST.Export the symbol to modules so lguest can use it.
Signed-off-by: Nick Piggin
Signed-off-by: Rusty Russell
31 Jul, 2008
2 commits
-
zap_vma_ptes() is intended to be used by drivers to unmap ptes assigned to the
driver private vmas. This interface is similar to zap_page_range() but is
less general & less likely to be abused.Needed by the GRU driver.
Signed-off-by: Jack Steiner
Cc: Nick Piggin
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
It has no user now
Also print out info about adding/removing active regions.
Signed-off-by: Yinghai Lu
Acked-by: Mel Gorman
Acked-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Jul, 2008
1 commit
-
mm_take_all_locks holds off reclaim from an entire mm_struct. This allows
mmu notifiers to register into the mm at any time with the guarantee that
no mmu operation is in progress on the mm.This operation locks against the VM for all pte/vma/mm related operations
that could ever happen on a certain mm. This includes vmtruncate,
try_to_unmap, and all page faults.The caller must take the mmap_sem in write mode before calling
mm_take_all_locks(). The caller isn't allowed to release the mmap_sem
until mm_drop_all_locks() returns.mmap_sem in write mode is required in order to block all operations that
could modify pagetables and free pages without need of altering the vma
layout (for example populate_range() with nonlinear vmas). It's also
needed in write mode to avoid new anon_vmas to be associated with existing
vmas.A single task can't take more than one mm_take_all_locks() in a row or it
would deadlock.mm_take_all_locks() and mm_drop_all_locks are expensive operations that
may have to take thousand of locks.mm_take_all_locks() can fail if it's interrupted by signals.
When mmu_notifier_register returns, we must be sure that the driver is
notified if some task is in the middle of a vmtruncate for the 'mm' where
the mmu notifier was registered (mmu_notifier_invalidate_range_start/end
is run around the vmtruncation but mmu_notifier_register can run after
mmu_notifier_invalidate_range_start and before
mmu_notifier_invalidate_range_end). Same problem for rmap paths. And
we've to remove page pinning to avoid replicating the tlb_gather logic
inside KVM (and GRU doesn't work well with page pinning regardless of
needing tlb_gather), so without mm_take_all_locks when vmtruncate frees
the page, kvm would have no way to notice that it mapped into sptes a page
that is going into the freelist without a chance of any further
mmu_notifier notification.[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Andrea Arcangeli
Acked-by: Linus Torvalds
Cc: Christoph Lameter
Cc: Jack Steiner
Cc: Robin Holt
Cc: Nick Piggin
Cc: Peter Zijlstra
Cc: Kanoj Sarcar
Cc: Roland Dreier
Cc: Steve Wise
Cc: Avi Kivity
Cc: Hugh Dickins
Cc: Rusty Russell
Cc: Anthony Liguori
Cc: Chris Wright
Cc: Marcelo Tosatti
Cc: Eric Dumazet
Cc: "Paul E. McKenney"
Cc: Izik Eidus
Cc: Anthony Liguori
Cc: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Jul, 2008
2 commits
-
This patch makes the needlessly global print_bad_pte() static.
Signed-off-by: Adrian Bunk
Reviewed-by: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Introduce a new get_user_pages_fast mm API, which is basically a
get_user_pages with a less general API (but still tends to be suited to
the common case):- task and mm are always current and current->mm
- force is always 0
- pages is always non-NULL
- don't pass back vmasThis restricted API can be implemented in a much more scalable way on many
architectures when the ptes are present, by walking the page tables
locklessly (no mmap_sem or page table locks). When the ptes are not
populated, get_user_pages_fast() could be slower.This is implemented locklessly on x86, and used in some key direct IO call
sites, in later patches, which provides nearly 10% performance improvement
on a threaded database workload.Lots of other code could use this too, depending on use cases (eg. grep
drivers/). And it might inspire some new and clever ways to use it.[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Nick Piggin
Cc: Dave Kleikamp
Cc: Andy Whitcroft
Cc: Ingo Molnar
Cc: Thomas Gleixner
Cc: Andi Kleen
Cc: Dave Kleikamp
Cc: Badari Pulavarty
Cc: Zach Brown
Cc: Jens Axboe
Reviewed-by: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
25 Jul, 2008
6 commits
-
On 32-bit architectures PAGE_ALIGN() truncates 64-bit values to the 32-bit
boundary. For example:u64 val = PAGE_ALIGN(size);
always returns a value < 4GB even if size is greater than 4GB.
The problem resides in PAGE_MASK definition (from include/asm-x86/page.h for
example):#define PAGE_SHIFT 12
#define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT)
#define PAGE_MASK (~(PAGE_SIZE-1))
...
#define PAGE_ALIGN(addr) (((addr)+PAGE_SIZE-1)&PAGE_MASK)The "~" is performed on a 32-bit value, so everything in "and" with
PAGE_MASK greater than 4GB will be truncated to the 32-bit boundary.
Using the ALIGN() macro seems to be the right way, because it uses
typeof(addr) for the mask.Also move the PAGE_ALIGN() definitions out of include/asm-*/page.h in
include/linux/mm.h.See also lkml discussion: http://lkml.org/lkml/2008/6/11/237
[akpm@linux-foundation.org: fix drivers/media/video/uvc/uvc_queue.c]
[akpm@linux-foundation.org: fix v850]
[akpm@linux-foundation.org: fix powerpc]
[akpm@linux-foundation.org: fix arm]
[akpm@linux-foundation.org: fix mips]
[akpm@linux-foundation.org: fix drivers/media/video/pvrusb2/pvrusb2-dvb.c]
[akpm@linux-foundation.org: fix drivers/mtd/maps/uclinux.c]
[akpm@linux-foundation.org: fix powerpc]
Signed-off-by: Andrea Righi
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
With Mel's hugetlb private reservation support patches applied, strict
overcommit semantics are applied to both shared and private huge page
mappings. This can be a problem if an application relied on unlimited
overcommit semantics for private mappings. An example of this would be an
application which maps a huge area with the intention of using it very
sparsely. These application would benefit from being able to opt-out of
the strict overcommit. It should be noted that prior to hugetlb
supporting demand faulting all mappings were fully populated and so
applications of this type should be rare.This patch stack implements the MAP_NORESERVE mmap() flag for huge page
mappings. This flag has the same meaning as for small page mappings,
suppressing reservations for that mapping.Thanks to Mel Gorman for reviewing a number of early versions of these
patches.This patch:
When a small page mapping is created with mmap() reservations are created
by default for any memory pages required. When the region is read/write
the reservation is increased for every page, no reservation is needed for
read-only regions (as they implicitly share the zero page). Reservations
are tracked via the VM_ACCOUNT vma flag which is present when the region
has reservation backing it. When we convert a region from read-only to
read-write new reservations are aquired and VM_ACCOUNT is set. However,
when a read-only map is created with MAP_NORESERVE it is indistinguishable
from a normal mapping. When we then convert that to read/write we are
forced to incorrectly create reservations for it as we have no record of
the original MAP_NORESERVE.This patch introduces a new vma flag VM_NORESERVE which records the
presence of the original MAP_NORESERVE flag. This allows us to
distinguish these two circumstances and correctly account the reserve.As well as fixing this FIXME in the code, this makes it much easier to
introduce MAP_NORESERVE support for huge pages as this flag is available
consistantly for the life of the mapping. VM_ACCOUNT on the other hand is
heavily used at the generic level in association with small pages.Signed-off-by: Andy Whitcroft
Cc: Mel Gorman
Cc: Adam Litke
Cc: Johannes Weiner
Cc: Andy Whitcroft
Cc: William Lee Irwin III
Cc: Hugh Dickins
Cc: Michael Kerrisk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
free_area_init_node() gets passed in the node id as well as the node
descriptor. This is redundant as the function can trivially get the node
descriptor itself by means of NODE_DATA() and the node's id.I checked all the users and NODE_DATA() seems to be usable everywhere
from where this function is called.Signed-off-by: Johannes Weiner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The double indirection here is not needed anywhere and hence (at least)
confusing.Signed-off-by: Jan Beulich
Cc: Hugh Dickins
Cc: Nick Piggin
Cc: Christoph Lameter
Cc: Benjamin Herrenschmidt
Cc: Paul Mackerras
Cc: "Luck, Tony"
Cc: Paul Mundt
Cc: "David S. Miller"
Acked-by: Jeremy Fitzhardinge
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
In order to be able to debug things like the X server and programs using
the PPC Cell SPUs, the debugger needs to be able to access device memory
through ptrace and /proc/pid/mem.This patch:
Add the generic_access_phys access function and put the hooks in place
to allow access_process_vm to access device or PPC Cell SPU memory.[riel@redhat.com: Add documentation for the vm_ops->access function]
Signed-off-by: Rik van Riel
Signed-off-by: Benjamin Herrensmidt
Cc: Dave Airlie
Cc: Hugh Dickins
Cc: Paul Mackerras
Cc: Arnd Bergmann
Acked-by: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
There are no users of nopfn in the tree. Remove it.
[hugh@veritas.com: fix build error]
Signed-off-by: Nick Piggin
Signed-off-by: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
15 Jul, 2008
1 commit
-
Manual fixup of:
arch/powerpc/Kconfig
