Roland Dreier reported in http://lkml.org/lkml/2008/2/27/194
[ 8425.915139] BUG: unable to handle kernel paging request at ffffc20001a0a000
[ 8425.919087] IP: [<ffffffff8021dacc>] clflush_cache_range+0xc/0x25
[ 8425.919087] PGD 1bf80e067 PUD 1bf80f067 PMD 1bb497067 PTE 80000047000ee17b
This is on a Intel machine with 36bit physical address space. The PTE
entry references 47000ee000, which is outside of it.
Add a check for the physical address space and warn/printk about the
stupid caller.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
> Don't we have a special section for page-aligned data so it doesn't
> waste most of two pages?
We have .bss.page_aligned and it seems appropriate to use it.
text data bss dec hex filename
- 3388 8236 4 11628 2d6c ../build-32/arch/x86/mm/ioremap.o
+ 3388 48 4100 7536 1d70 ../build-32/arch/x86/mm/ioremap.o
Signed-off-by: Ian Campbell <ijc@hellion.org.uk>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
we don't need get that so early.
Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The AMD Fam10h CPUs support new Gigabyte page table entry for
mapping 1GB at a time. Use this for the kernel direct mapping.
Only done for 64bit because i386 does not support GB page tables.
This only applies to the data portion of the direct mapping; the
kernel text mapping stays with 2MB pages because the AMD Fam10h
microarchitecture does not support GB ITLBs and AMD recommends
against using GB mappings for code.
Can be disabled with disable_gbpages on the kernel command line
[ tglx@linutronix.de: simplify enable code ]
[ Yinghai Lu <yinghai.lu@sun.com>: boot fix on 256 GB RAM ]
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
These new controls toggle experimental support for a new CPU feature,
the straightforward extension of largepages from the pmd level to the
pud level, which allows 1GB (kernel) TLBs instead of 2MB TLBs.
Turn it off by default, as this code has not been tested well enough yet.
Use the CONFIG_DIRECT_GBPAGES=y .config option or gbpages on the
boot line can be used to enable it. If enabled in the .config then
nogbpages boot option disables it.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Clean up the page table dumper (fix boundary conditions, table driven
address ranges, some formatting changes since it is no longer using
the kernel log but a separate virtual file), and generalize to 32
bits.
[ mingo@elte.hu: x86: fix the pagetable dumper ]
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch adds code to the kernel to have an (optional)
/proc/kernel_page_tables debug file that basically dumps the kernel
pagetables; this allows us kernel developers to verify that nothing fishy is
going on and that the various mappings are set up correctly. This was quite
useful in finding various change_page_attr() bugs, and is very likely to be
useful in the future as well.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: mingo@elte.hu
Cc: tglx@tglx.de
Cc: hpa@zytor.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Unify arch/x86/mm/Makefile between 32 and 64 bits.
All configuration variables that are protected by Kconfig constraints
have been put in the common part of the Makefile; however, the NUMA
files are totally different between 32 and 64 bits and are handled via
an ifdef.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Add debug information for DEBUG_PAGEALLOC to get some statistics about
the pool usage and split status.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
I believe http://bugzilla.kernel.org/show_bug.cgi?id=10318 is a false
positive. There's no way in which networking will be using highmem pages
here, so it won't be taking the KM_USER0 kmap slot, so there's no point in
performing these checks.
Cc: Pawel Staszewski <pstaszewski@artcom.pl>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Christoph Lameter <clameter@sgi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Really sad. We lose almost all real-life coverage of the debug tests
with this patch. Now it will only report problems for the cases where
people actually end up using a HIGHMEM page, not when they just _might_
use one. - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus noticed a second bug and an uncleanliness:
- we'd return on any instruction fetch fault
- we'd use both the value of 16 and the PF_INSTR symbol which are
the same and make no sense
the cleanup nicely unifies this piece of logic.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The first page of the compound page is determined in follow_huge_addr()
but then PageCompound() only checks if the page is part of a compound page.
PageHead() allows checking if this is indeed the first page of the
compound.
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
some early Athlon XP's and Opterons generate bogus faults on prefetch
instructions. The workaround for this regressed over .24 - reinstate it.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
fix the 3D performance drop reported at:
http://bugzilla.kernel.org/show_bug.cgi?id=10328
fb drivers are using ioremap()/ioremap_nocache(), followed by mtrr_add with
WC attribute. Recent changes in page attribute code made both
ioremap()/ioremap_nocache() mappings as UC (instead of previous UC-). This
breaks the graphics performance, as the effective memory type is UC instead
of expected WC.
The correct way to fix this is to add ioremap_wc() (which uses UC- in the
absence of PAT kernel support and WC with PAT) and change all the
fb drivers to use this new ioremap_wc() API.
We can take this correct and longer route for post 2.6.25. For now,
revert back to the UC- behavior for ioremap/ioremap_nocache.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
we could call find_max_pfn() directly instead of setup_memory() to get
max_pfn needed for mtrr trimming.
otherwise setup_memory() is called two times... that is duplicated...
[ mingo@elte.hu: both Thomas and me simulated a double call to
setup_bootmem_allocator() and can confirm that it is a real bug
which can hang in certain configs. It's not been reported yet but
that is probably due to the relatively scarce nature of
MTRR-trimming systems. ]
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
It appears that 64-bit PCI resources cannot possibly ever have worked on
x86-32 even when the RESOURCES_64BIT config option was set, because any
driver that tried to [pci_]ioremap() the resource would have been unable
to do so because the high 32 bits would have been silently dropped on
the floor by the ioremap() routines that only used "unsigned long".
Change them to use "resource_size_t" instead, which properly encodes the
whole 64-bit resource data if RESOURCES_64BIT is enabled.
Acked-by: H. Peter Anvin <hpa@kernel.org>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
so use nodedata_phys directly.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
quicklists cause a serious memory leak on 32-bit x86,
as documented at:
http://bugzilla.kernel.org/show_bug.cgi?id=9991
the reason is that the quicklist pool is a special-purpose
cache that grows out of proportion. It is not accounted for
anywhere and users have no way to even realize that it's
the quicklists that are causing RAM usage spikes. It was
supposed to be a relatively small pool, but as demonstrated
by KOSAKI Motohiro, they can grow as large as:
Quicklists: 1194304 kB
given how much trouble this code has caused historically,
and given that Andrew objected to its introduction on x86
(years ago), the best option at this point is to remove them.
[ any performance benefits of caching constructed pgds should
be implemented in a more generic way (possibly within the page
allocator), while still allowing constructed pages to be
allocated by other workloads. ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
resolve boot problem reported by Mel Gorman:
http://lkml.org/lkml/2008/2/13/404
init_cpu_to_node will use cpu->apic (from MADT or mptable) and
apic->node(from SRAT or AMD config space with k8_bus_64.c) to have
cpu->node mapping, and later identify_cpu will overwrite them
again...(with nearby_node...)
this patch checks if the node is online, otherwise it will not
update cpu_node map. so keep cpu_node map to online node before
identify_cpu..., to prevent possible error.
Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Revert:
commit 8be8f54bae
Author: Thomas Gleixner <tglx@linutronix.de>
Date: Sat Feb 23 20:43:21 2008 +0100
x86: CPA: avoid split of alias mappings
because it clearly mishandles the case when __change_page_attr(), called
from __change_page_attr_set_clr(), changes cpa->processed to 1 and
cpa_process_alias(cpa) is executed right after that.
This crashes my x86-64 test box early in the boot process
(ref. http://bugzilla.kernel.org/show_bug.cgi?id=10140#c4).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
avoid over-eager large page splitup.
When the target area needs to be split or is split already (ioremap)
then the current code enforces the split of large mappings in the alias
regions even if we could avoid it.
Use a separate variable processed in the cpa_data structure to carry
the number of pages which have been processed instead of reusing the
numpages variable. This keeps numpages intact and gives the alias code
a chance to keep large mappings intact.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Jan Beulich noticed it during code review that if a driver's ioremap()
fails (say due to -ENOMEM) then we might leak the struct vm_area.
Free it properly.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
recently the 64-bit allyesconfig bzImage kernel started spontaneously
rebooting during early bootup.
after a few fun hours spent with early init debugging, it turns out
that we've got this rather annoying limit on the size of the kernel
image:
#define KERNEL_TEXT_SIZE (40*1024*1024)
which limit my vmlinux just happened to pass:
text data bss dec hex filename
29703744 4222751 8646224 42572719 2899baf vmlinux
40 MB is 42572719 bytes, so my vmlinux was just 1.5% above this limit :-/
So it happily crashed right in head_64.S, which - as we all know - is
the most debuggable code in the whole architecture ;-)
So increase the limit to allow an up to 128MB kernel image to be mapped.
(should anyone be that crazy or lazy)
We have a full 4K of pagetable (level2_kernel_pgt) allocated for these
mappings already, so there's no RAM overhead and the limit was rather
pointless and arbitrary.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Use PF_MEMALLOC to prevent recursive calls in the DBEUG_PAGEALLOC
case. This makes the code simpler and more robust against allocation
failures.
This fixes the following fallback to non-mmconfig:
http://lkml.org/lkml/2008/2/20/551http://bugzilla.kernel.org/show_bug.cgi?id=10083
Also, for DEBUG_PAGEALLOC=n reduce the pool size to one page.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Make hibernation work with CONFIG_DEBUG_PAGEALLOC set on x86, by
checking if the pages to be copied are marked as present in the
kernel mapping and temporarily marking them as present if that's not
the case. No functional modifications are introduced if
CONFIG_DEBUG_PAGEALLOC is unset.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
* 'agp-patches' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/agp-2.6:
agp: fix missing casts that produced a warning.
agp: add support for 662/671 to agp driver
fix historic ioremap() abuse in AGP
agp/sis: Suspend support for SiS AGP
agp/sis: Clear bit 2 from aperture size byte as well
page_is_ram() has a special case for the 640k-1M bios area, however
due to a thinko the special case checks the e820 table entry and
not the memory the user has asked for. This patch fixes the bug.
[ mingo@elte.hu: this too is better solved in the e820 space, but those
fixes are too intrusive for v2.6.25. ]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch teaches page_is_ram() about the fact that the first
4Kb of memory are special on x86, even though the E820 table
normally doesn't exclude it.
This fixes the WARN_ON() reported by Laurent Riffard who was also
very helpful in diagnosing the issue.
[ mingo@elte.hu: we are working on doing this properly in the e820
space, but for 2.6.25 this is the better fix. ]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
reserve_hotadd() are only used by __init acpi_numa_memory_affinity_init().
Annotate reserve_hotadd() with __init is the trivial fix.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
New implementation does not use lru for anything so there is no need
to reject pages that are in the LRU. Similar for compound pages (which
were checked because they also use page->lru)
[ tglx@linutronix.de: removed unused variable ]
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Several AGP drivers right now use ioremap_nocache() on kernel ram in order
to turn a page of regular memory uncached.
There are two problems with this:
1) This is a total nightmare for the ioremap() implementation to keep
various mappings of the same page coherent.
2) It's a total nightmare for the AGP code since it adds a ton of
complexity in terms of keeping track of 2 different pointers to
the same thing, in terms of error handling etc etc.
This patch fixes this by making the AGP drivers use the new
set_memory_XX APIs instead.
Note: amd-k7-agp.c is built on Alpha too, and generic.c is built
on ia64 as well, which do not yet have the set_memory_*() APIs,
so for them some we have a few ugly #ifdefs - hopefully they'll
be fixed soon.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Dave Airlie <airlied@linux.ie>
When the CPA code is called with an virtual address in the range of
the direct mapping or the high alias then we do not need to run
through the alias check for this range.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
NX settings are not required to be consistent across alias mappings.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The early boot code maps KERNEL_TEXT_SIZE (currently 40MB) starting
from __START_KERNEL_map. The kernel itself only needs _text to _end
mapped in the high alias. On relocatible kernels the ASM setup code
adjusts the compile time created high mappings to the relocation. This
creates invalid pmd entries for negative offsets:
0xffffffff80000000 -> pmd entry: ffffffffff2001e3
It points outside of the physical address space and is marked present.
This starts at the virtual address __START_KERNEL_map and goes up to
the point where the first valid physical address (0x0) is mapped.
Zap the mappings before _text and after _end right away in early
boot. This removes also the invalid entries.
Furthermore it simplifies the range check for high aliases.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
c_p_a() did not discover all aliases correctly. (such as when called
on vmalloc()-ed areas or ioremap()-ed areas)
Push the alias checks to the lower, physical level and consistently
discover all aliases that might exist: the low direct mappings and
the high linear kernel-text mappings (on 64-bit).
Thanks to Andi Kleen for pointing out that this was buggy.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
the cpa API is page aligned - warn about any weird alignments.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
extern should not appear in C files. Also, the definitions
do not match the prototype currently, not sure what way you
want to go with this, I've switched the prototype to return
int, but I can see going to the void return as well.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
dump_pagetable() can now become static.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[ mingo@elte.hu: while gbpages cannot be enabled on mainline currently,
keep the code uptodate and this fix is easy enough. ]
Use correct page sizes and masks for GB pages in try_preserve_large_page()
This prevents a boot hang on a GB capable system with CONFIG_DIRECT_GBPAGES
enabled.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
At the early stages of boot, before the kernel pagetable has been
fully initialized, a Xen kernel will still be running off the
Xen-provided pagetables rather than swapper_pg_dir[]. Therefore,
readback cr3 to determine the base of the pagetable rather than
assuming swapper_pg_dir[].
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Tested-by: Jody Belka <knew-linux@pimb.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
pageattr-test.c contains a noisy debug printk that people reported.
The condition under which it prints (randomly tapping into a mem_map[]
hole and not being able to c_p_a() there) is valid behavior and not
interesting to report.
Remove it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
