Show node to memory section relationship with symlinks in sysfs
Add /sys/devices/system/node/nodeX/memoryY symlinks for all
the memory sections located on nodeX. For example:
/sys/devices/system/node/node1/memory135 -> ../../memory/memory135
indicates that memory section 135 resides on node1.
Also revises documentation to cover this change as well as updating
Documentation/ABI/testing/sysfs-devices-memory to include descriptions
of memory hotremove files 'phys_device', 'phys_index', and 'state'
that were previously not described there.
In addition to it always being a good policy to provide users with
the maximum possible amount of physical location information for
resources that can be hot-added and/or hot-removed, the following
are some (but likely not all) of the user benefits provided by
this change.
Immediate:
- Provides information needed to determine the specific node
on which a defective DIMM is located. This will reduce system
downtime when the node or defective DIMM is swapped out.
- Prevents unintended onlining of a memory section that was
previously offlined due to a defective DIMM. This could happen
during node hot-add when the user or node hot-add assist script
onlines _all_ offlined sections due to user or script inability
to identify the specific memory sections located on the hot-added
node. The consequences of reintroducing the defective memory
could be ugly.
- Provides information needed to vary the amount and distribution
of memory on specific nodes for testing or debugging purposes.
Future:
- Will provide information needed to identify the memory
sections that need to be offlined prior to physical removal
of a specific node.
Symlink creation during boot was tested on 2-node x86_64, 2-node
ppc64, and 2-node ia64 systems. Symlink creation during physical
memory hot-add tested on a 2-node x86_64 system.
Signed-off-by: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Impact: remove incorrect WARN_ON(1)
Gets rid of dmesg spam created during physical memory hot-add which
will very likely confuse users. The change removes what appears to
be debugging code which I assume was unintentionally included in:
x86: arch/x86/mm/init_64.c printk fixes
commit 10f22dde55
Signed-off-by: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
so users are not confused with memhole causing big total ram
we don't need to worry about 32 bit, because memhole is always
above max_low_pfn.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix crash with memory hotplug
Shuahua Li found:
| I just did some experiments on a desktop for memory hotplug and this bug
| triggered a crash in my test.
|
| Yinghai's suggestion also fixed the bug.
We don't need to round it, just remove that extra -1
Signed-off-by: Yinghai <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: change the implementation of the debug feature
the periodic corruption checks are better off run from a work queue; there's
nothing time critical about them and this way the amount of
interrupt-context work is reduced.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When nr_range gets decremented, the same slot must be considered for
coalescing with its new successor again.
The issue is apparently pretty benign to native code, but surfaces as a
boot time crash in our forward ported Xen tree (where the page table
setup overall works differently than in native).
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The check prevents flags on mappings from being changed, which is not
desireable. There's no need to check for replacing a mapping, and
x86-32 does not do this check.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
early_ioremap() is also used to map normal memory when constructing
the linear memory mapping. However, since we sometimes need to be able
to distinguish between actual IO mappings and normal memory mappings,
add a early_memremap() call, which maps with PAGE_KERNEL (as opposed
to PAGE_KERNEL_IO for early_ioremap()), and use it when constructing
pagetables.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Use one of the software-defined PTE bits to indicate that a mapping is
intended for an IO address. On native hardware this is irrelevent,
since a physical address is a physical address. But in a virtual
environment, physical addresses are also virtualized, so there needs
to be some way to distinguish between pseudo-physical addresses and
actual hardware addresses; _PAGE_IOMAP indicates this intent.
By default, __supported_pte_mask masks out _PAGE_IOMAP, so it doesn't
even appear in the final pagetable.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Move the prototypes from the generic kernel.h header to the more
appropriate include/asm-x86/bios_ebda.h header file.
Also, remove the check from the power management code - this is a
pure x86 matter for now.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Jeremy Fitzhardinge wrote:
> I'd noticed that current tip/master hasn't been booting under Xen, and I
> just got around to bisecting it down to this change.
>
> commit 065ae73c5462d42e9761afb76f2b52965ff45bd6
> Author: Suresh Siddha <suresh.b.siddha@intel.com>
>
> x86, cpa: make the kernel physical mapping initialization a two pass sequence
>
> This patch is causing Xen to fail various pagetable updates because it
> ends up remapping pagetables to RW, which Xen explicitly prohibits (as
> that would allow guests to make arbitrary changes to pagetables, rather
> than have them mediated by the hypervisor).
Instead of making init a two pass sequence, to satisfy the Intel's TLB
Application note (developer.intel.com/design/processor/applnots/317080.pdf
Section 6 page 26), we preserve the original page permissions
when fragmenting the large mappings and don't touch the existing memory
mapping (which satisfies Xen's requirements).
Only open issue is: on a native linux kernel, we will go back to mapping
the first 0-1GB kernel identity mapping as executable (because of the
static mapping setup in head_64.S). We can fix this in a different
patch if needed.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Interrupt context no longer splits large page in cpa(). So we can do away
with cpa memory pool code.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: arjan@linux.intel.com
Cc: venkatesh.pallipadi@intel.com
Cc: jeremy@goop.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Don't use large pages for kernel identity mapping with DEBUG_PAGEALLOC.
This will remove the need to split the large page for the
allocated kernel page in the interrupt context.
This will simplify cpa code(as we don't do the split any more from the
interrupt context). cpa code simplication in the subsequent patches.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: arjan@linux.intel.com
Cc: venkatesh.pallipadi@intel.com
Cc: jeremy@goop.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In the first pass, kernel physical mapping will be setup using large or
small pages but uses the same PTE attributes as that of the early
PTE attributes setup by early boot code in head_[32|64].S
After flushing TLB's, we go through the second pass, which setups the
direct mapped PTE's with the appropriate attributes (like NX, GLOBAL etc)
which are runtime detectable.
This two pass mechanism conforms to the TLB app note which says:
"Software should not write to a paging-structure entry in a way that would
change, for any linear address, both the page size and either the page frame
or attributes."
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: arjan@linux.intel.com
Cc: venkatesh.pallipadi@intel.com
Cc: jeremy@goop.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Perodically check for corruption in low phusical memory. Don't bother
checking at fault time, since it won't show anything useful.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
early_io{re,un}map() are __init and hence can't be called from __meminit
functions.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
While I don't have a hotplug capable system at hand, I think two issues need
fixing:
- pud_phys (in kernel_physical_ampping_init()) would remain uninitialized in
the after_bootmem case
- the locking done just around phys_pmd_{init,update}() would leave out pgd
updates, and it was needlessly covering code portions that do allocations
(perhaps using a more friendly gfp value in alloc_low_page() would then be
possible)
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
WARNING: vmlinux.o(.text+0x17a3e): Section mismatch in reference from the function set_pte_vaddr_pud() to the function .init.text:spp_getpage()
The function set_pte_vaddr_pud() references
the function __init spp_getpage().
This is often because set_pte_vaddr_pud lacks a __init
annotation or the annotation of spp_getpage is wrong.
spp_getpage is called from __init (__init_extra_mapping) and
non __init (set_pte_vaddr_pud) functions, so it can't be __init.
Unfortunately it calls alloc_bootmem_pages which is __init,
but does it only when bootmem allocator is available (after_bootmem == 0).
So annotate it accordingly.
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: H. Peter Anvin <hpa@zytor.com>
Do we actually want these DirectMap lines in the x86 /proc/meminfo?
I can see they're interesting to CPA developers and TLB optimizers,
but they don't fit its usual "where has all my memory gone?" usage.
If they are to stay, here are some fixes.
1. On x86_32 without PAE, they're not 2M but 4M pages: no need to
mess with the internal enum, but show the right name to users.
2. Many machines can never show anything but 0 for DirectMap1G,
so suppress that line unless direct_gbpages are really enabled.
3. The unit in /proc/meminfo is kB not number of pages: HugePages
messed that up, but they're an example to regret not to follow.
4. Once we use kB, it's easy to see that 1GB has gone missing (which
explains why CONFIG_CPA_DEBUG=y soon wraps DirectMap2M negative):
because head_64.S's level2_ident_pgt entries were not counted.
My fix is not ideal, but works for more and for less than 1G,
and avoids interfering with early bootup pagetable contortions.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Remove arch-specific show_mem() in favor of the generic version.
This also removes the following redundant information display:
- pages in swapcache, printed by show_swap_cache_info()
- dirty pages, writeback pages, mapped pages, slab pages,
pagetable pages, printed by show_free_areas()
where show_mem() calls show_free_areas(), which calls
show_swap_cache_info().
Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
it's separate functionality that deserves its own file.
This also prepares 32-bit memtest support.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix bug in kernel_physical_mapping_init() that causes kernel
page table to be built incorrectly for systems with greater
than 512GB of memory.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
optimization: try to merge the range with same page size in
init_memory_mapping, to get the best possible linear mappings set up.
thus when GBpages is not there, we could do 2M pages.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
when more than 4g memory is installed, don't map the big hole below 4g.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
fix phys_pmd_init to make sure not to return bigger value than end.
also print out range split:1G/2M/4K in init_memory_mapping().
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
handle head and tail that are not aligned to big pages (2MB/1GB boundary).
with this patch, on system that support gbpages, change:
last_map_addr: 1080000000 end: 1078000000
to:
last_map_addr: 1078000000 end: 1078000000
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
prepare for overmapped patch
also printout last_map_addr together with end
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When allocating a new pud, unconditionally populate the pgd (why did
we bother to create a new pud if we weren't going to populate it?).
This will only happen if the pgd slot was empty, since any existing
pud will be reused.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Ingo Molnar wrote:
> that fixed the build but now we've got a boot crash with this config:
>
> time.c: Detected 2010.304 MHz processor.
> spurious 8259A interrupt: IRQ7.
> BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
> IP: [<0000000000000000>]
> PGD 0
> Thread overran stack, or stack corrupted
> Oops: 0010 [1] SMP
> CPU 0
>
I don't know if this will fix this bug, but it's definitely a bugfix.
It was trashing random pages by overwriting them with pagetables...
Don't trash a large pmd's data when mapping physical memory.
This is a bugfix for "x86_64: adjust mapping of physical pagetables
to work with Xen".
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We will need to set a pte on l3_user_pgt. Extract set_pte_vaddr_pud()
from set_pte_vaddr(), that will accept the l3 page table as parameter.
This change should be a no-op for existing code.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
If PSE is not available, then fall back to 4k page mappings for the
vmemmap area.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This makes a few of changes to the construction of the initial
pagetables to work better with paravirt_ops/Xen. The main areas
are:
1. Support non-PSE mapping of memory, since Xen doesn't currently
allow 2M pages to be mapped in guests.
2. Make sure that the ioremap alias of all pages are dropped before
attaching the new page to the pagetable. This avoids having
writable aliases of pagetable pages.
3. Preserve existing pagetable entries, rather than overwriting. Its
possible that a fair amount of pagetable has already been constructed,
so reuse what's already in place rather than ignoring and overwriting it.
The algorithm relies on the invariant that any page which is part of
the kernel pagetable is itself mapped in the linear memory area. This
way, it can avoid using ioremap on a pagetable page.
The invariant holds because it maps memory from low to high addresses,
and also allocates memory from low to high. Each allocated page can
map at least 2M of address space, so the mapped area will always
progress much faster than the allocated area. It relies on the early
boot code mapping enough pages to get started.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Gary Hade